Soldering immersion flange to stainless tank

[Kev888]

Just out of interest why you putting in a brass piece to add an element. why not put in a Stainless piece and stainless weld it?

Because as I mentioned in a post higher up I don't have any suitable welding gear (or in fact a handy source of ss flanges) - the only welder I have is a crude stick/arc thing that struggles with thinner sheet even in mild steel. But on the other hand I do have soldering gear and have soldered brass immersion flanges into copper cylinders quite easily before; from what i can tell, there doesn't seem to be any reason why soldering to stainless should be any less successful (if you use the right flux anyway) so I thought it worth a go - aside from the flux it won't cost me anything much and so if it doesn't work out then there's nothing lost really.

If that goes pear-shaped then getting it welded somewhere would definately be a fall-back though.

Cheers,
Kev

[Talisman]

Ahh fair one. Was late when reading it. I did have brass connector on mine but it started weeping. Tried getting it re soldered but found everytime I tightened up the element again it snapped the weld. Thought sod it. Kncked it out n got someone to weld me in a stainless socket to take the element and put two in at the same time.

[Kev888]

Ahh fair one. Was late when reading it. I did have brass connector on mine but it started weeping. Tried getting it re soldered but found everytime I tightened up the element again it snapped the weld. Thought sod it. Kncked it out n got someone to weld me in a stainless socket to take the element and put two in at the same time.

No probs at all - I'm grateful for any thoughts and its definately worth bringing these things up, so thanks for chipping in. I've done lots of stuff with copper and brass, but working stainless isn't something I've as much experience with.

Its interesting what you say about the soldered joint; guess maybe there was a weakness in it somewhere. In theory there shouldn't be any real force on the joint through tightening the flange (except for rotational ones which it should be able to take easily), I wonder if the flange could have been slightly out of true or something (maybe due to the heat/contraction of soldering) and so getting pulled flat again when tightened up. Perhaps thats one issue where a thick stainless wall may differ from copper cylinders, in being less willing to conform if something isn't flat and true. Hmm.

Well I'm hoping to have a go next week sometime in any case. If the flux materialises I'll try soldering first, if not I'll probably go direct for the mechanical flange. I've used one of those before as well as the solder-in ones, they're nice robust affairs once in (though it was a b#@@£r to tighten without the right tools) and didn't rely on sticking/fusing to the tank so should work just the same. If I packed some LS-X or something behind the inner part it should be no worse than normal for cleaning, either.

Thanks again,
Kev

EDIT: - hmm the thing froze when I submitted - seems I managed to post twice, sorry about that. If any mods happen on this and can be bothered please feel free to remove one!

[Kev888]

Ahh fair one. Was late when reading it. I did have brass connector on mine but it started weeping. Tried getting it re soldered but found everytime I tightened up the element again it snapped the weld. Thought sod it. Kncked it out n got someone to weld me in a stainless socket to take the element and put two in at the same time.

No probs at all - I'm grateful for any thoughts and its definately worth bringing these things up, so thanks for chipping in. I've done lots of stuff with copper and brass, but working stainless isn't something I've as much experience with.

Its interesting what you say about the soldered joint; guess maybe there was a weakness in it somewhere. In theory there shouldn't be any real force on the joint through tightening the flange (except for rotational ones which it should be able to take easily), I wonder if the flange could have been slightly out of true or something (maybe due to the heat/contraction of soldering) and so getting pulled flat again when tightened up. Perhaps thats one issue where a thick stainless wall may differ from copper cylinders, in being less willing to conform if something isn't flat and true. Hmm.

Well I'm hoping to have a go next week sometime in any case. If the flux materialises I'll try soldering first, if not I'll probably go direct for the mechanical flange. I've used one of those before as well as the solder-in ones, they're nice robust affairs once in (though it was a b#@@£r to tighten without the right tools) and didn't rely on sticking/fusing to the tank so should work just the same. If I packed some LS-X or something behind the inner part it should be no worse than normal for cleaning, either.

Thanks again,
Kev

[AiredAle]

Kev,

Take a look at this thread on soldering stainless steel - http://www.homebrewtalk.com/f51/solderi ... el-155782/ Lot of information there. The products mentioned may not be available in the UK, but the information is still very useful.

