11xray

Frosty, thanks for the heads up on the “at” symbol.

Frosty: The melts are for enjoyment, NOT for scrap value. I’m building a collection that I’ll enjoy. The steam/brass explosion was the result of not sufficiently preheating my cast iron mold. I had a bunch of pencil-eraser sized 3rd degree burns, my Apple Watch was ruined, as my foundry gloves turned out to be crap. For the most part, just very shook up. I wear full protective gear, apron/gloves/face shield, and have a respirator for the more hazardous metals. Anyways, I’m going to fire it up this weekend, despite the propane prices (jeez). I get scrap stators and little motors from scrapping and from friends, dismantle and melt the goods. Thanks for the replies, it does this man good.

Despite being a combat veteran, I have been struggling with my foundry since a brass/steam explosion months ago. Over the last two months, I've managed to fire up the foundry 2 times, and my anxiety was palpable. It's an odd feeling to be THAT shook up by anything at this point in my life, it takes a lot to put me off-balance. Anyways, my scrap collection is brimming and I need to make some ingots. Apologies for limited participation on the forums recently, a few months ago I thought I was ready to get back into it but that wasn't the case. Here's to finishing out 2021 SAFELY and not letting anything stand in the way of a good time. Hope you all are doing well, and thanks for all the information I've learned here. Oh, and ALWAYS preheat your molds thoroughly.

I just want to say that I learned from this post, and appreciate the OP and commenters that contributed.

Thanks, for all the great information. I got the answer to my question.

OK, I’m currently using a monolithic castable refractory, rated to 3000F. I wasn’t differentiating between castable refractory and castable refractory cement.

Well, that’s two opposing opinions. Frosty, do you melt with exposed ceramic blanket?

Just dropping in to say that brass explosion hurts the ears and the pride, but the burns don’t because they’re so deep. But, ow my pride. And bye Apple Watch (I’m such a dum dum sometimes). Great question and overall topic, OP. I enjoyed this read and learned a bit myself.

I’m building a second foundry, and would like some suggestions on cement. What do y’all suggest?

Check out this video, with basic tools you can make a set of tongs. Same set I've been using since I started, and they've not let me down. I have progressed from bolted to welded, added some steel bar for extended handles, other than that mine are exactly as the video shows. The video gives very good instructions for creating the tools.

Anytime, friend.

I’ve definitely had a crucible fail mid-melt. Thank goodness firebrick and kaowool is hardy. Now that you’re definitely cooking with gas, I’d suggest getting a thermometer so you can melt with science instead of instinct. I check temps pretty regularly, and it adds a level of confidence while you’re working. Also, it’ll tell you if the mass of copper is a brief delay because: impatient, or because: this isn’t going to melt and I need to hit the forums again. BTMETER BT-1500 Non-Contact Pyrometer 30:1 Industrial Laser Thermometer Gun, -58℉ to 2732℉ (-50℃ ~ 1500℃)

Oh man, those are AWESOME!!! I love this site. Those skulls are so different from others, I really dig the creativity.

Excellent! Be careful with overheated brass too. Sounds like your problems are resolved with the new regulator. Oh, I generally run 15psi for aluminum, 20-25 for brass, and 25-30 for copper. Copper is as high as I go, as I have no need for melting steel. Also, take it from someone that learned the hard way, always preheat your ingot molds. After a steam explosion and almost losing my eyes, I warn everyone that melts.

Yeah, I haven't gone past 30psi ever. BigStackD is the best, I really enjoy his videos, also ArtByAdrock, they seem to have some affiliation. Anyways, I'll be checking in to see how it's going.

Nice! I dig the ingots, that's always good to see. Regarding the foundry, let us know what pressure you're getting. Also, thanks for the correction on the space in your foundry, I was looking at the pictures on my phone which adds an odd perspective. Regarding tongs, I followed this guide to make some:

A friend bought a burner online, and we sat there for 3 hours at full blast trying to melt copper. I kept telling him, the burner isn't getting it hot enough. Fortunately, I had my spare brass parts with me, and he had a bunch of scrap pipe, so we made one on the spot. Nothing special, 3/4" x 6" with a bell flare. Melted copper in 20min, no problem. Turned out it was the T on his burner, 3/4" x 3/4" x 3/4". I'm going to second this. There appears to be about 3/4" of space or less between the crucible and the wall, that's pretty tight, and a lot of direct heat on the crucible.

In my experience, not getting up to temp is either a burner issue, or propane pressure issue. What PSI are you running the propane? My God, that crucible is after four uses? I’d be pretty insistent on either returning it all, or being made “whole” somehow. I dig the overall design of the foundry, the port for the torch is a bit wonky, but that doesn’t mean it’s not functional. Burner aim is a very forgiving part of the whole equation. I’m thinking you’re getting about 10psi, or the air is really choked off. I’ve had the mass of brass after a three hour “melt” and it’s crazy frustrating. We can sort this out, I think. A couple questions: 1- Did you break in your crucible properly? Heat it up to red and let it cool organically. 2- I don’t see a pressure gauge on the propane line at the regulator, so you may not know the pressure. Never understood making a high pressure regulator without putting a gauge on it. Do you have a method of determining PSI?

I haven't made alu-bronze before, but that's just because I haven't had a use for it. One of the Youtubers I watch frequently is BigStack'D, and he does a lot of alloys. I like the Nordic Gold alloy in those videos. I'm also learning how to use my new CNC to mill graphite slabs into molds for pouring. There's a lot to learn, everywhere I look.

I do NOT recommend refreshing sand molds while melting. By "refreshing", I mean pouring into the mold, allowing to cool VERY briefly (just set), collapse the sand etc into a safe container and reload the mold with fresh sand and template, then take it out for pour. I made a ton of mistakes, but I did get 7 different castings done in one night. It would have been better to simply build more molds, kind-of a duh moment for me just now.

That seems to be the precursor to many of my missteps. That night with the brass, I was refreshing sand molds while brass was melting. I remember having to redo one mold, delaying the next pour, and I believe that time allowed the brass to get way too hot. Rushed outside, pulled the crucible, put the ingot mold into the foundry to preheat, poured the cast mold and pulled the ingot mold out, poured the leftovers into that and boom. Odd thing is, the crucible was fine (I managed to drop it sitting-up, thank GOD), and the ingot mold was fine. I'm still using both today.

Man, those sound like really fun projects. I made some near-Petrobond using pure bentonite clay and ULTRA fine (like, goes through a flour strainer) sand I got at Petsmart that is used for reptile aquariums. I’ve made some humorous items that I can’t mention here for a friend that dives. The punisher skull template was made using a 3D printer, then transferred to my green sand. I was going to keep working the metal on the sander/grinder but I kind-of like the imperfections. Lately, I’ve been testing some custom alloys using aluminum and zinc, but I haven’t found the right mix for this project. The current ratio leaves the product too brittle, so I need to tune down the zinc.

Indeed, I played it off initially. She was inside with earbuds in, and I cleaned up the mess quickly. Changed shirts, dressed wounds, and gave myself a minute to figure out exactly what happened and calm down. Fortunately, I had the foresight to have a full burn attention kit ready before doing my first melt over a year before. That silver-whatever prescription burn cream is so great.

Will do, and thanks for the warm welcome.

Oops, my mistake. Sometimes I forget the internet isn't only for old infantry trolls like me.