Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.

What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.

Thanks,

Bill

On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. ...Is there something else you would do
to make a presentable finish? ...
Bill

The reddish-brown Scotchbrite pads make a nice brushed finish quickly.
The green household ones aren't too bad either. Inside corners are
difficult, so if possible clean up the frame members before final
assembly.

Jim Wilkins

"Jim Wilkins" wrote in message
...
On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. ...Is there something else you would do
to make a presentable finish? ...
Bill

The reddish-brown Scotchbrite pads make a nice brushed finish quickly.
The green household ones aren't too bad either. Inside corners are
difficult, so if possible clean up the frame members before final
assembly.

*Maroon* scotchbrite.
Works well, I think first degreasing/cleaning the alum helps as well.
Steel wool ought to work just fine, too.
99c sell the green stuff in 6" stacks for, uh, 99c.
Also, if you are doing this in any quantity, you can get scotchbrite made
for belt sanders. For my 4x24, they were $10-12 *each*--goodgawd.....

Haven't tried it, but a sponge and Comet or its equivalent might work
nice--mebbe great.
Scotchbrite tends to get gummy from alum.

Face milling would not be a problem, as the pieces are short, and I don't
think you'd have to mill off more than .010, altho that might not get the
deeper dings/gouges.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

AND,
Make sure whomever you do vote for believes in
ABSOLUTE separation of Church & State--ferchrissakes

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs



Jim Wilkins

On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.

What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.

Thanks,

Bill

Try it. Or not. It's your choice.

How in the hell would you expect anyone to be able to give you a good
answer, without knowing the depth of cut necessary and the finish that
you want?

John Martin

*Maroon* scotchbrite.
Works well, I think first degreasing/cleaning the alum helps as well.
Steel wool ought to work just fine, too.
99c sell the green stuff in 6" stacks for, uh, 99c.
Also, if you are doing this in any quantity, you can get scotchbrite made
for belt sanders. For my 4x24, they were $10-12 *each*--goodgawd.....

This is one of my medium-sized "production runs" - aka two of them


Haven't tried it, but a sponge and Comet or its equivalent might work
nice--mebbe great.
Scotchbrite tends to get gummy from alum.

Face milling would not be a problem, as the pieces are short, and I don't
think you'd have to mill off more than .010, altho that might not get the
deeper dings/gouges.

It probably would not get all of them, but then neither would
scrotchbright. How would the scotchbright finish handle fingerprints?
The parts in question form the outer casing of the offending gizmo and
are likely to handled far more than the largely flycut and visible innards.

Bill

Bill,
A random orbital sander will create a finish that hides a lot of
"features". Medium grade sandpaper, or a scotchbrite pad is good.
DJ

On Nov 28, 12:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.

What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.

Thanks,

Bill

"Bill Schwab" wrote in message
...
*Maroon* scotchbrite.
Works well, I think first degreasing/cleaning the alum helps as well.
Steel wool ought to work just fine, too.
99c sell the green stuff in 6" stacks for, uh, 99c.
Also, if you are doing this in any quantity, you can get scotchbrite made
for belt sanders. For my 4x24, they were $10-12 *each*--goodgawd.....

This is one of my medium-sized "production runs" - aka two of them


Haven't tried it, but a sponge and Comet or its equivalent might work
nice--mebbe great.
Scotchbrite tends to get gummy from alum.

Face milling would not be a problem, as the pieces are short, and I
don't think you'd have to mill off more than .010, altho that might not
get the deeper dings/gouges.

It probably would not get all of them, but then neither would
scrotchbright. How would the scotchbright finish handle fingerprints?

Strictly speaking, scotchbrite is not a finish, but a grade of sanding, and
leaves raw unoxidized aluminum, which is a magnet for fingerprints, just
like polished stainless.
The oxide that forms over time seems to be much less of a magnet for prints,
but looks like, well, oxidized aluminum. Not necessarily bad, tho.

Before that oxide forms (if you want the brite finish), you can send it out
to get "clear-coated", or even anodized, or just
spray-lacquer/polyurethane/etc it yourself, which should look really nice.
That's the only way I know to keep off prints, and to keep the gray oxide
from forming.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

AND,
Make sure whomever you do vote for believes in
ABSOLUTE separation of Church & State--ferchrissakes

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs


The parts in question form the outer casing of the offending gizmo and
are likely to handled far more than the largely flycut and visible
innards.

