I believe that a buddy of mine was using the Eastwood starter system, $100, $90 on sale. He used an old kitchen electric oven to bake the powder, but I think he replaced the controls. He later upgraded to a higher end powder system. He liked the starter set, though. This was not for hobby use, he has a small business.
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- Look at the Original Hotcoat Powder Gun.
I have one of his powder coated panels in a multi-year field test, outside. The last time I checked, it looked great.
The coating is the easy part, all you need is an electrical contact to the workpiece, some air and the dusting gun. What comes after is the fun part. You need to slowly heat up the piece+coating to the point where it fuses to the substrate, not just fuses on the surface of the powder. When I was doing Q.C. for a motor home manufacturer, we had a
40' furnace with a U-shaped trolley line that ran workpieces in and out on a continuous basis. Hottest part was at the back, so they got gradually heated up and then cooled down. Took about 20 minutes from dusting to removal. Some guys use heat lamps on parts, I'd think you'd need a pretty well insulated box to do it that way. For small stuff you could use a toaster oven. No plastic parts need apply, fusing occurs with the polyester stuff we were using at about 400-450 degrees F. This was on aluminum extruded trim parts, like window frames and corner edging. I wouldn't consider using it on exposed steel parts, when they rust, the coating is going to trap water and they'll rust worse. Touch-up is limited to stripping and recoating. It's a great finish for aluminum parts, though, not much is better. After a 1000 hour salt spray+UV test on aluminum plates, all that was left was the powder coated ones, all other finish types were GONE. I don't mean the finishes were gone, the plates themselves were eaten!
The learning curve will be to get a uniform thickness on the dusting, then find a heating regimen that will give good adhesion without over- cooking the coating. If it's for one-offs, you might want to find a local powder coater that already has the experience(and the oven).
While we're talking powdercoat, what do people suggest to mask off threads when coating? For want of anything better, I used painters' masking tape: it came back carbonised, & the glue burned to the threads. It was a bear to clean off, but easier than the powdercoat would have been. What's the recommended method?
Use a high temp masking temp with a silicone adhesive and either a polyimide, kapton, aluminum, lead, or polyester backing. Not surprisingly it's called "powdercoat tape". Or you can use silicone cap plugs.
I have the Eastwood hobby gun (about $100) and it works OK, but sometimes it doesn't seem to cause the powder to be drawn to the part well enough in all situations. It operates at 7KV.
Caswell Plating
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now sells a gun that costs about $200 and operates at 30-50KV with variable output between these points. I'll probably upgrade to this gun in the near future.
You can use the powdercoater's tape, at about $12 per roll. I use the aluminum tape used for sealing ductwork that can be bought at Home Depot. It sometimes leaves a bit of gummy residue from the adhesive, but it won't melt or catch fire. Paint thinner will remove the adhesive.
Almost every motorcycle manufacturer in the world disagrees with you :>). A properly adhered powder coat will not allow water to penetrate , any more than a properly prepared and applied paint product will . And it's much tougher than any paint I know of . Takes a big oven for frames though ... I know several people who have successfully coated small items and fused them in a home baking-type oven . You won't want to use that oven for cookies anymore ...
As soon as the powder coat is punctured, the metal worm eats the frame. If they'd zinc spray the frames before powder coating, they would survive the odd scrape or stone chip (or, in Meriden Triumphs, the bloody frame number stamping :-|
Stuff a bit of hemp string down the far end of the hole, fill the rest of the hole with silicone sealant leaving about 1/2" or so of the string hanging out the hole. Put a thin smear of silicone on the exposed string. Leave it to cure for a couple of days.
Coat and bake then once its cooled down grab the string with a pair of pliers and pull out the plugs.
Alas, currently I'm not set up to do the coating myself: I send it out to a shop. They certainly won't meddle with their process that way. It needs to be something I can put on first.
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