Do you artificially patina your brass molds?

[justindad]

I don’t want to clean my mold anymore than necessary, and I’m thinking that an artificial patina will at the very least prevent the need to “clean” off any tinned alloy oxides.
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Can molds be easily damaged by someone who knows just enough to be dangerous (me)? Is this something that was tried and not really practiced anymore?
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Post 49 here is what I’m considering:
https://castboolits.gunloads.com/sho...ghlight=patina
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Post 53 looks reasonable too:
https://castboolits.gunloads.com/sho...a-Recipe/page3

[Nobade]

I use Moose Juice or smoke on mine, and cast bullets with them. Never had any problems with tinning.

[GregLaROCHE]

Sorry, but I can’t vote about brass, because I don’t have one, but I never do anything except start casting with steel and aluminum.

[Minerat]

I just let mine get a natural pantina. I cleaned each mould did 4 heat cool cycles and started casting. Sticking is not a big problem, similar to steel or aluminum moulds. It's a hobby for me not a production line so I don't sweat speed and a little sticking or bad fill out for a short time each session teaches me patience.

I do not smoke or add anything to cavity surface in the molds I own but I use lube on the cutter.

I follow the breaking suggestions from Mehi or NOE for their brass molds and that works.

[justindad]

...each session teaches me patience.

Auto repair teaches me anger management

[Mk42gunner]

I only have one brass mold, one of the tiny ones that make a ~.58 Minie ball. It has been years since I used it and I don't remember doing anything to it before casting, I may have, I just don't remember.

With that said, I believe you need to at least heat cycle a brass mold before using because a clean piece of brass is way to easy to solder together. Any plumber or jeweler will tell you clean brass or copper is easy to get solder to stick to, and what is basic solder? lead and tin.

An easy way to add patina to brass is to use the water and cleaning patches from cleaning a black powder gun. Sulfur residue will blacken brass right now, there will be no question if you missed a spot or not.

Robert

[M-Tecs]

I do the normal new mold cleaning and three heat cycles then I cast.

[justindad]

I do the normal new mold cleaning and three heat cycles then I cast.

That’s what I did. I may not have heated enough, only going up to 350F.

[bangerjim]

I aged all my many brass molds (1st time only, 3X to ~470F) as directed by the makers B4 ever casting. Never any sticking problems once the patina oxide layer is built up.

Why do you think solder uses a flux to "tin" wires or sheet metal when soldering? To eliminate the oxide patina formed on the copper wire or plating sheet metal so the solder will flow and stick. If you do not get anything in your brass molds that will "tin" the surfaces, Pb should never stick!

Mine doesn't.

And you are after that rich "golden" hue, not the new bright brass hue the come with, as the patina........NOT BLACK! Or brown. Or any other color than golden.

banger

[USSR]

Guys,

"heat cycles" so as to create a "patina" prior to casting is what he's polling about.

Don

[justindad]

Are there any cleaning processes that people have used, and accidentally removed patina? Seems like patina should not be removed.

[M-Tecs]

Guys,

"heat cycles" so as to create a "patina" prior to casting is what he's polling about.

Don

No the OP specifically pointed out chemical processes.

I don’t want to clean my mold anymore than necessary, and I’m thinking that an artificial patina will at the very least prevent the need to “clean” off any tinned alloy oxides.
*
Can molds be easily damaged by someone who knows just enough to be dangerous (me)? Is this something that was tried and not really practiced anymore?
*
Post 49 here is what I’m considering:
https://castboolits.gunloads.com/sho...ghlight=patina
*
Post 53 looks reasonable too:
https://castboolits.gunloads.com/sho...a-Recipe/page3

I think brass molds run a lot cleaner if the brass is oxidizI have some MP 503 clones in rotation and as they "tinned" and boolits started to hang I cleaned them and tried a new patina. The last one was a suggested by a member and it's the best yet.

Cleaning: MP molds are works of art and my goal was no dimensional change (including scratches from cleaning). I've had no warping from heating the mold halves, stripped of hardware, cavities up on a 3/16 steel plate sitting on a gas range burner. I have a HF Infrared thermometer and I don't let them go over 650F. At that temp most lead wipes off with a half drop of Sprue Lube on a long Q-tip. Beeswax and Popsicle sticks will get most of the tough spots. When it's down to molecules, after cooling slowly, I put the mold halves in a bath, 1 part Hydrogen Peroxide to 2 parts Vinegar for 15 minutes, clean, soak again. Seems to me I used M Pro 7 to get some black deposits off. That's to get a mold back to a pristine state.

I worked out the following out on one of my first 503s and was impressed so when HP mold arrived I only did one double check of my early work.

