Sticky sprue's

[SkookumJeff]

Howdy all -

Still a newbie getting up to speed. I'm very happy to finally be keeping some of my boolits to load up instead of remelting everything after every casting session. It's been a difficult journey that started last spring LOL. No matter, I'm having a LOT of fun with all this boolit casting business. I started out casting with a Lee 2 cavity mould casting boolits for my 444 Marlin & 44 mag revolvers. The last week or so I have been casting boolits with a new Lee 6 cavity mould for my 35 Rem casting a 190 grain FP tumble lube boolit. This is a custom Lee mould from Ranch Dog and I like it very much. I now understand why people claim the Lee 6 cavity moulds are a much better mould (design) than Lee's 2 cavity mould.

I am having some trouble with it though, the sprues are sticking after being cut and not dropping off the sprue plate. This gets worse as the mould gets hotter. I am ladle casting with a Lyman ladle if that makes any difference. I am pouring with the ladle pour spout smack on the sprue hole, and then rocking the ladle off the sprue hole, overfilling the cavity and letting the excess lead run off the side of the mould.

The only thing I can think is maybe the chamfer for the sprue hole needs to be polished? Does anyone ever polish the sprue hole chamfer? The only time I don't have trouble with the sprue falling off is when first starting out for about the first 4 pour cycles, after that the sprue sticks and I have to pull it off by hand. I lapped the bottom of the sprue plate before starting to use this mould, so the bottom is flat. The sprues seem to be cutting well. I don't know what else to do other than live with it. That's OK I guess but it's a bit of a PIA and complicates getting a good casting rhythm going.

Ohh and by the way, are tumble lube boolits harder to cast well than conventional groove boolits? Sure seems that way...

[geargnasher]

I've never had that problem with the Lee six-bangers, but have on other moulds at times. My fix is to wipe a very, very light film of Bullplate sprue plate lube on both sides of the plate and inside the wells while the plate is hot. I wipe it on with a Q-tip that has about 1/16" of the tip dipped in it, go all over the sprue plate with that same tiny drop, then wipe the plate all over again with a dry Q-tip. Recoat every session for the first several sessions then it should be good to go for a while.

If you don't have any Bullplate (it's currently not available), use some Permatex high-temp disc brake caliper slide grease, or some silicone dielectric grease (both available from any autoparts store, the dielectric is available in small packets like to-go mustard for a dollar or so at the counter and is used to water-proof spark plug boots), apply it to a HOT sprue plate, use VERY little, and wipe off most of it after you get an even coating on there.

I've recut and polished many sprue wells, but mainly to enlarge them. Most of the Lee two-bangers are pretty rough, but usually don't have trouble releasing the sprues. Sounds like you're doing it right, contact-pouring for a bit of head pressure on the cavity, then rolling the ladle back a bit to pour a sprue puddle. Are you linking the sprues? I always drag the stream back to the previous hole to finish the pour, thus linking the just-poured sprue puddle to the previous puddle. The weight of one, long sprue "log" makes it even easier to shuck it off the plate, and no individual "Hershey's kisses" flying everywhere when cutting the sprue. This is all much easier to do IMO with a bottom-pour pot, have you tried doing it that way? It really speeds production and helps keep that big mould up to casting temperature, plus is easy to make big sprue puddles due to unlimited lead supply.

Gear

[Mk42gunner]

I had the same problem with one of my six cavity Lee molds. My solution was to use a piece of soapstone on the sprue plate, (it was close to hand) and it worked okay.

It may not be the best solution, but it worked in my case.

Robert

[SkookumJeff]

Thanks Gear, I'll give the caliper grease a try. I lube the sprue plate hinge pin with alox stick lube (don't have any Bullplate), would that work as well for the sprue well? Also, yes, I was trying to link all the sprues into a sprue log LOL...sometimes I think I have more lead ON the sprue plate than IN the mould...

I'm really considering buying a bottom pour casting pot. I was watching Cowboy T's videos today showing him using the bottom pour pot with a 6 cavity mould and it looked a LOT easier to do than ladle casting. I like traditional tools and techniques, but I think I'm gonna bail on the ladle and get the bottom pour pot. As much as I like reloading and now casting, I still like SHOOTING best of all.

[Down South]

Some of the Lee Sprue plates that I have seen were in need of polishing/cleaning up. Sometimes they are cut rough or rather with grooves in the sprue taper. This can cause the sprue to stick. If your sprue plate resembles what I just described then a good polishing will definitely help. I’ve had to do several polishing jobs to resolve this same problem.

Be careful with lube. To much can cause poor fill out with rounded bases.

[geargnasher]

I would NOT put any kind of boolit lube on the sprue plate, it will burn on there and make a varnished mess, I don't care what the Lee instructions tell you. Also, as it's burning to tar, it will gas-off oil vapor and contaminate your cavities, causing wrinkles, pits, and poor fillout.

Gear

[Sonnypie]

I guess a lot of folks sneer at the old ways, but not me. [smilie=1:
I have two candles. One I use, and the other is a spare.
I smoke my molds, and the sprue plates. It has always worked well for me, even when as a child I was casting soldiers in the garage. Just a bit, and only once in a while. But the lamp black from the flame makes a great release agent.
If my sprue plate starts getting cantankerous, I take the butt of the candle and touch it to the pivot screw to get just a drap of the melted wax on the hinge.
It is amazing how free the sprue plate will swing afterwards.
I also use it on my handles pivot bolt.
But use it very sparingly.

