can't get mold hot enough.

[Muddydogs]

I just got a Lee 358 105 SWC 6 hole mold and I can't seem to keep the mold hot enough. The mold casts great at about 460 degrees but with the pot turned up to 850 I can't keep the mold over 430 degrees and at this temp the bullets stick a little and a couple get lines and wrinkles in them. I'm figuring that I need to increase the pot temp more but was wondering what is too hot. At 900 degrees pot temp do I have to worry about fumes coming off the lead or loosing needed metals. My other molds all like a pot temp around 750 and even then I have to watch the molds as they tend to get too hot. Just for info I am casting as fast as I can and using a wet rag to cool the sprue quickly so there is very little time between fills.

[ipijohn]

I might suggest that you cast faster to get your mold temp up and preheat it on a hotplate before you start.

[detox]

Stop using the wet rag and sharpen the sprue holes for cleaner cut.

[Muddydogs]

I preheat my mold up to 500 degrees but the temp drops and is back down to under 450 after a few casts. I can't cast faster there is just no way as right now i'm not wasting any movements and going as fast as the sprue and bullet drop will let me.

[ipijohn]

Try slowing down, a couple of seconds longer before you cut the sprue will add more heat to the mold.

[texassako]

Maybe you are dropping the boolits out to fast, takes a few seconds to transfer all the heat to the mold. I cut the sprue when I see it set then wait a few seconds before dropping them out to get the heat into the mold.

[Cane_man]

ladle cast and keep the mold over the top of the pot to keep it warm while you fill

[warf73]

I'm using a RD 100gr 6 cav mold and found that if you keep your pot around 775~800 and do around 3~4 castins a min the mold will hold the temp. I'm casting in the garage that is around 55*.

I turn the pot on and place the mold on top of the pot, once the pot is up to temp I dip the back side of the mold into the melt (nearest you holding the handles) till lead no longer stick, then the same with the front side. Then start casting at 3~4 per min it normaly takes less than 6 or 7 casting and the wrinkles are gone. Once you get rolling at around 25 or 30 castings start turning the pot down to your normal 750* mine is normaly 725*. At that time the mold is keeping the heat well and you can cast till you have half a pot or less your choice then add metal and start over with the proceedure.

The little boolits and big alum blocks are hard to get heated up and keep the heat in but once you get everything nice and heat soaked it will cast like any other 6 cav mold.

Others might have a better way of doing it but this works for me so maybe it will help you? And as for my mold temp I have no clue, I just know what works for that mold.

p.s If you don't back off the heat after 50 casting you start getting frosting over the whole boolit, at 25~30 it starts frosting the bands. Not that frosting is bad just letting you know what I got, read your boolits as they drop they will tell you what is needed.


Warf

[detox]

I watch to see how long it takes sprue to solidify and frost over. With pot melt at 725-750 degrees, it should take about 4-5 seconds for each sprue to air cool. Try not to speed cooling using wet rag or sponge.

Clean your mould cavities free of oil or grease.

I have less rejects using ladle.

Preheat your mould using hot plate or propane torch.

[P.K.]

Bottom pour or Ladle?

[bobthenailer]

Do you have a thermometer to ck pot temp or are you just going by the temp dial setting on the casting pot ? a non contact infa red temp guage doesent work correctly on the surface of molton alloy .

[Case Stuffer]

I use a RCBS Pro Melt bottom pour pot set at 750F . In a 50F shop starting with a room temperature Lee 6cav. mold it takes me 8 or 10 cast (pours) to get the mold up to temperature which yeilds good bootlits and at my normal casting rate after 15 minutes the mold is getting to hot , sprue is taking too long to cool and boolits are starting to frost. At this point I either flow down casting rate or use a small fan to cool the mold or use two molds alternating between them.

[jackmanuk]

I have 1 of these in .44 it takes an age to get hot enough by that time I'm bored with casting and give up for the day . Try holding the bullet in it for a couple of seconds before turning out , try dipping the mould in the lead you no when its hot enough because the lead won't stick to it or keep pouring lead over the outside of the mold to the same effect worked for me

[cbrick]

with the pot turned up to 850 I can't keep the mold over 430 degrees and at this temp the bullets stick a little and a couple get lines and wrinkles in them.

Yikes!


I'm figuring that I need to increase the pot temp more but was wondering what is too hot.

At 900 degrees pot temp do I have to worry about fumes coming off the lead or loosing needed metals.

