Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

"N_Cook" wrote in message
...
Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum
jelly over the threads .

https://en.wikipedia.org/wiki/Galvanic_corrosion
"A "lasagna cell" is accidentally produced when salty moist food such
as lasagna is stored in a steel baking pan and is covered with
aluminum foil. After a few hours the foil develops small holes where
it touches the lasagna, and the food surface becomes covered with
small spots composed of corroded aluminum."

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.

--
Ed Huntress

On 05/12/2015 15:37, Ed Huntress wrote:
On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.


Googling this , I came up with "galling" or "friction welding" , but
some sort of galvanic corrossion process going on looks likely, despite
no obvious iron rust or white aluminium corrossion product.

On Sat, 05 Dec 2015 16:58:04 +0000, N_Cook wrote:

On 05/12/2015 15:37, Ed Huntress wrote:
On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.


Googling this , I came up with "galling" or "friction welding" , but
some sort of galvanic corrossion process going on looks likely, despite
no obvious iron rust or white aluminium corrossion product.

Galling happens when the surface of the metal tears. It's more likely
when you're fastening or unfastening bolts under a high load. You
aren't likely to encounter friction welding without a lot of speed and
force.

A white corrosion on the aluminum is oxidatation. Likewise, red iron
rust. Galvanic corrosion can produce white compounds, or black ones on
iron or steel, but it also can result in a fairly clean-looking
surface.

On boats that are left in salt water, they use sacrificial anodes of
zinc, and the zinc preferentially erodes by galvanic corrosion. These
can be completely clean even when they're severely corroded away.

--
Ed Huntress

In article , Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.

Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

But aluminum is always a problem.

Joe Gwinn

On Sat, 05 Dec 2015 13:07:41 -0500, Joe Gwinn
wrote:

In article , Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.

Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Superstrut, Unistrut short-spring nuts, stainless bolts, galv lags
into the roof. I'll flash the top of each rail and elastomeric-goop
each thru bolt in the roof, never EVER wanting a water leak to pop up.

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

Larry Jaques wrote:
On Sat, 05 Dec 2015 13:07:41 -0500, Joe Gwinn
wrote:

In article , Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .
I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.
Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Superstrut, Unistrut short-spring nuts, stainless bolts, galv lags
into the roof. I'll flash the top of each rail and elastomeric-goop
each thru bolt in the roof, never EVER wanting a water leak to pop up.

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

Why not use a rubber isolation mount? That way one side would stay
attached to the steel and the other side would be in the aluminum. No
direct connection between them.
Or use a rubber bulkhead fitting. Self sealing and no connection between
the two components.

--
Steve W.

On Sat, 05 Dec 2015 13:07:41 -0500, Joe Gwinn
wrote:

In article , Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.

Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

But aluminum is always a problem.

Joe Gwinn

Yeah, stainless screws in aluminum in marine service is the worst.
Very common on outboards. I started using a very expensive Loctite
antiseize with about 50% by volume zinc powder. It helps a lot.

Pete Keillor

On Saturday, December 5, 2015 at 9:45:32 AM UTC-5, N_Cook wrote:
Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

With steel bolts in aluminum , you will get galvanic corrosion.
If the bolts are plated, it might be less so you do not see the white corrosion products. If you can find aluminum bolts, they would be better.

Dan

In article , Larry Jaques
wrote:

On Sat, 05 Dec 2015 13:07:41 -0500, Joe Gwinn
wrote:

In article , Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.

Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?

It's still current practice. I got the recipe from page 211 of the
following book, bought in 2004 from a West Marine store near Boston:

"The Complete Rigger's Apprentice - Tools and Techniques for Modern and
Traditional Rigging", Brion Toss, International Marine, Camden, Maine,
1998 McGraw-Hill.

By rigging, they mean the cables that keep the mast upright on a
sailboat, despite the wind forces that propel the boat.


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I have not tried these, and so cannot say, but the boating community
has no doubt tried these, so I'd ask on a boating newsgroup.

Stainless steel screws into aluminum masts famously become impossible
to remove due to corrosion.


I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Someone else mentioned having some success with something that was 75%
zinc dust in grease - sounds like the stuff electricians use when
making connections with aluminum wiring.


Superstrut, Unistrut short-spring nuts, stainless bolts, galv lags
into the roof. I'll flash the top of each rail and elastomeric-goop
each thru bolt in the roof, never EVER wanting a water leak to pop up.

