Planning on media blasting...But what primer to use?

[fro_drummer 10]

Question?? I am blasting my car this weekend with a Soda Blaster that we use here at work. The blaster itself is a trailer mounted unit and has a diesel compressor (I work in the Fire/water restoration business. Blaster is used to remove char from joists, floors etc). I have a small window of opportunity this weekend to get the car blasted (due to a break in the cold/wintery weather). Figured I had better get it blasted as it may be my last chance until spring. After blasting the car, I am planning on laying on a coat of primer. My problem is, I don't have an air compressor. The blaster's compressor is FAR too powerful for painting/bodywork. I have recently purchased a gravity fed gun, hoses, etc, but haven't purchased the compressor yet. I am wondering if I need to spray the initial primer with the gun, or is there a good "rattle-can" primer out there I can use?? I am not in love with the idea of rattle canning the car, but I may not have any other choice. I figured I could save up for the compressor, but I don't want to have to wipe down the whole car with mineral spirits ever 2-3 days. Any ideas??:helpsmilie:

[stangme428 33]

great question.... i too am awaiting everyone's input...:tongue_smilie:

[69RavenConv 286]

Probably any name-brand primer will tide you over for a while, but you'd want to sand it off again before you apply good epoxy primer later. Why do you say the blaster is too powerful for paint? Doesn't it have (or couldn't you attach) a regulator to reduce the pressure, suitable for a primer gun?

 

Also keep in mind paints react badly to soda; I'm told you have to wash or sand *all* the residue away or risk paint problems later.

[69again 10]

If you are going to blast your car, I would not use a rattle can. It is mostly solvents and will not give you a good base for a quality finish. I would suggest you use a two part epoxy primer. I use PPG dp50. It is expensive, but you need to have a good base to start from or your paint job will not last long. https://buyat.ppg.com/refinishProductCatalog/ViewProduct.aspx?ProductID=2d2ecd20-f2e7-4fee-8feb-797be5b5283a There are many others out there as well. You will need a good compressor and ventalation as well. Just my 2 cents. Dan

[S code 69 13]

I leave cars in bare metal for months but I live in the high desert, depending on your climate you might be fine.

 

The correct way to do it is strip the car, do all welding that needs to be done and the DP prime it . all your filler can be put on over the DP. if you have a lot cutting and welding to do before the DP can be put on and leaving it in bare metal isn't an option I'd probably put a light coat of primer sealer on and then DA sand it to bare metal when you're done before you DP it. I'd never use a cheap primer as my starting point but you could use it for a sealer you're going to remove.

 

I think there is a metal prep you can wipe it down with that will hold off rust for quite a while too, you might call your supply outfit and ask them.

[foothilltom 33]

I think the fellas covered it pretty well, but just to emphasize:

 

If you're going to go through a long, wet winter before painting your car, you want to make sure your primer is corrosion/moisture resistant. Epoxy primers (2-part as 69again mentioned) are the way to go. If you go with something cheap, your panels will rust as it sits in your garage awaiting warm weather as those primers afford no protection against rust.

 

I can see why you want to take advantage of your blaster, but you should rethink keeping your car in primer for too long awaiting paint.

 

My $.02,

Tom

[stangme428 33]

what about the eastwood products? the corroless/ rust encapsulator stuff that says it can be used as a primer? or POR15 ?

[SELLERSRODSHOP 13]

beg, borrow or rent a compressor for a day & do it right with the epoxy. if you want to use a quality epoxy at an affordable price, go here first:

 

http://www.southernpolyurethanes.com/Product%20lines.htm

 

i've been using their products for a couple years now & they are the best. excellent customer service too! give them a call & they will get you fixed up with what you need.

[fro_drummer 10]

Stupid question here....what do you mean by DP prime? The primer in question would only be temporary as I will have a moderate amount of filler work ahead of me. The majority of it will inevitably be removed for a better quality base once the filling is complete. How do the 2 part primers work? Never used them.

 

PS. Thanks for the ultra quick responses fellas.

