I have one of the original Hotcoat systems, used it with great success in the past, and I thought I knew how it works. I recently bought up a bunch of the Reflective Chrome powder and some topcoats (clear and transluscent), to coat the ramtubes on my injection system. I did four tubes last week and the results were disastrous. The chrome went on great and looked awesome- but there was a little bit of bubbling in it that I didn’t think too much about at the time, not in places you could see. I waited for the parts to cool, and hit it with the topcoat.
Many problems: the powder didn’t stick very well (bad ground, hard to achieve with the ramtubes), and, distressingly, “fisheyes” in the topcoat. You could see these before we even flowed out the powder- around the bubbles, it would do wierd circles, some kind of static effect, around the bubbles. After it cured, it was crap, and now I just ruined one of the tubes trying to remove it. It was also blotchy and streaky, and in general, just looked bad- I think the powder not sticking did that. But around those fisheyes it was totally dark, so it was spotted as well. Just horrible all around.
My process is:
Remove old coatings (sand, grind, blast, wire wheel, etc).
Prep with metal prep, wipe on, wipe off until it wipes clean. Allow to fully dry.
Coat with chrome.
Bake, allow to cool.
Coat with translucent
One thing I caught in these forums that I hadn’t heard to do before is prebaking the components to outgas them. This has never been an issue before, but I’ve never tried to coat thin spun aluminum before. Today, I tried again on another ramtube. Same process, to start, but after the coat of chrome (still had some bubbling), I ground out a spot for the ground electrode, hoping to get a getting ground. I also re-cleaned the part, thinking maybe some grease or wax had come up, out of the part, and maybe through the powder during the cure, which could have been part of the problem with the fisheyes. None of this helped- as I started spraying on the topcoat, it was obvious that I’d have exactly the same problems. Frustrated, I tried sanding the bubble areas before I topcoated- that just screwed up everything. Time to strip the part.
I’m pretty frustrated at the moment. I don’t think I’m doing anything too different from what I read on the forum about this two-step process, but so far the results have been bad. I haven’t tried using the actual clearcoat on any parts yet because of the bad results with the translucent, but I have a lot of other parts that need done and I’d hate to waste all this powder by giving up and going to a pro to get it done. Anybody have any ideas on what else I can do to get this process to work?