Thread: Charcoal Forge

Looks fantastic Ray.

Some photos of the forge in operation please.

Gday Ray,

I have made a foundry out of an old hot water heater. It works great. I couldnt find any refractory cement to use as the liner in mine so I used an old stainless steel bin and portland cement. I have done 10 melts and its still going strong.

So far I have only tried aluminum in it, and I usually burn plain old hardwood. My crucible is an old fire extinguisher cut in half, however these are too thin to be called ideal but it has been used for all 10 melts I have done to date. Aluminum melts in 5 to 7 minutes with this arrangement.

I love old heaters. You can pick them up for free almost anywhere and there is a lot of good steel in them.

You're in trouble now. Once you start hitting hot metal you won't want to stop. That is the same reason I started hitting hot metal. I've not had the time to forge that I'd like, but I find that for heat treating small tools (less than 6 inches) you need the hot center to be at least a 4 inch ball.

Anyway, if you haven't found it yet, here is an excellent on-line resource.
http://www.iforgeiron.com/

ron

Originally Posted by 19brendan81

I couldnt find any refractory cement

I bought two bags of refractory cement from this business over the phone... http://www.totalrefractorymanagement.com/

Originally Posted by Fossil

Some photos of the forge in operation please.

i second that looks great

Originally Posted by new_guy90

i second that looks great

I had it fired up last week, before it was really finished, but now I am waiting for a bit to let the refractory cure. I will post some pictures in a few days.

The refractory I used is from these guys http://www.foseco.com.au/ I went down to Melbourne and picked up the refractory and some silicon carbide crucibles for the foundry which is a joint project between my son and myself.


Changing the topic to the Foundry/Furnace...

Still working on the design, but felt that burner design might be a good place to start...

We built a propane burner based on the reil design http://ronreil.abana.org/design1.shtml and was pretty impressed by it. This picture is without the flare on the end, without which the flame just blows itself out, but with the flare it burns nicely, the choke was a bit of rolled up cardboard.



Then we discovered the t-rex style burners, so we built a second based on the t-rex design a bit like this one http://www.hybridburners.com/



The main thing we were looking for was a longer tube, to suit the furnace size, the rolled flare will be replaced by a cast refractory flare in the final version.



The mixture adjustment is a bit too fiddly and the position of the gas jet tip is finicky, so I am starting to think that the expansion chamber in the t-rex design is essential to create the right venturi effect and get good mixing. So... version 3 coming up..

But I have to say, it's fun to vaporize coke cans with!

Regards
Ray

Originally Posted by son_of_bluegras

You're in trouble now. Once you start hitting hot metal you won't want to stop. That is the same reason I started hitting hot metal. I've not had the time to forge that I'd like, but I find that for heat treating small tools (less than 6 inches) you need the hot center to be at least a 4 inch ball.

Anyway, if you haven't found it yet, here is an excellent on-line resource.
http://www.iforgeiron.com/

ron

Thanks for that ron, I hadn't seen that site before, that's a great resource. I can see how this could become addictive...

I won't know what size hot center I'll end up with until I fire it up with the new firebox, I guess I could always increase the area that air is applied to, and if needed increase the airflow if it ends up too small..

Regards
Ray

Originally Posted by .RC.

I bought two bags of refractory cement from this business over the phone... http://www.totalrefractorymanagement.com/

Thanks for the link RC. For a different project I finally got onto some refractory cement, it came from foseco in Fyshwick. If I ever make a version 2 Ill spend the extra fifty bucks and use refractory, but for now the portland works just fine.

The hardest part I have found is making proper green sand or buying petrobond. We have not been able to fine bentonite clay anywhere (for green sand). I found a bloke in melbourne who can sell petrobond, but its $25 a kilo or something. From what I have seen though, the results are worth the money. As petrobond doesnt contain any water (unlike green sand), the results are much much better as you dont get gas bubbles and dimples on the surface of your casting.

Originally Posted by 19brendan81

We have not been able to fine bentonite clay anywhere (for green sand).

Have you tried a stock feed supplier or garden supplier??

I think it is also used in kitty litter...

I have heard that its used in kitty litter, but you cant use that as a) its not pure and b) its granulated and would need to be pulverised first. All the "recipes" you find are american, and the stuff they allude to is a pure, fine powder. This is what you need to get quality results with green sand. Is this something that is used a lot in rural areas? Why would a livestock place stock it? Thanks for the tip though, ill give my local bloke at CRT a call.

Its the same with Petrobond. I found a recipe to make your own petrobond, but again there is a key ingredient called 'bentone' that is freely available in the states, and to date i havent been able to find it here.

Its very frustrating...it seems in the states you can walk down to any corner store and get all manner of useful things cheaply and easily....whereas here its very hard to get many things needed to do a lot of DIY casting/anodising/plating work.

P.S you can buy pure bentonite from health food places but its prohibitively expensive given the quantities you need to make green sand.

You might try the suppliers mentioned in this thread

Thanks for that link mate, very helpful....i'm back on the hunt!!!!

I bought my bentonite clay from The Clay Shed. they also have fine washed silica sand. You may be able to find a pottery supplier close to you, otherwise I believe these guys ship. Unfortunately their website wasn't working when I just checked.

The Clay Shed

U 2 24 Hi Tech Dr, Kunda Park, QLD 4556
p: 07 54765977





BTW- if you are looking at casting, this site is worth a look

http://backyardmetalcasting.com/forums/

Regards,

James