When I started casting stuff, I was dumbstruck on how expensive large crucibles were. So I tried cutting the end off an old un-useable Argon gas cylinder. I welded a 3/4 pipe on it and insert a steel rod to retrieve it from my forge. It has a hole to pin it from spinning when I pour. This forge is one I built for melting/knifemaking. Simple venturi burners. Most of my casting methods are unorthodox but I do it for fun, not precision. For melting aluminum, the crucible lasts for a long long time. Brass and copper, I get about 15 melts before too much metal sluffs off the outside and the walls get thin. Just an idea. I can usually find old ones for free. I'm sure some of you more technical people out there may poo poo it. But, it works for me.
Have mostly switched over to clay/graphite crucibles but still use the steel one I started out with when I need the volume. Made from 6" x .280" wall pipe, it has something like 40 aluminum melts on it. I have replaced the lifting/pouring rings once. Al
That would be the azzhats over at iforgeiron.. What ever works for you, works for us. We aren't a judgemental bunch. My first crucible was a chunk of oil well pipe the size of a paint can. I eventually got tired of watching it sluff off into my metal and made the switch to clay graphite. The guy on ebay sells reasonable priced crucibles and are good quality. I've been abusing an A6 with bronze for years now. I think it cost me 40bucks when I got it. Here he is. Prices have gone WAYY UP! That's what happens when you print the us dollar willy nilly. https://www.ebay.com/itm/Salamander...861623&hash=item2eb49a15bb:g:yTcAAOSw~gRV23YT
Blowing straight onto the melt is probably more of an issue than the iron uptake (debatable). Between the exposure to products of combustion and the agitation of the melt your likely getting gassy metal and/or the potential for dross inclusions. But I'll bet it melts fast! There are washes you can use to minimize the aluminum attacking the steel. Masteryoda uses a wash of some kind in his stainless milkshake cups and says he gets good results. The Navy Foundry Manual mentions "whiting" which is a mixture of calcium carbonate and water. I've never used a wash since I went to graphite crucibles pretty soon after starting casting. I was using 1lb propane cans in a charcoal furnace which didn't last long. Pete
Knife makers use white-out (liquid paper) as a non stick coating for making canister damascus... I wonder what's in that stuff? Olfoundryman on youtube uses boron nitride as a ladle coating. I think. But that might be expensive enough to drive you toward clay graphite crucibles, not sure. Jeff
thanks for the replies. Yes, I have gotten gassy pours, then some perfect. I have used salt and baking soda in attempts at degassing aluminum with ok results. Brass is ok. Im no technician and never realized the effect of the flame blasting directly on the metal. Dross inclusions are rare, unless I "oops" a pour. Anyone have input on the quality of PMC crucibles? or any of the ones sold on Amazon?
I'm using these from Amazon/OtoolWorld. No issues with aluminum...have yet to try brass but it's on the list for the summer. https://www.amazon.ca/OTOOLWORLD-Gr...d53b0&pd_rd_wg=kI2B9&pd_rd_i=B00U5BSN8A&psc=1 Al
I get mine from Legend Mining in Sparks Nevada. Look under assaying supplies. I've used their budget graphite and had some issues. I've started getting their salamander super and have had good luck with bronze and iron. http://forums.thehomefoundry.org/index.php?threads/crucible-failure.1109/ Pete
Bought both an A4 and A6 from Legend, also. They were about 54(?) shipped for the pair. Next is to secure a lid for the smaller one, to help with readily-oxidized melts like bronze.