Melting Cast Iron in a Microwave 

I just noticed that this video was unlisted for who knows how long, so I am just publishing it again. I don't know if people get notifications on videos that are unlisted and then made public again...if you did and you have seen it before, well now you know why. 😀😀

This was a very entertaining project. I learned a few things and had to search for more hammers after a failed cast. Not only did I find the hammers, but I also paid significantly less than their in-store price. However, the savings didn't cover the 30-minute car ride (1 hour in total) it took to get them 😃😃

Zinc loss is very probably from too high temperature. You've got to keep it fairly low. Check online for some ideas of what casting temps to use for brass, it varies from alloy to alloy. Zinc itself starts to get obliterated at about 900C, but less when alloyed. So try to fine tune your process, and work out a way to calculate the temperature for a given soak time (i do realise it'll vary from melt to melt due to changing volume, so maybe a quick check every x seconds with the digital thermometer?) The sprue idea at the end is correct, that would very much be how you combat the temperature shock and metal shrinkage in that part of the cast. Love the recycling of the silicone carbide material, very innovative, I've never seen that approach from anyone, same with the microwave kiln technique. I may well adopt it and give it a go for melting metals, as my crappy electric furnace keeps popping coils even with mere copper, which it barely gets to melting point! Thanks so much for sharing ^_^

This is amazing. I’m not sure why this video isn’t going viral. Thank you 🙏

Love your videos. Please keep them coming

You really do make excellent videos! I enjoyed watching. I don't know why but I loved the hole in the handle. It gave it a homemade look.

Have you considered building a ball mill (large rotating cylinder with heavy metal ball bearing balls) for turning hardened silicon carbide back into powder ? Does the sodium silicate you add the silicon carbide, burn away during curing or will it accumulate on each recycling until the silicon carbide is unusable for mold making ?

Wow this is awesome. Thanks for sharing. Following you!

Silica sand is cheap, and commonly used with sodium silicate and/or other binders in iron casting. Curious to know why you used expensive silicon carbide instead for your molds.

I just found your channel and you gained a new subscriber. I love how your stuff is actually DIY and not DIY*. (*you have to own all sorts of expensive equipment to do anything-type of DIY) EDIT: That wobbly table scares me! Hope you'll get something sturdier to play on with molten metal.

Si-carbide form - seems expensive (although reusable). Some use organic solvents to melt the plastic out of the form. Vinegar (some suggest even caustic soda) might destroy water glass polymer and ease the form grinding to recycle Si-carbide. I'm no expert, but from what I've read, a bit of Al (or Be or Si) added to crucible should reduce Zn evaporation: it will melt early and float, preventing Zn evaporation. Yes, this requires you to scoop it out somehow afterwards. Also, temp must be below 950C, but you already know this, I bet. One idea, perhaps. Metal-metal composites. I know they use steel to reinforce Al (it's preferable to cover steel with Zn-Al thin layer beforehand for good adhesion). I tried to look up zamak-steel or zamak-tungsten composite, but no luck thus far.

I appreciate some of the safety precautions you're taking but you're forgetting one of the most important ones. Please get some oxy-acetylene eye glasses, staring at crucibles or metal in those temperatures will damage your eyes. A welder's hood will protect your face skin from that radiation too though may not go too low unless you get a fixed lens.

Awesome video, can you make one on the specifics of making silicon carbide molds, what components do you need and proportions needed.

Gloves with plastic and molten metal is a nogo!

U r great guy 👍

Very entertaining!! New sub

How cool is that ❤

I will suggest a cover slag for your brass/bronze melts composed of a mix of powdered glass and borax. This cover slag will protect the melt until you are ready to pour. Skim the melt just before pouring to minimize zinc loss...

👍 quick question. graphite or SiC for heating. Bought a grobet graphite heating flask and it didn't work worth beans Had no problem fusing glass with the carbide, but the grobet flask just got warmish when it came to melting metal. Lots of work for me to do!. Your videos are so incredibly well done! And the knowledge you are presenting is so detailed! Eric in Calgary Alberta Canada

Very nice video! How is the Metall not poured into the vacuum cleaner?

When sandcasting (delft clay casting) jewellers not only create a sprue hole but also air vents to allow expanding air to escape, is this why you got a hole in the handle? very informative on many levels, thank you.

Where's your link to the other video? :-)

Could probably fix that hole issue with brazing wire/rod and a torch.

Would this method of casting work with a 2 pound mold

I think it's terrific how anyone could do this in their kitchen.

Can you use this technique to get enough details that you can make your own coins? I suppose 3d-print them and make the silicon carbide mold and then just do as you did? But I don't know if the details will get good enough. I suppose that at the very least you will need a fine grained silicon carbide?

is there a reason why you're not hardening the mould with CO2 since it contains waterglass/sodium silicate?

Would it be possible to make an open mold out of Silicon carbide/water glass that would be reusable to cast multiples of the same object.

I've never seen anyone use silicon carbide as a casting material before, neat. The hammer turned out pretty nice! No blemishes or voids or anything. Will the cast iron be more prone to shattering than wrought iron, or whatever hammers are made of?

It is now September 18th. Where's the revamped video on making a kiln. ?

Watching you drive that Monstrous 40" spike into the wooden block in 1 hammer strike was truly impressive! XD [edit] oops, sorry...it was almost 40 hammer strikes on a tiny 1" nail. My Mistake.

At 15:15, maybe add some background music by the composer Handel ? 🤪

The question I have is. Can we use the components from a microwave to build a bigger microwave? Then we can melt a greater quantity of metal?

Hi, what temperature do you reach when melting the cast iron? From what I can find, the melting temperature of cast iron (even in the low range with a lot of lead) is 1200C. What I don’t understand is how you reach temperatures above 900C based on your kiln design… If I get it right, your kiln works by microwaving the silica carbine lining. The microwaves should only be able to heat things that have a dipole moment (capable of dielectric heating; I.e are magnetic), but silica carbine has a Curie point at around 900C… So any microwaves above 900C should be affect the silica carbine anymore, and thus not be able to provide more heat anymore, which should mean the maximum temperature of your kiln is 900C. Or I’m missing something in its working principle. That’s why I’m so curious what temperature you reach!

Sticker on wrong side of the hammer!

"One" hammer to rule them all?

You have a Baltic accent

What is your original language i here your family speaking Spanish but your accent while speaking English is not from Spanish it sounds German or maybe one of the Nordic countries o and subbed who would have thought you could melt metal in the microwave 👍

So you basically leave the plastic handle of the hammer in place and spill the molten metal into it... the plastic will melt all right but is that a good thing where does that melted plastic goes? Into the coating you break off from it?