If you can arrange it mechanically, electrically isolating the aluminum
from the stainless steel with nylon washers and/or FR4 sheets (choose
materials that weather well) will stop galvanic corrosion more or less
completely. But make sure there are no sneak paths for electrical
currents to flow.

If this cannot be arranged, another nautical dodge is a sacrificial
electrode of zinc or magnesium.

Joe Gwinn

On Sunday, December 6, 2015 at 11:20:50 AM UTC-5, Joe Gwinn wrote:
In article , Larry Jaques
wrote:

On Sat, 05 Dec 2015 13:07:41 -0500, Joe Gwinn
wrote:

In article , Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.

Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?

It's still current practice. I got the recipe from page 211 of the
following book, bought in 2004 from a West Marine store near Boston:

"The Complete Rigger's Apprentice - Tools and Techniques for Modern and
Traditional Rigging", Brion Toss, International Marine, Camden, Maine,
1998 McGraw-Hill.

By rigging, they mean the cables that keep the mast upright on a
sailboat, despite the wind forces that propel the boat.


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I have not tried these, and so cannot say, but the boating community
has no doubt tried these, so I'd ask on a boating newsgroup.

Stainless steel screws into aluminum masts famously become impossible
to remove due to corrosion.


I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Someone else mentioned having some success with something that was
75% zinc dust in grease - sounds like the stuff electricians use when
making connections with aluminum wiring.

That substance is sometimes called Noalox. It stands for no aluminum oxidation. Its applied in between wherever copper and aluminum surfaces are touching to prevent fires, corrosion, loose connections, etc..

On 12/5/2015 6:58 PM, Larry Jaques wrote:

Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?



It's really the best solution for bare metals.


Lanolin is still used today - on some of the most exotic sailing rigs.

It really is the best solution to galvanic corrosion of bare metals in
contact.

I use it myself and I'm thankful when time comes to remove bolts from
aluminum.

On Sun, 06 Dec 2015 11:20:46 -0500, Joe Gwinn
wrote:

In article , Larry Jaques
wrote:

Joe said:
Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?

It's still current practice. I got the recipe from page 211 of the
following book, bought in 2004 from a West Marine store near Boston:

"The Complete Rigger's Apprentice - Tools and Techniques for Modern and
Traditional Rigging", Brion Toss, International Marine, Camden, Maine,
1998 McGraw-Hill.

It's currently 1998 where you live. Interesting.


By rigging, they mean the cables that keep the mast upright on a
sailboat, despite the wind forces that propel the boat.

Ayup, BTDT, got wet.


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I have not tried these, and so cannot say, but the boating community
has no doubt tried these, so I'd ask on a boating newsgroup.

Stainless steel screws into aluminum masts famously become impossible
to remove due to corrosion.

And, when you break off the head trying, they're nearly impossible to
drill out without a jig. Otherwise, the drill bit skitters off into
the very soft surrounding aluminum and drills deep INSTANTLY. DAMHIKT


I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Someone else mentioned having some success with something that was 75%
zinc dust in grease - sounds like the stuff electricians use when
making connections with aluminum wiring.

Ick! (not fond of AL wire)


Superstrut, Unistrut short-spring nuts, stainless bolts, galv lags
into the roof. I'll flash the top of each rail and elastomeric-goop
each thru bolt in the roof, never EVER wanting a water leak to pop up.

If you can arrange it mechanically, electrically isolating the aluminum
from the stainless steel with nylon washers and/or FR4 sheets (choose
materials that weather well) will stop galvanic corrosion more or less
completely. But make sure there are no sneak paths for electrical
currents to flow.

If this cannot be arranged, another nautical dodge is a sacrificial
electrode of zinc or magnesium.

I found out recently that Superstrut (unistrut) is zincked and then
yellow chrome plated. Hmm, more to think about with chromium against
aluminum PV framing + galv and stainless hardware.

Since PV panels are entirely electrically separated from their
framing, I wonder how much galvanic corrosion happens, during the
course of a year's weather, between the rack, the frames, and the
holddown hardware. Surely enough to warrant anti-sieze, but does all
the hardware need more? I'll have to ask the local PV guys.

I haven't seen anything used by the pros during pro installation on
YouTube vids, but what I have seen is all aluminum racking against
aluminum PV frames with stainless holddown bolts.

