remove surface rust

[adam38654]

I have on old vintage (70s?) Lyman 252435 .25acp/auto double cavity mould with some very light surface rust inside of the cavities. I was wondering if i could use some Birchwood/Caseys rust&blue remover on a q-tip to wipe away the surface rust.
I also considered some ultra fine steel wool and wd40 but i don't think i could get to all the ridges in such small cavities.

I was also wondering if polishing or fine particle blasting the cavities would help them fill out?

I hope this mould isn't toast because no one makes any 25auto moulds right now except a $100 custom one.

[No_1]

Have you tried casting with it? Very light surface rust may just work its way out.

R.

[mooman76]

Someone here advised me to try a pencil. A carpenters pencil works best. Just go over the mould on the enside with the lead and it will remove light surface rust. It even gets the little corners and you don't have to worry about getting oil in your mould.

[beagle]

I normally use a pencil and it comes right out./beagle

[adam38654]

Thanks guys. Can you cast with the pencil soot still on it?

I haven't tried to cast with it yet because i would like to prep it first like clean , lube,and smoke it. Aren't you supposed to use some sort of bullet lube or something at the pivots,pins, and under the sprew plate or is that just aluminum blocks?

I was afraid using the chemical rust remover would remove more rust than i thought and leave pitting or even etch the metal causing it to form air pockets.
I don't think these tiny bullets will have a problem filling out but i could be wrong.

[Heavy lead]

Adam, I don't use any lube on my iron moulds, and only very sparingly on my aluminum moulds. I would not use any rust remover as it will remove the blueing on the mould cavities. I would and have used Hoppe's number 9 and a bronze brush (a small welders brush) works well (I actually used a stainless one time without mould damage, but do not recommend that). Then wash it with hot to boiling water and brush (tooth brush) the cavities out with comet or something like that, then dawn to totally degrease it, then dry and start casting. That's my advise, but don't use the chemical rust remover, that could damage it beyond repair.
Good Luck.

[adam38654]

Polish cavities with a #2 pencil
Scrub w/ Hoppes#9 bore solvent and bronze brush
boil
Scrub w/ commet and toothbrush
boil
Scrub w/ dawn dish soap and toothbrush
boil
place in oven to dry at 100-200f for 15-30min
I will probably wax lube the the pins and under the sprew the first time for old times sake and if it wont fill out i will try to smoke it.

Sound like a plan.

Would it hurt to oil or wax the outside of the mould like seasoning a cast iron pan? I have some of the most corrosive sweat on earth and it is bound to rust over night after i handle them like my dies.

[DLCTEX]

The pencil lead (graphite) makes a good mold release. I use it on the cavities to help cure sticky boolits.

[Marine Sgt 2111]

If the pencil doesn't get it out then try wrapping 0000 steel wool around a small screw that will fit inside of the collet of a dremel tool. I ground off the extra sprials on mine.

Then dip the end of the steel wool, which is wrapped around the modified screw, in some lapping compound (from 400 to 600 grit), slide the steel wool Q-tip inside the cavity (mold halves together) and turn on the dremel tool to a low to meduim speed. count to 5, stop the dremel, withdrawn the steel wool q-tip.

Wash the mold halves off with either carb cleaner or some other type of good degreaser. The cavities will look like polished mirrors if you do it right.

Now USE COMMON SENSE and don't over do it. I have used brass brushes and steel to clean up surface rust but I avoid cavity edges and take my time and am careful.

I use 400 grit and it works great on cast iron molds for me....

[shotman]

I got one too I got it hot and casted about 6 boolits . I drilled a small hole in the bottom and started a screw in the hole .Put some fine valve grinding compound and spun with a drill. I cleaned it up and looks good If you got the one that is for a multi caster then the top will need to be milled to get plate to fit tight. rick

[dale2242]

If you can find an old typewriter eraser, try using it to gently remove the rust. I know, who uses a typewriter? Guess I am dating myself. Anyway, they look like a pencil with eraser in the center and a brush on the back. The eraser is not very aggressive and will not harm the mold.---dale