Furance plans or tips?

[Ethan D]

Hi there everyone.

I would like to build a smallish furance to cast mostly aluminum and cast iron.

There are alot of DIY stuff I have found on the Internet but I would like to see what others have done and if they have used or based there furance on these Internet ones?

Also, to my fellow aussie, where do you guys purchase your refractory from?

Cheers

 

[Cogsy]

I'm in Perth and had no trouble picking refractory up from a potter's supply shop but I then needed more and found refractory manufacturers/wholesalers are easily found and much cheaper.

I built a furnace from a 9kg bbq bottle and it works fine, but I do want to upgrade my burner for better efficiency. It'll melt aluminium and copper fine, and I imagine brass and bronze as well, but wouldn't be at all suitable for cast iron - I didn't use materials rated to those sorts of temps.

Good luck and remember to post pictures!

 

[bmac2]

Hi Ethan
Start with aluminum, melts at 659 degree (1200f). The idea of messing with a 1260 (2300f) degree crucible of iron just doesn’t sound like fun and the PPE and equipment required costs an arm and a leg.

I think it was stumbling across a Myfordboy video that first got me interested in home casting. This is a link to how he built his propane furnace. http://myfordboy.blogspot.ca/p/myfordboys-furnace.html It uses a simple inexpensive Perlite and Fire Cement refractory and is great for aluminum but I wouldn’t want to do a lot of brass and bronze. This is the same refractory I used to make my first coffee can furnace http://www.homemodelenginemachinist.com/showthread.php?t=23743. If you want to try something small simple just to try melting I made the furnace and burner for under $20.00 and the 2 crucibles for another $10 or $15.00 that let me melt about 3Lbs of aluminum.
I’m slowly getting the materials together to build a larger furnace and I’m basing it on his Oil Fired Furnace (beautiful, well executed design) though I’ll be sticking with propane for fuel. http://myfordboy.blogspot.ca/p/development-and-construction-of-my-oil.html

Have fun and play safe.

 

[ruzzie]

I'm looking to make a furnace also and have found a couple of suppliers in Sydney:
http://www.fieldfurnace.com.au/castables-ezp-3.html
https://www.sydneyfirebricks.net.au/product-category/castable-refractory-ovens/

Paul

 

[dnalot]

Hi

I made my furnace and burner to plans from the book "Gas Burners for Forges, Furnaces & Kilns" by Michael Porter. I used 3000 degree refractory and it has been in use now for several years. It works very well and is still in great shape despite heavy usage. I melt aluminum, brass, bronze with it using naturally aspirated propane. On one occasion I melted cast iron using a blower.

Mark T

 

[bmac2]

Hi Mark
That’s a great looking furnace. Are you using any assist for the lid?

 

[Wizard69]

Hi there everyone.

I would like to build a smallish furance to cast mostly aluminum and cast iron.

There are alot of DIY stuff I have found on the Internet but I would like to see what others have done and if they have used or based there furance on these Internet ones?

Also, to my fellow aussie, where do you guys purchase your refractory from?

Cheers

Cast iron is a whole different beast than aluminum or its various alloys. I would suggest working out a furnace design focused on Aluminum. You may be able to melt small charges of iron in it but I wouldn't focus on that unless you are up to spending a lot of money.

I don't have a home furnace but years ago I worked in a zinc die casting plant. Even in a commercial plant there where many approaches to furnace design mostly trying to accomplish the same thing. In the end you need to choose what works best for you.

 

[Tin Falcon]

+ 1 on the Michael porter book .
the google book link will let you browse through it to preview a good number of pages.

https://books.google.com/books/about/Gas_Burners_for_Forges_Furnaces_and_Kiln.html?id=nHkpb4cCKvQC
Tin

 

[gus]

Personal Safety.
Been casting aluminium with DIY Gas Fired Aluminium Furnace and DIY Cast Iron Gravity Cast Molds successfully with zero accident. During the casting I was in full control with no busy body bystanders and on-lookers.This included my bossy boss. In fact I did all the poring for all 400 castings. Demolding was done by a very well trained assistant.
Please ensure you are well protected from molten aluminium spillage. I used arm length asbestos gloves and thick leather apron. Safety shoes a must. Leg cladding good idea. All castings should be done at ground level. YouTube Videos posted by wannabes casting aluminium w/o ample safety protections worries me. All fresh charges must bone dry and preheated before charging into crucible. Cast iron crucibles best. Cast Ladle must be strong and robust.
Take great care.

