Rust inside my aluminum molds - what to get rid of it?

[Jcandleattic]

So I've been in and out of candlemaking and am now back in. I never get rid of my stuff because I never know when the mood is going to strike.

We have recently finished our basement and turned it into my own workshop. YAY - so I've been getting everything organized and when setting up my aluminum molds I've seen a few of them have rust spots in them.

Don't know how or why - I've never cleaned my molds with water - ever. But maybe in the storage there was some condensation?

Anyway, I was wondering if there is a way to get rid of the rust to fix the molds without causing further damage, or if they are just a lost cause and get rid of them?

They rust spots aren't bad, but there enough that it would cause problems if I don't get rid of it.

Thanks for the help.

[Stella1952]

Aluminum doesn't get the rust-colored rust - that's probably a tin alloy. Put it in a warm oven so the wax will liquify, wipe it out carefully with a paper towel. If the rust spots feel rough, use some triple 000 steel wool with oil on it to lightly smooth the spots. The stain may remain where the spot was, but it won't hurt the candle - no soap, no water! Aluminum will occasionally get some whitish oxidation, but the cure for that is the same... Tin alloy is more likely to just rust sitting around. It's a good idea to spray them lightly with silicon spray before storing them to protect the metal from moisture. Wipe them before use. HTH

[EricofAZ]

Ferrous metal will corrode with a red color and non-ferrous will corrode with a white color usually (copper is green). Corrosion eats away at the metal so when you clean it, you'll have some pits to deal with. You can buy rust remover chemicals at most auto stores. there are a few home made recipes on the internet. Depending on how deep it is, the pits may or may not show up in the wax. You could fill the pits and sand. Whether its worth it or not depends on how bad it is, how hard you want to work and how cheap the replacement moulds are.

I have a few and clean them with chemical and then some fine sand paper. Maybe the steel wool will work but do not use that on aluminum and do not use aluminum wool on steel. Mixing ferrous and non-ferrous results in embedded particles and more corrosion. It sets up an electrical imbalance in the metal called electrolytic corrosion. Carbon sand paper is not perfect, but it won't set up the imbalance and it does a good job of knocking down the spots that "grow."

[Jcandleattic]

Aluminum doesn't get the rust-colored rust - that's probably a tin alloy. Put it in a warm oven so the wax will liquify, wipe it out carefully with a paper towel. If the rust spots feel rough, use some triple 000 steel wool with oil on it to lightly smooth the spots. The stain may remain where the spot was, but it won't hurt the candle - no soap, no water! Aluminum will occasionally get some whitish oxidation, but the cure for that is the same... Tin alloy is more likely to just rust sitting around. It's a good idea to spray them lightly with silicon spray before storing them to protect the metal from moisture. Wipe them before use. HTH

Oh, okay thank you!

Yeah, these must be tin then. Don't know why I thought aluminum. :-/

Anyway - yeah, I never have and never will clean my metal molds with soap and water. Usually I just zap them with the heat gun and wipe them down, unless they are dusty then use mineral oil and swipe them.

Thanks for the help...

[Jcandleattic]

Ferrous metal will corrode with a red color and non-ferrous will corrode with a white color usually (copper is green). Corrosion eats away at the metal so when you clean it, you'll have some pits to deal with. You can buy rust remover chemicals at most auto stores. there are a few home made recipes on the internet. Depending on how deep it is, the pits may or may not show up in the wax. You could fill the pits and sand. Whether its worth it or not depends on how bad it is, how hard you want to work and how cheap the replacement moulds are.

I have a few and clean them with chemical and then some fine sand paper. Maybe the steel wool will work but do not use that on aluminum and do not use aluminum wool on steel. Mixing ferrous and non-ferrous results in embedded particles and more corrosion. It sets up an electrical imbalance in the metal called electrolytic corrosion. Carbon sand paper is not perfect, but it won't set up the imbalance and it does a good job of knocking down the spots that "grow."

Thanks for the advice!

I will try with some steel wool (these are tin molds, not aluminum) if it works great, if not, it really isn't a big deal. They were not that expensive in the first place, and IF I replace them, Peak carries them and I am local to them so no shipping charges which helps.

I appreciate everyone's help.