Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:

https://picasaweb.google.com/1113554...44852252275298


Unit is about five years old and arguably too new to have pinhole leaks
in the tank, but still had to basically bathe in soapy water (after
replacing the drain cock which was suspect, but didn't stop the problem)
until I found two more brass connection leaks.

The hardest to pinpoint was at the input _plug_ at the far right ...
tiny, tiny bubbles, almost imperceptible were the giveaway.

Some pipe dope and been holding steady for three hours, for the first
time in a year ... wish me luck.


--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 10/13/2012 12:34 PM, Swingman wrote:
Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:

https://picasaweb.google.com/1113554...44852252275298



Unit is about five years old and arguably too new to have pinhole leaks
in the tank, but still had to basically bathe in soapy water (after
replacing the drain cock which was suspect, but didn't stop the problem)
until I found two more brass connection leaks.

The hardest to pinpoint was at the input _plug_ at the far right ...
tiny, tiny bubbles, almost imperceptible were the giveaway.

Some pipe dope and been holding steady for three hours, for the first
time in a year ... wish me luck.



My now 18 year old compressor developed a high pitched chirping sound,
cast iron dual cylinders, and filled much slower than normal. This came
about about 7 years ago. I had "blow-by". The head gasket between the
intake and exhaust ports had a crack. New gasket fixed the problem.

Swingman wrote:
Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:

https://picasaweb.google.com/1113554...44852252275298


Unit is about five years old and arguably too new to have pinhole leaks
in the tank, but still had to basically bathe in soapy water (after
replacing the drain cock which was suspect, but didn't stop the problem)
until I found two more brass connection leaks.

The hardest to pinpoint was at the input _plug_ at the far right ...
tiny, tiny bubbles, almost imperceptible were the giveaway.

Some pipe dope and been holding steady for three hours, for the first
time in a year ... wish me luck.


When I had a slow leak in my distribution system (black iron) my
brother introduced me to the hand soap which comes out as a foam when
you press the pump handle on top. This stuff works great and stays
where you put it without running everywhere. Found the leak in a
female connector.

--
G.W. Ross

Megabyte: A nine course dinner.

On 10/13/2012 12:34 PM, Swingman wrote:
Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:
....

Just tested my brazing job on the small airless tank I had posted about
a while back--still have a small spot or two...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side of the patch (used a piece of 1/8" flat stock to
cover the stretch where the failure line was apparent) but can not seem
to get it to do so consistently on the other. I'm not an expert but
never had this kind of inconsistency on a single job so I'm at a loss of
what the issue is.

--

On 10/13/2012 2:53 PM, dpb wrote:

Just tested my brazing job on the small airless tank I had posted about
a while back--still have a small spot or two...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side of the patch (used a piece of 1/8" flat stock to
cover the stretch where the failure line was apparent) but can not seem
to get it to do so consistently on the other. I'm not an expert but
never had this kind of inconsistency on a single job so I'm at a loss of
what the issue is.

You're a better man than me when it comes to brazing tanks ... I totally
lack the gene, or something.

At one time I was a master at forge welding/brazing what we called
"Louisiana Grabbers" on the toes of handmade racehorse shoes, but that's
about the extent of it, and those days are long over.

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 10/13/2012 2:48 PM, G. Ross wrote:
When I had a slow leak in my distribution system (black iron) my brother
introduced me to the hand soap which comes out as a foam when you press
the pump handle on top. This stuff works great and stays where you put
it without running everywhere. Found the leak in a female connector.


My favorite hand soap, AAMOF, we have it in every bath and in the
kitchen. Never thought of using it for air/gas leaks ... good tip. Thanks!

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

dpb wrote:
On 10/13/2012 12:34 PM, Swingman wrote:
Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:
...

Just tested my brazing job on the small airless tank I had posted
about a while back--still have a small spot or two...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side of the patch (used a piece of 1/8" flat stock to
cover the stretch where the failure line was apparent) but can not
seem to get it to do so consistently on the other. I'm not an expert
but never had this kind of inconsistency on a single job so I'm at a
loss of what the issue is.

So... a couple of thoughts come to mind. One is cleanliness of the surface
to be brazed and the other is the actual integrity of the material. In
order to get a good braze joint, you have to be able to heat the metal to
red hot. If you're not doing that, then you're just flowing molten brazing
rod onto a surface that it won't adhere to. If the surfaces can't be heated
to red hot, perhaps because of corrosion, then same problem - no joint.
Brazing is a lot like soldering - you heat the surface and apply the rod to
achieve a melting together of the rod and the materials. You have to have
stable material and proper heat, and no buggers like dirt and rust.

