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Foundry furnace



Gadget
06-13-2009, 02:41 PM
I just converted my propane foundry furnace to waste oil. I made the burner from instructions at Back yard metal casting http://www.backyardmetalcasting.com/forums/viewtopic.php?t=3057

I hooked the unit up with just a siphon hose in a cup of waste oil, placed an oily rag in the furnace, lit the rag and turned the burner on. It started burning very nicely. I found that if you adjust the nozzle in and out of the tuere it changes the burn properties so I slotted the mount allowing for an inch of adjustment.

Next project, cast a mounting bracket for my plasma torch to hook it to my CNC table more securely.

HerbD
06-13-2009, 09:24 PM
Looks cool (hmmmn should that be HOT!)

Does the acorn nut have a hole or holes drilled into the end? I'll follow the link and see what it has. When you start it up is there a lot of smoke until it heats up?

I still haven't fired up my charcoal/flower pot furnace. Need to finish the metal brake that will help bend the transition piece from the rectangular blower to the round air injector. Week at the beach ends tomorrow, so I'll get back on finishing a couple of welding projects.

Also, daughter is a ceramics teacher so we're making our own clay mixture to get some crucibles fired. Fun, fun, fun.

Thanks for sharing,

HerbD 8-)

Gadget
06-14-2009, 06:43 AM
Herb,
It wasn't too smoky at the start but there was some. It got hot enough to burn clean fairly quickly. Still, I think this should be run outside or with a hood and blower vented outside. Propane is cleaner but waste oil is free and plentiful since I do my own oil changes.
I think I will do a melt today, I will take some videos and post them if I do. I will try to include the startup.
Dan
By the way, there is a hole in the end of the acorn nut, the oil feed sits inside the hole with enough air space around it that the compressed air siphons the oil.

HerbD
06-14-2009, 08:50 AM
Thanks Dan,

The setup looks pretty efficient, maybe my next step if I have success with the flower pot furnace I've built. I live in the city so I was concerned about the neighbors being upset about smoke, etc.

This might be a great project for my place in Michigan, nobody bothers you there and we have 12 acres of forest to play in.

My other project is a larger oven for my powder coating projects. I'm using propane for that. It is framed with metal studs and sheathed in aluminum. Only needs to get to 400 degrees. I'm having trouble locating a local source for mineral wool to insulate it with. The mineral wool just isn't popular in the desert regions.

Good luck on your first burn. I assume the furnace itself has already been used with an other burner? What are you casting by the way, if I may ask?

HerbD 8-)

KHK
06-14-2009, 09:57 AM
Dan, will an oil like mobil 1 work in the furnace?

Gadget
06-14-2009, 04:44 PM
Keith,
I suspect the synthetic will work in the unit when I get it fully tweaked.
I tried a melt today but it didn't turn out well. I guess I have more tweaking to do. The burner didn't sustain itself after the oily rag burned out at first. I started getting oil pooling in the bottom of the furnace and started getting concerned what would happen if it finally got hot enough. It did start to burn without the rag but it was pooling too much oil. I had to bail on the oil burner and used the propane to do a melt and clean all the oil inside the unit.
I'm not sure why it wouldn't sustain itself. Perhaps the tube was too small a diameter or the air flow was too restricted. I will keep playing with it and hopefully getting it working. I was sure counting on burning all my waste oil instead of using propane.
I got all my scrap aluminum melted down into ingots with the propane so the garage looks better now.
By the way, I did get lots of oily smoke. I was kind of worried the neighbors would complain.
Dan

Gadget
06-14-2009, 07:33 PM
Well I guess I should have read the burner article more carefully. I should have had a 2"tuyre and a blower behind the burner. I will give it another try next weekend. I am sure the burner works ok, the oil comes out in a fine mist, I just didn't have enough air behind it for proper combustion and too small a tuyre.
Dan

henrym
06-14-2009, 11:01 PM
nice. it is inspiring to see what can be done if you try. on another forum, someone made a very nice cast-aluminum tube-bender die out of scrap Alu, for a home-made bender. and the steel dies around here go for around $250+

I was thinking how cool it would be to make a blast furnace, but it is probably too messy to have around here. I might be better off making a mini arc furnace!

Gadget
06-15-2009, 05:10 PM
nice. it is inspiring to see what can be done if you try. on another forum, someone made a very nice cast-aluminum tube-bender die out of scrap Alu, for a home-made bender. and the steel dies around here go for around $250+

I was thinking how cool it would be to make a blast furnace, but it is probably too messy to have around here. I might be better off making a mini arc furnace!

I have thought about making tubing bender dies out of cast AL. It may take more than my crucible can handle right now. I have a larger furnace planned for the future. I just cut up a 40Lb propane tank for the shell a few weeks ago.

Dan

arandall
06-15-2009, 05:29 PM
Dan:

Did you take any precautions when cutting the propane tank open? I cut open a 20lb one last winter and got away with it, but I was definitely holding my breath while doing it - didn't know if any lingering propane would pop or not.

Cheers,
Art R.

Gadget
06-15-2009, 05:47 PM
I left the tank open for a month. Then I used a hole saw to cut an opening in the bottom (1.5"). I then filled the tank with water for a few days. I laid it on the side and started cutting while the water was still draining. I was holding my breath when cutting with the hole saw but after that I wasn't too concerned.

Dan

henrym
06-15-2009, 10:47 PM
i have a propane cylinder I want to use for other things, too. except I want to try unscrewing the valve etc. and filling with water. an open, apparently empty cylinder can have a proper fuel/air mix for exploding! just remember that propane gas is heavier than air.

is there anything that might cause trouble if one were to simply go at the valve with a wrench? it seems unlikely that brass on steel can ignite anything.

Gadget
06-16-2009, 05:49 AM
I don't see a problem but the valves tend to be on so tight you cannot remove them. I couldn't on mine which is why I drilled the 1.5" hole. I stored the tank with the hole up for awhile (days) then down to insure no residue.