ppg dp primer

[kustom paint workz]

having some problems with some DP90LF
heres what i did. Sand tank to bare metal with 80. Do minimal mud work sand again 180. Wipe down with DX320. Sprayed the DP90LF with 402LF Catalyst. One coat on body work and then the second on entire tank. Let the tank dry for two days (didn't have time to work on it). Wet sanded the primer to level it out a bit. When I wet sanded the tank i brke through in one spot on the back corner. When i dried the tank i noticed the paint peeled up a bit. If i rubbed it with my finger it peeled more and more. Obviously an adhesion problem but why? I followed the mixing ratio correctly? any ideas on what may have gone wrong and where to go from here. I also noticed that the can says non sanding primer. Does this mean it doesn't need to be sanded or that it cant be sanded.

 

[kustom paint workz]

by the way i wanted to add this is the first time using dp I always used the cheaper omni line. The salesman recommended the dp. Heard alot of people used it so i figured i'd give it a try.

 

[BonesFX]

OK -- there's a lot about the DP Primers going around on these pages - Thats the one thing I hate about PPG - They tell you to use this that and the other thing for those them and these -- I think they want to sell you way more stuff than you really need!

I had a long two hour talk in person with my Jobber and the owner of the PPG distibutor and told them the reason I don't buy a lot of PPG products was because I don't wanna have a miilion different cans of PPG primers and reducers and catalysts - I used to use the laquer based primer all the time until I had a small problem with adhesion problems - My guys hooked me up with the DP (I can't remember the number but I think it's 32 or 36 or something) and told me to give it a try - hey - I'm not gonna turn down free stuff -- They also gave me some reducer for it and strongly recommended to use it. The thing to remember when sraying anything is the thicker it goes on the more "mil" might peel or flake when you bust through - When I shoot the stuff I mix up 5oz primer to 1oz catalyst to 2 or 4 oz. reducer. I use it to seal, for fill primer, under - over body work... The stuff's been great - expensive - but great!!

KPW -- in your case I think your Jobber hooked you up with the wrong stuff - I would take the label as meaning you can't sand it -- I'll post the numbers of the products I use tomorrow -- Bones!~

 

[big john 2]

Dp's are not made to be put over an all bare metal part. Try to use ncp 272 over bare metal then a Dp . When the new Dp's came out I had the same thing happen to me.

hope this helps .

 

[Jim]

I started another thread about DP but,I think I'm going with HOK's KP21 instead,It takes longer to cure but,I don't hear the problems or confusion as I do with the DP.I used the KP and it sands nice and didn't flake with HOK base/clear,I sprayed it under then over some filler and had no bleed through,I did spray black base which I'm sure covers better but,I used it,know it works and had no problems!If the jobbers don't know what to use with the DP,how can they advise me?PPG sells sooo many differant products,I think thier salesman are getting confused!HOK sells one epoxy,no guessing!Just my opinion.Jim

 

[kustom paint workz]

big john on the tech sheet it said it was ok to apply over the bare steel sanded with 80-180 grit sand paper. unless maybe i have an old p sheet or something. i'm starting to get really confused about what to and what not to do. i think i might go with jim and try the hok epoxy next time. i figured i'd give the ppg a try. but this is kind of leaving a bad taste in my mouth. the only problem is that my jobber said that to get gallons shipped costs alot of cash because of hazmat garbage. I just may have to try to get some from autocolordepot over the net.

 

[Jim]

I bought some stuff last yr from autobodysupply,they shipped it to me in Indiana for like 8 bucks.It was quarts of paint,primer,clear and reducer.

 

[Kyle]

Spend more than $250 (we know how easy that is when buying paint!) at www.autobodydepot.net and they will ship it for free, no hazmat, no nothing. Last time it took two working days from the time I ordered it to when I recieved it.

 

[rex]

I don't think it was a DP problem as much as a prep thing.I tout the DP here and I just did my buddy's fender and went to feather out the DP to prime the bodywork and it did the exact same thing.I've had the DP under bodywork peel because you got on it too fast but never like this case.I tracked it to wiping the thing down with lacquer thinner before a quick scuffing and the prep solvent doesn't take off the residue from the thinner.This was one of those slimed down raw steel fenders so thinner's the quickest way to wipe it off but I got careless and in a hurry,had to strip it and start over.DP is designed specifically to cover bare steel or whatever the substrate and is basically worthless for anything else other than a cheap sealer.Sanding it affects nothing basically unless it's sat more than a week.I like my steel either blasted or I sand it with 180 on a DA just like I was sanding paint,every square inch is scratched up to the max.