Primer
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I am almost ready for primer in my project car and I need to know want type of primer to use. I was thinking a high build primer so I can block sand it and get a flatter finish. What should I use
how much bare metal is showing?
what type of project is this?The only parts that are down to baremetal are the roof and half of a fender and the spots I sanded though to remove light surface rust there are a good number of the spots. It’s a complete car painting project on an 87grand prix. I don’t want an outstanding paint job but a decent one. I don’t want to put a lot of money into paint either
Well, most urethane primers will require an etch or DTM epoxy to be applied over the bare metal areas for proper adhesion and corrosion resistance.
Do you have any particular brands of products available from your local jobber?
You will likely need a little etch primer and a gallon of 2k urethane. There are many, many brands and a huge range in cost as well. Will you be priming over any flexible plastic (such as bumpers)?
The front and rear bumpers are fiberglass. I do know that at least one of our parts suppliers caries ppg. We can also get napa brand and I think omni. There may be a few more as well
order up SPI epoxy – fantastic stuff. I’m at the point where I’m finding reasons to use up my Napa epoxy primer, which was twice as much…
1 quart set up of epoxy should do.
1 Gal setup of urethane to top it off and have some left over.
Get roughest parts to 180 grit and the rest 180-320.
Apply 1-2 wet coats of epoxy especially to the bare metal areas…..you did tape it up first huh?
Let the epoxy flash as recommended then apply your urethane.
Wait over nite or next day before sanding.
Guide coat.
Block with 400 wet for solids and 600 wet for metallics.Single Stage paint is what you prob need.
Enamel will be the cheapest top coat.
Urethane most durable.
Solid color most user friendly.[quote=”timbo” post=14449]1 quart set up of epoxy should do.
1 Gal setup of urethane to top it off and have some left over.
Get roughest parts to 180 grit and the rest 180-320.
Apply 1-2 wet coats of epoxy especially to the bare metal areas…..you did tape it up first huh?
Let the epoxy flash as recommended then apply your urethane.
Wait over nite or next day before sanding.
Guide coat.
Block with 400 wet for solids and 600 wet for metallics.Single Stage paint is what you prob need.
Enamel will be the cheapest top coat.
Urethane most durable.
Solid color most user friendly.[/quote]timbo said it 😉
[quote=”timbo” post=14449]1 quart set up of epoxy should do.
1 Gal setup of urethane to top it off and have some left over.
Get roughest parts to 180 grit and the rest 180-320.
Apply 1-2 wet coats of epoxy especially to the bare metal areas…..you did tape it up first huh?
Let the epoxy flash as recommended then apply your urethane.
Wait over nite or next day before sanding.
Guide coat.
Block with 400 wet for solids and 600 wet for metallics.Single Stage paint is what you prob need.
Enamel will be the cheapest top coat.
Urethane most durable.
Solid color most user friendly.[/quote]word
Our one parts supplier came in today and I talked to him about what paint I needed and he looked at the car and said a poly primer would work best for what I was doing. And a single stage urethane
Ok bud …..you can and I have top coated poly without sealing with urethane primer but you might be rolling the dice on DOI and holdout as poly doe have more porosity….
Do you have the gun to shoot poly?
What tip size?
Maybe you should just go with his advice and forget all this time spent here asking and typing… :blink:I’m just trying to get a few different opInions on want to use. I’ve got a 1.4 but I’m probably going to need a 1.8 or so to spray the poly. He’s been doing body work for more than 35 years and does exceptional work. He told me to do some research so that’s why I’m on here. I’m only looking to get a few years out of the car before I either sell it or chop it into another stock car for me. Never hurts to have a backup car.
[quote=”Jbracing” post=14468]I’m just trying to get a few different opInions on want to use. I’ve got a 1.4 but I’m probably going to need a 1.8 or so to spray the poly. He’s been doing body work for more than 35 years and does exceptional work. He told me to do some research so that’s why I’m on here. I’m only looking to get a few years out of the car before I either sell it or chop it into another stock car for me. Never hurts to have a backup car.[/quote]
If you are spraying poly, I would go bigger than a 1.8 (maybe even a 2 or 2.5). Also, poly is not supposed to be sprayed over paint, so you will need the panels to be completely stripped. Spray it only over bare metal and body filler. If you use it read the can. Some may require an etch or epoxy first although most wont.
Although poly is cheaper than a good 2k Urethane, I would just go with the urethane. It is easier to spray, builds well and will give you a good foundation for your top coat.
I usually only use poly on high end jobs or large repairs on flat panels that need to be incredibly, perfectly straight.
Polyester primer isn’t really a topcoat primer, It’s more of a liquid bodyfiller and should be top coated with a good urethane primer afterwards. Timbo said it best you can top coat it, but your kind of rolling the dice. It’s definitely not an accepted method in the trade, most poly primer tech sheets will state that they should not be topcoated over.
If it were my car I would spray a coat of epoxy over the whole thing (giving me some anti corrosion and adhesion properties, then wait about 15-20 minutes and spray my 2k urethane primer (giving me some build). And I wouldn’t bother with a poly primer unless your not confident in your bodywork or you want a showcar finish.. or both
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