Here’s a 3 parts update on the smelting foundry.
-First,the complete burner design and assembly with a test on propane.
-Preparing,casting and removing the inside form in the foundry.
-Quickly built casting flask with 2 planks of red spruce.
I know what I’m doing and I use the proper safety gear. I assume anyone attempting to follow this build log to have an equal or better understanding of the risk involved and to use said log correctly. I strongly encourages you to gather tons of info before attempting a build like this. I,the blog or Badwolf.ca shall not be held responsible for whatever you’re doing in your workshop. Liquid metal is REALLY DANGEROUS. As propane. In case of doubt,refer to a specialist,especially when handling propane.
Be safe folks,I wanna hear success stories,not see accidents pics.
And this is how it works inside:
1 – 4,5″ x 2′ galvanized steel tube (burner housing)
1 – Heavy duty fan propeller,aluminum (spinvane) something like this
1 – Delavan siphon air atomizing adapter and nozzle (17147 and 30609-11) Here
X – fittings,pipings and elbows to plug the siphon
X – Sheet metal (enough to build adapter plates,covers and other misc stuff)
X – Rivets (steel)
1 – AC Electric Blower (industrial type)
X – Fittings,tubes,air regulator,propane regulator,rheostat,electric cord,misc.
The first thing to do was to create a Y pipe in order to get the burner’s tubing out of the way and to have a direct line for the blower to work.In order to fit 2 pipes together at a definite angle we use a miter program (Tube miter program (395)) and print out the pattern to trace it back on the pipes. Once it’s traced on,you use whatever tools you have on hand to cut and sand it as smooth as you can and then weld the two parts together.
Once we got the housing done, we need to assemble the spinvane. The spinvane is a metal impeller of appropriate size used at the “blast end” of the burner to spin the air supplied by the blower around the flame and therefore concentrate it. The “roaring sound” comes partly from this effect. The air coming from the back also prevent backdraft of propane in case you didn’t fit all the pipes correctly together. I was going to weld it directly to the housing but then I realized it was made out of aluminum. The obvious solution was to cut out an adapter plate,to weld it to the housing and rivet the spinvane to it.
Delavan nozzle; The main part of the burner is a special siphon nozzle made from Delavan which is meant to siphon oil from one of it’s port using the low pressure created by the flow of air in another port. It also vaporize it all and enhance burning. A lot of folks over the net prefers to use propane to start up the foundry and heat it up and then switch to oil for the smelting duty,I’m one of em. So in the air port I added a T connector and some fittings to make it a 2 lines in allowing me to use propane or air as the propulsing agent and the oil line got regular connectors and quick connect (not installed on pics).
Once the burner is in,adapting plates are then grinded to size and adjusted to correct fit. The blower plate is welded at the back of the burner tube and holes are drilled to attach the said blower. Clearance is verified,blower is bolted on. I had a small 400 C gauge from a barbecue lying around so I decided to fit it on the side of the burner to see if any heat was actually generated/flowing back into it. Testing so far indicates no heat inside.
That’s it for the burner assembly.
-Get the Delavan siphon nozzle,it’s worth your money. (about 100$ shipped via eBay)
-Be careful with propane,use flair connectors and appropriate “Teflon”
-A MIG welder is a must have, same goes with 2 grinders with one fitted with a zip-cut disc.
Starting it :
1-I start by putting some air in at very low pressure (2-3 psi)(this is to prevent the propane from coming back the air line,the shop didn’t have any check valve on hand….)
2-Turn on the blower at half power to vent any leaks (there shouldn’t be any but just in case. (when smelting,the blower will also prevent the burner from melting due to heat coming back)
3-Slowly open up the propane regulator with a torch lit in front of the nozzle,after 2 seconds it light in a “woooosh” way,pretty intense.
4-Adjust pressures, blower to full power and more propane.
When switching to oil:
5-Slowly open up the oil line so it start being sucked out and burn
6-Add more air pressure while removing propane pressure
7-Completly close the propane tank and adjust the air pressure/oil line to desired flow.
*As I was missing a fitting for the oil line,I wasn’t able to test it yet,next post for sure.*
Casting the inside wall of the foundry:
The inside form for casting the wall of refractory was made out of sheetmetal,thing gauge. Using binding straps I got it down to the exact size and riveted it with aluminum rivets (important,they are way easier to grind after!).
Once the form was fitted and cut to to size,casting the refractory took about 30 minutes. I forgot to stir it with a rod so some pockets were formed but they’ll be fixed later on. After 24hours of curing,the form is removed and the foundry now weight about 600-800 pounds. It’s not going anywhere =P
Making of a casting flask:
As I got some petrobond ordered from Smelko in Ontario and was tired of working with metal, I set on to build a simple casting flask. A casting flask is used to hold the sand mold when casting.
From wiki: A flask is a type of tooling used to contain a mold in metal casting. A flask has only sides, and no top or bottom, and forms a frame around the mold, which is typically made of molding sand. The shape of a flask may be square, rectangular, round or any convenient shape. A flask can be any size so long as it is larger than the pattern being used to make the sand mold. Flasks are commonly made of steel, aluminum or even wood. A simple flask has two parts, the cope and the drag, and more elaborate flasks may have three or even four parts.
So this is how it turned out. Using some wood on hand and a couple of tools I now have a flask ready for use.
Questions,comments,drop it below!