drop tube questions

[mountain man]

hey everyone. i am currently planning a drop tube project for next year[2014]. 1st question:would or do pans need to be emptied before a good freeze up seeing as copper would split easily?2nd :i have a length of 1.5" id copper ,would 1.5" be too wide for some reason or another?i know flaring would be more of a challenge than smaller diameter material.any feedback would be appreciated.

[lfdiaff]

I am about 90% done with mine. I got the idea from here. I used 3/4 type M pipe due to it being cheap and 3/4 caps are cheap. With 1.5'' you might want to price material first. If I had to do it again i would just buy a flue pan. I was going to this year but ran out of time I could not have one made by the start of the season. The people on here must be way better at metal working then I am because they made it sound easy. It took me 10 hours to drill the holes and flare the tubes. That was the easy part. Silver soldering them in was another story. For one thing when I went to buy silver solder they asked for the deed to my house. For a 1 Troy Ounce roll which did about 15 tubes was $27. I did 150 tubes. When you first start to solder it goes good. As you get closer and closer to each pipe it becomes a different story. Obviously when you heat up the stainless is warps the bottom and it will either go up or down in a bowl shape about 1''. As you get close to other tubes the copper absorbes the heat so one side will hump up and the other will stay some what flat. This becomes a big problem. I almost had a breakdown a few times. I can say that every other part of the new evaporator build was alot of fun but not the drop tubes. I am pretty anal when it comes to the looks of things and wanting it to look good and the pan I did does not look good at all. The bottom of the pan is warped and I had to sand blast the bottom to get the flux off. As far as draining yes you would have to drain if the temps got below freezing or keep a little heat on your pan all night. Unless you have almost syrup in your pan. I am thinking about putting a small propane flame or 100 watt light bulb in mine overnight.

[HyeOnMaple]

Hey Ifdiaff,

My hat is off to you for 150 tubes! I finished my 58 just last week. And, Yeah, I spent a month on mine, nights and weekends. You were smart to cap the ends, I crimped 58. I think I would have gone berzerck if I had done 150. Mine was 1" (mostly M, some L), but at $1+ per cap, crimping was closer to the budget. As I told the clerk at our local plumbing shop, I have more time than $$$. Next time, BUYING. BTW, I used soft solder (SilvaBrite 100, Wolverine Joining Mfg.) $29/lb, and went thru about 2 lbs total (and I was wasteful). The trick to joining onto the pan is to tin the holes first under very low heat, and then tin the underside of the copper lip. Once the copper is in place, using a LITTLE higher heat, warm the inside of the copper tube and let the solder on the pan melt from that. When I did this, my pan wanted to warp a little, but once it cooled down, it regained its original shape. Also, I had eight rows of 8 tubes (minus a couple). I would solder in a row, flip the pan, seam and solder the ends (check for holes), flip the pan and do the next 8. This kept any one part of the pan from staying too hot.

Hey, MM

What others have said is to use thin wall (type M) tubing. but I wouldn't want to try to anneal, flare, flatten, (and crimp?) something that large. As for the draining, since straight sap doesn't freeze well, I wouldn't be inclined to worry about anything that had boiled for any period of time. It's not like you take out the coals at the end of the night and replace them with blocks of ice. Eventually, you have to do what will help you sleep at night. If you do tackle that 1.5", God bless you. You'll need it. How many drops are you thinking of making?

Tap, tap, tap

[mountain man]

thanks for the responses!i was assuming similar results.i think i would be close to insanity trying first to cut holes in a perfectly good pan and then trying my hand at inexperienced soldering[copper to stainless].i bought a dollar store stainless bowl to practice on with regular paste flux and regular copper solder and had impressive results but i think lady luck was looking on.to answer your question hye,i have 6' of 1.5" so to start with 14 -5" tubes and then the rest to be decided most likely using 3/4 pipe.i see the project as being able to add more every year up to a certain point.i'm into this for the fun of it, so maybe i should see if i'm happy enough with just a flat syrup pan.i don't know if the syrup goddesses would forgive me for ruining a pan!

[mountain man]

mm again. sorry.i don't know if my wife would forgive me either!