I'm now pulling the cab, fenders hood etc off my 56 to media blast, I've never heard great things about sand blasting, and although I have soda blasted a few mustangs, I recently heard that soda blasting isn't that great a option either, I was told that if every bit of soda is not vacuumed, washed out, blown out etc. of all the cracks and cervices, that paint will not adhere to those area's and will begin to flake in a short period of time. I've never had this happen but a very experienced body shop told me this recently. Thoughts, opinions?

 

My media blaster used a product called "green diamond". Great results and no warping of any metal.

 

Yeah, I wouldn't do soda. No painter will want to touch it.There were a bunch of soda blast companies around here a few years ago, they all went broke when the paint started falling off. Also it doesn't remove rust. If just stripping paint, you can use walnut shells, ground corncobs, or plastic media. I use sand because I usually have to deal with rust.....but only on separate parts, I wouldn't use it on an assembled vehicle.

 

I agree with staying away from soda. I've personally seen plenty of failed paint jobs after soda blasting, and none of the paint manufacturers will warranty their products if used over soda blasted parts/cars.

Sand is fine for what it's intended. The only real downside is if the blasting is done by inexperienced or stupid persons who aren't careful, thereby destroying the panels from excess heat buildup and warping. On heavier stuff, or being extremely careful, it's one of the better ways to go, imho. Using a number 70 silica won't pit deeply and leave a nice surface that 80 grit on a DA sander will clean up really sweet.

 

Neither option is optimal...the best setup right now is "dustless blasting". This system uses ground recycled glass and pressurized water to remove everything, including rust. It is environmentally friendly and can be done in your own driveway. No warpage since the water keeps the surface of the sheetmetal cool. There is an additive in the water that is a rust preventative so you have a few days to get the bare metal prepped and primered before any surface rrust forms. Cost around here in SoCal runs about $600 to do a whole car/truck...most vendors are mobile and will come to you.

 

I've seen that on tv and the internet. It looks interesting. I've not heard of anyone anywhere near me that does the work, though.

 

I work for the abrasive sand company green diamond. Our sand is some of the best for blasting and comes in a lot of different sizes for different applications. Was the product he uses our sand or something else called green diamond?

 

The blast guy I use says he sprays with soda only to degrease (if necessary), then finishes rusty parts (everything I bring him!) with copper... I had never heard of it but everything comes out great and never had an issue with paint, warping, etc.

 

The warping does not primary come from heat build up of the metal but from the impact velocity and weight (kinetic energy) of the particles used. This means that you build up residual comressive stresses in the sheet metal. Compressive stresses that is not evenly distributed this leads to warpage.

Of course this also lead to some heat, but its not the heat it self that is the problem, it the induces compressive stresses.

Use some kind of glass material as it is hard enough to remove rust and paint but brittle enough to crack before inducing residual stresses (warpage) and it will not react to the applied paint and fall of.