How do you clean a brass mold ?

[zymguy]

I’ve used a torch and a toothpick , I’ve used a sprue like an eraser. What do you do? https://uploads.tapatalk-cdn.com/20211127/f9ef01dc19e77935015ef3085b493e01.jpg

This mold was scrubbed with a tooth brush and dawn . Then heat cycled in an oven 3 times .
I’m tempted to drop it in a sonic cleaner


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[ranger391xt]

Looks like you have some tinning. Here is an article about one way it can be removed.

https://www.shootandreload.com/2014/07/08/fixing-a-tinned-brass-mold/


There are also several threads on the topic on here. Here is one of them...

https://r.tapatalk.com/shareLink/topic?url=https%3A%2F%2Fcastboolits%2Egunloads%2Ec om%2Fshowthread%2Ephp%3Ft%3D215409&share_tid=215409&share_fid=9688&share_type=t&link_source=app



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[GregLaROCHE]

If you happen to have access to some Mercury, you could soak it. As long as you are not breathing heated vapors from it or eating too much fish that contains it, it’s not dangerous. They used to use it in fillings.

[Mal Paso]

I let the tinning be unless it’s keeping the mold from closing/making larger boolits or pushing the pins off center.

When I do clean, I disassemble the mold, put the pieces on a hot plate and use 6” cotton swabs. The wood end is good for scraping and the cotton end with sprue lube or beeswax to remove semi molten lead. Your mold looks to have enough color that at the right temperature the alloy should wipe off. Amazon basic swabs are good. Had a batch from a major online gun store that broke in the middle, what a pain.

[JonB_in_Glencoe]

My technique is similar to Mal Paso's.
I don't disassemble the mold, I mount one mold block on the handles.
I heat that on a hot plate to casting temp (375º to 400º).
While the block is hot, I melt a tiny bit of beeswax on the 'tinned" spots, then rub with a bamboo skewer.
Now this may take a couple tries, as the mold cools off before I can get all the "tinning" removed.
Once all "tinning" is removed from both blocks, I remove the beeswax residue with MS, then wash with dishsoap, hot water, toothbrush.
Then I will heat cycle the mold 3 times.

[DHDeal]

I use carpenters pencils and/or burlap as soon as I see any hint of tinning while casting.

I would disassemble that mold so you can work on it better. There is little doubt tinning is on the other side of those pins too. You can get Caveman (ish) on the pins without harm as long as you don't use a file.

The times I've had any tinning (not so much any more), I disassemble the mold so it will lay flat on the hot plate and carefully scape the tinning off while the mold half is hot. I will use besswax to help it lift off and use that carpenters pencil as my scraper. If I still have any tinning still there after the above, I have used SharpShooter Lead Remover on the spots. It works, but I don't like to remove the patina I've worked hard on.

No sarcasm intended but the best way to use a brass mold is carefully. I force myself to slow down and pay attention to the mold faces while casting. If I notice any discoloration along the faces, I wipe with some folded burlap or stiff Ramrodz qtips. I never have had any lead or tinning on the pins and I have 10 MP HP Molds. You must have been having a good day when that happened!

A sonic cleaner isn't going to touch that...