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

"Larry Jaques" wrote in message
...
On Sun, 06 Dec 2015 11:20:46 -0500, Joe Gwinn
wrote:

In article , Larry
Jaques
wrote:

Joe said:
Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used
only
in the past, or does its use continue to this day?

It's still current practice. I got the recipe from page 211 of the
following book, bought in 2004 from a West Marine store near Boston:

"The Complete Rigger's Apprentice - Tools and Techniques for Modern
and
Traditional Rigging", Brion Toss, International Marine, Camden,
Maine,
1998 McGraw-Hill.

It's currently 1998 where you live. Interesting.

I've sailed into Camden harbor on a day when the forest of tall wooden
masts made it seem like 1898.
http://www.etravelmaine.com/attracti...iling-cruises/

-jsw

On Sun, 06 Dec 2015 21:54:21 -0800, Larry Jaques
wrote:

On Sun, 06 Dec 2015 11:20:46 -0500, Joe Gwinn
wrote:

In article , Larry Jaques
wrote:

Joe said:
Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?

It's still current practice. I got the recipe from page 211 of the
following book, bought in 2004 from a West Marine store near Boston:

"The Complete Rigger's Apprentice - Tools and Techniques for Modern and
Traditional Rigging", Brion Toss, International Marine, Camden, Maine,
1998 McGraw-Hill.

It's currently 1998 where you live. Interesting.


By rigging, they mean the cables that keep the mast upright on a
sailboat, despite the wind forces that propel the boat.

Ayup, BTDT, got wet.


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I have not tried these, and so cannot say, but the boating community
has no doubt tried these, so I'd ask on a boating newsgroup.

Stainless steel screws into aluminum masts famously become impossible
to remove due to corrosion.

And, when you break off the head trying, they're nearly impossible to
drill out without a jig. Otherwise, the drill bit skitters off into
the very soft surrounding aluminum and drills deep INSTANTLY. DAMHIKT


I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Someone else mentioned having some success with something that was 75%
zinc dust in grease - sounds like the stuff electricians use when
making connections with aluminum wiring.

Ick! (not fond of AL wire)


Superstrut, Unistrut short-spring nuts, stainless bolts, galv lags
into the roof. I'll flash the top of each rail and elastomeric-goop
each thru bolt in the roof, never EVER wanting a water leak to pop up.

If you can arrange it mechanically, electrically isolating the aluminum
from the stainless steel with nylon washers and/or FR4 sheets (choose
materials that weather well) will stop galvanic corrosion more or less
completely. But make sure there are no sneak paths for electrical
currents to flow.

If this cannot be arranged, another nautical dodge is a sacrificial
electrode of zinc or magnesium.

I found out recently that Superstrut (unistrut) is zincked and then
yellow chrome plated. Hmm, more to think about with chromium against
aluminum PV framing + galv and stainless hardware.

Zinc Chromate paint was the stand-by for treating aluminum in the
airplane business for years and years.




Since PV panels are entirely electrically separated from their
framing, I wonder how much galvanic corrosion happens, during the
course of a year's weather, between the rack, the frames, and the
holddown hardware. Surely enough to warrant anti-sieze, but does all
the hardware need more? I'll have to ask the local PV guys.

I haven't seen anything used by the pros during pro installation on
YouTube vids, but what I have seen is all aluminum racking against
aluminum PV frames with stainless holddown bolts.
--
cheers,

John B.

In article , Larry Jaques
wrote:

On Sun, 06 Dec 2015 11:20:46 -0500, Joe Gwinn
wrote:

In article , Larry Jaques
wrote:

Joe said:
Boat riggers use lanolin or a mixture of tar and lanolin for such
things.

Sounds like a great heritage mix, like oil-cloth. Was that used only
in the past, or does its use continue to this day?

It's still current practice. I got the recipe from page 211 of the
following book, bought in 2004 from a West Marine store near Boston:

"The Complete Rigger's Apprentice - Tools and Techniques for Modern and
Traditional Rigging", Brion Toss, International Marine, Camden, Maine,
1998 McGraw-Hill.

It's currently 1998 where you live. Interesting.

Ayup, things travels slowly around these parts.


By rigging, they mean the cables that keep the mast upright on a
sailboat, despite the wind forces that propel the boat.

