First time with raw metal

M

Mick

Guest
I am a novice at this painting thing. I have painted two Harley sets sucessfully. However I just tried my hand for the first time working with raw metal. Here is what I did.

1. sanded raw metal to get out any imperfections.
2. sprayed 2 coates filler/primer
3. wetsanded with 600 grit to smooth out nubs
4. sprayed 3 coates of ppg dbu base coat
5. sprayed 3 coates of ppg dcu 2002
6. wetsanded with 600 grit to smooth out spots
7. taped out flames
8. sprayed real light coat to give ghost flame effect.
9. removed tape and my entire paint job peeled off in huge sheets down to the primer!!!!

It is about 55 - 60 degress in my home town right now. Is this a temperature problem, or do I need to use some sort of adhear-to product before spraying my clear coats???

Any thoguhts would be appreciated.
 
B

big stinkie

Guest
Doh! I hate when that happens! /ubbthreads/images/graemlins/crap.gif

I'm a hobbyist, so I don't have any professional experience, but the PPG guys told me to use an epoxy primer over bare metal. It sticks to the metal like, like...well...like glue, and everything else seems to stick to the epoxy primer. I've done a half dozen bare metal jobs and none have come off yet. Like you, I sand the dickens out of the bare metal. I use 80 grit. Sounds kinda aggressive, but I feel that it gives the primer something to dig its fingernails into, and the primer fills in the scratches. Make sure the metal is completely clean. Then clean it again, just for grins.

Epoxy primer has its quirks, though. It takes a while to cure/set up. It dries to the touch soon enough, but if you sand right away it balls up on ya. I wait several days after spraying before I sand it. Once it sets up, it is hard as a rock. There is a recent thread on the board that has some details on this phenomenon. Try the 'search' feature to find it. (I'd do it for ya, but I'm lazy.) /ubbthreads/images/graemlins/haha.gif

I use an HVLP gun and found that if I don't tune it up to spray a lot of fluid that I get a surface kinda like the texture on a basketball. Hard to sand it smooth. So, I pump up the air pressure and open up the fluid control.

Good luck, and let us know what happens.

Andy aka Big Stinkie
 
R

rex

New member
My first guess is the temperature,I'm sure they gave you a catalized primer so under 60 dgs. the chemical reaction stops for curing.What primer did they give you to use?
 
R

rex

New member
Oh,not good.It's almost guarranteed it's lacquer and this stuff really doesn't like to stick to lacquer.There's a sealer that will let you and I want to say it's 1980 Delseal but not sure it's been so long.The lacquer isn't a good primer for corosion protection also.DP40 is your best bet but like Andy said it has some quirks-best stuff I know of for steel other than HOK's primer but I haven't used it and don't know if there are any probs putting DBU or DBC over it.I wouldn't think so though.Sorry for the bad news man.
 
M

Mick

Guest
You live and you learn. I will try the DP40 and see how it goes.
 
B

BDsbigZRX

New member
I use PPG's K36 right over bare metal. I just clean the metal real good, go 5:1:1 (it says you don't need reducer, but it just helps it spray better, and only slightly effects the "build" of the primer) It's great stuff. 2 or 3 good wet coats, next day sand it with 220 (yes, 220!), then tack it, and spray another 2 medium coats (just a touch more reducer this time, maybe 1.5) as a seal coat. By the time you clean the gun and mix your basecoat, you can spray over the K36 with a couple coats of base color. Flame/clear as needed. Granted, NONE of this will work unless it's at least 70 degrees in your paint environment.....

Bryan
 
R

rex

New member
Are you using a metal prep or etch primer under the 36?All the K and NCP series primers shouldn't be put directly over steel,although 99% of the time you won't have a problem.It's that 1% that will cost you because PPG won't stand behind it.
 
M

Mick

Guest
...and I am in the process of insulating my booth and adding an electric space heater to insure correct temperature
 
R

rex

New member
On bare steel use it straight 2-1 mix with catalyst and use the dp40 to get the higher zinc content.The 402 fast hardner is easiest to use too.If the temp is real high I just put a splash of reducer in but you don't need to.Normally you only reduce it when you use it as a sealer but it isn't the best choice for sealer.
 
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