Aluminum materials related questions

cavelamb wrote:
wrote:



WIth pencils, the issue is the graphite. There is a similar problem
if steel wool is used on aluminum.

A lot of sandpapers use Aluminum Oxide (Alundum) grit. That is
the same oxide that forms naturally on aluminum so that should not
be a problem. But most of the wet/dry papers use silicon carbide,
(carborundum) which may be a problem.


You don't sandpaper the edges - you file them...

The trick to good looking parts is finishing the edges.

Are they smooth, flat, free of nicks and scratches?

Sandpaper alone won't do that...


I agree that file would be better. Consider 'draw filing', which
is done by holding the file like drawknife which reduces the
angle of attack of the teeth and produces a finer finish.
Do you load a file with soap or something to keep soft
metals like aluminum from sticking in the teeth?

Sandpaper on a rigid sanding block would work too. I
personally _hate_ sanding so would much rather use
files, scrapers, stones, or burnishing tools.

Would you ever use sandpaper to prepare Aluminum for
epoxy, or rely entirely on chemical pre-treatment?

--

FF

Do you load a file with soap or something to keep soft
metals like aluminum from sticking in the teeth?

You could, but unless you want to work yorself to death, get a vixen
file, 10 or 12 inches long. Aluminum won't clog a vixen, and it
removes material quickly.

Dan

In article .com,
"Dan Horton" wrote:

You could, but unless you want to work yorself to death, get a vixen

Whoa! Just a quick glance at that first line will get ones attention!
I go to read the next line...

10 or 12 inches long.

Makes ones heart bounce again.
Then I start to wonder if I missed a Hangar Queen thread?

Please think about carefully wording your sentences to reduce the risk
of heart attack to the speed readers.

wrote:
Would you ever use sandpaper to prepare Aluminum for
epoxy, or rely entirely on chemical pre-treatment?

3M Scotchbrite pads nicely scuff up the surface for bonding or
prime/paint. Maroon is finer than green, either works fine (just don't
go nuts with the green since it is coarser). You can find the green
just about anywhere, but I've only found the maroon (7447) in a few
stores or online.

Also, since you're basically putting tiny imperfections in the surface,
consider metal fatigue and the load on the workpiece when it is in
service. Better put, for example, when prepping a wing spar, it is
preferable to sand along the length (in the direction from wingtip to
wingtip, back and forth) rather than across/around it. Did I mention to
go light on the sanding pressure? You want to remove some oxides and
lightly scuff up the surface.

I find that after scuffing (on steel too) there is a very fine dust that
takes a few wipes to clean off. My favorite to clean this is denatured
alcohol on paper towel.

Oh... since I brought up steel, it initially takes some serious cleaning
up that is way beyond what I have the patience to do by hand.

Peter Dohm wrote:
To deburr use a deburring tool which will take the sharp edge off the
inside of the tubing and the edges of sheet, finish with scotchbrite
pads. Use the 6061-T6.

Bob


There is also a rotary version of the scotchbrite pad(s) that is really
slick.

Peter



And of what use is slick sandpaper, my good man 8*)

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

john smith wrote:


Makes ones heart bounce again.
Then I start to wonder if I missed a Hangar Queen thread?

Please think about carefully wording your sentences to reduce the risk
of heart attack to the speed readers.


I dunno, a hanger queen sounds like something to be avoided. ;o)

Tony

Ernest Christley wrote:
Peter Dohm wrote:

To deburr use a deburring tool which will take the sharp edge off the
inside of the tubing and the edges of sheet, finish with scotchbrite
pads. Use the 6061-T6.

Bob


There is also a rotary version of the scotchbrite pad(s) that is really
slick.

Peter



And of what use is slick sandpaper, my good man 8*)


Polishing!

"cavelamb" wrote in message
ink.net...
Ernest Christley wrote:
Peter Dohm wrote:

To deburr use a deburring tool which will take the sharp edge off the
inside of the tubing and the edges of sheet, finish with scotchbrite
pads. Use the 6061-T6.

Bob


There is also a rotary version of the scotchbrite pad(s) that is really
slick.

Peter



And of what use is slick sandpaper, my good man 8*)


Polishing!

A better answer that I had when I got back to the computer.

Scotchbrite will definitely polish aluminum.

"Peter Dohm" wrote in message
...

"cavelamb" wrote in message
ink.net...
Ernest Christley wrote:
Peter Dohm wrote:

To deburr use a deburring tool which will take the sharp edge off
the
inside of the tubing and the edges of sheet, finish with scotchbrite
pads. Use the 6061-T6.

Bob


There is also a rotary version of the scotchbrite pad(s) that is
really
slick.

Peter



And of what use is slick sandpaper, my good man 8*)


Polishing!

A better answer that I had when I got back to the computer.

Scotchbrite will definitely polish aluminum.



Grrr! I used to have a little 4 line poem with 12 errors,
and a spelling checker wouldn't catch any of them!

I was trying to say that Rchard gave a better answer THAN mine.

Peter

Peter Dohm wrote:
"Peter Dohm" wrote in message
...

"cavelamb" wrote in message
hlink.net...

Ernest Christley wrote:

Peter Dohm wrote:


To deburr use a deburring tool which will take the sharp edge off

the

inside of the tubing and the edges of sheet, finish with scotchbrite
pads. Use the 6061-T6.

Bob


There is also a rotary version of the scotchbrite pad(s) that is

really

slick.

Peter



And of what use is slick sandpaper, my good man 8*)


Polishing!

A better answer that I had when I got back to the computer.

Scotchbrite will definitely polish aluminum.




Grrr! I used to have a little 4 line poem with 12 errors,
and a spelling checker wouldn't catch any of them!

I was trying to say that Rchard gave a better answer THAN mine.

Peter



S'ok Peter.