Curing Times For Lead Free Jigs

[RJD]

I purchased some higher melting point lead free jigs from Keith (Hawnjigs), and want to powder paint them. AtticaFish suggested 315 degrees for 20 minutes for curing Harbor Freight powder. Any suggestions for other brands such as Pro-Tec, Columbia Coatings, etc. Thanks.

Ron

 

[smalljaw]

270 degrees for 30 to 40 minutes, that is what I was given from component systems inc the makers of pro tec powder. I sent them an email about some of the paints not curing properly and I expressed concern about high temps over longer periods and I was told to try the lower temp for a longer time and it worked. The problem I had was I was using multiple colors using columbia coatings that specified 400 degrees for 10 minutes and what was happening was the colors were bleeding together as the pro tec was getting too soft and when I lowered the temp it didn't get hard enough so I did the 270 for 40 minutes I believe and it came out great but they told me 30 to 40 so I imagine 30 probably would have worked.

 

[cadman]

RJD,
I'm sure you meant lower melting lead-free jigs. Nonethless, yes I do the same as smalljaw. I might be around 260 degrees at 30 minutes. The thing to watch for is test one jig at a time, so you get the correct temp. Don't do them all at once like I did the first time. This way if you are running too hot, you will only ruin one jig. There will be a lot of trial and error here, as different paints will react differently to the heat temp. Lower heat and longer time is the key. I don't know what Keith's alloy make-up is, but I think 315 degrees will be too high. JMO.

 

[AtticaFish]

That temp/time i had mentioned previously has changed some. After several curing tests with different lead free stuff..... i now keep the temp and time as close to what the manufacture states as i can. 350* for around 20 minutes. I will add, after the initial cure, an xtra 10 minutes and drop the heat to 325* if i think it will not be totaly cured. I am using almost all CSI Pro-Tec powder as well.

Hawnjigs had given me a rough estimate at what the melt point was for his bismuth alloy mix and it was (if i remember right) above the cure temp fro Pro-Tec so i have raised my temp to 350* and have not had any problem.

Melt point for tin is ~450. What is the melt point of pure bismuth?

I do cure them in singles before i do a larger batch and test them after they come out of the oven to make sure they are cured good. A couple thumps on concrete and a knife blade pushed against the paint will tell if it is going to chip. If it chips...... back in the oven it goes.

One problem i have run into with some of the leadfree alloy heads i have, is when i am re-heating them to do a second color. If the head gets too hot it makes odd lumps push out from the metal. Metalic pimples is my best description. Only happens when i 're-heat' a jig TOO hot after it has one coat of paint on it already. Need to get some pics. of the zits.

whew - that was alot of typing.

 

[cadman]

Wow, I would have never thought that it would work at such a high temp. If I go to 350, my lead-free jigs melt. So with that said my alloy must be way different than Hawn jigs. Good info Attica, thanks.

 

[AtticaFish]

I have yet to melt off any of the alloy heads in the oven..... have melted a few by accident over flame though.

I actually have adjusted how i cure alot since i started, to help keep away from drips and nips and make it possible to cure multi-color and powder eyes with out them sagging. May start another thread to explain.

 

[Fatman]

Lot's of great info. I'm just waiting for the shoe to drop here, and neighboring states have already gone lead free.