heat treating problems

[parrott1969]

I am haveing problems with my boolits slumping when i heat treat them. I know it is caused by over heating them. But here is what has me stumped, They are slumping at around 340-350 degrees, does this make sense to anyone? I purchased my lead online and it is supposed to be wheel weights plus 2% lead. Could they have gotten the lead content too high and therefore lowered the melting point? If i can only heat my boolits to 335 degrees, how will this affect my heat treating? will it work at this temp? My first thought was that oven temp was off, but i have sense read that the melting point of pure tin is around 367 degrees so i think the problem is with the ingots. Any thoughts?:confused:

[Slow Elk 45/70]

Hullo Parrott1969 , and welcome.

It sounds to me like your "alloy" is off . Have you done any of the simple test on it to get an idea of what you really have ?? Ring test, squeeze in vice or wire cutters ??

I would not put any faith in on line --poured ingots, if you buy on line, buy the material in the orginal state: Lead , WW , Linotype , Monotype , Rotometals has alloy you might want to check them out.

[c3d4b2]

Have you checked the temp of the oven? We had an oven that was significantly off of what the was set. We were baking with the temperature set at 250 F when the recipe called for 350 F.

[briang]

If they put to much lead in (assuming pure lead) the melting point would be higher than wheel weight lead. Do you have any wheel weights? A wheel weight or two (clip on) in with the boolits would serve as a gage to tell whether its the alloy or the oven temp gauge.

[dwtim]

First thing I would check is the actual temperature of whatever contains the bullets, i.e. I wouldn't trust an oven dial.

I'd test it with an infrared remote temp sensor if possible. A good one.

This is why I WQ.

[303Guy]

Try standing the boolits on a shiny tray instead of a black one.

You can check the oven thermostat by setting a tray of water in it and seeing if it simmers at 212F and boils above that. But the oven thermostat measures the air temp in the oven, not the radiant heat so much.

[oneokie]

As others have said double check the temp of the oven. Have you gone ahead and water quenched any of the slumped boolits and checked the hardness of them?


supposed to be wheel weights plus 2% lead.
Do you mean plus 2% tin?

[parrott1969]

sorry yes i meant 2% tin, I do not yet have a hardness tester, and i have not checked the temp of oven but i will here shortly. I have been lurking around here for sometime and it seemed as if everyone was haveing a lot of fun casting so i bought so cast boolits loaded them, shot em and decided that i liked the idea, so two weeks ago i bought a pot, mold and lead. I cast my first batch last weekend and discovered casting is kind of like crack, ONCE YOU START IT IS REAL HARD TO QUIT!

[fredj338]

FIrst let me ask, you are NOT using your cooking oven are you?:shock: Definitely get a therm. into that oven & see what the real temp is. If you had too much tin, that would lower the melting point.

[243winxb]

Your slump temperatrue is 340. Set the oven to 325. Heat for 30 minutes. drop in water. Lyman bases everything on there #2 alloy. Your temerature would be different, different alloys.
Quote:
Q: Is there anything I can do to make the bullets harder?
A: Cast bullets can be heat treated to increase their hardness providing your alloy has some antimony present. To heat treat your bullets: Cast your bullets in the normal manner, saving several scrap bullets. Size your bullets but do not lubricate them. Place several scrap bullets on a pan in your oven at 450 degrees and increase the temperature until the bullets start to melt or slump. Be sure to use an accurate oven thermometer and a pan that will not be used again for food. Once the bullets start to melt or slump, back off the temperature about 5 to 10 degrees and slide in your first batch of good bullets. Leave these in the oven for a half hour. Remove the bullets from the oven and plunge them into cool water. Allow them to cool thoroughly. When you are ready to lubricate, install a sizing die .001" larger than the one used to initially size them. This will prevent the sides of the bullets from work-softening from contact with the sizing die. Next apply gas checks if required and lubricate. These are now ready for loading.

[parrott1969]

Just finished testing my little toaster oven. I set it for 350 degrees, well it's off by just a tad, actual temp was 450 degrees. It's no wonder they melted. I originally had it set for 450, so the actual temp was in the ball park of 600 degrees. Who would have thunk that a cheap, chinese made toaster oven would have a thermostat that is inaccurate. LOL

[Shuz]

That's exactly why I keep a thermometer in my heat treat oven. I watch it ramp up to 475 deg F. and after the boolits have been in there for 30 to 40 min., out they come and into the water. Once I determined the correct "setting" on the dial of my Chinese toaster oven, to get 475 deg., I now turn the oven off by pulling the plug outta the wall. I don't wanna damage such a high grade temperature control. (hee hee) Or perhaps more accurately, I don't wanna waste time looking for the "sweet spot 475 deg F. temperature"!

[dubber123]

Just finished testing my little toaster oven. I set it for 350 degrees, well it's off by just a tad, actual temp was 450 degrees. It's no wonder they melted. I originally had it set for 450, so the actual temp was in the ball park of 600 degrees. Who would have thunk that a cheap, chinese made toaster oven would have a thermostat that is inaccurate. LOL

He He, I can laugh, because I did the same thing first time out.. :oops: You want to watch the thermometer through several cycles, to make sure it doesn't go too high. Also move the thermometer around to check for hot spots.

It took a bit of figuring to get even my decent quality GE convection oven working right. I ended up putting the tin crumb tray right over the lower elements, and using the center rack on the convection setting. It stays within about 5° that way. Any other settings or placements, forget it. My dial is off by at least 50° also. BTW, 425° for 1 hour gets me 25 Bhn in straight WW's.

[snaggdit]

I remember another post a month or so ago on this same issue. IIRC, the oven ramped up to over the target temp before the thermostat adjusted it back to a steady final temp. I think the poster said he preheated and once the temp had steadied then he put in the boolits.

[AZ-Stew]

This thread (link below) may give you some more insight as to what's going on with your toaster oven. It was a learning experience for me, so I thought I'd pass my learning on to the group.

http://castboolits.gunloads.com/showthread.php?t=42870&highlight=toaster

Regards,

Stew

[mroliver77]

I cover my heating elements to keep direct heat from boolits. I also have a stone pizza sheet on the rack that acts as a heat soak or buffer if you will. Diiferent alloys will melt where another stays hard so you must kep the same alloy or adjust for each.
Jay