Do you suffer from sprue plate lead smear?

358156 hp

Well-Known Member
Back to the lead smears on the sprue plate, I made an interesting observation last night whilst casting 9mm in a four cavity Lyman mould. I check the bottom of the sprue plate from time to time and noticed that while the first two cavities showed no lead smears, the third cavity showed very slight smearing, and the fourth cavity light to moderate smearing. I immediately slowed my pace a bit more since I'm obviously not letting the third & fourth cavities freeze completely. Another five or so seconds seemed to fix everything. I'm not certain why I'm mentioning it except that its another factor that's all in the timing. I was cutting my timing just a few seconds too close. The fourth cavity is also right by the sprue plate swivel bolt, and that likely added just a tiny bit more residual heat for that last cavity as well.

I gotta get a life!
 
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Ian

Well-Known Member
Sometimes alternating which end you begin the pour sequence cand help even out the heat when pushing the timing really close.

Sounds like a fine life to me, if you think bullet casting is trivial and nerdy you should hang out with some machinists sometime. Entire forums related to coding tricks and hour+ videos on the mere introduction to hand-scraping precision machine surfaces.
 

358156 hp

Well-Known Member
Well, I do feel a little better. I've spent a life where the details of every action and transaction have been terribly crucial, and I can't break my basic analytical (anal-ytical?) instincts at this late point. I do suppose it could be worse, I could have taken up golf instead :sigh:
 

RBHarter

West Central AR
Rules , rules , rules drove my work for 22 yr and I look at stuff every day and think " oh that's not ok " . But those rules kept us from being ID'd by toe cap DNA . Before that it was spec , spec . It's hard to go from .018-.022 to 1/4" is close enough .

As far as hot/cold sprue goes I tend to get cold on the hinge end but if I try to chase it I end up cold on the swing end . Mostly aluminium moulds though but even the 8C H&G does it . I just pour something along the lines of 3-5 toward , 2 away from me . Seems to keep both ends hot that way . Subtle changes like sprue puddle .
 

358156 hp

Well-Known Member
At one time I was casting back to front on 4 cavity moulds because the last cavity always had issues with fillout. As I progressed and learned how to preheat moulds and better regulate mould temps during longer casting sessions, the cold fourth cavity issue went away and I forgot all about it. I think preheating sprue plates probably did that particular issue in, but I neglected to keep an eye out for other potential issues.

Complacency...
 

Walks

Active Member
I cast very fast from 3-4 molds at a time. And I use a Sprue Plate Lube.
750degree alloy. Never have a lead smear. Cast beautiful bullets every time, no lead smears. Unless I screw up in some way.
 

Ian

Well-Known Member
Harter, I hear you on tolerances, it was tough for me to concede that half a saw blade is close enough for framing walls.
 

JonB

Central Minnesota
half a saw blade
Is that a 7.25" or 10" or 12" ...LOL :p

Tolerances:
Before I retired, I built/wired industrial control panels (for about 20 years).
We ran the wire in plastic wire ducts.
Most of my co-workers cut it with a saw, and 'fit' it like stone blocks on a Egyptian Pyramid.
BUT, I score it and break it like sheetrock, saves time looking for a saw. But it only breaks at a gap in the teeth. The saw guys will cut right through a tooth, if thats what it takes to make a perfect fit. My technique can leave a gap up to 1/2"...but no one sees the gaps or the lack there of.
I had a lot of time saving tricks that would drive a engineer crazy, but I always made the Big Boss happy when I finished a panel in half the time as the others, and he's the one that would give the pay raises ;)
 

GRMPS

Active Member
Every time I use a mold after I cut the sprue on the first cast I put a thin coat of synthetic 2 stroke additive under the sprue plate, on top of the mold and touch the alignment pins with the almost dry Q-tip. then I wipe it off leaving a thin film. I also use a needle tip bottle with the same solution and put a very tiny drop on the sprue pin, This helps prevent galling under the sprue plate and keeps the screw from working out so fast due to lack of friction.
 

GRMPS

Active Member
Wally how hot is the alloy your using? I cast between 680 -- 720 degrees using a PID, only time I go hotter is when casting pure lead. IF I can't get good fill out with a preheated mold (pre-warmed to 400 -450° on a hotplate) I toss in 1/2 oz pewter (tin)
what was your sponge damp with?
 

Wallyl

Member
I don't have a thermometer to know...I do tend to use my Lee Production pot with the dial set in teh middle. I use water to dampen the sponge.