r/Metalfoundry

I'd like to invite you to our Iron Pour in Lamberton, Minnesota on September 11-12.

It will be the 22th annual city festival centered around the Saturday Afternoon Pour and the historic Hanzlik Blacksmith Shop. There will be Blacksmiths demonstrations through out the day Friday and Saturday. Visiting Smiths are also encouraged to bring a portable forge and set up onsite if they wish. There will be sand mold shops running both Friday and Saturday as well. We welcome everyone from artists pouring museum quality pieces to children to the farmer making pieces to restore their tractor.

We encourage anyone to participated in the pour and can provide all the necessary safety equipment if you wish to try your hand at pouring.

In addition to the pour there will be a craft market, sand volleyball and various food vendors, an antique tractor/car show, and blacksmithing demonstrations.

Feel free to ask any questions you may have and I hope to see you there.

Here is a link to the Facebook event.

My DIY forge will almost melt copper but not quite. I'm really at a loss as to why it's not getting hot enough. Any pointers would be great. It uses a forced air propane burner. 2" Kastolite-30 walls, surrounded by 1" of kaowool. The burner enters at an angle so that the flame will "swirl" around the crucible. In this video I had moved the crucible closer to the flame to see if that would make a difference.

Hi everyone, I'm just starting out with aluminum casting and these are some of my first attempts, so I have very little experience.

I'm having a problem when pouring the molten aluminum: I can't seem to control the flow. As soon as I start pouring, a large amount comes out all at once instead of allowing me to pour it slowly and accurately into the mold.

The furnace temperature is set to 790°C (1454°F).

I've attached a photo of one of my recent attempts.

Is this mainly a matter of technique, or could the crucible/pouring setup be causing the problem? What should I change to get a more controlled, steady pour?

Any advice for a beginner would be greatly appreciated!

So I’ve been wanting to cast for a very long time but recently I have a project that I’m wondering if it’s even really possible and if it would even be worth it. So I do a good bit of cosplaying one of my favorite things to do is from a video game called Halo ODST. If you look online, anyone that makes ODST armor makes it out of EVA foam or 3-D printed plastic. I really wanna make mine out of aluminum or some other type of metal to make a more durable. Like I want to not be worried if I slip in a fall that I’m not going to bust up my thousand plus armor is it something that is even really possible or would it be supposed to be too heavy to do or too annoying to cast? I will include a picture of the armor pieces themselves just to give y’all an idea. I understand some pieces like the wrist armor or the helmet could not be casted without being annoying as hell to wear or make a wearable.

I did like 10 pours today then BOOM

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Hi everyone, I’m having a problem with getting a rough surface finish when casting jewelry printed with BlueCast X-Wax Filigree. After printing, I wash the pieces in 99% IPA for 5 minutes, dry them completely, give them a second IPA bath for 2 minutes, and cure them for 10 minutes. I’m using Infinity Premium casting powder, initially at a 40:100 powder-to-water ratio and also tried 38:100. I vacuum the investment for about 2:30 minutes, pour it into a 2.5 × 7 inch flask, then vacuum it again for another 2:30 minutes and let it set for around 3 hours. For burnout, I’m following the BlueCast cycle of 150°C for 2 hours, 450°C for 2 hours, and 730°C for 3 hours. I’m casting 925 silver and have tried different flask temperatures of 580°C, 600°C and 650°C, as well as silver temperatures of 980°C, 1000°C, 1020°C and 1050°C, but the surface is still coming out rough. The printed pieces look smooth before casting, so I’m trying to figure out where the problem is. Could the issue be the investment ratio, washing/curing, burnout cycle, flask temperature, silver temperature, silver quality, or something else? I’d really appreciate your advice on what I should change first.

My first attempt of smelting a 5 lb copper bar got some very heavy pitting used borax and made sure it got hot enough any recommendations

I mention this from time to time in comments but I don't think I shared photos. I have a cooling bucket from a pour in there and thought why not grab some photos. This is a couple years old now. Been through a hundred and fifty or so temperature cycles. Original idea from here: https://youtu.be/Aq3\_K9I4dA4

Used these elements and power it from 220 50A: https://kilnparts.com/collections/kanthal-heating-elements/products/element\_240v\_24amp

Temperature sensor is a cheapo high temp k-type from AliExpress to some MAX31855s.

The inside is made from white firebrick, mostly

9" x 4-1/2" x 2-1/2" and an additional layer of 1-1/4" for the lid and bottom. Those dual layers are laid rotated at an angle that modeled the fewest joint crossings between the layers. The bricks were cut to rough shape with a masonry blade on a rotary arm and table saw and fine tuned with a hand saw meant for wood. Easy physically but required a lot of fitting and refitting because my 55 gallon barrel wasn't true. It was from a farm and had been kicking around. I used a refractory cement at all contact surfaces and filled in any voids. I spent probably 20 hours with FreeCad making models for optimal brick placement but ultimately they were not terribly useful as neither the bricks nor the barrel are particularly true and that time would have been better spent doing instead of planning which is something I rarely say.

Got a nice base with wheels intended for rolling around full drums and it is super easy to move.

Welded up a hinge for the lid and welded it to the barrel. Painted the whole barrel with high temp exhaust paint or BBQ. I can't recall which but honestly if it is getting hot, I messed up and as it is, it stays nice and cool. Old hockey stick for the handle.

The controller is an esp32 with some inexpensive SSRs running this software that lets me control the kilns with Home Assistant (HA): https://github.com/beckdac/qtkiln Working on a version with kiln swarming so I can put two or more kilns on the same line and as long as they negotiate the combined duty cycle not to exceed 100% they will not exceed the breaker power budget. Kind of painful for doing annealing but great for bulk heating.