I have soldered both brass and stainless fittings to stainless pots/kegs, and it ain't so easy. I am pretty good at normal copper and brass soldering, but stainless is (for me at least) more difficult. The issues are cleaning, keeping the parts from overheating and keeping enough flux in the joint to get good wetting and flow of the solder. It can be done, and is strong enough for your purpose. You might try to get the solder and flux at a local welding supply shop, that's where I got mine, but that was here in Minnesota.

Good luck.

[Kev888]

Kev,

Take a look at this thread on soldering stainless steel - http://www.homebrewtalk.com/f51/solderi ... el-155782/ Lot of information there. The products mentioned may not be available in the UK, but the information is still very useful.

I have soldered both brass and stainless fittings to stainless pots/kegs, and it ain't so easy. I am pretty good at normal copper and brass soldering, but stainless is (for me at least) more difficult. The issues are cleaning, keeping the parts from overheating and keeping enough flux in the joint to get good wetting and flow of the solder. It can be done, and is strong enough for your purpose. You might try to get the solder and flux at a local welding supply shop, that's where I got mine, but that was here in Minnesota.

Good luck.

Thanks very much for that. Yes that sort of supports what I was thinking/expecting, which is good stuff.

I tried the local welding suppliers, they seem to only sell suitable flux for welding or at the very least braizing, and that isn't said to be suitable at soft soldering temperatures. I have found another supplier of it though, at a price.

I think with all the help here I'm heading towards a reluctant conclusion though: Soldering is looking expensive for what it is, its difficult to get hold of the flux, and theres a general feeling coming through that soft soldering would work but isn't especially easy to get right and even then isn't as good as welding. So probably its looking like the mechanical flangeis the way to go (maybe its fortunate I couldn't get the flux!). It'll be cheaper, much more physically robust, I can still do it myself, there's far less concern of not getting it right, and the only issue is the internal part offering a place for stuff to lurk behind. I can get over that by using some sealant before I clamp it up.

Excellent, very helpful so thanks again.

Cheers
kev

[boingy]

I have to say that unless you have a reasonable amount of experience of that type of soldering you are most likely to mess it up.
Go for the screw-on flange plus a sealing washer or two every time.

[Subsonic]

I have to say as well, that I soldered my stainless keg and it was an UTTER PIG! It worked but after a bit the joint started to fail from work fatigue. Welders are easily bribed with beer. Try and get food grade welding and a few pints will be money worth spent. I welded the stainless and also used brass tank connectors. My setup is now lovely, and more to the point - able to withstand a few donks and dings. Cutting stainless is also a b@$tard. Tip - a chainsaw file in a drill with coolant (water from hose) makes a nice 'small grinder' for your tank connector hole. If the keg / pot is too round to be 'flat' bash it with a hammer. Stainless is very forgiving. If you are using a keg feel free to ask me....Subsonic.

[Kev888]

I have to say that unless you have a reasonable amount of experience of that type of soldering you are most likely to mess it up.
Go for the screw-on flange plus a sealing washer or two every time.

Well i've done a few flanges in copper cylinders, but its looking like stainless is a different boiler of fish.. so I'm definately coming around to the same opinion.

I have to say as well, that I soldered my stainless keg and it was an UTTER PIG! It worked but after a bit the joint started to fail from work fatigue. Welders are easily bribed with beer. Try and get food grade welding and a few pints will be money worth spent. I welded the stainless and also used brass tank connectors. My setup is now lovely, and more to the point - able to withstand a few donks and dings. Cutting stainless is also a b@$tard. Tip - a chainsaw file in a drill with coolant (water from hose) makes a nice 'small grinder' for your tank connector hole. If the keg / pot is too round to be 'flat' bash it with a hammer. Stainless is very forgiving. If you are using a keg feel free to ask me....Subsonic.

well I think that nails the coffin. I'd still like to do it myself so am keeping the friendly welder in reserve at the mo - hopefully if it comes to that I'll be able to remove any incriminating evidence of incompetence before I take it anywhere.. I've not had 'too much' trouble with cutting stainless in the past, though its not exactly the nicest i agree; with a slow speed and a cobalt holesaw it's always seemed reasonably achievable (after a recent bathroom alteration, drilling 3/4" holes in porcelain tiles is my new bench mark!). Bashing a flat on the tank was what I had in mind as well, so thats good to hear too.

Thanks for all the advice - I'll try to take/post some pics after I do it!

Cheers
kev