Powder Coating

Question about using filler and powder coating. One guy at the shop said you can't use ANY type of fillers if your powder coating - apparently the oven cracks fillers such as bondo. Have to fill w metal only. Another guy said you can use a product called "Lab metal", which is a 2 part product that can withstand high heat. He was also pretty sure you can use JB weld. The newer stuff I have is good up to 500 degree's. Any one here have any experience with JB weld (or "Lab Metal") and powder coating?

Thanks, JBeasty (not weld :smile:)
I was told the same thing years ago...but I've found it to NOT be true. I've had gas tanks braised with metal...I've also used JB weld and I've also used Bondo. NONE of them cracked...HOWEVER if you use JB or bondo you have to make sure that the PC people don't sandblast it out when they are blasting. Personally I think JB Weld works the best and is the cheapest for smaller application...it sands nice and smooth as well. Obviously filling with metal is the best, but it's also the most expensive. I'd go with JB Weld, but go slow and do a nice job....Good Luck!
I used JB on a powder coat frame. I was told it was safe to use and it was as far as cracking. The color was copper illusion, a two part powder. there was a little discoloring in the areas that had the JB. Nothing terrible but if your looking you can see it.
Wow, lots of good responses. So, to the 2 guys w powdercoater in their names (how lucky is that?!):

This will be on a little tank with some minor dents. Is the 24 hour JB weld (that handles 500 degrees) going to show through in a simple color, as happened to smwtnbndr? I have not decided on a color yet. Could be yellow, or a metallic blue. I'd like to use JB weld, as it's readily available, and I'm familiar with it. Wonder if the "lab metal" is available in small quantities - guess I got some shopping to do. I did do some JB weld on the frame, and it's being coated a satin black - so it's less of a concern.

Thanks again everybody
Got the frame back, and the JB weld didn't crack or come out discolored, but it developed little pin holes. Glad I tested it on the frame first. Considering where it is I'm not worried about it. But after talking to the powercoat guy, the cost and prep just isn't worth it to me. I'm on to other things.

I did bake the tank with the JB weld on it, and it also developed pin holes. I'm sure my lack of skill has a lot to do with it. :wink: The dent repairs however are now very strong. I'll just finish it off with some USC Icing and paint the tank myself. Thanks for the input guys. I learn as I go.
just asked this question when I was at our powdercoters a few days ago.and I want to add they coat massive amounts of parts each day.they told me that nothing really works good,even the one the tried that was specifically made for pc. although they will withstand the heat they all have a tendency to "gas out"