Mold release agent?

[Sothoth]

Ok I see tons of conflicting info on whether a release agent is necessary or not, and several thing suggesting they're bad for the mold and cast quality. I'm hoping someone can help clear this up for me. It seems to me that aluminum molds shouldn't need it, that the expansion/contraction of metals is pretty different between Al and lead so the lead should not stick to a clean mold. I also find it hard to believe that not using a release agent is bad for the mold since the melting temp for Al is much higher than lead.

I have also seen some reports of using lube on the moving components, which makes perfect sense, provided it doesn't get into the mold itself.

Am I off on any of this?

Thanks in advance!

[Artful]

Different molds seem to have different needs, I have a few that require a release helper - whether it be smoked or coated with an agent.
Before going to that I first look for any burrs or other machining abnormalities that need to be taken care of.

[Gtek]

One thing I have done in past chasing a sticky mold. After you cut sprue before dump attempt, take pick or something and put a line on one side in base of boolit for orientation for inspection. Get a 10X or so and inspect parting lines and lube grooves for abnormalities. Take a sharp blade and drag 90% on boolit parting line very lightly and see if you have any voids indicating a rolled edge of cavity. I will say I do not use or own aluminum molds but does not matter in the end, but aluminum is soft which means they hurt easier. You need to figure out what THAT mold wants and you cannot get there with out getting your fingers hot. Lubing of moving parts seems to work out as what works for you with many ways to get there. With four post welcome aboard, fantastic group with centuries of experience to get you down the road. Gtek

[montana_charlie]

I have also seen some reports of using lube on the moving components, which makes perfect sense, provided it doesn't get into the mold itself.
Using a lubricant (one which will withstand the heat) on pivoting parts makes good sense as long as it is 'lubricant' ... not 'bullet lube'.
Those are different things entirely, with decidedly different functions.

CM

[btroj]

I use an appropriate lube on pins and sprue plate of moulds. I don't put anything in the cavities except lead

[Sothoth]

Ok so why not use a release agent all the time?

[btroj]

Makes bullets smaller in many cases. Clogs up vent lines. Isn't needed.

More important, why use one at all? A properly cleaned and set up mould just doesn't need it.

[high standard 40]

I agree with btroj. I have a couple dozen molds in calibers from .224" to .500"........both in aluminum and iron......and I have not found a need for release agent in any of them.

[Old Caster]

Using a release agent is just using something to clear up a problem while causing other problems. Some molds have the holes off center which make bullets hang up when trying to free them. Using a release agent might make them fall out easier but it then does as btroj said, clogged vent lines and smaller bullets.

[Sothoth]

Ok this is exactly the info and feedback I wanted. Much appreciated!!