I asked this a little while back and got a lot of good replies, but now I am actually ready to begin. I will be sand blasting the underside of my 69 Camaro. I was told to use a Zinc-Etch primer. I will probably be using PPG or Dupont brand paint and primer. Any Ideas/Suggestions from the pros who have done this before? Thanks for all the help.

One suggestion I can make is to be very carefull about sanblasting the underside of your car. And for that matter any part of your car. The sheetmetal in the floorpans is not the same guage as your body panels and you could seriously deform these areas. Especially if you have some heavy deposits of undercoating (won't come off by snadblasting) or caked on grease and grit. I did not have the luxury of a rotiserie and cleaned mine by removing the undercoating with a heat gun and cleaning the rest with several cans of oven cleaner and a pressure washer. It was very labor intensive but turned out very nice.
Good Luck,

John

I recently used a $50 sandblaster from Sears on the undercarraige of my 67. It turned out great. I first wiped it all down with lacquer thinner if I remember correctly, and then used the blaster on it. It doesn't appear to have done any damage to the floor pans or frame rails, or anything for that matter. Then I used Sherwin Williams etching primer, followed by color, with a hardener in it. The only caution I would have, is it is extremely messy. I'd make sure you use a blasting hood which you can get from Eastwood. I had my car on a homemade rotisserie which helped alot, especially when painting. It looks great, but as others have said, you will have sand everywhere.

Thanks for the information. I don't think warpage should be a big problem on the underside, with all the stiffening grooves and double metal on the floorboard. I am mainly concerned about what type of paint and primer to use. I will probably be using PPG products, since that is what my nearest local dealer stocks.

PPG DX 1791 is the best PPG metal etch. It transperent yellow in color and you only need 1-2 coats (depending on how its applied). You don't want it on too thick, whatever brand you go with ask for a copy of the p-sheet so you can see recomended process.
Austin

I prefer the por15 products for the undercarriage. This stuff is really tough and the sell a semi gloss black.

69er

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69 Camaro 454
71 Nova 454

If your not living on the edge then your taking up too much space

I've heard a lot of mixed reviews on the POR15 products, I would prefer to stay with something a little more conventional and proven.

The only bad experiences I'm aware of is when the prep directions aren't followed. I've used most of their products with very good results. My only concern would be how you would ensure that the underside is prepped completely. You should degrease ( Marine Clean ), then metal prep ( Metal Prep ), then apply the final coat.

I'm almost at the same point... I've got the underside all cleaned and then I wire-wheeled the whole thing. It's down to the original paint and/or metal which looks great, besides the wire brush marks. I want to POR15 the entire bottom of the car but do I need to take it all the way down to the metal first??? From what I can get off of the POR15 website, it almost looks like I need to. Hmmmm... good thing this car won'y be a show car!



[This message has been edited by HwyStarJoe (edited 04-23-2001).]

The PPG (or other brand) spray on metal etch would be easier for the bottom side of a car. The "metal ready" is a metal etch but needs to stay on the surface "wet" for about 20 min. then thoughoughly rinsed with water. The spray on would be much easier on the bottom side. DON'T use both metal ready and a spray on type, either will work but a spray on etch is not meant to be used on metal that has already been etched. The POR 15 from what I understand will stick to exsisting paint, but the paint will need to be sanded for adheasion.
Austin

Thanks Austin, that's what I needed to hear!