"Zapping" your parts?

[Guest]

I use an Eastwood hobby gun and early on I was having trouble with my ground (aligator clip was clamped on to the insulation ) anyway, I got in the habit of "zapping" my parts by moving the tip close enough to the part to cause an arc, so I knew the ground was good.

So I started doing second coats lately (clears) and I noticed that wherever I zap the part, powder wouldn't stick.

I know, I know... conductive parts, the charge is spread evenly across the surface, yadda yadda...

There's something funny about the way a coated part dissipates the charge when you zap a part like that. It's very localized, and it's repeatable (with my equipment anyway)

Has anyone else experienced this? I imagine arcing is a bigger problem with the higher voltage guns; surely someone out there has zapped a part before?

Any tips on getting the powder to stick in those areas?

-Deek

[tedsfab]

Re: "Zapping" your parts?

yes i used to do that trick awhile back also with the cheaper guns . when doing a 2nd coat just turn your air pressure down a bit and back up to about 10" it usually works well for me doing this .


also when doing the zap trick becarefull . sometimes if the powder and air mixture is just right it will create a cool little flame thrower from the gun . yes its neat but may mess up your coating

[Guest]

Re: "Zapping" your parts?

I think I read on here that if you heat the part up in the oven it will remove the charge from the part-cannot remember how hot but I heat mine up to curing temp. I have a EW gun too and have had that happen to me and if I left it after the cure I would make a crater on the cured powder.

[Guest]

Re: "Zapping" your parts?

I've also been told, if you get this going on, to wipe it down and it should take care of it. I've done it, but it's been awhile, so can't really remember if it helped, but must have or I would remember it as a part from hell.

[FirstYearDeek]

Re: "Zapping" your parts?

Thanks for the replies, guys. I've noticed that backing off the part helps a bit... If the voltage on my gun were adjustable I would turn it down as suggested, but the EW hobby gun isn't adjustable.

I wanted to get this technique down before I started on candy coats. I imagine the coverage has to be very even or it would be splotchy; it doesn't seem to matter too much with clears!

My current project is the motor for my GL1000. The carb rack is nearly finished and I'm going to polish the shiny bits and do black chrome on those.

I've painted for years; my dad is a professional body man and paint expert for a Chrysler dealership and I've tried to mimic him, but I'm just no good at it. Powdercoating is easy, in comparison! It's just a whole new skill set and I'm finding not much translates! (Except prep, prep, prep!)

-Deek

[Guest]

Re: "Zapping" your parts?

Second coats are done between 20-30 kvs

[Doogles]

Re: "Zapping" your parts?

Could you put a rehostat on the power supply to drop the output voltage?

[wiseguyz]

Re: "Zapping" your parts?

It's a solid state power supply that is not designed for variable input voltage. You'll probably fry it if you try the rheostat.