Ayup, BTDT, got wet.


But aluminum is always a problem.

So, how well do the triple anti-sieze compounds work for this?
Copper/Aluminum/Graphite in a petroleum lubricant base. [I've used an
old tube of Permatex aluminum AS (and dielectric grease) for
tune-ups/spark plug installations for 40+ years, all without
problems.] AS has always been good for steel-to-potmetal outdoor
equipment, too.

I have not tried these, and so cannot say, but the boating community
has no doubt tried these, so I'd ask on a boating newsgroup.

Stainless steel screws into aluminum masts famously become impossible
to remove due to corrosion.

And, when you break off the head trying, they're nearly impossible to
drill out without a jig. Otherwise, the drill bit skitters off into
the very soft surrounding aluminum and drills deep INSTANTLY. DAMHIKT


I was about to purchase one of these for the solar installation early
next year. http://tinyurl.com/z8r45jk Comments?

Someone else mentioned having some success with something that was 75%
zinc dust in grease - sounds like the stuff electricians use when
making connections with aluminum wiring.

Ick! (not fond of AL wire)


Superstrut, Unistrut short-spring nuts, stainless bolts, galv lags
into the roof. I'll flash the top of each rail and elastomeric-goop
each thru bolt in the roof, never EVER wanting a water leak to pop up.

If you can arrange it mechanically, electrically isolating the aluminum
from the stainless steel with nylon washers and/or FR4 sheets (choose
materials that weather well) will stop galvanic corrosion more or less
completely. But make sure there are no sneak paths for electrical
currents to flow.

If this cannot be arranged, another nautical dodge is a sacrificial
electrode of zinc or magnesium.

I found out recently that Superstrut (unistrut) is zincked and then
yellow chrome plated. Hmm, more to think about with chromium against
aluminum PV framing + galv and stainless hardware.

Since PV panels are entirely electrically separated from their
framing, I wonder how much galvanic corrosion happens, during the
course of a year's weather, between the rack, the frames, and the
holddown hardware. Surely enough to warrant anti-sieze, but does all
the hardware need more? I'll have to ask the local PV guys.

I haven't seen anything used by the pros during pro installation on
YouTube vids, but what I have seen is all aluminum racking against
aluminum PV frames with stainless holddown bolts.

Asking around in the relevant communities is the best way to find the
best approach. I'd ask around in boating circles - if it works in a
salt air environment, it will work all the better inland.

Joe Gwinn

On 12/5/2015 9:45 AM, N_Cook wrote:
Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .


What about thread inserts or Helicoils?

On Sat, 05 Dec 2015 16:58:04 +0000, N_Cook wrote:

On 05/12/2015 15:37, Ed Huntress wrote:
On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.


Googling this , I came up with "galling" or "friction welding" , but
some sort of galvanic corrossion process going on looks likely, despite
no obvious iron rust or white aluminium corrossion product.

What is actually happening is that the galvanic corrosion produces
aluminum oxide which as it has a greater volume then the aluminum
causes the bolts to "freeze" in place. It is not a galling or friction
welding process, but rather the effect of a bolt in a much too small
hole.

To prevent this the usual practice is to insulate the aluminum from
the steel in some manner. There are special sealers on the market and
in emergency I have used silicone sealant.

But for long term service, the usual practice in making a two, or
more, piece aluminum mast for instance, is to use fasteners what are
very close to aluminum in the galvanic scale and thus eliminate the
cause.
--

Cheers,

John B.

On Sat, 05 Dec 2015 10:37:09 -0500, Ed Huntress
wrote:

On Sat, 05 Dec 2015 14:45:31 +0000, N_Cook wrote:

Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?

Yeah. Corrosion. It's typically galvanic corrorion, and you aren't
going to stop it permanently. Depending on the application, your best
bet may be to bolt and unbolt them frequently. Stainless steel bolts
will not help.

Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .

I use lead-based anti-seize (from a tin I've had for 40 years). It
only helps a little. It''s probably no better than petroleum jelly,
but it makes me feel better.

Steel and stainless steel fasteners corroding aluminum is such a
common problem, especially in marine applications, that a variety of
coatings and even electrical protection schemes have been developed.
The electrical methods work but are only practical on things like
boats.

Actually stainless increases the problem as it is even further down
the galvanic scale then plain steel.


