pre heat coil ?

[Sweet Shady Lane]

I am a small back yard guy 20 taps and use a 12 inch x 20 inch x 6 inch deep pan in 55 gal drum set up with a 6 inch smoke stack how many coils of 1/4 copper tubing should i use for my pre heat set up. Looking to improve for next year.

[Kev]

its probably more contingent on how much heat you have at the location on the stack with the fire you normaly run with, than a specific amount of coils for all situations.

[Piscataquis]

I made one once that had about 7 or 8 coils wraped around a 6 inch stove pipe. One the end I had a ball valve cracked just enough to maintain the level in the pan I wanted. I worked great the sap would be around 190 when it hit the pan. On occasion the flow would become vapor locked so you had to watch for this. Good luck

[KenWP]

Any reason your using 1/4 inch copper.It will vapor lock real quick on you.The 1/2 inch will work a lot better. I use about 20 wraps due to wanting hot sap pouring in.

[maple6275]

KJB, I'm in about the same boat as you. 24 taps on my homemade evap with a 6" pipe. I just set up a pre-heater last weekend, and can tell you that 5 wraps (10 feet) of 1/2" copper tubing doesn't do squat! I wanted to stick with 1/2" to help avoid vapor lock. So, faced with the choice of going back to home depot for the $50 20-ft coil of copper, instead I decided to put my pre-heater inside the pipe. I just wound the coils a little tighter, to about 5.5" diameter, then cut a 1" wide slit 12" down the lower section of stove pipe to slide the coil down in. Dropped the upper sections of stove pipe back on top and down over the slit. I haven't fired it up yet, but am anxious to see what happens next weekend! Will post a pic later if you're interested.

[vtjeeper]

KJB, I'm in about the same boat as you. 24 taps on my homemade evap with a 6" pipe. I just set up a pre-heater last weekend, and can tell you that 5 wraps (10 feet) of 1/2" copper tubing doesn't do squat! I wanted to stick with 1/2" to help avoid vapor lock. So, faced with the choice of going back to home depot for the $50 20-ft coil of copper, instead I decided to put my pre-heater inside the pipe. I just wound the coils a little tighter, to about 5.5" diameter, then cut a 1" wide slit 12" down the lower section of stove pipe to slide the coil down in. Dropped the upper sections of stove pipe back on top and down over the slit. I haven't fired it up yet, but am anxious to see what happens next weekend! Will post a pic later if you're interested.

I used 3/8 tubing last year around the outside of an 8 inch stove pipe, 2x6 flat pan on cement blocks. used 25 feet and it didn't seem to do much, moved up to 50 feet and still didn't do much, even with insulation around it. this year I went back to 25 feet but put it inside the stack and very very quickly it vapor locked and nothing would come out but steam. I dissconnected it and blew it out with my compressor and ran with a pot and spout pouring the sap in again. today or soon I will either try the 1/2 copper as mentioned or try cutting the 3/8 tubing back to maybe 3 loops inside. I actually have the 1/2 copper but don't have fittings for it, but it does sound like it would work better for my situation. there doesn't seem to be a hard and fast rule for what works for everyone.

[nace]

i used a 10' piece of 1/2" copper around an 8" stack. my so called evaporator is a turkey fryer and roasting pan with propane. i had cut a thin sheet of steel to match the oval bottom of the pan and glued regular stove door gasket around the cutout. i also covered around and under the burner and had a stove flue out the back with a damper above the tubing. i wraped 3 rounds of heavy aluminum foil around the tubing and would have used insulation but didn't have any. all that to say it hepled some and i think it was worth it. averaged about a gal/hr. at about 10 drops/sec. the tubing would be hot enough that you couldn't hold it. when i had to open the valve to a small but steady stream it would cool to luke warm. again that was with propane and a closed damper. good luck...nace