Bachhus

Recipes 

I've tried searching for a while but havn't found a thread that covers what I've been looking for.

For those who use aluminum pots what are your thoughts on welding in aluminum couplings vs soldering or brazing in ss couplings or fittings? Which do you think would be better and or stronger? Seems like an aluminum coupling would be prone to stripping out but how much on/off of fittings would be done once you got the system dialed in?

Thanks for the help, im trying to plan my brewing rig and am shopping options at this point.

Mark

dmfa200

Recipes 

Well, welding would definitely be the strongest choice, but I suggest going weldless.
Reason being the difference in thickness between an Aluminum coupling and the wall thickness of most Aluminum pots makes for a tricky weld. An experienced Aluminum welder should have little trouble. If you've never welded Aluminum this is not a project you want to take on.
If the pots wall is of a heavy duty construction it's pretty easy to do.
The other issue is with warpage. The pot will most likely be warped where the coupling is welded to the pot. The shrinking stresses will pull that pots wall where ever it wants it to go.
Unless you can get to the back side of the coupling to weld, a full-pen weld on Aluminum is even harder. This will result in a weld with incomplete penetration.
Of coarse if this pot is for the hot side of your brewery than it's not a big deal, but who wants to see the seam of an incomplete weld? Plus debris will tend to collect in that seam.
Weldless fittings although not as strong will make the most sense for Aluminum.
They will look better aesthetically and you can remove them if you want to clean around the joint. In addition you'll save money by not having to pay for the welding, and possibly make a mess of your nice pot.
There's a lot of guys that say they can weld, but few that I call a "Welder"

Bachhus

Recipes 

Great info, never even thought about those points you brought up. Would the warpage issues be there in regards to using the soldering methods i've been reading about on here? I know there were some people having good success with some special solder that bonds to the aluminum and a ss coupling.

thanks again
Mark

dmfa200

Recipes 

Soldering will cause minimal warping, but is not nearly as strong as welding. Personally I think soldering, and brazing looks ugly.
If you already have the Aluminum pot, I would go for weldless fittings.
If you buy from http://www.bargainfittings.com/ you will better off.
Their products look to be of high quality and everyone on this forum that uses them seems to be happy with them.
I personally don't use weldless because my kettles are stainless and I weld for a living. Otherwise that's the route I'd take.
Unless you know someone that is a very good welder you always take the risk of getting something you're not going to be happy with.
Who wants to pay good money for crappy service?

Patirck

Recipes 

I was about to ask a very similar question - I have an 8 gallon alluminium pot that came with a turkey fryer. I have used it for brewing a few times before I got a keggle. Now I use it as an hlt - can I drill it and put a weldless fiting? It's pretty thin compared to the stainless stuff.

dmfa200

Recipes 

You should probably ask someone from bargainfittings to get a definite answer about minimum wall thickness, but I'm going to say that I don't see a problem as long as the fitting has full thread up to the shoulder of the fitting.

Check this page out on bulkhead install...
http://www.bargainfittings.com/index.php?route=information/information&information_id=7

bgrubb7

Recipes 

I've got the thinner gauge aluminum turkey fryer pots with weldless fitted ball valves... works great. Every now and then I get a little drip and need to replace an o-ring, but not very often.

If you want to solder, this is the stuff you need. I know it will work soldering brass or copper to aluminum, but I don't know about stainless. I would stick with brass or copper fittings & couplings if soldering to aluminum.