Bill

"Pre-Meltdown" wrote in message
...


"Bill Schwab" wrote in message
...
*Maroon* scotchbrite.
Works well, I think first degreasing/cleaning the alum helps as well.
Steel wool ought to work just fine, too.
99c sell the green stuff in 6" stacks for, uh, 99c.
Also, if you are doing this in any quantity, you can get scotchbrite
made for belt sanders. For my 4x24, they were $10-12
*each*--goodgawd.....

This is one of my medium-sized "production runs" - aka two of them


Haven't tried it, but a sponge and Comet or its equivalent might work
nice--mebbe great.
Scotchbrite tends to get gummy from alum.

Face milling would not be a problem, as the pieces are short, and I
don't think you'd have to mill off more than .010, altho that might not
get the deeper dings/gouges.

It probably would not get all of them, but then neither would
scrotchbright. How would the scotchbright finish handle fingerprints?

Strictly speaking, scotchbrite is not a finish, but a grade of sanding,
and leaves raw unoxidized aluminum, which is a magnet for fingerprints,
just like polished stainless.
The oxide that forms over time seems to be much less of a magnet for
prints, but looks like, well, oxidized aluminum. Not necessarily bad,
tho.

Before that oxide forms (if you want the brite finish), you can send it
out to get "clear-coated", or even anodized, or just
spray-lacquer/polyurethane/etc it yourself, which should look really
nice. That's the only way I know to keep off prints, and to keep the gray
oxide from forming.

Which got me thinking:

If the gray oxide finish on fresh/polished aluminum is not so bad (actually,
"natural anodizing", and is itself highly protective and hard), I wonder if
accelerating its formation in an oven would be practical? Esp. as your
parts would fit.
Just don't get fingerprints on it before you put it in the oven....

Strictly speaking, say from a conductivity pov, these oxides start forming
almost immediately, within minutes, enough to effect contact conductivity.

Sending stuff out to be anodized is expensive, but actually a pretty easy
diy. There were/are some outstanding web sites on how to do this.

I'll have to try the oven ditty myself.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

AND,
Make sure whomever you do vote for believes in
ABSOLUTE separation of Church & State--ferchrissakes

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs




--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

AND,
Make sure whomever you do vote for believes in
ABSOLUTE separation of Church & State--ferchrissakes

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs


The parts in question form the outer casing of the offending gizmo and
are likely to handled far more than the largely flycut and visible
innards.

Bill

"Pre-Meltdown" wrote in message
...

snip


If the gray oxide finish on fresh/polished aluminum is not so bad
(actually, "natural anodizing", and is itself highly protective and hard),
I wonder if accelerating its formation in an oven would be practical?
Esp. as your parts would fit.
Just don't get fingerprints on it before you put it in the oven....

Strictly speaking, say from a conductivity pov, these oxides start forming
almost immediately, within minutes, enough to effect contact conductivity.

Sending stuff out to be anodized is expensive, but actually a pretty easy
diy. There were/are some outstanding web sites on how to do this.

I'll have to try the oven ditty myself.

Another cheap and easy finish that works on *most* grades of aluminum is the
bright satin effect you get from dipping it in a lye solution. I use this
for the chassis on electronics projects.

Dissolve a few tablespoons of household lye in a quart of warm water; wash
the oil off the aluminum with strong detergent; submerge the aluminum in the
lye solution. Leave it there until it looks good -- usually minutes. If
there are any oil spots on the aluminum that show up as the lye bath
continues, pull the aluminum out, wash with water, brush the spot with
Scotchbrite, and put it back into the solution.

When you like the look, rinse it thoroughly, dry while it's still warm, and
spray with clear lacquer or something tougher, if you prefer.