I use the same software and controller on my Vevor front loader and Skutt 181 and it lets me monitor them via HA and with the web app manage them remotely on my phone. Same cheapo k-types and max31855+esp32 setup. You have to tune the PID a bit for each kiln, but this isn't a post about qtkiln.

In the drum kiln, I mainly do Al and some alloys for metal casting and then glass casting and fusing. The large volume with exquisite and uniform temperature control is nice and not using propane is abs fabs. Being able to run an actual annealing schedule is useful in a number of settings, like glass casting and some alloys.

My biggest regret is using an old Nabu device as the electronics chassis (the box on the side). Retro computer people really like them and while I kept the motherboard without its case and ancient power supply, it isn't so useful.

I will also give a shout out to: https://github.com/Saur0o0n/PIDKiln which is another esp32 kiln controller setup I used to use. Has a nice web ui and OTA, but no HA integration, or at least it didn't, but if you don't need that, it is definitely worth eyes.

Hi everyone! I work at a bronze foundry that exclusively uses ceramic shell molds and recently we have been getting this strange casting defect. Raised bumps have been appearing on the majority of our pieces that are inconsistent with the normal boogers that you would get from air bubbles in the slurry. They are forming on both high and low texture/relief areas, on the face and inside of the piece, as well as on the cup and sprue bars. We burn out in a flash kiln and there are no visible defects on the interior surface of the ceramic after they come out of the kiln. We thoroughly blow out the molds and they are properly preheated prior to pouring. This issue started maybe 3 months ago, before that we had pretty flawless surface texture aside from the occasional burn in or cold spot. But apparently this problem has happened several different times before I worked here and nobody seems to be able to tell me how it was fixed, just that it eventually went away. We use Ransom & Randolph Primcote Binder for 2 primary coats and Customcote Binder for the 8-10 backup coats. We stay on top of the PH and the mixers are on an automatic timer. We pay special attention on the primary coats, making sure to brush away excess sand and using tools to lightly scrape any crevices to make sure air bubbles don’t get trapped for the first few dips. I am personally convinced that this is an issue with the structural integrity of the primary coat breaking down when the molten metal hits the mold. I feel like I have tracked down every other variable but I would really appreciate any advice I can get. Has anyone else ever had this problem?

Hey guys, I wanted to ask some questions and would be glad to gear some tips regarding foundry and metal casting.

First of all, together with a friend we previously attempted casting copper (barely but we got to the melting point). We built our own "foundry" using whatever materials we had -

Paving bricks and mix of; wood coal ash / powder and sand between every brick. (We put this mix also in any gaps to prevent heat from escaping.

A metal pipe with hairdryer blowing from behind at about 20° angle.

And some metal sheet cover leaving only a small gap for air circulation in front.

Then we put it a carbon crucible with metal inside to melt, we tried covering it with tiny metal bucket so its somewhat closed (although it did not matter in my opinion).

Now the problem is, we ran out of ideas how to increase the heat inside, and the temperature is barely enough, so how could we increase it further?

Second, the crucible kept breaking because it was put directly into coals, and we needed to move it around to keep from falling when putting in more coal, are there other more durable ones or is the setup main problem?

I guess those are my main questions, but like i said any tips would be great, also i know its a terrible setup but we used whatever materials we had avaiable for free, we are thinking about putting in some money so what would you recommend getting first? We really want to use coal and not gas nor induction.

So I'm have a really limited space in my workshop. I wanted to make add on to my coal powered blacksmithing furnace so I could melt aluminium, bronze and copper. First version (picture 1, picture 2) managed to melt bronze and copper, but furnace really struggled and the pour wasn't hot enough. It was made of two skins of sheet metal with clay mixed with quarc sand inbetween for insulation. New version (picture 3, picture 4) has a bit bigger diameter, much thicker walls and no insulation.

Now problem is, V2 works even worse, I couldn't melt aluminium bronze. I think it's combination of problems, whole thing is bottom feeded with air, and coal can't get under the cruciable so it blows directly at it which cools it down and i didn't add an insulation to the walls.

My question is, is it worth trying, or should I start building new furnace. Did anyone use anything other than ceramic wool for insulation (it's a bit hard do get it for some reason).

Pretty frustrated with greensand overall. I've got my furnace going fine, my alloys come out good, but I cannot get greensand to work right. I've been just doing sand cast with foam for lost foam, but it's hit or miss with the knife I'm trying to cast.

The third image is the knife blank, yes I know it's a funky shape for the tang but it's what my design calls for. I am trying to cast it with aluminum bronze for use as a veggie/soft cutter.

Since I've had the issues with foam casting, I decided to bite the bullet and make some greensand. I don't have the budget to get petrobond or just buy greensand, so I am making it myself. I've been sitting all day, and got 25 pounds of fine sifted sand. I crushed up and sifted 3 pounds of bentonite clay for a 10-12% clay-sand mix. I got that all mixed together while adding about 30 oz of water as I went and... It kinda of sticks together. I can't tell if I have put too much water or not enough. I had to mix it all by hand, which took me 3 hours or so. It was sticking together better, but that only lasted long enough to pack a mold before it changed and now doesn't stick as well.

AND the sand didn't mold the knife blank well at all. I used baking soda to make it not get stuck in the 3d printed blank, but the blank fell out as I lifted the first part to flip over for the second part.

I just don't know what I am doing and no amount of YouTube videos showing how "easy" it is has helped me. Any advice is appreciated.