"Baking Soda Blasting for paint removal?" Topic

I recently discovered the use of soda blasting, with Baking Soda, for cleaning up metal mechanical parts. It is inexpensive, minimal abrasiveness (it does not damage chrome, or aluminum parts, won't scratch them, easily removes with soap and water, otherwise it may interfere with paint adhesion), and it is environmentally safe. My purpose in buying a setup to do it with, was to degrease motorcycle parts (wheel spokes, rims, and engine parts,), but it occurred to me that this might be quite effective in removing paint from miniatures, without damaging the metal, should not remove any metal at all. Anyone tried this yet?

Here is a link to a DIY soda blaster gun:

link

Here is the blaster gun I purchased:

link

In addition, I purchased a pressure regulator (gun needs 90 PSI max. pressure), and some attachment bits to mate it all to my air compressor. The total cost for parts (gun plus misc. attachment pieces) was around $30. USD Have not tried it yet, on either mini's or my motorcycles. Hope to test it over the holiday weekend. Cheers!

Wow that sounds real interesting. The DIY blaster is clearly simple and easy to make but frankly I agree with you for $20 USD it's easier just to buy one.

Let us know how it works out.

I have a pair of cabinets…smaller one for cleaning parts and a larger one that I can fit a bumper in.

I think my issue (at least with my setup) would be trying to hold the mini with the gloves while avoiding shooting them across the room with the air pressure. Even with soft materials like walnut husks, it stings a good bit when the stream comes into contact with your skin.

I suppose you could clamp it in a vice in order to blast them – but I would need to mess around with it in order to get that to work.

That does sound really intriguing!

James

Very interesting idea – I look forward to hearing how it comes out. I had no idea the guns were that inexpensive.

Doug

Good points, Scoutll. Had not thought about the stream hitting my fingers!… Baking Soda is abrasive, obviously, but it is much milder than walnuts, or any other material usually used for this purpose. It is somewhat harsh on the sinuses, and lungs -- not toxic, but uncomfortable, as it reacts with the moisture of the mucus membranes, from what other have said, so wearing a dust mask, at the very minimum, is recommended. It is also recommended to do it outside, to help the powder fly away from you.

I looked at blasting cabinets, at Freight Harbor, but they were pretty expensive for relatively small objects. They also sell bigger soda blasters, made just for soda, but they, too, were $149+! I just need it for some small jobs, and then it occurred that this might be quite nice, if not downright perfect, for miniatures.

I have some old Grenadier miniatures from the early 1980's, covered in Testors Enamel paints, some of my first painting attempts, ever. They are atrocious -- Ack! -- from my early years of High School. Perfect candidates for a test.

When I looked online, at what FH had, I could not see the point of making one. When I talked with the HF salesman, he said that the gun I bought (meant for ground walnut shells) had too big a nozzle for Baking Soda, but I plan on trying it, as is. He had some ceramic nozzle tips, for the $149+ units, which concentrate the powder, but they would need to be cut down to fit my gun's nozzle, if they would work at all (more money, too). Experimentation is King, Baby! Cheers!

Sgt Slag, soak the minis a day or two in Simple Green. It WILL take it off.

I cleaned up some old minis that had 5-6 layers of paint on them.

Speaking as someone who has felt the stream of abrasive media on my skin…I would definitely recommend working that out first. A vice would be ideal, but dragging a bench vice out into the driveway to run the blaster isn't. Might consider a pair of cheap vice grips with a good long reach. Long reach to give you room to maneuver…cheap because although you can wash off the baking soda relatively easily…it will still gum up the locking mechanism.

Hopefully it has standard threads on your gun nozzle (and hopefully it is removable). If it isn't able to stream the baking soda you should be able to pick up a smaller nozzle through a company like NAPA. I know I pick up replacements for mine from there. If your local NAPA isn't too helpful, McMaster Carr also carries a goodly assortment of nozzles. If it uses standard threads there is a good chance that you might even be able to take a pipe cap and drill it out to find the right size (don't try that if you plan on using sand or shot though….they will eat through normal metal faster than you think).

Beyond that – I am not too sure if I would consider baking soda to be milder than walnut husks. The crystals are friable – but you get to a point where they don't break down any further. It is much finer than walnut husks (which feel a bit like rubber) – and that would have benefits on miniatures.

Once you get done blasting, be sure to wash them…then wash them again…then wash them again… The small soda particles will lodge in every nook and cranny and crevice on the miniature. When you wash it, it will dissolve with the water and then when the water dries…you will still have soda particles that have redeposited on the miniature. I know that most the paint companies (auto paint) that I have dealt with will not warranty their products on surfaces that have been soda blasted. It is very, very difficult to remove all the soda…and a particle like that under paint can lead to big problems down the line.

You also have the carbonic acid to contend with. I know tanic acids can accelerate lead oxidization – but I haven't checked the chemistry on carbonic acid (though at first blush I would suspect that it would as well). The old Grenadiers are probably solid (or nearly so) lead – so stay on top of them. With a catalyst, you may well see it go from perfectly clean to pitted and blooming over night.

Anywho, don't mean to dissuade you…those are just a few things that I thought of while considering how it might work.