HELP - Sand Paper contents

G'Day,

I need some help with a conflict in information I have about sand paper.

I have read that certain sand papers or wet & dry papers can't be used on alluminium because some cause corrosion!!

Does Silicon Carbide paper cause corrosion on Alclad and alluminium or is this the paper I should be using (i've read different things on different sites?)

I've got a scotchbrite wheel and i've used that to round the edges and ends of the rear spar strengthening bars, now I just need to remove the milling marks. What are people using and how can I assure it won't cause corrosion? Vans says the finish should be like 400 grit sand paper but I'm not sure which sand paper to buy.

Any information on this would be greaty appreciated!!

Use aluminum Oxide or similar.

Grit containing Carbon is not good. Same reason you don't use pencil to mark parts. Use a sharpy or similar. Carbon migrates into aluminum and creates weak areas allowing the oportunity for cracks to migrate from that area. Same reason you don't use your Scotch Brite wheels on steel parts then use them on your good aluminum parts. Steel has Carbon in it that hangs up and is applied rather forcefully back onto to your aluminum parts. So back to your question: Silicon Carbide is made in an electric ark by mixing oil (Carbon based) and Silica sand together.

Didn't think about it...

I never thought to look at what my sandpaper was made out of (aluminum oxide apparently)...I don't use it very often.

I wonder what those little sanding sponges frm 3M are made out of? I use those from time to time because they get into the nooks and crannies nicely.

I'm interested in what others have to say on this subject as well.

-John
Houston (Wings)(still!!)

Al oxide

compren said:

......
I wonder what those little sanding sponges frm 3M are made out of? I use those from time to time because they get into the nooks and crannies nicely.

I'm interested in what others have to say on this subject as well.

-John
Houston (Wings)(still!!)

Click to expand...

If it's these, they are aluminum oxide...

http://solutions.3m.com/wps/portal/.../Products/Abrasives/Softback-Sanding-Sponges/

If in doubt, the manufacturer's web site is usually a good place to look....

If you want to see what others say, start with the "Basic Corrosion Removal Techniques" section of AC 43.13-1B... silicon carbide is only recommended for feerrous alloys and titanium....

gil A