--
Ed Huntress

On Nov 28, 9:58 am, Bill Schwab wrote:
...
It probably would not get all of them, but then neither would
scrotchbright. How would the scotchbright finish handle fingerprints?
The parts in question form the outer casing of the offending gizmo and
are likely to handled far more than the largely flycut and visible innards.
Bill

In my experience brushed aluminum doesn't show them objectionably;
stainless is worse. My fingerprints don't rust steel and darken brass
only slightly after a few weeks but I've built prototypes, demos and
trade show toys that were handled by lots of people and I don't
remember any issues with the Scotchbrite'd aluminum finish. One
fingerprint on polished metal shows up whereas 1000 blend into a
continuous even surface.

The well-handled field return EMT equipment on the rack behind me
doesn't show fingerprints on the matte beige plastic or the black
anodized aluminum handles.

Jim Wilkins

"Ed Huntress" wrote in message
...

"Pre-Meltdown" wrote in message
...

snip


If the gray oxide finish on fresh/polished aluminum is not so bad
(actually, "natural anodizing", and is itself highly protective and
hard), I wonder if accelerating its formation in an oven would be
practical? Esp. as your parts would fit.
Just don't get fingerprints on it before you put it in the oven....

Strictly speaking, say from a conductivity pov, these oxides start
forming almost immediately, within minutes, enough to effect contact
conductivity.

Sending stuff out to be anodized is expensive, but actually a pretty easy
diy. There were/are some outstanding web sites on how to do this.

I'll have to try the oven ditty myself.

Another cheap and easy finish that works on *most* grades of aluminum is
the bright satin effect you get from dipping it in a lye solution. I use
this for the chassis on electronics projects.

Dissolve a few tablespoons of household lye in a quart of warm water; wash
the oil off the aluminum with strong detergent; submerge the aluminum in
the lye solution. Leave it there until it looks good -- usually minutes.
If there are any oil spots on the aluminum that show up as the lye bath
continues, pull the aluminum out, wash with water, brush the spot with
Scotchbrite, and put it back into the solution.

When you like the look, rinse it thoroughly, dry while it's still warm,
and spray with clear lacquer or something tougher, if you prefer.

Very interesting.

There's a guy not far from me with the biggest-assed circular vibratory
tumbler I've seen, the size of a small bedroom/large closet, who puts in
some chemical with the media that gives aluminum an almost galvanized look,
and claims this finish is protective.
I don't know if I like it, it's certainly not like a brushed/satin look, a
little industrial/cobby, but not bad.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

AND,
Make sure whomever you do vote for believes in
ABSOLUTE separation of Church & State--ferchrissakes

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs





--
Ed Huntress

"Pre-Meltdown" wrote in message
...
"Ed Huntress" wrote in message
...

"Pre-Meltdown" wrote in message
...

snip


If the gray oxide finish on fresh/polished aluminum is not so bad
(actually, "natural anodizing", and is itself highly protective and
hard), I wonder if accelerating its formation in an oven would be
practical? Esp. as your parts would fit.
Just don't get fingerprints on it before you put it in the oven....

Strictly speaking, say from a conductivity pov, these oxides start
forming almost immediately, within minutes, enough to effect contact
conductivity.

Sending stuff out to be anodized is expensive, but actually a pretty
easy diy. There were/are some outstanding web sites on how to do this.

I'll have to try the oven ditty myself.

Another cheap and easy finish that works on *most* grades of aluminum is
the bright satin effect you get from dipping it in a lye solution. I use
this for the chassis on electronics projects.

Dissolve a few tablespoons of household lye in a quart of warm water;
wash the oil off the aluminum with strong detergent; submerge the
aluminum in the lye solution. Leave it there until it looks good --
usually minutes. If there are any oil spots on the aluminum that show up
as the lye bath continues, pull the aluminum out, wash with water, brush
the spot with Scotchbrite, and put it back into the solution.

When you like the look, rinse it thoroughly, dry while it's still warm,
and spray with clear lacquer or something tougher, if you prefer.

Very interesting.

There's a guy not far from me with the biggest-assed circular vibratory
tumbler I've seen, the size of a small bedroom/large closet, who puts in
some chemical with the media that gives aluminum an almost galvanized
look, and claims this finish is protective.
I don't know if I like it, it's certainly not like a brushed/satin look, a
little industrial/cobby, but not bad.

