Gilldiver
Contributor
Media blasting has a number of variables:
If you go to a commercial blaster, first ask what they will blast with. Some use sand or slag on everything. Both are bad for aluminum but Slag is the worst as it will put other metals into the aluminum surface and promote corrosion.
The best is plastic media Type V, after that is Type III which is harder and more aggressive. Then you get into the baking sodas, glass bead, aluminum oxide, walnut shell, etc.
I will not go into the other variables above as the blaster will do what he wants.
Back to an aluminum tank, the one thing you do not want to do is take all the oxide or anodized surface off the tank, so the less aggressive the better - NO SANDIND. What do I use? I use a paint stripper from Home Cheapo. Aircraft stripper, Zip Strip, etc. they are all the same as they have Methylene Chloride in them which is the active ingredient, look at the label. If you use these strippers, only strip outside, have old clothing on to protect all of you - no t-shirts, and use good gloves and rinse them every now and then in a bucket of water. After the paint is stripped, use an abrasive pad like RED Scotch Bright and warm soapy water to remove any remaining stripper and any white oxide dots of corrosion that were under the paint.
Never use the paste strippers that require a paper to pull off the paint. These strippers are very alkaline and will etch the aluminum surface.
- Media type
- Air pressure
- Angle of impingement
- Stand off distance
- Training of the operator
If you go to a commercial blaster, first ask what they will blast with. Some use sand or slag on everything. Both are bad for aluminum but Slag is the worst as it will put other metals into the aluminum surface and promote corrosion.
The best is plastic media Type V, after that is Type III which is harder and more aggressive. Then you get into the baking sodas, glass bead, aluminum oxide, walnut shell, etc.
I will not go into the other variables above as the blaster will do what he wants.
Back to an aluminum tank, the one thing you do not want to do is take all the oxide or anodized surface off the tank, so the less aggressive the better - NO SANDIND. What do I use? I use a paint stripper from Home Cheapo. Aircraft stripper, Zip Strip, etc. they are all the same as they have Methylene Chloride in them which is the active ingredient, look at the label. If you use these strippers, only strip outside, have old clothing on to protect all of you - no t-shirts, and use good gloves and rinse them every now and then in a bucket of water. After the paint is stripped, use an abrasive pad like RED Scotch Bright and warm soapy water to remove any remaining stripper and any white oxide dots of corrosion that were under the paint.
Never use the paste strippers that require a paper to pull off the paint. These strippers are very alkaline and will etch the aluminum surface.
