2.5" Copper Woes

[iDrinkWash]

So, I am FINALLY starting my column build (after years of prep and reading). I just recently got a smokin' deal on some 2.5" Type M pipe. Basically almost scrap prices.

So now I'm trying to figure out how I am going to modularly connect the stack to the head (or maybe even the head right to the boiler for pot still runs). The pipe that I have is 2.5" ID. It seems like all the tri clamp ferrules (copper or stainless) are sized for OD (and nobody makes a copper one that big, anyway). I have a 4" TC fitting on my boiler - so I was going to use a reducer anyway to fit the stack. I don't want to use any brass. I was hoping to braze on some stainless or copper TC ferrules.

My only choices seem to be:
1) have a machine shop bore out the center of a 3" TC blank to fit the OD of my pipe (about 2.6"), or
2) (from another thread here) have a muffler guy flare out the ends so the OD is 3" - and I can use a 3" ferrule

#2 seems extreme. I don't think they can flare it out that much.

Any help or advice for modular connections would be greatly appreciated. Thanks!


iDrinkWash

[nuntius01]

well, that is an odd size pipe. if you go to your plumbing supply house you can order a reducer. down side is its going to cost you. personally, if you have enough material, let your friend flair it. i'm personally a big fan of free or cheap. if it cracks then at least you tried. i can tell you that i have flaired all my pipes to fit over my ferrules. but that was only maybe a quarter inch at most. good luck

[cranky]

I once tapered a pipe by cutting multiple slits in it then forcing it inside a 2" opening and soldering it to fill the slits. It worked very well and cost almost nothing.

[cob]

you need to look in the right place. https://www.jmesales.com/bradford-l14am ... -ferrules/" onclick="window.open(this.href);return false;" rel="nofollow

[Yummyrum]

IDrinkWash
If your pipe is ID and your ferrule is OD I can't see why you can't stick the ferrule inside the pipe and solder it together .I believe it is a tight fit but if you anneal the copper first ( heat it to almost red hot ) it will be quite maluable and expand easily which is also something you should do first should you go the route of the muffler expander guy . Un-annealed pipe cracks , annealed pipe stretches.

[thecroweater]

get some 1/4" copper tube, wrap it tight around ya pipe and mark at the point it overlaps. Saw it at this point then hard solder it to form a ring, at this point you have two choices but my favourite is simply stand the pipe on a hard surface and slip the ring over the pipe then hammer the ring flat. It will compress tight to the pipe and taper so just hard solder to the pipe. The other way is soft solder and then you will want to hammer out a lip on the column first for extra strength.

[iDrinkWash]

well, that is an odd size pipe. if you go to your plumbing supply house you can order a reducer. down side is its going to cost you. personally, if you have enough material, let your friend flair it. i'm personally a big fan of free or cheap. if it cracks then at least you tried. i can tell you that i have flaired all my pipes to fit over my ferrules. but that was only maybe a quarter inch at most. good luck

I know I can get 2.5" stainless ferrules. Without flaring, the ID of my pipe would match the ID of the ferrule - so if I had it flared, it wouldn't have to go too far. Just enough to slide over the flange of the ferrule. Next question - any tips or tricks for brazing copper to stainless? Can I use mapp gas? Will I pull too much carbon to the surface if I don't purge with inert gas? I assume that liquid flux and silver brazing rod will work.

Thanks again for any advice.


IDrinkWash

[iDrinkWash]

you need to look in the right place. https://www.jmesales.com/bradford-l14am ... -ferrules/" onclick="window.open(this.href);return false;" rel="nofollow

Ah, those might work. Thanks, Cob. I'll give those a try.


IDrinkWash

[Tapeman]

you need to look in the right place. https://www.jmesales.com/bradford-l14am ... -ferrules/" onclick="window.open(this.href);return false;" rel="nofollow

Ah, those might work. Thanks, Cob. I'll give those a try.


