Hopefully, one of the HAMB experts will school me on how to prep metal after soda blasting. I have read online that some sort of surface prep is necessary after soda blasting metal, or else you will have problems with paint adhesion...something about ph changes due to the soda medium. Most websites just want to sell you their particular brand of skunk oil. Is there any special after blasting prep required? If so, what should I use? A solvent, like Prep-Sol? Regular grease and wax remover? Etching primer? Regular primer?
I sand with 80 grit all body panels and clean with something like prep- sol before primer. I do this with all media......
talk to shop that will be doing the soda blasting - if you have decided on brand of paint to be used check their website, and paint store that will provide the paint for recommendations - had a truck soda blasted,and they did the air blasting to help clean surfaces and very tight areas where build up can occur - then used a surface cleaning solution - finished with self-etching primer - most recent paint shop used would not do any type of soda blasting, etc - only did manual sanding - only way that they could guarante their final product
I once had a trunk underside blasted. Apparently didn’t prep it correctly as the sealer, color and clear actually blew off with air pressure. I think I washed with water and used a red scotch brite pad to scour it clean. At least I thought it was clean. Never again. I think some paint companies do not recommend this process at all.
I have had bodies soda blasted and chemically stripped. My body/paint person has a pink chemical that he uses on every piece no matter what was used to remove the paint. I have helped him a few times, we spray the pink stuff on, scotch brite the surface and rinse with clean water. After the piece is dried with an air hose the surface has a very light white haze on it which he applies epoxy primer directly. I have never had an issue with paint or primer lifting. One note: on the last vehicles I have had “dipped” I have also had them e coated, this insurers that every part of the body has been protected from future corrosion inside and out.
http://www.chesapeakesodaclean.com/info/after/ Eastwood has a product called after blast. Check it out. Soda blast is a paint removal process. Not a paint prep process. Paint manufacturers will say they won’t warrantee products over soda. Honestly they rarely warrantee any product on a vintage car. Soda gets a bad rap because folks don’t prep the car. I’m not the soda expert but I have followed behind one and some chemical dipped parts before. I always sand after any blasting. 80 on a DA and 100-150 for the hand sanding part. It’s tedious but necessary in my opinion. PPG has metal preps that work well. Everybody says epoxy is direct to bare metal. Read the tech sheet in the product you use. Most epoxies recommend a metal prep or precleaner. Follow their directions. Soda does leave a residue and some recommend a red scuff pad and warm water. That will neutralize the metal. Now you have flash rust. The metal prep will remove that. So what is the answer? I’m following this thread so I can learn that also.
Soda blasting leaves a very smooth, babys ass smooth feel on the metal, when done blasting wash the metal,hot pressure wash washing is best and a lot of it get it in all the cracks and wash the hell out of it, if not a year down the road the soda gets damp and starts corrision, now your really screwed, after the metal drys squirt it down with Ospho its a metal prep and let it dry it will leave a fuzzy haze on the metal just wipe that fuzz off with scotch bright,just wipe the fuzz off no need to sand then prime. A few years ago I had a bus body soda blasted, it was done by a guy that had been sand and soda blasting for years and that is how he told me to prep the metal when we got done, I had pulled the body off the frame and set it on a rail frame I built and we did the main frame seperate. Its been sitting on my shop for several years now and there are no primer bubbles or problems. Before After
Wow, blasted the doors right off! Thanks @Vimtage Iron ! That is the kind of info that I needed to know.
I did a 56 chev that was soda blasted. Here is what you use. P.M me if you want to talk. https://holdtight.com/
Although I don’t have the personal experience with it but I have heard that the wet blasted crushed glass method is even better than soda.
I just had an O/T car blasted with the crushed glass DRY. If the guy knows what he's doing it comes out great. Had one wet blasted inside and out, the media forms kind of a mud in the seams inside if not cleaned out. So you end up washing it out anyway. I would recommend doing the outside wet and the inside dry maybe. JMO Lippy
Pats55, I didn't have the 56 I did soda blasted, I don't have a clue what that oily film was on the car but it was all over inside and out. You never would have got it all clean with metal prep. I had it on a rotisserie outside and used the Hold tight 102 , one gallon to I think it was 50 gallons of water. I was amazed how well it worked. Blew it off out in the sun and it was spotless and NO flash rust at all. But a soda blasted car is so smooth you must then DA it then Epoxy or whatever your gonna do. I epoxied it inside then DA on the outside and direct to metal primer. Lippy
After it's cleaned and degreased then I usually add the metal prep is the last step. Metal prep's today have a cleaning agent that clean residual oils. There are metal prep's that do not require a water rinse. This prep was designed for cars waiting to get to a paint booth. It was developed in Texas, thousands of gallons were sold at Carlisle by my friend Capt. Lee before he passed on.
It should be sodium bicarbonate so I would think you could use a dilute citric acid solution to "neutralize" it and then rinse with water and use the correct prepping solution prior to painting. It may flash rust after the citric acid so dry it quickly. If it was mine, this is what I'd try.
This doesn't answer your question, and I don't know exactly what you're doing, but... Are you simply wanting to be less aggressive then sandblasting would be? I wonder if fine ground black walnut shells would serve your purpose? No causticity. Hey guys. Try this while you're stuck at home wondering what else to eat. Super easy, super good. Hot cook-style chocolate pudding poured over vanilla ice cream. You're welcome. LOL
I had a truck blasted by dustless blasting and it had a flash rust resistant solution in the final wash. It sat for 3 days in the Florida humidity before we could get back at it and there was no flash rust. I pressure washed the truck and we DA'ed the whole thing. It took all of the bondo out from previous repairs. Worked really good. Thinking about having someone do my Comet.
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