mold cleaning question

[colbyjack]

so whats the best way to clean a mold? i took some steel wool and CLP/breakfree and rubed down the out side. looks alot better. but is that ok for casting or do i need to strip all the oil off it?

as far as taking the oil off can i just spray it with gun scrubber? -chris

[mooman76]

You need to get the oil off the inside so you get proper mould fill out. Something like brake cleaner and a light brush like tooth brush.

[lovedogs]

People have lots of opinions and methods on this. I always put a rust preventative on my moulds before storing them. When ready to cast again I dump them into a bowl of paint thinner... any petroleum cleaner will probably work; I just happen to have thinner on hand. After scrubbing them clean with thinner and an old toothbrush I blast them with a degreaser like Electo-Motive or Brakleen. After drying them I smoke the cavities heavily with a wooden match. After smoking I wipe all the smoke out as good as possible with a Q-tip. I do this smoke/remove twice. It pulls excess fluids out of the moulds and leaves a carbon deposit on the inside surfaces. I then lightly pre-heat the moulds with a small propane torch before moulding.

[freedom475]

acsetone is what I use on the mould faces and cavs. just use a q-tip and wipe down well then lightly smoke with match of lighter.

[monadnock#5]

First I attach the blocks to the handles and then head to the kitchen sink. I use Dawn detergent with a toothbrush and lots of hot water to thoroughly wash all the metal parts right up to the ferrules on the handles. When I think it's clean, I do it all over again just to be sure. I want to remove any oil that could migrate into the cavities after casting has begun. After double washing and double rinsing, the blocks go onto an electric range burner set on low, then its on to the next block. When I'm ready, its off to the casting bench, where I have a hot plate for preheating moulds and ingots.

Between making my blocks squeaky clean, and preheating them until ready to work them into the rotation, I'm casting better boolits much faster and much more efficiently than ever before. Thanks guys.

[leftiye]

Clean the oils off (as discussed). DO NOT polish the cavities (reads remove the seasoned surface), unless the mold sticks, or you want the cavities to be larger. Smoking is unnecessary, and can even cause problems. Like when it comes off and causes uneven heat transfer.

[lovedogs]

Leftiye... that's why I don't use mould release and why I wipe the surface smoke out of the moulds. After two smokings and wipings it's just my opinion that the pores of the metal hold some carbon to aid in release but not enough film that it'll cause dimensional problems. Just my opinion and it does seem to work for me.

[colbyjack]

thanks for the info guys. -chris

[Forester]

I used to clean molds with acetone but I got tires of dealing with the nasty stuff and tried just plain old dish soap. I have a dedicated sponge/scrubber so as not to use anything that stays in the kitchen. I think dish detergent works at least as well as anything else I have tried.

I seem to have good luck smoking aluminum molds but using nothing on steel molds.