Question about degreaser use before primer
 

First, I am a novice about painting so pardon my ignorance. I've been stripping the paint on my '72, doing some body repair, and laying down PPG epoxy primer as I go. So far, I have been using the degreaser and metal treatments over bare metal just before primer. But I got a replacement door shell recently that needed quite a bit of body filler. I've got everything ready for primer, but it just doesn't seem right to use the degreaser and metal treatment over the body filler. My gut tells me that the filler (Rage Extreme Gold) shouldn't get wet before the primer. If I can use this stuff over the filler, will I need to let it dry first before laying down the primer?

Thanks

Steve, I'm by no means a body/fender/paint specialist (let alone expert), but having painted a couple of cars in my time (including my Carrera) this has been my experience: If there's a good basecoat beneath it, the days of cutting the entire car down to bare metal are pretty much in the past unless there's a real good reason. Many suggest that the areas that have been taken down to metal be first shot with an etching primer, as it will "bite" into the metal and provide a good base for your catalyzed primer. The use of a wax/grease removal solvent is pretty much only required if those contaminents are present on the surface prior to coating with anything. I'd say that if your hands are not greasy when you're sanding things out, it's not necessary to wipe the body filler down before priming it. You're going to want to have the surface of the car dust free prior to applying your color, so after blowing it off and taking a tack cloth to it, you may wish to spritz some wax/grease remover over it and wipe it down with a clean microfiber cloth as an added precaution.

always degrease. leave the filler a little longer before priming so the degreaser can evapoate. I've always used PPG epoxy straight on bare steel/filler. I don't like the idea of catalysed product ( epoxy) over evaporative cure types ( etch primer)

Not to offend anyone but there is a few ways to do what you want. PPG epxoy primer depending on which type it is, is really not for bare metal.It is a high build and ment to be blocked. If you strip to bare metal and do plastic work on bare metal, you then need a self etching primer on the metal showing, let it dry, then epxoy. You can strip to metal, self etch prime, and you your bondo over the self etch primer.
the epxoy . PM me if any questions, let me know what epoxy you are using, the nct 270 has etching primer in it and is a high build.

then why does it say 'non-sanding' ;)

from PPG website..........

'DP90LF is a black epoxy which is an excellent corrosion-resisant primer. This primer provides excellent adhesion to many types of properly prepared metal, fiberglass, and aluminum, as well as plastic filler. This Primer may also be used as a sealer and topcoated with most PPG products. DP90LF requires a 2 to 1 mix with DP401LF activator to spray (up to 25% DT reducer is optional)'



there are as many ways to do things as there are techs. best bet is to use one manunfacturer's system and stick with their reccommendations for the products you're using.


http://forums.pelicanparts.com/uploa...1347151472.jpg

That is the self etching, that is for bare metal, I thought you were using the nct250 or nct 270. The 270 is self etching and high build in one, I do not use ppg, but I still like to use the products separately anyway. self etch 1st then a highbuild so I can block. What "degreaser" you are talking about? Before you prime, just use a prep sol over the entire panel, it will not hurt the plastic. It evaporates very fast. Then blow it off and prime.

Thanks for thr input guys. I am using DP90LF as well and the insert indicated that it was appropriate for bare metal.

After haycait911 replied, I used the degreaser. I am glad I did as I definitely picked up dirt and grease from what I thought was a pristine surface.

The bad news is that my paint gun completely crapped out on me just as I started. So another problem to solve...

Sounds like you're well on your way, Steve, except perhaps for the crapped-out gun. Arrgh, I hate it when that hapens! You didn't say whether you've doing this at home or not, but by all means be safe! Your lungs will thank you the rest of your life for using a properly fitting and rated respirator, your house will appreciate you having a sparking compressor or other ignition source well away from any volatile vapors, and the EPA will be pleased if you properly contain and dispose of your waste solvents. Good luck, and post some pics if you have the means to do so!
Don

Note to self: Check 3 times for typo errors before posting... 2 times just ain't frickin' getting 'er done.

I use DP as my go-to for lots of things. can be used as a finish coat for underbody stuff, but will chalk a little if exposed to sun much. mix using the catalyst for a long pot life and the stuff sticks ridiculously well. it's a nice idea to put on black epoxy then your gray high-build wet-on-wet. good chemical adhesion and a guide when you're running out of high build when blocking.

donagain1 - I am doing this in my garage. I've put up plastic everywhere and it's a mess of course. I definitely respect the toxicity of this stuff. I use a respirator and I am an asthmatic. I can't imagine that anyone would do this without a respirator.

After cleaning my gun three times, I finally managed to get a layer of primer down, but the gun (Kobalt POS) sputtered the whole time. I think I will try a HVLP gun next time. I have a large 50 gallon compressor that can probably handle the volume flow.

you may wish to spritz some wax/grease remover over it and wipe it down with a clean microfiber cloth as an added precaution.http://www.yono.info/h.jpghttp://www.yono.info/d.jpg