I'm loving the recent posts on this forum about propane burners and keg furnaces. I want in on that action. Up to now, I built the mini metal foundry from "The King of Random"s youtube video, I then improved it with some actual castable refractory material. It's not the usual foundry furnace lining stuff like Mizzou or Kast-o-lite, but it has held up better than the plaster/sand. This was filled with hardwood lump charcoal and air was provided by a hair dryer. Using that, i've made a few things:
Aluminum ingots, Copper ingots (that was not easy), and some key chains:
Lots of videos of these and other foundry related things i did here: Metal Casting Playlist
However, I have discovered after trial and error (and everybody telling me pretty much non stop) that charcoal isn't ideal. A burner was in my future. But what kind? There are lots of different fuels, but in the end I decided on propane. Why propane? It's not that I love Hank Hill and his propane accessories. The real reason is because I already had a propane tank for my grill. I didn't have to go get more, and laziness wins.
For the design I went with a simple one, the Oliver Upwind Burner. I ran into a problem when my local Menards didn't have all the stuff mentioned on the shelf. It's pretty well stocked, but the very few empty shelves i found were the exact ones I needed. In the end, I used this amount of things:
a 1"x12" black pipe nipple, a 1" to 1.50?" thing for a flare maybe, i might get rid of that, and then a cap, 90 degree elbow, 2" (didn't use this in the end, but it's in the picture), 3", and 4" nipple all in 3/8" diameter. All that in black pipe, and a 3/8" NPT thread female to female brass gas valve. Not pictured is a 3/8" male to male NPT to flare adapter that I had to order (i have since found one in stock at a larger hardware store) and a 0-30psi propane regulator with high pressure hose. Total cost for all of that was about $28 for the adapter and regulator/hose from amazon, and under $20 for all the black pipe. If i removed the brass valve and just made a flare from some scrap sheet steel instead of that bell thing, the total would drop to under $40. I like the brass valve, so that's staying, and i might make a different flare later. Who knows.
I drilled the holes according the this chart:
(more details available at the website link above)
For the injector pipe i used the 4" 3/8 pipe, then the cap on one end. Elbow on the other, then the 3" pipe to the brass valve. For the big pipe, i arranged all the holes and stuff as though it was the recommended 7" length, but left the back of the pipe longer. Maybe i'll mount it to something using that. Here it is assembled:
Obviously i'm holding where the fire comes out. The NPT to flare adapter goes into the end of the brass valve, the hose goes onto that and it goes back to the regulator attached to the tank. It's pretty simple, but drilling those holes in a black pipe using a hand held drill and a chinese step drill ended in some casualties. Notice under the bigger drills in the top left of that picture you see a step drill that appears to be in 2 pieces? yeah...
Anyways, the test firing:
https://www.youtube.com/embed/UQwrXP2ZJJI
The one thing I like about this burner is that you can start it with a lighter and have a pilot light kind of situation, then crank it up. No need to turn it on, light and duck as a ball of fire shoots out. Then it can be throttled down and turned off. Easy. The flame started shooting sparks and stuff, I suspect that's because of all the filings and burs left over from drilling the holes. The flame doens't have easily defined cones, but the inside of the flare is not smooth at all, it still has all the threads and everything. I'll fix that, maybe, or use a different flare. Also, there is no way to easily adjust air on the fly like fasted56's design. As a result, low gas pressure results in a rich, lazy, smokey flame as it can't pull enough air in. This design can be adjusted by drilling more holes or covering holes, but in a configuration it seems to have a set gas pressure that results in a neutral flame. Not as adjustable on the fly, but it's pretty simple to build. I'll live. I'll probably tune it later.
I made a build video of this burner:
https://www.youtube.com/embed/qyVPtvbExXs
Now that this is burning away, i'm going to make the furnace to match, but probably not for a little while. I might mess with this and get it 'tuned' a bit better, though I have heard burner will act differently in the open versus inside a furnace. Since this just uses shooting gas to suck air through it, i'm sure sticking the end into a semi-enclosed area like a furnace will mess with airflow a bit.
one nice thing I noticed here versus other burners, i don't get any popping, pulsing, big WOOF's of gas burning, or any of that. So far. Furnace coming soon... Until then I do have a bunch of aluminum scrap i could melt with the old charcoal one. If i was only doing aluminum i might just stick with charcoal, it's easy and effective, but i want to make aluminum bronze stuff.
