I'm using PPG DX1791 Wash Primer then K36 Primer. My paint guy told me I could buy 5 gallons of their thinner (Grow Automotive H.E.T. 4262 Lacquer Thinner)instead of the recommended cleaner to use to pre-clean the metal before using the DX1791. He said just wipe it down and let it evaporate for about 30 minutes. Then to shoot the Wash.
So I did all of that and of course there were some areas that either reacted to the thinner or would not let it bond, it pushed it away leaving patches of small bare areas (about 1/8 diameter) but not everywhere. I think it was a reaction to the thinner since I could see the pattern of the cleaning strokes in the bad areas.
I only painted my doors and one fender so its not a disaster. My question is should I sand all of this stuff off before continuing or just sand it and recoat? I only shot a thin coat as recommended. I will be purchasing one of the recommended cleaners tomorrow before proceeding with the body, should I use the DX330 or DX393 or the DX394, all are recommended for the DX1791?

Thanks Chris

Let me get this right.
You have bare metal then wiped on some lacquer thinner allowing it to dry?
You can clean with thinner as a first go around but you really need to use a wax and grease remover before you apply any product.

Did you notice the small bare spots right when you applied the DX1791 or when you applied the K36? If you applied the k36 then noticed the spots you put on the k36 too soon or applied too much DX1791.
If the spots appeared in the DX1791 then you had a reaction on the surface.

I would wipe the parts down with DX330 or DX440, am not aware of those other two cleaners, but DX330 is a good cleaner. Wipe the parts with the cleaner then sand. If you start sanding without cleaning you can sand the containments right INTO the metal!!

Sand with 180 grit, blow the parts off with air clean again with DX330 til your cloth is clean. Take one rag pour some Dx330 on it, wipe part, take a NEW CLEAN rag and wipe dry. Do this til your wipe dry cloth shows no dirt.

I did not apply the K36 only the 1791, knew something was wrong. Some areas look very good and some have the spots. I was also a little thick in a couple of areas. I assume that the 1791 will cause problems if it too thick? I intend to sand these parts and reshoot. I will clean as you recommended.
Chris

laquer thinner can be used as a cleaner on bare metal but it should be wiped off and thoroughly dry before applying any primers. The DX330 works well IMO. Two coats of the etch primer should be all you need.

I cleaned the panels with the 330 then sanded back to bare metal and cleaned again with the 330. After work tomorrow I intend to wipe one more time then shoot the 1791 and follow with the K36 soon after.
I was reading the tech sheet on the 1791 and it said "slight overlap of the DX1791 onto painted surfaces and body filler is acceptable but should be kept to a minimum". Since my body work is no more than some small door dings I intend to use it over the body filler.
Is this wrong, has anyone had any bad results using the DX1791 over body filler? And if so what steps should I take when I do the body of the car which has a couple of areas that have some body filler on them?

Thanks Chris

Yes Dx1791 can be applied over filler and paint just dont go hog wild, some slight overspray wont hurt...Eric

If I remember right, the 1791 is a very transparent primer.And says to use light coats. Don't put this primer on heavy thinking you need to make it thick. Thin is better. You should still be able to see the metal thru it and it'll have a yellowish look to it....

graemlins/waving.gif
Rick

Why are you using DX1791? What is it the idea behind using it. Wash car with soap and water then DX330 W&G remover Wait atleast 30 minutes before sraying. I have seen the DX 330 cause reactions if srayed over to soon. If you have bare metal use a primer made for metal on those spots first. Good luck.

Yes, the tech sheet does say that if you will be using a second primer to shoot one thin coat or two thin coats if no other primer is to be used, thanks.

Decided to go with PPG. First salesman told me to use K36 primer, he checked with a rep on the phone who said for bare metal (my whole car is bare metal) you must use 1791 first then the K36. Now I have a gallon of K36 and the 1791 so I must continue this path.

Does PPG make a primer that can be shot onto bare metal and over filler, if so what is it?

Thanks Chris

Does PPG make a primer that can be shot onto bare metal and over filler, if so what is it?

YES Its called DX1791.
The tech sheet says safe over filler and paint just keep it to a miminium

Why are you using DX1791? What is it the idea behind using it. Dx1791 is an acid etch product THATS MEANT TO BE APPLIED OVER BARE METAL, IT PROTECTS AGAINST RUST AND PRODIVEDS ADHESION.

Wash car with soap and water then DX330 W&G remover Wait atleast 30 minutes before srayingWhat good does washing bare metal with water do
expect make it rust??

PPG offers the LIFETIME warrenty when using DX1791 on bare metal so its a good idea to use it.

Thanks for all your help guys, I'm ready to shoot again.

Chris

[/QUOTE]What good does washing bare metal with water do
expect make it rust??
I did say if there is any bare metal to prime it first. Thanks.