Do you suffer from sprue plate lead smear?

358156 hp

At large, whereabouts unknown.
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

Notorious 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

At large, whereabouts unknown.
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

At large, whereabouts unknown.
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

Well-Known 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

Notorious 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

Halcyon member
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

Active 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.
 

Walks

Well-Known Member
Wake this thread up .

I was just on the N.O.E. website. They have TEFLON - COATED Sprue Plates now.

But what does this mean to my method of polishing my sprue plates with 320, 400 & 600 grit.
I think that may be why I don't have lead smears.
That and like GRMPS, I add sprue plate lube after the 1st cast.
 

L Ross

Well-Known Member
Walks...what kind of sprue plate lube do you use?
I'll be interested to hear from Walks also. I use several two stroke tools, chainsaws, ice augers, pole saws, string trimmers and more. I use Stihl Synthetic two stroke oil in my mix. I used to rinse the plastic bottle with gasoline and dump it into the tank, frugality after all. Now I just save those little bottles with the drainage in them. Just what clings inside the bottle is enough for dozens of casting sessions. I dampen a Q-Tip and wipe the face of the blocks when hot and I lube the pins and matching sockets a couple of times per casting bout.
 

popper

Well-Known Member
Not any more. Made a rig (posted here about it, can't find for reference) so I can cut an absolutely cold sprue without hitting the plate and changed to the graphite pencil rubbed on the plate. If I get a slight 'dusting' of lead from the sprue hole, pencil removes it. Tried the A/C oil, buildup (pins) is impossible to remove. Good 2 stroke oil on the sprue bolt and handle. Might try to make my own 'lock-ease', powdered graphite and alcohol for the sprue bolt.
 

Wallyl

Active Member
I have used candle wax as a "bull plate" lube.....you touch the edge of the mold block, at the edge that the sprue pate makes first contact, with a candle lightly. I do this when there are bullets still in the cavities, tipping the mold slightly downwards. This works well but after so many casts you must do it again. The trick is using a small amount of wax. It will be slightly smoky when first applied. It will not build up nor get in the bullet cavities.
 

CZ93X62

Official forum enigma
Bill Lose, Rick Tunell, and I looked on once when Bruce Bannister did one of his "production casting" sessions at his home just outside Winnemucca. We had been "snowed out" from a trip north on U.S. 95 to varmint-hunt, which should be instructive to onlookers as to prevailing conditions that make such a speed-casting method viable. Not a thing for warm weather or an indolent nature (like my own) when pouring bullets. He used a wetted orange shop towel, IIRC, as a heat sink to enable the accelerated pace, touching both mould base and sprue plate extension as needed--which was most casts. Using a Lyman 4-cavity 44 caliber mould, he could make a PILE OF BULLETS in one short hurry. That wet towel sizzled!

Bruce B was a fine man and a great friend. I learned a great deal from him, both what TO DO and NOT DO. It is very likely that Bruce's lessons have enabled me to remain alive and active today. I miss him greatly.

I have used synthetic 2-stroke oil a bit on block tops and sprue pivots to prevent galling. To prevent sprue metal "wiping", I wait until the sprue puddle "freezes", give it a 3-second delay, and cut the sprue with a leather-gloved hand. I seldom have to resort to the rawhide mallet to cut sprues.
 
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