Tining on brass mold removal ? How?

[Teddy (punchie)]

Just a simple question. I know not simple answer.

Have a brass mold was told, no instructed is a better way to put it. To run it hot very hot. Now I have a mold that is holding on to everything.

Any ideas on how to clean it. remove the soldered on lead alloy, tinning?

After cleaning will MIG (welding) nozzle dip work to keep things from sticking to it?

Thanks !!

Teddy

[375RUGER]

get it hot and brush it with a brass brush. Needs to be hot enough to at least turn the lead to mush so it will release.
.
Then do this.....
http://castboolits.gunloads.com/showthread.php?173350-Seasoning-a-Brass-Mold
.
seasoning (patina some call it) helps a lot. I think there are at least 2 methods described in that thread.

[Teddy (punchie)]

Thanks for reply , I have read that posting, going to retread it tonight.

Then may use graphite powder and spur lube to coat the mold. Take up to temp and cool and recoat and heat again.

Planing on to coat with just a little spur lube and brush on graphite.



get it hot and brush it with a brass brush. Needs to be hot enough to at least turn the lead to mush so it will release.
.
Then do this.....
http://castboolits.gunloads.com/showthread.php?173350-Seasoning-a-Brass-Mold
.
seasoning (patina some call it) helps a lot. I think there are at least 2 methods described in that thread.

[PbHurler]

Here's a link to a "Sticky" on just this subject:

http://castboolits.gunloads.com/showthread.php?213156-Lead-Adhearing-to-Mould

[gray wolf]

I would not coat it with anything, after a few heat cycles it will darken ( patina )
The patina act somewhat like an anti flux. they do need a little more heat but don't over do it, try picking up the casting speed,---AND STOP LOOKING AT THE BULLETS just cast, look latter.

[dbarnhart]

I will quote the great and wise Gearnasher:


It is accumulated oxides of mostly tin, it starts a 'seed' in a shiny spot and just builds and builds a few molecules at a time from the flash-oxidized molten surface of the metal you pour into the cavities. It's the same sort of stubborn crud that clings to the sides of a casting furnace as the alloy level drops. A reducant like beeswax or paraffin quickly takes care of it once you get the mould up to the melt point of the elemental metal.

Being an oxide, and beeswax being a reducant as JonBinGlencoe pointed out above, you can heat the mould to the point that the tin would start to melt if it weren't oxidized, apply the wax to instantly reduce the oxides to elemental, liquid metal, and wipe them away.

The melting point of tin is 450F. I carefully heat the mold on a hotplate and use a digital laser thermometer. Dab the spot with some beeswax and them pop it off with a bamboo skewer. Works every time.

BTW, Gear, let me take this opportunity to express my appreciation for this tip. WIthout it I would have discarded a perfectly good mold.

[remy3424]

Bees wax. I get some of the tinning on the bands of mine. I remove the handles and place the halves on a hot plate, medium/high heat, using a small wooden dowel dab with bees wax on the silver area and then keep rubbing. For the lead leeching out onto the mold faces, I also dab with bees wax and then do more of a scraping with the wooden dowel or pointed skewer. I am trying to blend more soft lead into my CWWs to reduce this "tinning".

[357maximum]

Brand new brass mould + very little simple cheap cold blueing and a Q-tip will prevent all of this...sure it "colors" the mould a bit but boy does it ever work. Call it instant oxide if you want,....... it works. I do the cavities and the working surfaces of the mould. One heat cycle and the mould is ready to "run", and from then on you can treat the mould like a steel mould as far as normal sprue plate lubing and such.

[Old School Big Bore]

I hadn't thought of cold blue, thanks.

[357maximum]

When you wanna find an esier way to do something.....get a lazy man to do it. :lol:

[Beagle333]

Cold blue! And I spent all that time baking and cooling and baking and cooling for nothing! AAiiigghh!!! :veryconfu

[Teddy (punchie)]

Thanks for all of the replies and ideas.

Here is what I did last Sunday.

Heated mold very hot on gas stove. Got a fine cheap brass brush and brushed all the tinning off only thing left was some discoloring on top between the mold top and spur plate.

Took hot mold and heated again and coated with olive oil. Like I was seasoning a cast iron skillet. Using a Q-tip and redoing until mold was smoking hot and turning brown. Oil was burning off (smoking off) . Let cool and reheated slowly and turn alloy up as I went checking mold and castings. After about 300 casting 4c mold a about an hour with not one good casting (not filling out, wrinkled ) , I found the sweet spot of temp. Was just about as hot as I had it before. Take about 8-10 count for lead to set. Counted 2-3 more for lead to harden just enough as to not have melted lead between spur plate and mold top. Upon shearing by hand and a shake to upon opening the casting just fell out, if I needed to hit the mold it was only a small tap or two. Any tinning at this point I just would brass brush off. Yes by the way cheap little brush and fine bristled brush with wooden handle, that I used to rub off any very hard spots.

After the next 10 minutes of casting had about 130-150 frosted casting that looked okay. After cooling and the magnifying glass I had about 90-100 good useable casting. That being said, I'm picky and looking for any cracks and or fine detail that are not right. If I was going to just shot them up most could be used as seconds and shot.

So tonight or tomorrow I, try again a see if I have it seasoned enough. Sure looks like it is all browned up.