Wrinkled bullets

[faraim]

I finally got a chance to cast using my new MP aluminum mould and ended with wrinkled bullets. I've tried different lead temperatures, heated the mould, cooled the mould, cleaned it twice with brake cleaner, even alternated between dipping and bottom pour. Finally, I switched to my old Saeco mould and got perfect bullets. The ones on the left are from the MP mould, the ones on the right are from the Saeco mould. I'm beginning to believe I'm not smart enough to cast with an aluminum mould. Any ideas would be appreciated.

[Walks]

When this happened to me. This is what I tried.
Heat mold on hotplate; put on FULL FACE shield and welding gloves. Put closed mold on wood bench far away from any source of heat or flame. Stick tip of little plastic tube close to sprue hole, lean WAY back and squeeze for a long time.

Works for me. Cleans up and cast Beautiful Bullets.

But try at your own risk.

[FLINTNFIRE]

Scrub it out , use lighter fluid or just hot water and soap , heat it dry , then pre heat on a hot plate up to temp. and cast start out dropping bullets to the side as rejects and watch for wrinkles to stop when they do which should be quick after cleaning and pre heating you are good to go .

[44Blam]

Your mold/melt is not hot enough.
Cast a bunch of boolits in a row fast to heat up the mold and once they start dropping consistently, start keeping them.

[Sasquatch-1]

When I have this problem and it persist, I open the mold and stick it in the melted lead till it get very hot to burn out any oils or wax. I then put over the loaf pan I use to catch sprues and give it a few good taps on the hinge bolt to knock off any clinging lead. I then pour a couple bullets that I will discard and then let the mold cool a bit. I have been doing this for years with Lee molds and have not had any problems with the molds.

Also, this usually happens to me when I lube the sprue hinge bolt with wax and it infiltrates into the cavity.

If it continues you may want to add some tin to help fill out.

[Tatume]

Could be oil in the new mold; could be the mold isn't hot enough; could be the alloy isn't hot enough; could be you're casting too slow. Scrub the mold well with a toothbrush and dish washing detergent, rinse well, dry it in a warm oven. Then take it to your shop, preheat it well on the edge of your melting pot, and start pouring bullets. Turn up the heat in the pot, you can always turn it down later. When you start getting good fill-out and frosty bullets, turn it down a tad and keep making bullets. The perfect combination of mold temperature, pot temperature, and casting cadence will result in slightly frosted bullets and complete fill-out, with no voids. Enjoy.

[gwpercle]

When this happened to me. This is what I tried.
Heat mold on hotplate; put on FULL FACE shield and welding gloves. Put closed mold on wood bench far away from any source of heat or flame. Stick tip of little plastic tube close to sprue hole, lean WAY back and squeeze for a long time.

Works for me. Cleans up and cast Beautiful Bullets.

But try at your own risk.

What is in the little plastic tube that you squeeze for a "long time " ... not understanding this process .
Gary

[gwpercle]

Clean mould and "Heat Cycle" the mould ...three times .
Acetone is best oil remover . During machining cutting oils are forced deep into the aluminum pores ... heat brings some oil out ... cleaning and heating three times will get the oils out and help season the mould . Casting a few boolits while heat cycling also helps with mould break in .
Aluminum moulds are a bit different than steel . Once all the oils are driven out and the cavities seasoned it will cast just fine ...but you have to do the mould prep first .
I like to soak blocks in acetone to help pull out the oils .
Gary

[oley55]

the wrinkled bullets just look way too shiny to me, which normally indicates mold is not up to temp yet.

[reloader28]

the wrinkled bullets just look way too shiny to me, which normally indicates mold is not up to temp yet.

Agreed. You need to crank up the heat some more

[JonB_in_Glencoe]

Need more heat.

BUT...sometimes new molds need to have a few casting sessions before they start performing in a excellent way.
Keep trying.

[Thumbcocker]

Cold mold.

[JoeJames]

Need more heat.

BUT...sometimes new molds need to have a few casting sessions before they start performing in a excellent way.
Keep trying.

I don't have near as much experience as y'all do, but with a new Lee aluminum mold I have found that it just takes more than one casting session to throw good boolits. In a way kind of like seasoning a good cast iron frying pan.

[Martin Luber]

All good advice above. I would add advice to pressure cast with a bottom pour pot.

Put the mould firmly in contact with the spout, fill, and pull away with lead still running. This prevents spout freeze. Good luck

[Multra]

Spray the mold down with some brake cleaner, get the mold hotter, and if that fails try adding a bit of tin to the melt.

[white eagle]

after you use the mold a few times that will go away
just use it without doing any scrubbing with anything
the mold needs to be used

[Minerat]

For MP brass mould I start at 750°, use a hot plate to preheat and cast fast till the boolits frost then back off till they have a very light frosting. From then in it throws good boolits. You should also heat cycle 3 to 4 times to get a patina going.

[country gent]

What is the alloy your using? What temp? Method pouring?
It may also be results of a to slow pour filling the mould. alloy solidifying before filled. Here more heat or a larger stream from pot.
Cleaning vent lines with a fine soft tool like bamboo skewer stick or small dowel sharpened in a pencil sharpener may help. you want a fine point to get down in to the bottom
New moulds sometimes require a break in of several sessions. heat cycling my help by burning out the cutting fluids from the pores in the metal

[Conditor22]

Looks like residue in the cavities

If you didn't do it this "heat cycle 3 to 4 times to get a patina going." (clean mold well then heat mold to 400° then let cool completely 3 to 4 times)

I've found that when I clean a mold it works best to use first a solvent, acetone (preferred) brake cleaner, carb cleaner --- THEN dawn dish soap scrubbing with a nylon brush (I've found that a denture brush from the dollar tree works best for getting into cavities.

Pre-heat the mold on a hotplate set to 400° (put a piece of metal [like a sawblade] on it {I use 3/8 steel plate} and cut an opening in an inverted coffee can so the mold just fit into it and it works like an oven.

I usually cast at 720° (lower for harder alloy hotter for pure)

I use a needle tiped dropper bottle to aply only a very small drop of synthetic 2 cycle fuel additive (oil) on the sprue hing ONLY after I fill the mold and cut the sprue leaving the boolits in the mold
I wil dampen a q-tip and wipe the top of the mold and the bottom of the sprueplate then work the sprue plate back and for 10 - 20 times to let the drop of oil work it's way down then I get a paper towel and wipe the top of the mold and bottom of sprue plate dry.

I useually pressure pour (hold the sprue plate to the spout) on my first 2 or 3 pours

IF all this fails lightly smoke the cavities with either a butane lighter or kitchen match.

[Soundguy]

Your mold/melt is not hot enough.
Cast a bunch of boolits in a row fast to heat up the mold and once they start dropping consistently, start keeping them.

agreed... heat the mold.. heat the melt. might try adding tin if there is none.. but it's usually a temp issue.