Homemade Gas Forge / Foundry

[bluebanana32]

Hi all,
This is my latest project. I have for some time now wanted a gas forge and have looked at a variety, some very expensive pro stuff like Swan and some cheaper eBay jobs.
I liked the idea of making my own, but was put off by making the gas burners. I found that you can buy burners from Castree kilns but they are around the £280 mark each .
So last month for my birthday I purchased £45 worth of steel, £60 worth of burner parts and £12 worth of kiln blanket and the pictures below are the result. I still need the 1" vermiculite boards for inside but otherwise it's almost complete.
After a burner test yesterday afternoon I have decided I need a heat deflection plate underneath the gas line and a wire loop to keep it away from the body.
The normally aspirated burners are an adaption of an idea from YouTube:

They cost about £7 each to make, however if you add the pressure gauge, needle valve, flame failure etc it soon mounts to about £60. The homemade flares are made from 1" schedule 10 S/S pipe, which can be difficult to source.

 

[rtbcomp]

The video won't play - there's an error message saying it must be viewed in YouTube. You need to click on "How to build a ......." at the top left of the image.

 

[bluebanana32]

Sorry all, the photos won't load I will tweak the video address later and upload some pics of the build ASAP.

 

[bluebanana32]

These 2 and the one above are of the finished forge to date.

 

[bluebanana32]

Ok.... So here's the piccies.
The initial plan was for a 5mm 'rectangular box' that could be used in the horizontal or vertical position to either forge steel or when turned vertical would provide equal heat top and bottom to a crucible for casting ally. The forge needed insulated doors that could be shut down enough to keep the heat in.
I purchased some 5mm sheet and cut it into 35cm x 30 cm lengths that would form the outside of the box. This would give a 25x30cm internal capacity when used with 1" thick vermiculite boards.
The outside frame is 25x5mm bar to strengthen the structure and stop the vermiculite moving.

 

[bluebanana32]

The doors are constructed of two bit of 5mm plate which have nuts welded to the inside, for two reasons....
1. I don't have metric tap and die set! and 2. The doors are packed with two lots of 13mm kiln blanket which then gets squashed down to the tickness of the nuts. It also means the back of the doors sit flush with forge.

 

[bluebanana32]

The burners were assembled as per the video above, the top gas fittings are different as I wanted to connect two burner and the flame failure device.

 

[bluebanana32]

Here is the primary burner firing for the first time:

And here are both:

 

[bluebanana32]

The forge has been designed to have fire bricks and vermiculite in the bottom to add extra refractory and strength when the steel is resting on it, for this reason there is a mini hinged door at the bottom that can be opened when it is in the lateral position for foundry work to allow the crucible to be able to get in and out.
During normal forging the bottom door will remain closed. The top doors front and rear are sliding closure as opening with a hinge will allow too much heat out.

 

[MrFluffy]

Nice job, and this comment is a bit late now so maybe at other skiprats looking at this and wondering about replciating, but if you see the alcosa brazing hearths on ebay, theyre the same thing as their smelters but with no side and tops, and usually go for less than a hundred quid. For that you get a high volume air blower, a burner, flame failure device, ignition system, valves and a burner even if you dont use the original chassis. If you pick the ones up with the torches too, you can use them for brazing. Most of them are 3 phase though, so if you dont have that, you will have to do something with the air blower. On mine the pumphead is mounted direct on a motor, so total replacement could be tricky.
I am part way through converting mine into a full smelting setup that can be mounted on it or taken off at will. I have a dog food can as a mould, and some refactory cement to just make a round section to drop onto the original hearth to put a crucible in, plus I can remove the round bit and use it as a general hearth still, or the gas air torches for brazing. Even without the extra insulation of a refactory cylinder as a open hearth running on air/propane its quite capable of melting aluminum in a cruicible if left for long enough.