1 cavity of a 4 cav brass Mp mold sticking

[sfcairborne]

Ok got a new mold, broke it in by heating four times, cast on the 5th was doing great. Then today casting with it had one cavity with the bullet sticking. Had to use a pick to get it out each time. Mold was at temp, bullets looked good, just one sticking. Should I coat it with some pencil lead? Open to suggestions. There is no lead build up in the mold or on its edges.
Mold is brass MP Mold
Thanks

[Minerat]

An HP mould with a pin in that cavity? Maybe you are not getting the pin pushed all the way out. I have this happen once in a while with the new cup pin on the second one from the end away from the hinge. I find if the mould is too hot it happens most, even to the point of having the hp damaged getting it lose. I usually lightly tap the handle hinge till it drops.

Sometimes there is a burr in that cavity so take a q-tip and run it along the edges to see if it has a burr and if so you'll have to fix that.

[sfcairborne]

I’m running the cup pin, so the pin doesn’t go in. I may have had the mold too hot, I checked it for burrs didn’t find any, other three cavs performed great. Lead temp was 700 pulled mold off hot plate once the lube started smoking. The mold is the 359 hammer from MP. Only sticks to one side and you have to use a spoon or pick to get it free. Cleaned it again checked for burrs, none found gonna try again on Monday.

[Minerat]

I just found something interesting, the "C" clips that hold the pins in next to handle does not have good clearance and causes the pins to bind. I took the clips off the pin shafts next to the handle and everything moves like it should allowing the clearance to drop the boolit. Have not tried casing with it yet so we will see if that fixes the problem.

Handles are MP.

[gwpercle]

If no burrs were found with the Q-Tip you might want to try a weird sounding little trick for balky moulds... Liquid Wrench Dry Lubricant (LWDL). #L504 is the 4 oz. liquid in a bottle , #L512 is the spray can .
Liquid Wrench makes about a dozen different dry lubes ... the two noted both work .

Before heating up your mould , give the balky cavity a thin coat of LWDL , I use the liquid applied with a Q-Tip . Let dry ( 30 seconds ) and to insure complete coverage apply another thin coat .
Heat the mould and start casting .
The LWDL is a suspension of micro teflon particles in a alcohol base , the base evaporates and your cavity is micro thin telon coated . The stuff doesn't contaminate cavities and the boolits seem to jump out of the cavities...this little known trick is great for the one balky cavity .
After a while the balky cavity gets nice and broken in , well seasoned and all and you no longer have to do it .
Personally before I put my cool mould away I give all the surfaces a coat, keeps the steel parts from rusting and the next time I want to cast...no cleaning required just heat it up and cast away .

I know this sounds weird...but if you get desperate just try it once .
Gary

[Gamsek]

Pins (shafts) must move freely. if there is any binding back of the pins 1/8 or 1/16 of a turn. See photo.


Pour, cut sprue. Tap tap on a bolt hinge to start open the mould.
Turn the mould and tap tap. Shafts and pins should slide out.

I have the same mould. I preheated it 4times but it start dropping perfect bullets on 4th casting. Some of my MP brass HP moulds worked without any prepping just preheating, 3 out of 15 MP started to produce keepers only after 2-3 casting sessions.

[sfcairborne]

Thanks for the lube truck I will try it on that one cavity. Yes the mold cast great. Just that one cavity sticking.

[gwpercle]

Also , the dry lube works great on both sides of the sprue plate , top and bottom and on the block top ...keeps lead from sticking to these areas. Try It and post your results .
The first time I used it all 4 boolits literally jumped out of the mould on opening . A tap on the hinge was all it took after that .
Don't forget to tap tap the handle hinge pin to begin opening the mould , that helps loosen things up .
Good luck ,
Gary

[sfcairborne]

Thank you I will

[JimB..]

Just FYI, you can buy .6 micron powdered ptfe online. I’ve mixed it with HEET in a Sure Shot sprayer.

[gwpercle]

Just FYI, you can buy .6 micron powdered ptfe online. I’ve mixed it with HEET in a Sure Shot sprayer.

The cost of a 4oz. bottle of Liquid Wrench Dry Lube #L504 at Pep Boys is only $1.50 , are you really saving any money by buying .6 micron powdered ptf, HEET and a sure shot sprayer .

Application of the liquid dry lube with a Q-Tip is so much more efficient .

[Wayne Smith]

The lube mentioned also works well to lube the HP pin shafts.

[JimB..]

The cost of a 4oz. bottle of Liquid Wrench Dry Lube #L504 at Pep Boys is only $1.50 , are you really saving any money by buying .6 micron powdered ptf, HEET and a sure shot sprayer .

Application of the liquid dry lube with a Q-Tip is so much more efficient .

I’m experimenting with it for a bunch of stuff, so it made sense for me, and I already have the sprayers.

[gwpercle]

I’m experimenting with it for a bunch of stuff, so it made sense for me, and I already have the sprayers.

That sounds interesting , keep us abreast of any developments . I've become a fan of dry lube when used with boolit moulds and bet there are other good uses .
I would have never thought to use it in a mould but a fellow member posted his positive results and after trying it I was amazed at how good it worked .
Gary

[Shuz]

Gary, so you use the L504 to lube things instead of the blue stuff in the little bottle that Miha sends?

[gwpercle]

Gary, so you use the L504 to lube things instead of the blue stuff in the little bottle that Miha sends?

I use the LWDL #L504 inside the mould cavities as a mould release agent , in place of smoking the cavities . It doesn't contaminate the cavities and cause wrinkles like the blue liquid mould lube in the little bottle does , which is a synthetic 2-stroke oil .

I later discovered lead would not stick to the sprue plate , top or underside , when coated with LWDL #L504 , so I started using it there also .

I still use the bottle of mould lube on the mould alignment pins , hinge bolt and sprue plate pivot but I have to be careful to not apply too much....it will migrate and start making wrinkled boolits... I have a habit of using too much ... Extremely sparingly is what I have to keep saying .

The beauty of the dry lube is you can coat the cavities , the boolits will practically jump out and the cavities are not contaminated by the stuff ... it's just a thin film of teflon...non-stick !

Doe this make any sense ?
Gary

[Shuz]

Gary,
Sure does! Thanks!

[sfcairborne]

Well finally got pep boys to send me a bottle of rye L504, gonna give it a try and let you know what happens.

[Shuz]

I live in the state of Washington and there isn't any Pep Boy's out here.Does any auto parts store in Washington carry L504?

[AggieEE]

Just a note of caution about PTFE. I don't remember the exact temp, I think we are well below it casting, but overheat PTFE and it gives off some nasty chemicals. If the guys here have been using it for a while it should be OK, but like the tinsel fairy it shows up even when you know how to keep it from happening.