Your best bet is to keep them dry with really good coatings, and try
to avoid entrapped air. Use lots of petroleum jelly. Entrapped air
leads to pitting corrosion, which is not as bad as having a completely
wet galvanic cell, but it's something to avoid.
--

Cheers,

John B.

On Mon, 07 Dec 2015 21:02:17 -0500, Joe Gwinn
wrote:

In article , Larry Jaques
wrote:
I found out recently that Superstrut (unistrut) is zincked and then
yellow chrome plated. Hmm, more to think about with chromium against
aluminum PV framing + galv and stainless hardware.

Since PV panels are entirely electrically separated from their
framing, I wonder how much galvanic corrosion happens, during the
course of a year's weather, between the rack, the frames, and the
holddown hardware. Surely enough to warrant anti-sieze, but does all
the hardware need more? I'll have to ask the local PV guys.

I haven't seen anything used by the pros during pro installation on
YouTube vids, but what I have seen is all aluminum racking against
aluminum PV frames with stainless holddown bolts.

Asking around in the relevant communities is the best way to find the
best approach. I'd ask around in boating circles - if it works in a
salt air environment, it will work all the better inland.

PING Gunner: Please ask your sailor buds which anti-sieze works best.

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

On 2015-12-08 03:48:51 +0000, Tom Gardner said:

On 12/5/2015 9:45 AM, N_Cook wrote:
Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .


What about thread inserts or Helicoils?

The same corrosion process will freeze helicoils as well. I suppose a
solid stainless insert would work - it would be frozen in place, but
unless the pressure was enough to crush the insert, the screw would
still be free to turn.

Joe Gwinn

On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:

On 12/5/2015 9:45 AM, N_Cook wrote:
Is there a proper name for the process where steel bolts in tapped
aluminium, bind so much that normal unscrewing is impossible and an
impulse driver just sheers the bolt or strips the head ?
Sort of cold semi-welding process.
When come across , the replacement bolts get a smear of petroleum jelly
over the threads .


What about thread inserts or Helicoils?

The same corrosion process will freeze helicoils as well. I suppose a
solid stainless insert would work - it would be frozen in place, but
unless the pressure was enough to crush the insert, the screw would
still be free to turn.

Joe Gwinn


But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)
--
cheers,

John B.

On 2015-12-10, John B wrote:
On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:

[ ... ]

What about thread inserts or Helicoils?

The same corrosion process will freeze helicoils as well. I suppose a
solid stainless insert would work - it would be frozen in place, but
unless the pressure was enough to crush the insert, the screw would
still be free to turn.

Joe Gwinn


But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)

Solid inserts are probably fine -- like the Keenserts which are
locked in by some square pegs driven into the threads parallel to the
axis.

However, Helicoils are a spiral of diamond shaped steel
(stainless?) which compress a little as they are screwed in. If the
corrosion above happened, it might squeeze the coils in too tight on the
installed screws.

Note that the Helicoils are screwed in by torque applied to a
cross-bar at the leading end of the screw, letting what follows wind
inwards to reduce the diameter until it stops going in. The first screw
into it likely causes the coil to expand slightly. The cross-bar is
normally broken off (at a designed-in weak point) once it is installed.

However -- it is possible to remove the insert. An arrowhead
shaped point on a tool bites into the last turns of the coil, and winds
it out -- again shrinking the rest of it to make it turn more easily.
(No bets what happens in the presence of the corrosion described above,
however. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 10 Dec 2015 01:21:35 GMT, "DoN. Nichols"
wrote:

On 2015-12-10, John B wrote:
On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:

[ ... ]

What about thread inserts or Helicoils?

The same corrosion process will freeze helicoils as well. I suppose a
solid stainless insert would work - it would be frozen in place, but
unless the pressure was enough to crush the insert, the screw would
still be free to turn.

Joe Gwinn


But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)

Solid inserts are probably fine -- like the Keenserts which are
locked in by some square pegs driven into the threads parallel to the
axis.

However, Helicoils are a spiral of diamond shaped steel
(stainless?) which compress a little as they are screwed in. If the
corrosion above happened, it might squeeze the coils in too tight on the
installed screws.

Note that the Helicoils are screwed in by torque applied to a
cross-bar at the leading end of the screw, letting what follows wind
inwards to reduce the diameter until it stops going in. The first screw
into it likely causes the coil to expand slightly. The cross-bar is
normally broken off (at a designed-in weak point) once it is installed.

