Soda Blasting?

[Phil]

I'm getting ready to remove a pretty substantial amount of self etching primer. MEK and all the typical stuff won't touch it.

I could use some stripper chemicals and probably touch it, but it sounds like that's a nasty and painful process.

I'm thinking soda blasting might be the best way to get the primer off and do it without all the hassle of dealing with the nasty process of chemical stripping.

For those of you who have experience with the soda blasting process:

1) Does soda blasting etch the skins enough to remove the alclad and require the application of alodine or some other corrosion inhibitor?

2) Does soda have any chemical properties that long-term exposure to aluminum could cause corrosion? AKA: Would I have to do anything to neutralize it?

Thanks,
Phil

[Sig600]

I would call a local body shop/restoration shop that deals with media blasting. I know shops around here use everything from glass beads to sand to baking soda depending on the material. Not sure, but soda blasting aluminum may pit the surface. Never heard of anyone doing it on anything other than steel, particularly body panels and frames.

[John Clark]

Here is a "car-guy" site with some good pro/con discussion on soda blasting:

http://www.crankshaftcoalition.com/wiki/Soda_blasting

There are some real issues with getting the sod medium out of laps, and even around fasteners.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

[rocketbob]

I've had pretty good luck with the $90 soda blasting setup I got from Harbor Freight. I stripped an engine mount with it and did etch the steel. And it killed the grass where I did it in front of my hangar, but no problem with residue. Its not as effective as blasting with other media, such as copper slag or aluminum oxide.

[caryr]

When I think of soda blasting, I'm thinking about the leftover debris that sand leaves behind.

That's usually the reason to use a media that disappears with a little clean up water.

I would think bead blasting would be the ticket.

Etching primer penetrates into the surface and may be tough to remove.

[Mike D]

Hey Phil,
If you do use paint stripper be careful of the type you use. The alkaline type can eat aluminum quick. It is how we etch designs into our aluminum in the PC industry. It's better than acid based for eating through.

There are aircraft paint strippers specifically made to be safe on aluminum and aircraft. Here is a link to some info. Many auto body paint suppliers carry these.
http://www.aircraftpaintstripper.com...t-remover.html

As far as blasting, soda, wheat starch, or plastic media work well on aluminum. Sand blasting will destroy aluminum sheet.

For large surfaces like a car or a plane, I have always used stripper first and then used some form of soda blasting to get the paint out of the corners.

For cars, I would normally leave the primer or paint on and just prep it and paint. But for a plane, weight is a concern. I will have to admit I have never stripped a plane and only a couple of aluminum bodied cars.

There are also chemical conversions you can use after stripping that will help stop the aluminum from oxidizing.

BTW, what are you going to strip? The wings?

[Phil]

Yeah Mike....

I'm wanting to strip some primer from the wings...

[rocketbob]

Try lacquer thinner or denatured alcohol. Usually they'll take primer right off.

[az_gila]

Originally Posted by rocketbob

Try lacquer thinner or denatured alcohol. Usually they'll take primer right off.

...an epoxy or urethane primer...

If it is, then it might be best to bite the bullet and use the nasty MEK based stuff designed for aircraft.

The PTI-PRY stuff from Spruce works well, but put on all of your safety gear first.

http://www.aircraftspruce.com/catalo...tiremovers.php

[Geico266]

Why not just use paint stripper?