Waste Oil Heater Forum - Your definitive source for burning waste oil for heat.

 The easy way is to order from Aireco or ReMichael or any HVAC supply the factory replacement. Have Model and serial numbers with you. Most residential units have that roundish hut looking deal in them. Firebrick works but I stopped using it years ago in preferance of plastic refractory

http://refwest.com/plastic.aspx

 The plastic is ment for bigger industrial boilers, it "works" like half dryed out play doe, you put a piece in place then use a air hammer or dead blow hammer (orange plastic hammer) to tamp it into place. I would be carefull with the tamping force as the residential units are thin steel.  If you need it overhead or vertical for a good distance up then you need to tack weld pins on the wall to hold the refractory in place till cured.

 To cure/harden the plastic run heat on it, take your sweat ole time do it slow, if you fire it to fast the escaping steem from within will make cracks in it  ( you will allways get a few hair line cracks no biggie). Start with an electric heater for a day then salamander heater

 

Chaz,
 In my furnace the refractory was crumbling apart. I was under the impression that refractory was only used as a sound deadener. So I took the refractory out and didn't replace with anything. If I'm wrong in doing that somebody please tell me so I can make it right ~

 VERY BAD idea Chaz, Refractory is very high temp insulation that protects the steel from melting,warping,cracking,and general fatigue.
 I was on a recent call (Fire dept) were the oil boiler (not modifyed but about 15 year old) burned out the combustion chamber. The unit was sitting on a concrete pad that got so hot it started the floor under it smoldering.
 I ran big boilers at work (12 million btu vapor heaters) for 10 years, we took them apart every year and repaired the refractory.

It is even more important to have good refractory when the cycle rate is high (fire on,fire off) as the steel will expand and contract with each cycle leading it warpage and cracking, once a crack is there the superheated gas will blow through it and become a big hole very fast.

Looks simple enough. How do you regulate the heat with this set up?~

 Ohh dang I forgot a few important details- Wile brazing them together add into the joint area a 1/4" coupler (used to join all thread, looks like a super fat 1/4" nut), this is were the thermocouple fits in. or if you get  enough fill in the joint (sil phos) drill and tap.

  I use this pid and k thermocouple

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350267486390&ssPageName=STRK:MEWAX:IT

Add a relay and cartridge heater and you are set.


 

For cheap do this.

Im glad you work metal

 Well its not the right stuff to make a drip style out of. Its a good unit for pressure or siphon. The drip system is built in a tank were the gun style is fired into an exchanger.

 Cheers D.E.

Started the Combustion Chamber~ Built of 10 inch pipe inside a water tank.

No pics yet but a drawing I made.

Depends on how hot. I say mig weld it.

You could try plastic refractory, roll it then work it in place like play doe.  Then slow fire it hard. 

 Looking good nik. Thanks for the update.

 How will you go about the metering pump?  On the altfuelfurnace group there are a few people using a standard gear type pump driven by a dc gear motor (about 300 rpm I THINK) and a pwm supply to control the speed.

D.E.