However -- it is possible to remove the insert. An arrowhead
shaped point on a tool bites into the last turns of the coil, and winds
it out -- again shrinking the rest of it to make it turn more easily.
(No bets what happens in the presence of the corrosion described above,
however. :-)

Enjoy,
DoN.

Helicoils don't seal off the aluminum underneath. You'd still get
corossion -- between the helicoil and the aluminum, which will squeeze
the helicoil into the bolt.

--
Ed Huntress

Ed Huntress wrote:
On 10 Dec 2015 01:21:35 GMT, "DoN. Nichols"
wrote:

On 2015-12-10, John B wrote:
On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:
[ ... ]

What about thread inserts or Helicoils?
The same corrosion process will freeze helicoils as well. I suppose a
solid stainless insert would work - it would be frozen in place, but
unless the pressure was enough to crush the insert, the screw would
still be free to turn.

Joe Gwinn

But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)
Solid inserts are probably fine -- like the Keenserts which are
locked in by some square pegs driven into the threads parallel to the
axis.

However, Helicoils are a spiral of diamond shaped steel
(stainless?) which compress a little as they are screwed in. If the
corrosion above happened, it might squeeze the coils in too tight on the
installed screws.

Note that the Helicoils are screwed in by torque applied to a
cross-bar at the leading end of the screw, letting what follows wind
inwards to reduce the diameter until it stops going in. The first screw
into it likely causes the coil to expand slightly. The cross-bar is
normally broken off (at a designed-in weak point) once it is installed.

However -- it is possible to remove the insert. An arrowhead
shaped point on a tool bites into the last turns of the coil, and winds
it out -- again shrinking the rest of it to make it turn more easily.
(No bets what happens in the presence of the corrosion described above,
however. :-)

Enjoy,
DoN.

Helicoils don't seal off the aluminum underneath. You'd still get
corossion -- between the helicoil and the aluminum, which will squeeze
the helicoil into the bolt.


That was why I suggested isolation mounts. You can buy them with
aluminum on one side and whatever you want on the other.

Drill & tap the holes, apply some Noalox to the aluminum stud side and
screw it down. Between the noalox and the rubber of the mount it should
seal it pretty well.

Now you have a rubber isolated stud to mount the panel racks to. Gives
you a stronger mount, the rubber will allow the pieces to flex a bit
easier and it would be electrically isolated as well.

--
Steve W.

On 10/12/2015 08:23, Steve W. wrote:
Ed Huntress wrote:
On 10 Dec 2015 01:21:35 GMT, "DoN. Nichols"
wrote:

On 2015-12-10, John B wrote:
On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:
[ ... ]

What about thread inserts or Helicoils?
The same corrosion process will freeze helicoils as well. I
suppose a solid stainless insert would work - it would be frozen in
place, but unless the pressure was enough to crush the insert, the
screw would still be free to turn.

Joe Gwinn

But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)
Solid inserts are probably fine -- like the Keenserts which are
locked in by some square pegs driven into the threads parallel to the
axis.

However, Helicoils are a spiral of diamond shaped steel
(stainless?) which compress a little as they are screwed in. If the
corrosion above happened, it might squeeze the coils in too tight on the
installed screws.

Note that the Helicoils are screwed in by torque applied to a
cross-bar at the leading end of the screw, letting what follows wind
inwards to reduce the diameter until it stops going in. The first screw
into it likely causes the coil to expand slightly. The cross-bar is
normally broken off (at a designed-in weak point) once it is installed.

However -- it is possible to remove the insert. An arrowhead
shaped point on a tool bites into the last turns of the coil, and winds
it out -- again shrinking the rest of it to make it turn more easily.
(No bets what happens in the presence of the corrosion described above,
however. :-)

Enjoy,
DoN.

Helicoils don't seal off the aluminum underneath. You'd still get
corossion -- between the helicoil and the aluminum, which will squeeze
the helicoil into the bolt.


That was why I suggested isolation mounts. You can buy them with
aluminum on one side and whatever you want on the other.

Drill & tap the holes, apply some Noalox to the aluminum stud side and
screw it down. Between the noalox and the rubber of the mount it should
seal it pretty well.