--

-Mike-

On 10/13/2012 4:02 PM, Mike Marlow wrote:
dpb wrote:
....

For some reason I've been unable to figure out the brazing stuck very
nicely on one side ...but ... not
... consistently on the other. ...

So... a couple of thoughts come to mind. One is cleanliness of the surface
to be brazed and the other is the actual integrity of the material. In
order to get a good braze joint, you have to be able to heat the metal to
red hot. If you're not doing that, then you're just flowing molten brazing
rod onto a surface that it won't adhere to. If the surfaces can't be heated
to red hot, perhaps because of corrosion, then same problem - no joint.
....

Ground to shiny surfaces on all faces before starting...heat shouldn't
be problem; rod flows but then on cooling is occasional minute fracture
line along one surface edge. Meanwhile, same technique to best as can
replicate worked perfectly on other edge.

--

On 10/13/2012 3:23 PM, Swingman wrote:
On 10/13/2012 2:53 PM, dpb wrote:

Just tested my brazing job on the small airless tank I had posted about
a while back--still have a small spot or two...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side of the patch (used a piece of 1/8" flat stock to
cover the stretch where the failure line was apparent) but can not seem
to get it to do so consistently on the other. I'm not an expert but
never had this kind of inconsistency on a single job so I'm at a loss of
what the issue is.

You're a better man than me when it comes to brazing tanks ... I totally
lack the gene, or something.

At one time I was a master at forge welding/brazing what we called
"Louisiana Grabbers" on the toes of handmade racehorse shoes, but that's
about the extent of it, and those days are long over.

Well, I'm not sure I'm better than anybody at this point... (or ,
maybe is more like it)

It's small and figured not much to lose--it's toward the bottom side of
a horizontal tank so if it does fail it'll not be going anywhere except
towards the floor so it's not like I've got something that could go
sailing across the shop...

--

On Sat, 13 Oct 2012 12:34:36 -0500, Swingman wrote:
Unit is about five years old and arguably too new to have pinhole leaks

Depends if you open the drain cock and purge collected condensation on
a regular basis. I know you would, but many people don't.

dpb wrote:


Ground to shiny surfaces on all faces before starting...heat shouldn't
be problem; rod flows but then on cooling is occasional minute
fracture line along one surface edge. Meanwhile, same technique to
best as can replicate worked perfectly on other edge.

Almost sounds like contamination - wouldn't you agree? I know you ground it
down but, if the metal is sound where you are brazing, I'm not thinking of
anything else that could booger you up like this.

--

-Mike-

On 10/13/2012 5:50 PM, Mike Marlow wrote:
dpb wrote:


Ground to shiny surfaces on all faces before starting...heat shouldn't
be problem; rod flows but then on cooling is occasional minute
fracture line along one surface edge. Meanwhile, same technique to
best as can replicate worked perfectly on other edge.

Almost sounds like contamination - wouldn't you agree? I know you ground it
down but, if the metal is sound where you are brazing, I'm not thinking of
anything else that could booger you up like this.

Me neither, but don't know where it could have come from...if were
disparate pieces that acted differently I'd see it at lot more readily...

--

dpb wrote:
On 10/13/2012 5:50 PM, Mike Marlow wrote:
dpb wrote:


Ground to shiny surfaces on all faces before starting...heat
shouldn't be problem; rod flows but then on cooling is occasional
minute fracture line along one surface edge. Meanwhile, same
technique to best as can replicate worked perfectly on other edge.

Almost sounds like contamination - wouldn't you agree? I know you
ground it down but, if the metal is sound where you are brazing, I'm
not thinking of anything else that could booger you up like this.

Me neither, but don't know where it could have come from...if were
disparate pieces that acted differently I'd see it at lot more
readily...

You're on solid metal there, correct? You're not trying to braze a hole
over, are you?

--

-Mike-

dpb wrote:
On 10/13/2012 5:50 PM, Mike Marlow wrote:
dpb wrote:


Ground to shiny surfaces on all faces before starting...heat
shouldn't be problem; rod flows but then on cooling is occasional
minute fracture line along one surface edge. Meanwhile, same
technique to best as can replicate worked perfectly on other edge.

Almost sounds like contamination - wouldn't you agree? I know you
ground it down but, if the metal is sound where you are brazing, I'm
not thinking of anything else that could booger you up like this.

Me neither, but don't know where it could have come from...if were
disparate pieces that acted differently I'd see it at lot more
readily...

The reason I asked the previous question (about being on solid metal and not
filling a hole), is I'm wondering if capilary action may be drawing moisture
from inside the tank to that area of your work when you apply the heat.

