Pre Heater

[brikel]

I am considering making a pre heater for my rig using the flu. I thought of making my flu (8 inches) coming out of the evaporated out of stainless for the first 4 feet. I would then make a section out of stainless to slide over the 8 inch flue that is 12 inches in diameter ( jacket) Weld a top and bottom to it then put in threaded taps for inlets and outlets for the sap to flo through. My thoughts would be that the heat from the flu inside would heat the sap in the space between the jacket and flu. Has anyone ever seen this or tried something like this?

[optionguru]

Many of us have. I had pretty good results on my old oil tank arch. Check my gallery for pics, the sap was coming out of the preheater at about 120 to 140 degrees. The only issue I had was continuing to run water through it after I was out of sap so I wouldn't scorch the copper pipe. Takes a little preplanning. Good luck