Double yikes! Ok, here's the deal. If you are using an alloy with tin in it a 750 degree pot (melt temp) is maximum. The hotter the melt the faster the oxidation starting with the tin. Past 750 degrees tin cannot do what it is in the alloy to do and that is reduce the surface tension of the alloy for good mold fill out. The tin will begin oxidizing first and past 750 degrees tin oxidizes very rapidly.

A good casting temp is 100 degrees over liquidus. For an alloy a max pot temp of 700 degrees is plenty hot. You say your mold needs to be 460, that's a bit hot but ok, you are saying that 700 degree alloy temp won't keep the mold 240 degrees less than that . . . Of course it will and easily.

Aluminum looses heat very rapidly, you need to pre-heat the mold on a hot plate and cast at a pace that will keep the mold temp correct. Stop inspecting the boolits between pours, keep the blocks closed and full as much as possible, stop using the wet rag, pour a very generous sprue puddle and wait only long enough for it to freeze. While your admiring your new creations that aluminum mold is cooling fast. Plenty of time to inspect the boolits when finished casting.

You are correct that boolits can stick in a too cool mold.

Rick

[Muddydogs]

Yes I have a thermometer in the pot as well as a mold block thermometer. From what I have noticed this mold acts different then the Lee 6 hole molds that throw bigger slugs. I have 5 Lee 6 hole molds starting at 230 grain 45 and working down to the little 105 grain 38. The 45 and 44 molds both run about the same but then they are close in size, the 165 grain 40 mold likes things a little hotter and the 158 38 mold like hotter still but this little 105 seems to really like things hot. Again I preheat the mold on a hot plate. When I started out with this mold I did my usual which is start the pot at 700 and the mold at 400 then start casting until the bullets come out clean which took the pot up to 850 and I had to put the mold on the hot plate and heat it to 500 as I couldn't increase the temp past 420 ish.

[Muddydogs]

Yikes!
Aluminum looses heat very rapidly, you need to pre-heat the mold on a hot plate and cast at a pace that will keep the mold temp correct. Stop inspecting the boolits between pours, keep the blocks closed and full as much as possible, stop using the wet rag, pour a very generous sprue puddle and wait only long enough for it to freeze. While your admiring your new creations that aluminum mold is cooling fast. Plenty of time to inspect the boolits when finished casting.Rick

When I wait just long enough for the puddle to freeze and open the mold I get little specks of lead on the top of the blocks and sprue plate, now that I have started to use Bullplate lube I noticed that they don't stick to much but they do tend to build up in spots. Do you worry about these specks of lead? I found that the wet rag sets the sprue so the flecks disappear, as soon as the puddle freezes I place the puddle on the rag for just a couple seconds then cut the sprue. No I didn't stop to look at bullets once I realized that the mold wanted to be hot and I had to pick up the pace.

[cbrick]

Look at it as your not pouring alloy . . . Your pouring heat and a 105 grainer isn't much heat even though there are 6 of them.

Higher pot temp isn't the answer. If it works with 40-60 gr 22's it will work with your 105's. Cast faster and I'll mention it again, pour a very large sprue because again your pouring heat and the larger the sprue the more heat.

Trust me . . . It does work. As with anything new there is a learning curve, hang in there and before ya know it you'll be wondering what the problem was.

Rick

[Muddydogs]

Thanks for the tips. I was able to keep my pot at 750 and the mold at 460 by slowing down and letting the mold set longer when full. It was all I could do to keep the mold at this temp as it would start to fall off temp after a couple casts and I would have to let it set full for 30 + seconds about every 3 or so casts to get the temp back up but in an hours time I was able to cast up about 500 or so bullets. The mold sure likes 460, when the temp is dead on 460 all 6 slugs fall out of the mold when I open the block, anything above or below this temp and it takes a couple light taps to get a couple of the bullets out.

Thanks for the help guys.

[runfiverun]

try turning the mold upside down when the sprue freezes, and do your count to opening the sprue plate from that point.

[fecmech]

I cast with the Ranch dog 100 gr .380 bullet in 6 cavity Lee blocks at 675 deg. with WW+2% tin. I start out with setting the mold on top of my RCBS Pro melt at max setting covered with aluminum foil. After about 20-25 minutes pot and mold are up to temp and after about 2-3 cycles of fill and dump the mold I'm casting good bullets. I then turn the pot down to the 675 deg setting and continue casting. If the mold gets too hot and sprus get soft I turn the mold over and touch the spru to a wet rag for about 1 second and then cut and dump. Once I'm down in the 675 range that's not too often. My normal pace is approximately 3 mold cycles per minute.