Aluminum is so reactive that there have been many chemical finish treatments
cooked up for it over the years. Most of them don't really protect; only a
few produce a tight enough oxide or other compound to really protect the
aluminum. Anodizing, particularly "hard" anodizing (which is no harder, only
thicker) is among the most effective, but there are several types of
anodizing for different purposes. PAA (phosphoric-acid anodizing), for
example, is preferred when you want to make the surface receptive to
adhesives and strong enough for adhesive bonding.

There is a mild acid treatment that gives similar results to the lye
treatment, but I've never used it and can't remember which acid it is. It's
also suitable for home- or small-shop use. Neither the acid nor the lye
treatment provides any protection. They just leave a nice-looking surface
which, if you don't let it sit around for days before coating, is also
chemically active and will make a good bond with paint or clear coats. I try
to coat within a half-hour or so.

Some alloys don't behave very well in this treatment -- they leave a
smutty-looking surface -- but I can't remember which alloys those are. I do
remember using it on 2024 and 1100, and it works well on both of those. I
think it works on 6061, or so I've been told. You may have to experiment
with concentration to get some alloys to work but they make not work anyway.

The lye treatment is well-known among crafty people who make things with
aluminum and I've seen it recommended several times in books about making
electronic projects. I said I use it for chassis; I should have said I use
it for panels and covers.

--
Ed Huntress

John Martin wrote:
On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.

What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.

Thanks,

Bill

Try it. Or not. It's your choice.

How in the hell would you expect anyone to be able to give you a good
answer, without knowing the depth of cut necessary and the finish that
you want?

John Martin

Well, I have developed considerable respect for the frequent
contributors here. You might care to read some of their replies,
because they are insightful, based in experience and professionalism.

Ironically, one of them even suggested a depth of cut, of the same order
of magnitude that I had in mind.

Bill

"Bill Schwab" wrote in message
...
John Martin wrote:
On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.

What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.

Thanks,

Bill

Try it. Or not. It's your choice.

How in the hell would you expect anyone to be able to give you a good
answer, without knowing the depth of cut necessary and the finish that
you want?

John Martin

Well, I have developed considerable respect for the frequent contributors
here. You might care to read some of their replies, because they are
insightful, based in experience and professionalism.

Ironically, one of them even suggested a depth of cut, of the same order
of magnitude that I had in mind.

And to finish that point, as I deal with 1/8 wall alum tube often, I'd fall
over if a .010 cut did anything to the tube ito twist or anything else,
besides the very slight structural weakening due to thinning the wall.

And, if you were doing this in a CNC, you could take this cut in rapid,
literally about a couple of seconds per face (or less!), with a *near-mirror
finish*!
Much faster than Scotchbriting, and with fewer consummables, in this case.
And, no need to clean, if you cut it dry.

For tubing and long-ish material, I toyed with idea of making a home-made
"time-saver" sander type-deal out of two to four beltsanders mounted in some
kind of tension-loading fixture, and just run the tube through, and Walla,
four finished sides--well, finished as far as the current grit you are
using, which might have to be sequential.

And as other posters have said, the more satiny the finish, the less
fingerprints will show, altho I seem to recall my prints showing up pretty
well on the scotchbrited stuff I did (satiny), altho these were also
unwashed "shop hands".

Professionalism, eh? I guess I should go back to my previous handle
(Proctologically Violated®©), and remove all doubts.
--
------
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY

Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the *Single Best Way*
to Materially Improve Your Family's Life.
The Solution is so simple--and inexpensive!

AND,
Make sure whomever you do vote for believes in
ABSOLUTE separation of Church & State--ferchrissakes

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs




Bill

Pre-Meltdown wrote:
How in the hell would you expect anyone to be able to give you a good
answer, without knowing the depth of cut necessary and the finish that
you want?

John Martin
Well, I have developed considerable respect for the frequent contributors
here. You might care to read some of their replies, because they are
insightful, based in experience and professionalism.

Ironically, one of them even suggested a depth of cut, of the same order
of magnitude that I had in mind.

And to finish that point, as I deal with 1/8 wall alum tube often, I'd fall
over if a .010 cut did anything to the tube ito twist or anything else,
besides the very slight structural weakening due to thinning the wall.