Now you have a rubber isolated stud to mount the panel racks to. Gives
you a stronger mount, the rubber will allow the pieces to flex a bit
easier and it would be electrically isolated as well.


Is this the neoprene rubber that over 20 years degrades to a gooey black
paste? with the structural integrity of marmalade

N_Cook wrote:
On 10/12/2015 08:23, Steve W. wrote:
Ed Huntress wrote:
On 10 Dec 2015 01:21:35 GMT, "DoN. Nichols"
wrote:

On 2015-12-10, John B wrote:
On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:
[ ... ]

What about thread inserts or Helicoils?
The same corrosion process will freeze helicoils as well. I
suppose a solid stainless insert would work - it would be frozen in
place, but unless the pressure was enough to crush the insert, the
screw would still be free to turn.

Joe Gwinn

But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)
Solid inserts are probably fine -- like the Keenserts which are
locked in by some square pegs driven into the threads parallel to the
axis.

However, Helicoils are a spiral of diamond shaped steel
(stainless?) which compress a little as they are screwed in. If the
corrosion above happened, it might squeeze the coils in too tight on the
installed screws.

Note that the Helicoils are screwed in by torque applied to a
cross-bar at the leading end of the screw, letting what follows wind
inwards to reduce the diameter until it stops going in. The first screw
into it likely causes the coil to expand slightly. The cross-bar is
normally broken off (at a designed-in weak point) once it is installed.

However -- it is possible to remove the insert. An arrowhead
shaped point on a tool bites into the last turns of the coil, and winds
it out -- again shrinking the rest of it to make it turn more easily.
(No bets what happens in the presence of the corrosion described above,
however. :-)

Enjoy,
DoN.
Helicoils don't seal off the aluminum underneath. You'd still get
corossion -- between the helicoil and the aluminum, which will squeeze
the helicoil into the bolt.

That was why I suggested isolation mounts. You can buy them with
aluminum on one side and whatever you want on the other.

Drill & tap the holes, apply some Noalox to the aluminum stud side and
screw it down. Between the noalox and the rubber of the mount it should
seal it pretty well.

Now you have a rubber isolated stud to mount the panel racks to. Gives
you a stronger mount, the rubber will allow the pieces to flex a bit
easier and it would be electrically isolated as well.


Is this the neoprene rubber that over 20 years degrades to a gooey black
paste? with the structural integrity of marmalade

You can spec the isolation material. The rubber I normally use is the
same used for engine mounts. You could also use urethane if you wanted
less flex.

--
Steve W.

On 10 Dec 2015 01:21:35 GMT, "DoN. Nichols"
wrote:

On 2015-12-10, John B wrote:
On Wed, 9 Dec 2015 09:40:48 -0500, Joseph Gwinn
wrote:

On 2015-12-08 03:48:51 +0000, Tom Gardner said:

[ ... ]

What about thread inserts or Helicoils?

The same corrosion process will freeze helicoils as well. I suppose a
solid stainless insert would work - it would be frozen in place, but
unless the pressure was enough to crush the insert, the screw would
still be free to turn.

Joe Gwinn


But, helicoils, or solid inserts for that matter, are normally
considered permanent installations and are usually locked in place in
some manner. If they were to "freeze" no one would ever know it :-)

Solid inserts are probably fine -- like the Keenserts which are
locked in by some square pegs driven into the threads parallel to the
axis.

However, Helicoils are a spiral of diamond shaped steel
(stainless?) which compress a little as they are screwed in. If the
corrosion above happened, it might squeeze the coils in too tight on the
installed screws.

Note that the Helicoils are screwed in by torque applied to a
cross-bar at the leading end of the screw, letting what follows wind
inwards to reduce the diameter until it stops going in. The first screw
into it likely causes the coil to expand slightly. The cross-bar is
normally broken off (at a designed-in weak point) once it is installed.


And helicoils that are intended to be permanent have a serrated
portion and you install the helicoil and then use an expander to force
the serrated portion into the parent metal. A bit more difficult to
remove then your arrowhead tool will handle.




However -- it is possible to remove the insert. An arrowhead
shaped point on a tool bites into the last turns of the coil, and winds
it out -- again shrinking the rest of it to make it turn more easily.
(No bets what happens in the presence of the corrosion described above,
however. :-)

Enjoy,
DoN.
--
cheers,

John B.