Works great for me.:-D

[Crawdaddy]

What I do when tis happens is use Lee Alox on the spruce plate. Not the bullet lube but the stick stuff. I think it is beeswax mixed with something. It's late and I am drawing a blank.

Works like a charm.

[Sonnypie]

Yeah, I can draw blanks like a charm, too.

[cast405]

My solution to the sticky spru was to get the mold hot cast a boolit, leave it in the cavity, then spray the spru plate top and bottom with moly spray dry lube; it has the benefit of baking on and you never have to lube the mold again.

[Suo Gan]

I'm really considering buying a bottom pour casting pot. I was watching Cowboy T's videos today showing him using the bottom pour pot with a 6 cavity mould and it looked a LOT easier to do than ladle casting.

Then it will be a Star, and a Dillon 650, and a Magma bottom pour, and round and round she goes. Don't quit your day job! Excuses like efficiency, casting for buddies, and the like seem to work on the wife in weak moments!

Anyway, Some Lee molds I have used have had the same problem. You will need to polish out the tooling marks. Take a piece of 440 wet dry and cut it up in inch squares, take a precisely whittled 3/8 inch or so dowel that more or less meets the contour of the chamfer and then chuck it in your drill. Sandwich the sand paper between the dowel and the s plate and start polishing. There is a process used on Lee molds called Leementing check it out too.

[geargnasher]

My solution to the sticky spru was to get the mold hot cast a boolit, leave it in the cavity, then spray the spru plate top and bottom with moly spray dry lube; it has the benefit of baking on and you never have to lube the mold again.

Tell us more! What brand of dry moly lube? I've been looking for something like that for several purposes.

Gear

[williamwaco]

Howdy all -

1) I am having some trouble with it though, the sprues are sticking after being cut and not dropping off the sprue plate. This gets worse as the mould gets hotter.

2) The only thing I can think is maybe the chamfer for the sprue hole needs to be polished? Does anyone ever polish the sprue hole chamfer?

3) The sprues seem to be cutting well. I don't know what else to do other than live with it. .

4) Ohh and by the way, are tumble lube boolits harder to cast well than conventional groove boolits? Sure seems that way...




Jeff,


1) In my experience everything gets sticker when the mold gets hotter. I find that most molds when they begin to get too hot will have one bullet that will begin to stick, then two. When the first bullet begins to stick, slow down until it quits. If it is a heat problem, you may be able to solve the sticy sprue problem by just slowing down.


2) In my opinion ALL Lyman molds need to have the sprue plates polished flat on the bottom. More than polish, they will usually have nicks and burrs on the sprue cuttng surface. I have never seen this with a Lee six cylinder mold. I also occasionally polish the inside of the sprue cutter but I have never done it with a Lee. Their sprue plates are very slick as they come from the factory.

3) You do not have to live with it. It is fixable. Many years ago, we fixed it by pinching a very small tip on a piece of beeswax and touching it lightly to the top of the inside of the chamfer. It is critical to do this with bullets in the cavity and apply the very smallest amount possible and keep it away from the sprue hole. Today, there are much better solutions. See Gearnashers ideas.

I have also used the dry molly spray, mold release, and locktite copper anti-seize. (Apply ONLY when the cavities are full and apply the smallest amount possible. ) They all worked for me. ( I never apply mold release to the cavities. Only to the sprue plate.)

4) I agree.

Tumble bullets are much more difficult to get perfect fill out than conventional bullets. The good news is that it doesn't seem to matter. If the base and front band are full diameter, with slightly smaller driving bands, they will probably shoot fine.

I have measured some Lee molds that have central driving bands slightly smaller than the front and base band even when they are perfectly formed. I have measured others that were the same size. I suspect, since the central driving bands are round on top instead of flat, that they were intended to be smaller.


------------------------

Welcome to the club and don't worry about the frustration, everyone gets it and beating it is a large part of the fun.

[cast405]

GEARGNASHER,
the moly lube is Dow Corning 321 dry film lubricant, long term assembly lube. I love the stuff have never tried it as bullet lube but it does say room temp cure and has a working temp range of -325 to +840 F used it in the mines for parts assembly. Hope this helps.

[leadman]

Look at your prue plate holes and see if the angle comes all the way to the hole. The hole should have no edges to it. I had a couple Lee prue plates and a ton of Lyman plates with this issue.
The cut sprue had a little step from the angle to the bottom of the prue hole, like a small cylinder of lead. don't know if I am describing it well enough for you to understand.
If your prue plate has this problem a countersink drill from the hardware or lumber yard will take care of it.
The polishing trick might also do it if it isn't to large.
A couple pictures of your plate and cut sprues may help in diagnosising the problem.

[geargnasher]

GEARGNASHER,
the moly lube is Dow Corning 321 dry film lubricant, long term assembly lube. I love the stuff have never tried it as bullet lube but it does say room temp cure and has a working temp range of -325 to +840 F used it in the mines for parts assembly. Hope this helps.

THANK YOU, SIR! That's just what I was after. :drinks:

Gear