--

-Mike-

Mike Marlow wrote:
dpb wrote:
On 10/13/2012 5:50 PM, Mike Marlow wrote:
dpb wrote:


Ground to shiny surfaces on all faces before starting...heat
shouldn't be problem; rod flows but then on cooling is occasional
minute fracture line along one surface edge. Meanwhile, same
technique to best as can replicate worked perfectly on other edge.

Almost sounds like contamination - wouldn't you agree? I know you
ground it down but, if the metal is sound where you are brazing, I'm
not thinking of anything else that could booger you up like this.

Me neither, but don't know where it could have come from...if were
disparate pieces that acted differently I'd see it at lot more
readily...

The reason I asked the previous question (about being on solid metal
and not filling a hole), is I'm wondering if capilary action may be
drawing moisture from inside the tank to that area of your work when
you apply the heat.

So... how is your rod melting in when you're on it? Look like a good flow
and all that? Try taking a wire coat hanger and wire weld it and see if
that behaves any differently. You've really got my curiosity up on this
one. I've been stymied like this before myself (just ask me about the
Toyota Corolla from hell...), and I understand the frustrations of doing
everything right and having unexplained problems.

--

-Mike-

On 10/13/2012 7:03 PM, Mike Marlow wrote:
....

The reason I asked the previous question (about being on solid metal and not
filling a hole), is I'm wondering if capilary action may be drawing moisture
from inside the tank to that area of your work when you apply the heat.

Don't think so (on the latter) -- it's a small tank that is open to air
and hasn't had anything in it for a month.

As for A), yes, I bridged the hole areas w/ a piece of strap ground to
match tank curvature pretty closely.

--

dpb wrote:
On 10/13/2012 7:03 PM, Mike Marlow wrote:
...

The reason I asked the previous question (about being on solid metal
and not filling a hole), is I'm wondering if capilary action may be
drawing moisture from inside the tank to that area of your work when
you apply the heat.

Don't think so (on the latter) -- it's a small tank that is open to
air and hasn't had anything in it for a month.

As for A), yes, I bridged the hole areas w/ a piece of strap ground to
match tank curvature pretty closely.

I'm sure you're quite capable at this, but it's also an unusual problem.
Any chance that "pretty closely" is contributing to your problems? Do you
have a good tight fit of the patch to the tank surface where you are
brazing? I know that you should be able to fill with braze, but I'm sorta
stretching my brain on this one. That makes my head hurt ya know...

--

-Mike-

On Sat, 13 Oct 2012 16:29:03 -0500, dpb wrote:

On 10/13/2012 4:02 PM, Mike Marlow wrote:
dpb wrote:
...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side ...but ... not
... consistently on the other. ...

So... a couple of thoughts come to mind. One is cleanliness of the surface
to be brazed and the other is the actual integrity of the material. In
order to get a good braze joint, you have to be able to heat the metal to
red hot. If you're not doing that, then you're just flowing molten brazing
rod onto a surface that it won't adhere to. If the surfaces can't be heated
to red hot, perhaps because of corrosion, then same problem - no joint.
...

Ground to shiny surfaces on all faces before starting...heat shouldn't
be problem; rod flows but then on cooling is occasional minute fracture
line along one surface edge. Meanwhile, same technique to best as can
replicate worked perfectly on other edge.


Perhaps your patch is too thick, and it cools at a different rate than
the base metal. The first edge worked good - the patch was
unconstrained. Now the second edge is moving around all over the place
as it heats and cools. Nice to have 2 different brazing metals - one
melting hotter than the other. Braze the one side with the "hot" rod,
then heat the whole thing - base and patch, to just under the plastic
temperature of the hot rod, which will hopefully be high enough to
melt the "cool" rod to braze the other 3 sides - while not melting the
first joint. Then let the whole thing cool slowly and evenly - with no
cracks.

The other way requires having the job set up so gravity hold the patch
in place. Have the patch formed to a close fit. "sweat" a coating of
braze onto the base metal, and while still hot, drop the heated patch
in place, and keep heating untill the braze flows out the edge of the
patch and wets the edges of the patch. You might want to flow a bit
more braze into the edges of the patch to be sure it is fully sealed -
then let cool slowly and evenly - no cracks or pinholes.

On Sat, 13 Oct 2012 19:12:07 -0500, dpb wrote:

On 10/13/2012 7:03 PM, Mike Marlow wrote: ...

The reason I asked the previous question (about being on solid metal
and not filling a hole), is I'm wondering if capilary action may be
drawing moisture from inside the tank to that area of your work when
you apply the heat.

Don't think so (on the latter) -- it's a small tank that is open to air
and hasn't had anything in it for a month.

As for A), yes, I bridged the hole areas w/ a piece of strap ground to
match tank curvature pretty closely.