I stripped the mold of removable hardware and cleaned the mold halves with warm water, Dawn, and a tooth brush to remove oil. I rinsed in Reverse Osmosis Water because I could. The mold then went cavities up in a bath of 1 part Hydrogen Peroxide to 2 parts Vinegar at room temperature for 30 minutes. Washed in water (RO) and dried. I applied Birchwood Casy Brass Black with a 6" Q-tip to the mold cavities, top and block face. You can't put the swabs back into the bottle after they touch brass so I'd put in 6 in at a time and throw each away after use. It takes about 5 to cover each block. Rinse, dry, and repeat. Brass is Really Hard to Patina. Just keep putting Brass Black on the bright spots until it evens out. Took me about 8 applications until it looked like an old, polished, statue.

Birchwood Casy is big in metal finishes not just guns any they say no dimensional change.

I cast almost 600 last night, lead doesn't stick. I raised my casting temp to 675F and slowed down a bit, left the mold open longer for more temperature difference between alloy and mold. Cleanest run ever. The new HP MP 503 clone is awesome.

For me it looks like problem solved. For those who never had a problem with brass molds: Nevermind (GR)

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[Chill Wills]

I have been using brass molds for many decades. I only recently hear there is a problem with tinning brass molds when new. Who knew? I guess it goes with out saying I never did a heat cycle on one. They cast fine from the start for me.

But then, being a contrarian, I get good results doing things the non-conventional way.

Carry on.

[justindad]

I have been using brass molds for many decades. I only recently hear there is a problem with tinning brass molds when new. Who knew? I guess it goes with out saying I never did a heat cycle on one. They cast fine from the start for me.

But then, being a contrarian, I get good results doing things the non-conventional way.

Carry on.

If you’re not a contrarian, do you really cast boolits?

[rintinglen]

I've a dozen or so, mostly MP (thank you Miha) but also a couple of NOE and Accurate. I've never used any artificial means of creating a patina.

[tomme boy]

Liver of sulfer is what you are supposed to use to patina brass

[JSnover]

If you’re not a contrarian, do you really cast boolits?

He melts bullets, casts them into ingots, melts them again, pours them into wheel weight molds, adds a little mud and grease and sells them to scrappers.

Back OT, I've never intentionally or artificially patina'd a mold. I have brass, steel and aluminum and after cleaning/deburring (lapping if needed) I just let the heat and oxides do their thing.

[bangerjim]

Liver of sulfer is what you are supposed to use to patina brass

When one kills a "SULFER" in the wild, what part of the body is the liver in, and how do you extract the needed compound? HA.....ha!

Actually "liver of sulfur" is a poorly defined mixture of potassium sulfide, potassium polysulfide, potassium thiosulfate, and likely potassium bisulfide. And I would never put it on my nice clean brass molds. Natural heating (3X) takes care of any patina you will ever need.

[longbow]

I have 3 brass moulds and have not done anything but clean then and pre-heat before casting. I have no issues with tinning or build up on them.

Having said that I normally cast using range scrap or ACWW and seldom add tin (solder). Mal Paso started a thread some years ago about problems with tinning on brass moulds and apparently it is actually tin oxides that start to build up. Once "seeded" they tend to grow and grow again =even after cleaning unless a patina is formed.

My process is to wipe down the mould with a paper towel or rag. I seldom use solvent or break cleaner and have never used dishwashing soap. I do pre-heat until the sprue plate lube starts to smoke... just. That is actually a bit hot. Then I start casting. Never had a problem doing it this way with any mould of any material and those being steel, mehanite (iron), aluminum, brass, bronze, stainless steel.

If you cast hot in a sparkly clean brass mould and have tin added to the alloy I can see the potential for tin/tin oxide build up starting. After a bit of use the brass will get an oxide layer on it (patina) and that should be the end of the issue.

Personally I would use a mould release like graphite or possibly smoke the mould in preference to artificial patina. After a few casting sessions the mould shouldn't require any further treatment.

If you want to put an artificial patina on the mould be careful the chemicals aren't to aggressive. You might want to read through this thread"

https://castboolits.gunloads.com/sho...na-amp-Smoking

YMMV

Longbow

[Mal Paso]

I put a lot of work into Patina at one time. I was having what I think now were tin oxides building up on the grooves next to the mold block face. The mold was the #503 with particularly deep grooves and I used to keep several in rotation so as to have a clean one ready. I switched to a 6 cavity Aluminum for that boolit.

MP brass is tarnish resistant. I've tried Liver of Sulfur, Birchwood Casey Brass Black, Peroxide, and a bunch of formulas. If you really want a good Patina, start with Bronze.

That said, brass molds run cleaner with oxidized surfaces so I still heat cycle new brass molds with the block faces open.

I suspect the guys that have zero problems with brass molds run them cooler and produce more shiny boolits. I like sharp corners and don't mind frost and I'm sure that's what gets me into trouble with brass.

I keep buying brass molds though. I try to stick to ones with shallow grooves but with the perfection of MP Hollowpoint Molds I can put up with brass.