Proper priming procedure

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dukess396

Sorry for the newbe question, but this is my first paint job and I don't want to blow it because I didn't understand the instructions. The Epoxy tech sheet says 1 coat, flash 10 to 30 min, 1 more coat. Thats 2 coats, so how long do I wait before spraying my 2k, and how many coats of 2k should I spray? I was thinking 3 or 4 coats because its not high build, and I want enough material to block out imperfections. Thanks guys.
 
Spray 2 coats of epoxy and then wait overnight before applying filler or primer. Only you will be able to tell how many coats of primer you will need, depending how it looks as you are blocking the car. I usually spray 2 coats, let it cure, then block (repeat as necessary). But I am in no hurry.
 
make sure your metal is prepped squeaky clean and youre not shooting epoxy in the cold. epoxy likes it warm.
 
Weather is nice today, a little muggy. I'm not quite ready to spray, I'm hoping this weekend. So I should be able to lay down the epoxy Saturday, then 2k Sunday. How long should I wait before blocking the 2k?
 
Form has a good point. Make sure to check out Bob H's instructions for preping bare metal before you spray epoxy.
 
I see where its suggested to use waterborne W&G. Is that really necessary? My primers and clear are SPI, but I got my W&G remover from the PPG jobber. I DA'd the whole car with 80 grit, stripping all the paint down to old primer and bare steel. I tried not to go through too much of the old primer because I didn't want to disturb too much of the old filler. So if the bulk of my car still has sanded primer, should I really invest in waterborne W&G?
 
Its a Chevelle. If I had to guess, it was last painted in the mid eighties. The old paint was lacquer, so I would guess the primer is too. The old primer is redish brown. Red oxide?
 
That's what I thought you where going to say. I have no experience with painting over laquer, maybe some of the pros on here could advise on this. But my guess is that the laquer will have to go.
 
Well if I was forced to primer over an existing finish like that, I would not use heavy applications of epoxy primer. Use 1 coat of reduced epoxy over the bare metal spots, and use regular 2K urethane after that.

The problem I have repeatedly had is that 2 coats of curing epoxy become a barrier to the solvents that are absorbed by the underlying substrate, causing it to be released well after the job is done. This can cause ringing or edge mapping of the finish.

Thin applications of epoxy seem less likely to have this problem. 2K urethanes are more porous than epoxy and will also let solvent out more readily.

Now, for pure bare metal, there is nothing better than two wet coats of epoxy.

I would get water based wax and grease remover, because it cleans the metal better than solvent base. I know that seems weird. but it should be OK with DX330, if you are not too worried about having maximum adhesion and minimum contamination.
 
Well thats not what I wanted to hear. I have spot primed a couple repairs with epoxy. Are you implying that I'd be better off knocking down all the old stuff?
 
When you don't know what you are working with, it is always best to start from bare metal. I guess it depends what kind of job you are trying to do.
 
i have pics of using solvent based w&g remover that i thought was evaporated out of evercoat featherfill g2, coming back to haunt me months later. if youre going to all the trouble to prep and paint id take ALL the old primer off. if you think it might come back to haunt you it will...post pics. personal ride or job?
 
form406;7697 said:
i have pics of using solvent based w&g remover that i thought was evaporated out of evercoat featherfill g2, coming back to haunt me months later. if youre going to all the trouble to prep and paint id take ALL the old primer off. if you think it might come back to haunt you it will...post pics. personal ride or job?
Click to expand...

Its my personal car. I bought it last year, it was a nice "ten footer". Really needs a frame off, but I want to enjoy it for a while and save cash before committing to a multi year project. My goal right now is to make it respectable up close, not mint. Something I can take to a cruise night without being laughed at. It had lacquer checking on the hood, little rust on the corners of the doors. Lots of signs of old school body work, brass brazing filler and such. It was done by a pro, or someone who had a clue. There was filler on panels that looked fine,so someone really went all out to make it strait. I'm a mechanic at a Chevy dealership, we used to have a body shop, but those days are gone. The old painter used to use lacquer primer under BCCC, so I thought I'd be ok. I read lots of good things about SPI, and after the shock of PPG pricing, I got all my materials from here. I already bought the base, PPG DBU. Dusk Blue. Again, I want it too look good, I know I wont get show quality. I also don't want trouble months down the road. I'm trying to absorb as much knowledge as I can from those who know. Chevelle.jpg
 
you have the knowledge available and the materials. i would take it all the way down to filler and metal, the extra time will be worth it. that car is way too nice to half ass... others here will have more experience with old laquer primer...
 
A few coats of epoxy over all that old work would be a really nice solvent barrier to have. If I had to do it I would shoot one coat of unreduced epoxy and let it set for 24hrs then shoot another and allow that to set for 24hrs then shoot your 2K surfacer with a half hour flash time between coats. Give it a few days in good temps before sanding. Sometimes old lacquer will soak up solvent based cleanersso if you're using that make sure to give it time to purge off the solvent, I've seen some old lacquer jobs that are so saturated with wax that it's almost impossible to draw it back out-the polymer style wax is a real pita when the paint has soaked it up, it's like trying to remove decal adhesive when the wax is soaked into that old paint.

Stripping the car to bare metal would be the best for sure.
 
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I have a gallon of DX330 W&G, if that matters as far as what type of cleaner I'm using and how long to wait before its evaporated. My biggest issue is not disturbing much of the old filler. I have already made a bunch of repairs and sprayed them with epoxy. The car is now ready for primer, the only hold up is wether the old primer is gonna be trouble or not. I talked to the old painter from work. He said just what you did about the epoxy being a barrier. He also added that I should get some reducer for the epoxy to spray as a sealer after the 2k. Sound ok?
 
SPI Waterborne cleaner-awesome stuff. Looks like old red oxide laquer primer, I would definately shoot two coats of epoxy on there with 24hrs between coats then shoot your 2K on the 3rd day. Unreduced epoxy won't offer up much solvent to soak into the old primer if you don't hose it on, sure makes a nice barrier once it's fully cured. Use regular urethane reducer for reducing the epoxy as a sealer. My experience with doing paint work over that old primer and bodywork is: it will fail, how soon is the question, 3-4 years would be my bet.
 
i wouldnt use solvent based w&g remover and i would take all the old laquer primer off and touch up body work. why not?
 
saw you post over at the chevelle site.

question isnt CAN you do this or CANT...its how long it will last. if you are OK with your job only looking good for a few years, then yes you can apply the epoxy over the red oxide like bob has described and keep going. If you want a long lasting job then this isn't the way to go, the red must come off. problem with that red oxide is nothing will bite to it. it sticks like crazy..but nothing sticks to it. I just got done re-doing a vette that was primed with laquer primer then painted right over with bc/cc, by another resto shop.

the black paint peeled off in sheets. was a 2004-2005 restoration i believe.

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i know it makes you sick...but how sick will you be 3-4 years down the road when the paint starts failing and you have to do this all over again? your going to be spending twice the amount of money on materials.
 
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