One possibility comes to mind, the patch material may be overall a
lot hotter than the tank, when cooling it pulls a crack in the last edge.

basilisk



--
A wink is as good as a nod to a blind horse

On 10/13/2012 12:34 PM, Swingman wrote:
Some pipe dope and been holding steady for three hours, for the first
time in a year ... wish me luck.

24 hours later and holding 120 psi steady as a rock. By jove, I think
we've got it!

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 10/13/2012 10:22 PM, wrote:
On Sat, 13 Oct 2012 16:29:03 -0500, wrote:

On 10/13/2012 4:02 PM, Mike Marlow wrote:
dpb wrote:
...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side ...but ... not ... consistently on the other. ...

....

....[various inputs elided for brevity]...

OK, followup here--

After consideration of the points raised, decided perhaps it was a
heat/cooling issue after all.

So, went to a larger tip and reflowed the problematical area and voila!
-- seem to have a good seam all the way around now. We'll see how it
stands up to pressure and temperature (it's in unheated shop and
winter's coming on) cycling over next few months...

--

On 10/16/2012 1:09 PM, dpb wrote:
So, went to a larger tip and reflowed the problematical area and voila!
-- seem to have a good seam all the way around now. We'll see how it
stands up to pressure and temperature (it's in unheated shop and
winter's coming on) cycling over next few months...

Good luck ... just checked mine this morning and it's still holding rock
steady at 120psi since Sat AM ... since this is about the longest its
gone without being used in a couple of years I'll hold what I got.


Good to get rid of that little irritant/thorn in the side ... I'm keenly
aware of each and everyone of my tools that is not performing up to spec
and it bugs me no end/get no rest until that's rectified.

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 10/16/2012 2:28 PM, Swingman wrote:
On 10/16/2012 1:09 PM, dpb wrote:
So, went to a larger tip and reflowed the problematical area and voila!
-- seem to have a good seam all the way around now. We'll see how it
stands up to pressure and temperature (it's in unheated shop and
winter's coming on) cycling over next few months...

Good luck ... just checked mine this morning and it's still holding rock
steady at 120psi since Sat AM ... since this is about the longest its
gone without being used in a couple of years I'll hold what I got.


Good to get rid of that little irritant/thorn in the side ... I'm keenly
aware of each and everyone of my tools that is not performing up to spec
and it bugs me no end/get no rest until that's rectified.

The big compressor holds when off but the valve at the tank leaks around
the stem when open. It _should_ be replaced at some point but it's been
that way from the time I was a kid so it's a feature that tells you when
you didn't turn the air off if the compressor cycles w/o being used...
That's my story and... vbg

--

In article , dpb wrote:
On 10/16/2012 2:28 PM, Swingman wrote:
... other quotes snipped...
The big compressor holds when off but the valve at the tank leaks around
the stem when open. It _should_ be replaced at some point but it's been
that way from the time I was a kid so it's a feature that tells you when
you didn't turn the air off if the compressor cycles w/o being used...
That's my story and... vbg


That is sort of like older Harley Davidsons; You could tell when they
were really low on engine oil because they stopped leaking...

--
There is always an easy solution to every human problem -- neat,
plausible, and wrong." (H L Mencken)

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

On 10/16/2012 5:30 PM, Larry W wrote:
In , wrote:
On 10/16/2012 2:28 PM, Swingman wrote:
... other quotes snipped...
The big compressor holds when off but the valve at the tank leaks around
the stem when open. It _should_ be replaced at some point but it's been
that way from the time I was a kid so it's a feature that tells you when
you didn't turn the air off if the compressor cycles w/o being used...
That's my story and...vbg


That is sort of like older Harley Davidsons; You could tell when they
were really low on engine oil because they stopped leaking...

First Charger we bought was from a dealership in small Piedmont VA town.
Shop head was old-timer who crew-chief'ed for Lee Petty in the MoPar
factory days. He told me when I complained "when a MoPar engine
_doesn't_ use a little oil, then it's got a problem..."

So, it went nearly 200k w/ an extra qt/change...

--

"dpb" wrote in message ...
On 10/13/2012 12:34 PM, Swingman wrote:
Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:
...

Just tested my brazing job on the small airless tank I had posted about a
while back--still have a small spot or two...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side of the patch (used a piece of 1/8" flat stock to cover
the stretch where the failure line was apparent) but can not seem to get
it to do so consistently on the other. I'm not an expert but never had
this kind of inconsistency on a single job so I'm at a loss of what the
issue is.

--

Nearly always cleanliness of the parent metal. Get all corrosion gone, and
grease or oil. Use acid resin, and het it and use a stainless steel brush
(only) on it, then braze.
--
Jim in NC