Just thought I'd ask. I know that at some point, one can release a lot
of residual stresses.


And, if you were doing this in a CNC, you could take this cut in rapid,
literally about a couple of seconds per face (or less!), with a *near-mirror
finish*!
Much faster than Scotchbriting, and with fewer consummables, in this case.
And, no need to clean, if you cut it dry.

Regardless of what I decide to do (or not do), thanks!


And as other posters have said, the more satiny the finish, the less
fingerprints will show, altho I seem to recall my prints showing up pretty
well on the scotchbrited stuff I did (satiny), altho these were also
unwashed "shop hands".

Professionalism, eh? I guess I should go back to my previous handle
(Proctologically Violated®©), and remove all doubts.

That might have been pushing itG, but it seemed appropriate to come to
everyone's aide.

As an aside, who/what's meltdown are you anticipating?

Bill

On Nov 28, 2:01 pm, Bill Schwab wrote:
John Martin wrote:
On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,

I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.

What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.

Thanks,

Bill

Try it. Or not. It's your choice.

How in the hell would you expect anyone to be able to give you a good
answer, without knowing the depth of cut necessary and the finish that
you want?

John Martin

Well, I have developed considerable respect for the frequent
contributors here. You might care to read some of their replies,
because they are insightful, based in experience and professionalism.

Ironically, one of them even suggested a depth of cut, of the same order
of magnitude that I had in mind.

Bill- Hide quoted text -

- Show quoted text -

OK, Bill, I'll try it again.

I, too, have a good deal of respect for most of the contributors
here. You got some good information on finishes for aluminum, but no
one fully answered your questions, did they?

One person "even suggested a depth of cut, of the same order of
magnitude that I had in mind." What an amazing coincidence. I'd have
suggested a depth of cut of .0000", because to me those dings don't
look any deeper than that. From here in Maine, though, it's a bit
hard to see your workpieces. You go on to say that the cut of .010"
will not get off all the dings and gouges. Well, what will it take - .
030", .050", .075", more? If you'd simply stated the depth of cut
necessary to clean up your workpieces, someone could have readily
advised you whether you were likely to get any significant warping.

Same criticism of your "presentable" finish. To some, it might mean a
mirror polish. To others, a smooth but dull finish. Or a rougher
brushed, machined or shotblasted surface. I'm not a mindreader, and I
don't know of any in the group. I could be wrong, though.

John Martin

John Martin wrote:
On Nov 28, 2:01 pm, Bill Schwab wrote:
John Martin wrote:
On Nov 28, 2:20 am, Bill Schwab wrote:
Hello all,
I am using 2 inch square Al tubing (0.125 thickness) as part of a frame
for an experimental fixture. Part of me wants to flycut it to remove
some dings, and part of me wants to leave well enough alone. Knowing
that I can always start over if the tubes (11 in long each) were to warp
like mad, I might just try it.
What is your best guess? Would knocking the skin off of the tubing
cause it to warp or twist a lot? Is there something else you would do
to make a presentable finish? It is not terribly important. I can
probably get to a sandblaster, though it is not as accessible as in the
good old days. Something I can do in the comfort of my garage gets
extra points.
Thanks,
Bill
Try it. Or not. It's your choice.
How in the hell would you expect anyone to be able to give you a good
answer, without knowing the depth of cut necessary and the finish that
you want?
John Martin
Well, I have developed considerable respect for the frequent
contributors here. You might care to read some of their replies,
because they are insightful, based in experience and professionalism.

Ironically, one of them even suggested a depth of cut, of the same order
of magnitude that I had in mind.

Bill- Hide quoted text -

- Show quoted text -

OK, Bill, I'll try it again.

I, too, have a good deal of respect for most of the contributors
here. You got some good information on finishes for aluminum, but no
one fully answered your questions, did they?

Don't be so sure...



Same criticism of your "presentable" finish. To some, it might mean a
mirror polish. To others, a smooth but dull finish. Or a rougher
brushed, machined or shotblasted surface. I'm not a mindreader, and I
don't know of any in the group. I could be wrong, though.

.... several posters provided useful answers and advice. You seem to be
bent on finding fault. Enjoy.

Bill