6º F is all we've got between cured powder paint and small puddles of bismuth/tin alloy on the crumb tray of the toaster oven. Kurt Urban at CS Coatings informed me that "powder paint meeds a minimum of about 275º to achieve the chemical cross-linking for a complete cure." A rep at Rotometals agreed that when using their 281 alloy "that was cutting it pretty close."
I had gone to casting bismuth/tin when Massachusetts enacted what I consider to be overly zealous lead regulations in 2012. And I continued to use CS vinyl paint to finish . . .drip . . .drip . . . drip . . . The result is fine but getting there is an extremely tedious process. So I decided to try Pro-Tec powder paint at 275º for 45 minutes.
Hmmm . . . The alloy softened up enough to allow the wire weed guards to spread the head, the soft plastic bait keepers deformed and the amount of powder paint was too much. The paint was completely cured, however.
I won't be whacking a jig head as hard on Quabbin's rocks as I did this one on a vise; the cured powder finish is more than adequate. But on what?
I'm thinking pewter, specifically Rotometals R92, 92% tin/8% antimony. Melting temp is 466º which Lee Precision says "will melt in their Pro Pot IV." I knew that but had some concern about using it because Lee's instructions list pewter as a metal not to use in this melter.
To make a full commitment to powder paint I'll need a fluid bed to fluff the stuff to apply a light coat
http://www.barlowstackle.com/Powder-Paint-Fluid-Bed-P1009C134.aspx
and a proper oven.
http://www.eastwood.com/eastwood-bench-top-powder-coating-oven.html?reltype=3
If any of the more experienced jig makers care to offer input on the observations and ideas I've described above, I'd welcome it.
WW