Need advice, first time making evaporator.

[spason]

Thanks all for the encouragement to make a copper evaporator. It's done. Problem is, I made it with the plan to use cinder blocks. Now I have come across a primo oil tank, which I have cut to make an arch, but it is shorter than my pan.

Does the whole pan have to be above the fire? Could the part where I add the sap be hanging over the edge, or the part where the syrup will be? Should I split the difference? Or (please say it ain't so) do I need to weld another piece on to the tank to make it as long as the pan?

Here are pictures to explain, since I didn't do it so well with words:
http://www.mdimaine.us/jason/evapinator

Thanks! I'm hoping to boil tomorrow, so whatever advice you give I will put to use directly after work.

-spason

[KenWP]

I would say that the cold end would bring down the boil for the rest of the pan. Wheres your stack going to be. Add a box to the end with the stack added and your done.

[Gravel]

I too would say add on to the stack side!

[C.Wilcox]

I'd take that cut off piece of the drum that you had lying on the ground and weld it back on the end where your stack will be. That way your entire pan would have heat under it. Having part of it hanging over like it is now is probably not a big deal and you'll still boil in the rest of the pan, but how rigid is your pan? Will the overhanging copper support the weight of the sap in it?

[BarrelBoiler]

spason, i agree with wilcox get fire under all if you can
if you don't weld get some angle iron or brackets you can bolt together, of some kind to support the end and use it for a preheat area with the heat off the stack

i firgured that you would come out past the end of the pan before going up with the stack. some people have boxed in that area with sheet metal to gather and direct that heat toward their preheaters

[morningstarfarm]

how deep is that pan? looks like it should roar...

[spason]

Well, Wilcox hit the nail on the head, I measured that piece of tank to weld it back on, but was hoping I wouldn't have to. I think it is the way to go, though- thanks for your input all! I will post pictures when we boil tomorrow.

spason