Welding Copper To Stainless

[Salt Must Flow]

I'm considering building a ridiculous size 3" Shotgun Condenser 4' long for stripping. I have a bunch of 3" stainless pipe I got for free. Would just need a couple of 3" ferrules and some copper pipe. I'm guessing the TIG welding would cost me $30.

I found some 3" copper disks - 0.08" 12 Gauge. I'm thinking it would be really simple to just sandwich the copper disk between the ferrule and the stainless pipe then having it TIG welded. Anyone see any issue with welding it like this? When in use, the shotgun condenser would be used at an angle and the end would be suspended/supported/hung by paracord so there shouldn't be any EXTREME forces applied to the welds.

Copper Disks.png

I initially planned on buying 3" stainless steel disks, but copper is MUCH easier to solder the pipes to.

[Deplorable]

How much power do you have available?
With enough cooing water flow, I can't overpower my 2"×20" all copper shotty.
Or are you doing this "just because"?

[Salt Must Flow]

How much power do you have available?
With enough cooing water flow, I can't overpower my 2"×20" all copper shotty.
Or are you doing this "just because"?

I'm mostly concerned with the integrity of the weld.

I strip at 11000W. With a 2" x 24" copper shotgun condenser, the low wines exited at 101F-107F at 252-307 LPH. I then joined two 2" x 24" copper shotgun condensers together and my low wines exited at 95F at 245 LPH. A 3" shotgun has approx 50% more surface area so it's just an idea I've been considering.

[Deplorable]

Ahh. I see.
That would be my concern as well, but I suppose it would be fine, them Chinese manufacturers are welding SS ferrules to Copper pipe, and I've yet to hear of anyone saying their equipment from Oak Stills has bad welds.

[MooseMan]

I can't see an accomplished welder having an issue with what you propose SMF, especially since it's very thin so they will be bridging the weld over the two stainless faces anyhow

Maybe ask before you buy the copper if that's possible, but the guy who's welded for me would not hesitate to weld copper tubing to stainless when I mentioned it, so I don't think this would be a problem at all.

[Thumperbunny]

Prolly best to silphos it. Hi silver an it sticks well.

[Salt Must Flow]

The wife's sick, got bored and started cutting some 1" copper pipe to make 10 baffles for a ridiculous 3" x 50" shotgun condenser. So far I've cut the disks, center punched each spot and ground the disks to fit. Just need to drill the baffles out on a wood jig. These are just the internal baffles. This thing is going to be crazy. 14 x 3/8" (1/2" OD) copper pipes.

09 Grind To Fit.jpg

I have everything to complete this other then 2 ferrules, two 3" copper end plates and the copper pipe. Once I get the rest in, I'll post a complete build thread.

[MooseMan]

Holy shit that's going to be a monster!

[NorthWoodsAb]

A 3"x50" shotgun will definitly have a cool factor. Looking forward to seeing it completed.
Filled with water it is going to be heavy. Going to have to be self supported or suspended.
Edit on the weight.

[Salt Must Flow]

Holy shit that's going to be a monster!

Oh yeah. I figure since I strip at 11000W, my last stripping run was with two 2"x24" shotgun condensers and the product was exiting at 95F, I might as well make a shotgun that's just as long, but twice the internal surface area, see if that drops the product temp and/or reduces water consumption. The length is convenient for me.

Stripping 04.jpg

I searched this site and I recall only finding one other guy who built a 3" shotgun, but it was 18" long. I don't know when I'll complete the build, but I suspect it will be around Spring. Being bored, I stayed up and completed all 10 baffles

[Salt Must Flow]

A 3"x50" shotgun will definitly have a cool factor. Looking forward to seeing it completed.
Filled with water it is going to be heavy. Going to have to be self supported or suspended.
Edit on the weight.

Yeah I calculated what the weight would be and it should be around 19 lbs dry and if my calculations are accurate, it should be approx 26.5 lbs filled with water. If you look close at the pic in my previous post, the end of the shotgun condensers are suspended by paracord from a 2x4 above.

[MooseMan]

Yeah 11000 is gonna need a fair bit of knockdown!

Forgot to say, I hope Mrs SMF gets well soon.

[Oldvine Zin]

I searched this site and I recall only finding one other guy who built a 3" shotgun, but it was 18" long. I don't know when I'll complete the build, but I suspect it will be around Spring. Being bored, I stayed up and completed all 10 baffles

here is my 3x24" shoty build
viewtopic.php?p=7380509#p7380509