Adding fins to bottom of flat pan (?)

Ken you have inspired me to upgrade my back SS sink pan as you are doing. My pan is 15x 21 and is now marked with 15 one inch circles which I will start to punch out with a Greenlee punch, flare, and soldere in place.
Made a test piece with a scrap piece of SS and it went quite easy. The key to easy soldering is in the proper flux, which needs to be acid based.
I am making my drop tubes 3 inches long which will add about 9 square inches of surface area each, or 135 added to the 325 inches of the flat pan. I suspect it should really give my rear pan a real shot in the arm.
The only concern I have at this time is, what effect of it may have on the pan in terms of warping when I put the fire to it.

Rick

Already thought to go to 3/4 as that,s easy to come by in the hardware in town and I have the tools already to drill holes that size. The 1 inch is a problem to find here for some reason. I am thinking to much on heating up a 3/4 inch tube might cause the sap to spout up to much.

Ken,

I found a left over scrap and my copper tubes were about 1.125 OD, like yours.

3rdgen,

No reason to avoid other sizes. Rather than caps, if i was doing this again I would flare one end, solder in place, pinch and solder the bottoms. Cheaper than caps.

Rick,

I'd make them longer if you can. Mine were 6 or 7 inches deep and worked great. Liquid acid flux, clean surfaces, low heat and tinning both surfaces firs made soldering (almost) easy. The bottom of the pan remains unwarped.

I'm looking forward to seeing how you guys like the flue tubes. I sure did!

I am thinking of adding a manifold to the bottom of the drop tubes by using Tees with elbows on the first and last in each row. Using 1" copper, 3" Drops. Does anyone know if by adding manifold to the drops will the sap make geysers at each hole opening?

I was thinking of Drop Tubes with a manifold connecting all the drops. Now rethinking maybe 2" Copper thru the pan end to end 1/2" off bottom. Re thinking because Tees are 8 bucks a piece and 10 holes to solder are easier than 50. 2" Copper is 145.00 per 10' Length
2 lengths will give 5 thru tubes in 4' flat pan. 5 Tubes will add 1508 Sq" of area to pan. Current pan size is 28" x 48" (1344 Sq"). If I calculate right that should give 112% better boil rate. Has anyone ever tried thru flues? Basically the way I am thinking is that they are just like drop flues but are attached on the end of the pan and flue gas is directed into them and out the back of the pan as well as going under pan. Any ideas will be appreciated as I would like to get started soon.

Martin
1st yr 5 taps 2 steam table pans
2nd yr 20 taps 4 steam table pans
3rd yr ?? Maybe 50

Here is a cool drop tube evap from along time ago I found it by doing a search for patents at Google Patent.

It is kind of cool that it uses the tubes as the grates.

That's sort of how a old coal frired boiler worked. Was made of hollow plates in a square and the coal burned in the middle. I took many of them apart out of old CPR train stations .

I wonder how well new sap would replace the soon to be syrup. I think the tubes could vapor lock and you would get scorching.

MartinP,

Drop tube evaporators are made commercialy the way you are thinking (horizontal). I believe WF Mason makes them. I know a guy who has one and loves it. It might be had to find, but price out a 20' length of stainless. I bet it would be cheaper than copper. You would need a plasma cutter to cut, but it would be easier to clean.

Makng tubes connected on the ends was my dea also as it would requre less holes to solder up. I would lke to use SS tubeng but who knows where to get it around here also. I used to use it in half inch water pipe for years but its expensive.