Should I sandblast my cab?

[cedorris]

I'm in the process of a cab swap and need some advice on whether or not I should have the new cab sandblasted.

I understand there are some risks associated with the blasting such as warping.

My cab has some serious rust underneath with at least one front support rusted through in one spot. The firewall appears to be in good shape with only a little bubbly spot of rust where the AC condenser was bolted. There has only been a bit of bondo work that I want removed (it was poor quality and I'd just as soon have the body work done right).

How do I know if I should blast it or not?

[dwcsr]

warping occurs when you use high pressure above 60 psi and a slow sweeping motion creating hot spots. Don't think you have to knock it down to the metal in one pass. It will take 3or 5 passes to keep the warp away.

[oldblue1968chevy]

wata bout soda blasting...really thinking about this..

[cdowns]

you could have just the floor and firewall sandblasted

sodablasting has lots of residule problems loads of shops wont touch something that's been soda blasted

[dwcsr]

Originally Posted by oldblue1968chevy

wata bout soda blasting...really thinking about this..

Soda is only good on paint and light flash over rust, It won't do any good on heavy rust. Soda also has more work after the blasting to neutralize the soda.
It does leave a much better finish than abrasive blasting.

I much prefer walnut shell for body parts that don't have a lot of heavy scale. You remove the paint and dirt and then work the areas with rust scale using an abrasive.

[redbaron69]

IMHO i would blast. getting ready to blast mine. by doing this you will take care of all the rust and not worry about it coming back in a few years. but you can really get your feeling hurt when those "solid looking" areas turn out like swiss cheese.

[watahyahknow]

the blasting allso makes for a rough finish it needs to be sanded anyway the soda blasting is a little better though
chemicly dipping might be an idea after that you can take the paint off in sheets with a powerwasher
there are a couple of companies in the states doing that mostly to classics to preserve the metal and shape of the car and remove only rust

[watahyahknow]

another thing with the blasting is that the metal will rust again faster

[cedorris]

Originally Posted by watahyahknow

another thing with the blasting is that the metal will rust again faster

That's only true if I don't get it to primer immediately after the blast, right?

[mjensen]

I had mine blasted and I'm glad I did. The blaster immediately covered it in epoxy primer because I knew I wouldn't have a chance to work on it for a while. He used Green Diamond for the blasting media and I'm very pleased with how it turned out.

[watahyahknow]

Originally Posted by cedorris

That's only true if I don't get it to primer immediately after the blast, right?

it depends , the newer cars and trucks are bathed in a solution that leaves a coating on the metal that looks like zink and it keeps the metal from contact to the atmosfere even paint isnt totally watertight and some spots you cant reach with paint .

the blasting removes the coating dipping doesnt .
if you want the body to last a looooooooooong time and you dont have to weld anything on it you could coat it with zink (in the netherlands thats called skopperen it involves a special spraygun that melts zinkwire with a propaneflame and sprays the melted stuff ontoo the metal this zinkcoating will preent rusting for a long time to come but its poisonous when you need to weld it (gets you a headacke and makes you dizzy like youre stoned or drunk )

[special-K]

I only sandblast rusted or nooks and crannies.Things that make no sense to do any other way,like brackets,frames,etc.

[CG]

I had everything (sorta) sand blasted on my panel. All the edges and rounded areas were blasted inside and out. All the flat parts were left to be sanded. Side of body, hood, sweet spots on the doors...those flat areas.

[Dingfodgy]

I'm with "watahyahknow" in that caustic soda dipping is the best method for prepping a classic vehicle for restoration. All paint, rust, undercoating, glue, bondo, everything but steel & lead is dissolved away. You have to make sure the outfit doing this does a good job of rinsing the solution out of the nooks and crannies and the parts go through a final phosphate or iron-oxide conversion bath and drying oven, before they hand 'em back to ya. Granted this is significantly more costly than media blasting, but the results are like day and night compared to sandblasting. I did this to a '62 Ragtop VW back in my younger years and it was awesome to have the metal so clean and not having to worry about sand or whatnot being trapped in seams and blind crannies....only to rear it's ugly head after the paint has gone on. I will be doing this again to my SWB frame and suspension components, as well as the inner fenders, core support and bed. If I wasn't already replacing most of the sheetmetal on the cab...I'd probably dip that too.

[AusMarty]

One thing I wouldn't do is acid bath it, a bloke I know had his car done and months later there was still acid dripping out of it through all the nooks and crannies, it would get up in the double skin of the roof in our trucks and chew it out in no time, when I had my car stripped I done all I could easily do with paint stripper and stripper wheel then sent it to the sandblasters to do the rest, don't let them blast the dash as they warped my one.
I guess there's fores an againsts any way you do it

[71blksuper4x4]

I would go the walnut shell method on body components. I would never do an acid bath on a body. Heard to many horror stories about it and if you don't remove your vin tags, it will dissolve it badly. All aluminum if any on the body will be destroyed. Sandblasting can warp body panels if the person doesn't know what he is doing, and soda blasting is just to be of a paint to clean up afterwards and worry about painting thereafter. Trevor

[watahyahknow]

they do drill holes in the car to let the acid out of those hollow spaces and sumtimes they bake the car to get the rest out