18 replies to this topic

[jrwnova]

im thinking of building a waste oil forge, i like the idea and i can get as much used cooking oil as i want. i was looking at this design, http://www.backyardm...lburners10.html and it looks like it works, a few questions i have is what kinda fan can i use for this set up? i found a few forge blowers but $250 is kinda steep and im not sure how much cfm do i need. is there anything else i can use instead of a forge blower? another question i wanna ask is i would like to use this design to heat rods and square tubing so i'll have to make one that lays flat and with a different door any ideas or things i should look out for?

[OddDuck]

They work like a champ, although they can be finicky on startup. I use a version of this on my foundry furnace and I love it. A couple of notes on this style, though. You have to preheat your forge to at least a dull red to start it up, the way these injection oil burners work is that the oil is delivered through the center tube, and flashes to vapor in the hot furnace environment and self-ignites. they will put out copious amounts of heat. They will also put out copious amounts of thick black smoke if you arent careful. I reccomend highly having a propane pre-heat, this makes startup a breeze. here's a rather dark pic of my current setup:

A couple of design hints for the plumbing, don't skimp on the size of the tube from the tank to the burner. These things need good flow rates. Put a ball valve right at the burner, and one on the fuel tank. I would also highly reccomend a large needle valve to dial in the fuel flow accurately, a ball valve has a very short range of adjustment between full on and off.
You will also need a pretty good blower. Oil needs a good supply of air to burn correctly, and you need to overcome the restriction of the burner tube. Squirrel cage blowers don't handle this restriction well, my blower is a homemade radial-fan blower, 10" in diameter being turned by a 1hp 3500 rpm motor. A bit of overkill, but I have more than enough airflow. I also have a piece of sheet metal to adjust the airflow.
Now, one more thing you will have to keep an eye on, and that is the forge atmosphere. It will be tricky to maintain either a reducing or oxidizing atmosphere. Also, have plenty of ventilation, please note the comment on smoke signals.

[jrwnova]

thanks for all the info i'll use a needle valve but im still stuck on the air source. i noticed that everyone is making there own fan but i never casted anything before i could try to cut everything out of sheetmetal and weld it together but Im wondering of someone has any plans for the housing or the rotor i can look at. i would love to use propane to preheat the forge but i guess i never worked with it so im kinda iffy about it. do i just hook up the tank to the pipe and turn on the blower and the blower will keep the flame from going back to the propane tank?

[ThomasPowers]

Have you checked with a local HVAC company to see if they have a blower from a commercial oil fired unit that was scrapped out that you could get cheap? Find a fellow that works there that's interested and you might get the materials and expert help *free*!

Uh propane doesn't burn without air so unless you are putting air into the delivery tube it can't "burn back" into the tube.

Now acetylene can "exothermically disassociate" without the presence of air and is generally used at low pressures coupled with high pressure pure O2 and that can cause problems. But it's not what you are using right? (Sort of like worrying about gasoline issues when your vehicle is a diesel...)

[Mainely,Bob]

I`ve seen blowers made of high grade plywood sides and sheet metal screwed on to follow the outer curve.Don`t know what CFM you would need but but you could look at home made woodworking dust collection systems(cyclone type) to get an idea of how to construct such an animal.
I think Shopnotes ran an article with drawings a while back(within the last 3-4 years).

[OddDuck]

Jr, a shop vac would work for an air source, noisy, but it would work. Or, find a junk vaccuum and gut it for the blower. Again, noisy, but it works. You would have to set up a dump gate for both of those to control the airflow, that is as simple as a plastic tee with one of the tees covered with a moveable piece of sheet metal. You can build a blower out of sheet metal and plywood, even pop rivet it together, the biggest issue is make sure the rotor is as balanced as you can get it, otherwise it will be noisy and vibrate like crazy. Look on the BYMC forum, there's lots of posts about homebuilt blowers. Get creative, the main thing is you want a blower that will overcome the backpressure of the smaller burner tube. My burner tube is 1 1/4" black pipe, for reference.
The idea with the blown propane part is you simply add propane to the airstream, all mine is is a copper tube epoxied into the back of the burner pipe, with the inside end pinched down to form a smaller orifice. This has the added benifit of making the burner a dual fuel unit, you can run it on either oil or propane. I'll try to get some better pics in the next couple of days and post some details if that will help.
I just remembered somewhere where there are "plans" for a blower, I'm out of time at the moment but i'll find and post the link later.

[Francis Trez Cole]

Granger sells a blower Dayton #2c647 catalog 398 page3052 $56.85 is you belong to Abana you get a discount I use them on forges I build they work great.

[OddDuck]

Ok, here's the link to the plans I remember, these are intended to be built out of sheet metal:
http://www.gekgasifi...e-224/page/773/
Hope that helps.

[jrwnova]

those plans will help me out a lot thanks i found a motor at work that im not sure if it will cut it. its a 1/5 HP 115V motor that runs 1750RPM im gonna try to make that blower for it and i guess if it doesn't cut it i'll look for another motor

[Bob S]

jrwnova, on 03 February 2010 - 08:38 PM, said:

those plans will help me out a lot thanks i found a motor at work that im not sure if it will cut it. its a 1/5 HP 115V motor that runs 1750RPM im gonna try to make that blower for it and i guess if it doesn't cut it i'll look for another motor

I have a nice blower that would be plenty big. I will take a picture tomorrow. Reasonable. I am in southeast Minnesota.

Bob

[jrwnova]

ok thanks

[Bob S]

Bob S, on 03 February 2010 - 09:48 PM, said:

I have a nice blower that would be plenty big. I will take a picture tomorrow. Reasonable. I am in southeast Minnesota.

Bob

Here it is. It's has a General Electric 1/2 hp, 3450 rpm, single phase motor. The blower is 12" diameter and made of cast aluminum. Blower 'fan' is also cast aluminum. Runs good but cord is badly dry rotted. Easy fix.

Will sell and box for $100. You pay shipping.

Bob

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[jrwnova]

looks great, can you find out how much it would cost to ship it to tuxedo zipcode 10987?

[Bob S]

jrwnova, on 04 February 2010 - 08:33 PM, said:

looks great, can you find out how much it would cost to ship it to tuxedo zipcode 10987?

will try to weigh and get ups quote tomorrow.

Bob

[Bob S]

Bob S, on 04 February 2010 - 09:20 PM, said:

will try to weigh and get ups quote tomorrow.

Bob

Didn't get out there to weigh the blower today but guessed high at 50lb from my zip (55987) to yours was around $40.

That would be $100 to me and $40 approx for shipping=$140.

If you're interested send me a private message to exchange details.

Bob

[jrwnova]

ok what about refractory cement i found someone saying i can mix my own out of a few things but i dont wanna spend tons on it

[OddDuck]

JR, you want a good refractory. Don't use anything with portland cement in it. It will melt, and flux everything else in the mix as well. Same goes for perlite or vermiculite. These burners when running right will easily melt iron, and get close to steel melting temps. You will want something rated at at least 3000F, 3200 would be better.. An EPK Kaolin based clay refractory would work, Mizzou would be okay. Don't skimp, you will be rebuilding it quickly if you do.

[jrwnova]

i cant find anywhere that sells this...i did find some websites that sell it for $99 for 55lbs is that the going price or is there somewhere else i can get it

[jrwnova]

i did find "heat stop" by my house for $60 it says it handles past 2000* can i use this?