New Mold Breakin???

[Krag 1901]

I got a new mold 314299 and want to start casting, just wondered if there is a break in process needed?
I have only used Lee Molds, and some well used Lymans before.

New mold is oily and thought I'd use ligher fluid to clean it first, then smoke it with my Bic, warm it up on the Lee pot and just have at it?

Expect that the first few drops will be wrinkled but should warm up soon with 200 gr boolets?

Anything elese I should do?

[Burnt Fingers]

Iron mold?

Degrease it with brake cleaner, heat it up and see how it casts. I've never had to smoke many iron molds.

[zarrinvz24]

I'd recommend against brake cleaner. I've had best results with white gas (coleman fuel). Let it soak for a day or two, let it dry for a bit and then take it out and heat it up on the hot plate. Once its up to temperature cast it. Iron molds don't need lube so leave it dry. Also, make sure you set the sprue plate tension very light, so that the sprue plate will swing open and closed on its own by tilting the mold. Once everything gets warmed up it will expand and should be easy to manipulate and won't scar the top of the mold blocks.

[Conditor22]

First of all congratulations on your new mold

I suggest getting a hotplate to pre-warm your molds for casting (I set mine to 400° and turn it on when I turn my pot on)

new molds need to be scrubbed well with a nylon brush (aka toothbrush/denture brush) many use dawn dish soap and hot water

Don't forget to lube the sprue plate screw, top of the mold, and bottom of the sprue plate after your first cast [I like to pressure cast my first couple of times with any mold- give better fill when warming the mold more] (cut the sprue and leave the boolits in the mold when you lube the sprue plate screw, top of the mold, and bottom of the sprue plate. work the sprue plate 6-8 times so the lube works its way done when screw and any excess comes out on the top of the mold and bottom of the sprue plate, now wipe off all the excess lube. open the mold (I leave the boolits in just in case you bo-bo lubing the pins/holes and lightly lube the pins/holes with a q-tip.

some people like to heat cycle all their molds (heat to 400, cool completely 3 or four times before casting.

***With steel molds they often have small burs left on the edge of the cavities, this can easily be removed with a piece of wood like the bottom of a carpenter pencil, rub it around the edges of the mold IF the boolit doesn't want to drop out easily

I've used brake cleaner but always clean again with lighter fluid or dawn wish soap. Sometimes I've felt that just dawn didn't get the cavities completely clean and used brake cleaner/acetone/carb cleaner first (maybe dawn professional will work better than standard dawn)

You can also clean the cavities on a hot mold by squirting lighter fluid into the cavities (like ronsonal for zippo lighters) it bubbles and evaporates

[Krag 1901]

Mold lube? Using what? I was thinking about using a carpenters pencil to cover the mold top and sprue plate with grapite, but hadn't thought about lube.

[Conditor22]

I've heard of people using graphite/carpenters pencil and spray but it's hard to lubricate the sprue thing screw without taking the sprue plate off.

I use STIHL High-Performance Ultra synthetic 2 Cycle Engine Oil (gas additive) for my yard tools. 1 jar will last several lifetimes. I keep it in a Steel Needle TIP Plastic Dropper Bottles, so I can put just a micro drop on the sprue plate hinge and not worry about it migrating into the nearest cavity
Don't forget to lube the sprue plate screw, top of the mold, and bottom of the sprue plate after your first cast [I like to pressure cast my first couple of times with any mold- give better fill when warming the mold more] (cut the sprue and leave the boolits in the mold when you lube the sprue plate screw, top of the mold, and bottom of the sprue plate. work the sprue plate 6-8 times so the lube works its way done when screw and any excess comes out on the top of the mold and bottom of the sprue plate, now wipe off all the excess lube. open the mold (I leave the boolits in just in case you bo-bo lubing the pins/holes and lightly lube the pins/holes with a q-tip.

like this https://www.amazon.com/0781-313-8007-Performance-Engine/dp/B005DC0JPQ/ref=sr_1_16?dchild=1&keywords=synthetic+2+cycle+oil&qid=1619539606&s=automotive&sr=1-16

Steel Needle TIP Plastic Dropper Bottles, like this https://www.amazon.com/gp/product/B01IAZUALU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

[sigep1764]

Mold lube? Using what? I was thinking about using a carpenters pencil to cover the mold top and sprue plate with grapite, but hadn't thought about lube.