 

[dnalot]

Are you using any assist for the lid?

No, the lid is not that heavy. There is a handle welded to the lid that does not show in the photo. Heavy gloves required.

Mark T

 

[Ethan D]

Hi Everyone,

Thanks so much for all your input, link, experience and information. Its much appreciated!

I think ill just stick to starting with aluminum.

Michael porter's book looks like a good buy! I will get my hands on this

I have some old aluminum engine blocks that need a face lift and to be turned into handy ingots!

 

[aonemarine]

I would start by figuring out how much metal you need to be able to melt and pour, think about pattern size, shrink bobs, risers, and sprue and decide what size crucible you will need to hold all that molten metal. Then design your furnace for that size crucible and lifting tongs. Propane is probably the easiest fuel source to get started with. On the refractory, this is where to spend the money. Build your furnace to handle iron temps using a good commercial refractory even if you only want to cast aluminum. No sense in putting alot of work into constructing your furnace only to use a refractory that will have to be chiseled out and replaced.

 

[Ethan D]

I would start by figuring out how much metal you need to be able to melt and pour, think about pattern size, shrink bobs, risers, and sprue and decide what size crucible you will need to hold all that molten metal. Then design your furnace for that size crucible and lifting tongs. Propane is probably the easiest fuel source to get started with. On the refractory, this is where to spend the money. Build your furnace to handle iron temps using a good commercial refractory even if you only want to cast aluminum. No sense in putting alot of work into constructing your furnace only to use a refractory that will have to be chiseled out and replaced.

Hi Aonemarine,

Thanks for your input. I ended up purchasing commercial castable refractory and cloth. I agree that there is no point in putting in all this work only to redo it later down the track.

 

[Ethan D]

The weekend has passed and I now have a furance, that will sit for a week to fully cure. I will have the burner finished saturday morning and then I shall light it up to let it dry out.

To the people in sydney, Where are you guys getting your green sand from? Or are you all making it? Google isnt much of a help

 

[Cogsy]

Again, I'm in Perth, but I make my green sand. I do need some finer stuff (see Bmacs awesome whippet casting thread) but my current lot is just play sand from Bunnings and some 100% bentonite kitty litter that I picked up from Big W - I'm fairly sure it's called kittysan, catsan or something like that. Comes in a 15kg red and blue cardboard box - it's marked 100% bentonite so it's easy to find. It comes pelletised but turns into a smooth slurry with just a little water so easy to work with.

 

[Ethan D]

Again, I'm in Perth, but I make my green sand. I do need some finer stuff (see Bmacs awesome whippet casting thread) but my current lot is just play sand from Bunnings and some 100% bentonite kitty litter that I picked up from Big W - I'm fairly sure it's called kittysan, catsan or something like that. Comes in a 15kg red and blue cardboard box - it's marked 100% bentonite so it's easy to find. It comes pelletised but turns into a smooth slurry with just a little water so easy to work with.

Hi Cogsy,

Thanks for the tip. Bunnings and Big W are only a few minutes away.

So once the kitty litter has soaked up the water, does it become slurry with just a little bit of mashing?

I noticed some people use blenders. Surely doing that will drastically shorten the life of the blender...

 

[gus]

Please make sure you are well protected from hot metal spills and splash. Bystanders are best to stay away for their own protection.
Take care.

 

[Ethan D]

Please make sure you are well protected from hot metal spills and splash. Bystanders are best to stay away for their own protection.
Take care.

Hi Gus,
Thanks for the heads up! ☺

 

[Cogsy]

I just added water to about 100gms at a time in a bowl and used a spoon to mush it into paste. Definitely don't need a blender.

 

[Ethan D]

Hi Cogsy. Over the weekend I did what you said and it worked perfectly. The brand of kitty litter was Catsan.
After the water is added there is no need for a blender.
Thanks for the tip