[Phil]

I burried this question into another thread, does anyone know anything about Zirconia Aluminia as an abrasive? Is it considered safe to use on aluminum?

Thanks for the info on Silicon Carbide. Do you know anything about Zirconia Aluminia?

http://www.vsmabrasives.com/Literat...Fs/Zirconia.pdf

http://en.wikipedia.org/wiki/Zirconia_alumina

I have it on my belt sander and have used it only a couple of times. I'm a little paranoid, since I haven't heard any feedback on it.

Phil

 

[minute2]

Non issue

I quick google search led me an abrasive mfg who markets this product specifially for use on aluminum.


Kerry Stevens

 

[az_gila]

Sometimes...

I quick google search led me an abrasive mfg who markets this product specifially for use on aluminum.


Kerry Stevens

Not always a good assumption.

3M says their Silicon Carbide is OK on aluminum, the FAA (AC-43.13) says it isn't... your choice....

But in this case, the Zirconia Aluminia is also know as "cubic zirconia" - aka fake diamonds of late-night TV fame. That should be pretty non-reactive with aluminum. Sounds like it would be safe.

gil A

 

[Ted Johns]

"3M says their Silicon Carbide is OK on aluminum, the FAA (AC-43.13) says it isn't... your choice...."

This is a bit of a mystery. AC-43.13 has a table entry that says not to use silicon carbide on aluminum, but the text says TO use silicon carbide (6-136.d(1)(a)). The only TEXT that says not to use it is in the magnesium section (6-152.e(1)(a)).

In addition, I cannot find any commercial cites against using silicon carbide sandpaper on aluminum. Indeed, silicon carbide is used as a alloy in aluminum, although it is subject to inter-granular corrosion. This is no different than good old 2024 aluminum, which has the corrosion problem due to copper as an alloying agent.

Sure would like to see a site describing the science behind the silicon carbide - aluminum worry.

 

[koda2]

Silicon carbide

I thought I was taught somewhere that the carbide portion of the silicon carbide is the culprit in corrosion. Same reason you don't use pencils on aluminum or exhaust metals. Somebody correct me if I am wrong; I went through all my references and couldn't find what I was looking for. A lot of the fine sandpaper, i.e. wet-to-dry, also contains silicon carbide. Any one have a comment on that?
One other useful source of information for new RV builders is the "General" volume of the A&P technician textbook series. You can often pick up a used copy cheap on one of the internet book sellers. I like the Jepperson series the best.
Dave A.
6A QB

 

[az_gila]

Hummm....

"3M says their Silicon Carbide is OK on aluminum, the FAA (AC-43.13) says it isn't... your choice...."

This is a bit of a mystery. AC-43.13 has a table entry that says not to use silicon carbide on aluminum, but the text says TO use silicon carbide (6-136.d(1)(a)). The only TEXT that says not to use it is in the magnesium section (6-152.e(1)(a)).

In addition, I cannot find any commercial cites against using silicon carbide sandpaper on aluminum. Indeed, silicon carbide is used as a alloy in aluminum, although it is subject to inter-granular corrosion. This is no different than good old 2024 aluminum, which has the corrosion problem due to copper as an alloying agent.

Sure would like to see a site describing the science behind the silicon carbide - aluminum worry.

Yep... it does say that in conflict with the Table 6.1

However, the Table 6.1 is a lot more specific with it's "no"....

Also, when it talks about removing heavier corrosion from aluminum in (6.136.e(1)(a)) with power tools, it does call specifically for aluminum oxide material...

I don't know the mechanism, but I assumed (always with risk.. ...) it was similar to the carbon problem with aluminum, which is why we use Pilot pens rather than pencils to do our layouts...

gil A