Get a little bottle of synthetic 2 stroke oil, the kind you mix for weedeaters, blowers, etc. Dip a QTip in it and that is enough to lube the hinge, pins, and pin holes for an afternoon of casting.

[Wilderness]

I live in the Tropics so prefer to oil moulds when they are to be put away where they can't be watched, so I go through this cycle quite a bit. Bringing a new mould on stream should be similar to what I would do for a mould coming back out of retirement.

I remove the sprue plate while I boil up the kettle. Then give the mould a good scrub with degreasing fluid and an old toothbrush, and keep scrubbing while applying the boiling water. Squirt some dishwashing liquid into the cavities, scrub as applying more boiling water, drain, mop with paper towel and allow heat to complete the drying. All of this is done with the blocks in the handles. An additional scrub with methylated spirits (alcohol) somewhere in there is optional

I agree with others about applying a smidgin of synthetic two stroke oil to sprue pivot point, locator pins, top of blocks and both sides of the spue plate BUT wipe off all but the pivot pins so what is left is a really thin film with no chance of migrating to the cavities. You'll know if you've underdone this step once you start casting. Reassemble.

Also agree very strongly with adjusting sprue tension so the plate can almost swing under its own weight - the only need for tension is to keep the plate from swinging open while you pour the bullet. Too much tension will score the mould around the pivot screw, and will lift the plate off the blocks. Check your tension by holding the mould up to the light to see if there's a gap beneath the plate. If there is a gap, the screw is too tight.

The final step is heating the mould, in the first instance to be dead sure there is no water remaining. I put mine in contact with the lead pot as it heaps up, though I see others use a dedicated hot plate.

The last action is contentious, but so far so good. I use an open top pot and dipper. I pour the bullet, and run some metal over the sprue plate, all the while keeping part of the bottom of the mould in the metal. When the lead blob on the bottom of the mould will drop off of its own accord, that's about right. The first bullet(s) will reflect the condition of the mould before it was heated. Dump, cast again and inspect. If bullets are still a bit wrinkly or sprue is setting too fast, mould might need another dip. At this point you might see the blocks smoking slightly. This could be oil you missed, or the two stroke oil you applied earlier. Either way it's a good sign that the mould is ready to go. Leather gloves are handy for wiping any smears of lead still clinging to the dipped portion. Now you should be ready to go.

Needless to say, this mould cleaning should be followed immediately by a casting session to make absolutely sure there is no after rusting.

[GregLaROCHE]

Sometimes it just takes a few casting sessions before you see the real potential of the mold.

[Krag 1901]

Thanks guys.

[38SuperAuto]

All brake cleaners aren't the same chemical makeup. Here's a snip of the Autozone AZP-10CA brake cleaner MSDS. Composition is two solvents, heptane and acetone with CO2 propellent. Some brake cleaners have these two chemicals + naphtha.

Other brake cleaners use the chlorinated solvent tetrachloroethylene AKA dry cleaning fluid.

Knowing all chemicals have risk, I'd rather use a cleaner with heptane and acetone, rather than a chlorinated solvent, such as tetrachloroethylene.

282022

[Krag 1901]

Back in the 70's I worked in an ground radio shop and the gear drives were leaned with triclorethelyene. One lady spilled a batch on her lap and her synthetic pants just evaporated! She took the rest of the day off.

[dimaprok]

You can also get a bottle of 2 stroke synthetic oil for $0.99 in Walmart. I have old rag soaked a little in it and I use it to wipe sprue plate.

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