nightmare job

[Guest]

this is a set of tanks I am doing for a friend, I have put 4 coats of Lab Metal and 3 coats of KL primer on it to get all the dents out , Now the powder won't stick at all. Used a china gun to put the primer on and a wagner 2008 to put mirror black on. Any help?

[BeeBob]

Re: nightmare job

Does the lab metal act nonconductive like JB weld? That "could" be part of the prob. It looks like your getting some back ionization also, do you have a good clean ground? I agree with HD, you might need to warm them up a bit with all those coats and or lower your kv.

[wiseguyz]

Re: nightmare job

Along with lowering the voltage, increase your distance to the part also to help prevent the starbursts. Looks like you might have a bit too much powder velocity also and it's blowing the powder off where it's back-ionizing. Try backing down the dosage air a bit.

[panheadstan]

Re: nightmare job

it looks to me like you have a bad ground connection. that is where the starburst pattern comes from, the metal cant dissapate the charge and it blows back out. some times after the primer i shoot the top coat about as low as i can, on my gun thats 20kv. i shoot slower and give the part time to bleed off the charge. the primer can be a little touchy,i dont know why but if i wet sand and clean with denatured alcohol and reshoot with a good ground it comes out better. try to grind a spot on the underside of the tank for a new ground spot then remove the ground and dust that area when you are done shooting.

[Guest]

Re: nightmare job

Everyone has given superior advise, a different nozzle tip may also be helpful:

Deflector Cone
Deflector cones tend to generate a picture frame affect. The smaller the deflector plate the less critical is this effect.

Fan Spray
The Fan spray nozzle is widely used in modern coating plant. The reason for this is the more uniform coating and the greater effective depth.

Wide Fan Spray
This nozzle system, also known colloquially as a duck's bill, is used for larger outputs of powder due to its geometry.

[Guest]

Re: nightmare job

I have tried everything thats been suggested and Iam wondering if its the KL primer (too many coats)

[Guest]

Re: nightmare job

so you have tried to pre-heat the part and still can not get the powder to stick?

[Guest]

Re: nightmare job

yes I preheated it and still looked the same.

[BeeBob]

Re: nightmare job

Did you have any probs putting on 3 coats of primer with the China gun? If not, maybe you should try the China gun with the black cold and then warmed up if doesn't stick cold. That's really the only thing done different was using a diff gun.