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Posted: 2/14/2005 7:30:42 AM EDT
| I have a A1 upper that has been refinished in a black finish. I'm not sure what was used, but it is a real thick coat. I want to use Moly Resin to refinish the upper in Colt gray. Some say to sandblast others say no. To get it back to original, should I blast the thick black finish off? If so, what about the anodized finish? [:\] |
did u try dipping it in acetone or any paint thinner ? see if u can remove that thick coat |
| I had a similar situation with my M16A1 upper I bought from Buffertech last year - it turns out that it was refinished with black spraypaint. I bought a can of Methyl Ethyl Ketone from Home Cheapo, and after 5 minutes with some paper towels, the paint was completely removed, with no harm done to the anodizing. I would try this before any kind of blasting, since it's certainly less destructive. If it doesn't work, you can still blast. |
No no no no no no! If you need to blast it, it must be done with an abrasive media, and not with beads. Your finish will NOT adhere if you bead blast it, as it will be too slick. Try to remove it with chemicals, if that doesn't work, give it a light sand blasting. |
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I would try to strip it with chemicals first. If that doesn't work glass bead down to bare aluminum and then sandblast with #80 grit aluminum oxide or silica at no more than 40 psi. The reason for sandblasting is to give texture for apperance and help adhesion. If you media blast aluminum with harsh abrasives such as silica, aluminum, oxide, black beauty, etc... it will remove material fast and impregnate the aluminum. Glass bead, plasti bead, and crushed walnut shells are safer to use on aluminum but don't alter the surface very much (finer grits may actualy polish the surface) witch is required for molyresin to adhere. At 40psi sand blasting will roughen the surface of aluminum but may not remove the existing finish very well thats why I would glassbead first with #70 grit at 80-90psi. |
Let me correct myself. Glass bead off the old finish so that you can see what you have underneath, then proceed from there. I wouldn't go directly to sand blasting until I knew exactly what I was dealing with. Edited: as mentioned above. |
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