[foothilltom 33]

2-part primers are just like a 2-part paint system: the 2nd part is a catalyst that makes the end product hard and tough. You mix the stuff just prior to application in the correct ratios. Obviously, rattle-cans don't qualify as 2-part as the mixture would harden in a matter of hours in the can.

[S code 69 13]

Unless you have cutting and welding to do just put your DP primer down and do your body work over the top of it. thats a no no with standard primer but with the epoxy ones that's how most shops do it now.

[BuckeyeDemon 211]

DP is the base part number for PPG brand epoxy primers. Epoxy primers seal out moisture unlike fill primers which can absorb moisture. Epoxy primers can be left as a topcoat in some situations.

 

Epoxy primers don't sand well either.

 

as mentioned in the other posts 2-part primers harden chemically instead of just air drying. the end result is a primer that doesn't shrink. it costs a lot more than the old 1 part primers but well worth it.

 

screwing around with rattle can primers is crazy.

 

just close your eyes and swipe the card for a good compressor.

[ccobra70 10]

one thing I havent heard anyone say which I was told on mine that after you soda blast you need to wash the car down very well with vinigar and water solution to neutralize the backing soda or it will eat at the car then let it dry and then use the epoxy primer that way the whole car does not rust while your doing your body work, just my 2 cents its propably worth exactly what you paid for it!!

[SELLERSRODSHOP 13]

yeah, i hear there are some extra steps involved in cleaning a soda blasted car, but i personally have never dealt with one. i do have some other guys i know who will refuse to work on a soda blasted car. all i've dealt with have already been sandblasted & epoxied or i handle getting them blasted .

 

fro drummer, i will be happy to p.m. you my cell number if you need any advice. i think a few of the other guys i've advised will vouch that i'll keep you going in the right direction.:shifty:

[fastwayfirebird400 14]

I've had used a product called Picklex 20 and really like it. I've blasted a hood hit it with a DA 80 grit and wipped it down with the Picklex and you can let it sit for 6 months with no rust (inside garage in Georgia) You will need to take care and wipe the car down with HOT DAMP towl one panel at a time after soda blasting. The hot water will help it evaporate quicker. then do the Picklex and you should be good to go. You may also try talking to a local body shop to see what they would charge you to just prime the car.

[Legion 10]

I've had used a product called Picklex 20 and really like it. I've blasted a hood hit it with a DA 80 grit and wipped it down with the Picklex and you can let it sit for 6 months with no rust

 

Good to hear it works, I just ordered it to give it a try. I ordered the 32oz jug, it's supposed to cover 400sq ft of bare metal. Maybe that's an option you can look into since you don't have a compressor.

 

http://1323464.estore.networksolutionsdesign.com/Categories.bok

[S code 69 13]

All the cars I've restored I've just used a DA and 80 grit to strip to bare metal. under the hood and places that this is impractical I use a small sand blaster.

 

Any sort of blasting has it's draw backs, my body shop won't warranty a soda blasted car, media blasting will get crap in the paint because you can NEVER get rid of all of it and sandblasting large panels can warp them if you don't do it super careful. when all is said and done I decided a few days with a DA is worth it in the end result.

[foothilltom 33]

Man, there are a lot of abbreviations in this game! DA? Is that some kind of sander? Not trying to be thick-headed, just want to keep up with the conversation to learn.

 

Tom

[JTG 10]

Yes. DA = Dual Action sander. Instead of the sanding disk spinning around one axis as it would if you put one in a standard drill a DA sander orbits around the central axis while its spinning.

[SELLERSRODSHOP 13]

Man, there are a lot of abbreviations in this game! DA? Is that some kind of sander? Not trying to be thick-headed, just want to keep up with the conversation to learn.

 

Tom

 

thats correct.. dual action sander... please keep the DA on the QT, because if it gets to the CP the CEO might turn it over to the FBI, which after an investigation might get the CIA involved & then we would all be DOA! :scared:

[rusty428cj 14]

I use SPI epoxy primer and they say NEVER use their epoxy after a car has been soda blasted. They also say not to use any metal preps because you get the best epoxy adhesion over bare metal.