Stainless Steel CFC build

[mwill07]

so I recently built a CFC from SS tubing. I detailed the build here and testing here. In summary, I purchased the tubing and fixtures from stainlessbrewing.com. The coil is 25', terminated with stainless tee fittings and using bushings and JB Weld.

total cost: $90.25, plus the cost of the hose (which I already had).

Why stainless? I may choose to go LoDo one day. I'm trying to future-proof myself a bit here. Plus, stainless is easier to clean, it's shiny, and the loss in thermal conductivity is negligible (I think), especially for a 25' chiller.

Here are some pics:

hose and tubing:

feeding the hose over the tube: this took about 2 hours to do.

Dry fitting the hardware:

JB welding on the bushings:

mounting the chiller (hard-plumbed to my rig with copper pre-chiller):

thermocouple to track wort exit temp:

Performance: (T1 = thermocouple - external temp of ss tube, T2 = directly measured temp discharging from CFC)

In summary, with ~60 F tap water, I can start draining into the carboy at pitching temp within 5 minutes of the end of the boil, which is pretty great. I can have the entire 5 gallons in the carboy at pitch temperature within 10 minutes. This is comparable with my old plate chiller, which could do the job in less than 7 minutes. In my opinion, the extra 3 minutes for the CFC is more than worth it, given the cleaning requirements of the plate chiller.

 

[apache_brew]

What's the JB weld for? Why not use compression fittings?

 

[mwill07]

What's the JB weld for? Why not use compression fittings?

1. more expensive.
2. I based my build on another user (his blog is down right now but here is the link) . He used JB weld instead of fittings because he jambed up the tubing while straightening the legs. becasue of the tightness, he couldn't get the fittings on. I figured I'd just skip to the end and go directly to JB-weld.

It didn't actually work for me. a month or so after this post, I mounted the chiller on my rig and the ends of the CFC weren't exactly where I wanted them - not quite parallel. So, I bent it in place and let it go. Well, that put a lot of torque on the fitting and it eventually popped the weld. so, I did buy a SS fitting and managed to get it in place. It wasn't easy - when straightening my tube, I squeezed it a bit and it was more oval than round. So, I brought it back into the shop, squeezed it the other direction and got it pretty close to round. To get the ferrule in, I used a lot of WD-40 to lube it up, a washer that fit snugly against the ferrule, and slipped a piece of pipe down over the washer. I was able to hit the pipe with a hammer, driving the ferrule down the tube and into place. It wasn't easy but I was able to make it work.

 

[Bobby_M]

It's hard to make compression ferrules work on tubing that has been beaten up so one trick is to upsize the fitting and replace the ferrules with a short stack of orings. It won't hold 100psi, but that's not really the point either.