IDrinkWash

I'd go with the right size ferrules. The stingy man spends the most, and I speak from experience. Nothing like the vapor pouring out of the pot when something lets go to make you rethink your build decisions!. Good luck and may you be in the best of spirits!

[nuntius01]

well, that is an odd size pipe. if you go to your plumbing supply house you can order a reducer. down side is its going to cost you. personally, if you have enough material, let your friend flair it. i'm personally a big fan of free or cheap. if it cracks then at least you tried. i can tell you that i have flaired all my pipes to fit over my ferrules. but that was only maybe a quarter inch at most. good luck

I know I can get 2.5" stainless ferrules. Without flaring, the ID of my pipe would match the ID of the ferrule - so if I had it flared, it wouldn't have to go too far. Just enough to slide over the flange of the ferrule. Next question - any tips or tricks for brazing copper to stainless? Can I use mapp gas? Will I pull too much carbon to the surface if I don't purge with inert gas? I assume that liquid flux and silver brazing rod will work.

Thanks again for any advice.


IDrinkWash

yes, you should be able to use mapp gas without a problem. just make sure everything is clean. should braze without any issue.

[iDrinkWash]

I'd go with the right size ferrules. The stingy man spends the most, and I speak from experience. Nothing like the vapor pouring out of the pot when something lets go to make you rethink your build decisions!. Good luck and may you be in the best of spirits!

Sound advice. Not sure how it applies in this particular case. Instead of the copper going inside the ferrule, the pipe will go over it - and it sounds like it will be a tight fit at that. Once brazed, it should be the same strength, either way - or am I missing something?


IDrinkWash

[Tapeman]

Inside or outside won't matter if the brazing is done properly. There isn't enough pressure inside the still to make a difference and since the only thing going up the column is pretty strong solvent it won't be contaminated. If your connection is inside the pipe going up (hope you follow my metaphor) then cleaning between runs will need to be more thorough. I would prefer to have pipes fit over ferrules for this reason but sometimes logistics get in the way. If you can, braze at the top of the connection to eliminate any gaps.

[thecroweater]

In Australia all copper to stainless ferrules fit inside, its just how our sizes are. Blokes use a bunch of ways to stick them together with the most common being soft solder, hard solder (brazing) and tig, I haven't heard of anyone bothering to weld up the internal joint so I think that might be a bit of a non issue.

[Tapeman]

Good to hear, I only applied the physics of pvc drain pipes and sanitary fittings to the thread but that's a completely different kind of issue.

[Yummyrum]

yes, you should be able to use mapp gas without a problem. just make sure everything is clean. should braze without any issue.

I beg to differ
Brazing requires you to get the copper up to red hot before the brazing rod will melt . Depending on how long the piece of 2.5" is , I don't think you will be able to do it . The problem is that the copper is such a good conductor it just keeps sucking the heat away and dissipating it into the air .
If your copper pipe is only about a foot long it might just work but if its any longer forget it . Mapp just can't supply enough heat . There is a trick which works though , you sick your work on a gas burner for about five minutes to pre heat it and then bring it up to red with the Mapp .
Heres a 2.5" shotty I was making . Its only about 1.5' long but there was no way Mapp would do it alone .

This was using the same tecnnique to braze some flanges on to 4". You will notice I have the flame up on the pipe but the ring is already up to temp .You need to watch this when soldering or Brazing that the Pipe will need the heat and not the ferrule . I cooked a few ferrules before I worked that out .

However I have always soft lead free soldered all my SS ferules to my copper pipe as it is adiquately strong and much easier to do than brazing .

[iDrinkWash]

However I have always soft lead free soldered all my SS ferules to my copper pipe as it is adiquately strong and much easier to do than brazing .

Hmm. Interesting. I didn't think copper and stainless would stick together at that low temp. Any liquid or paste flux?


IDrinkWash

[Yummyrum]

Definitely go for a liquid flux . Most will contain Zinc Chloride . The trick when soft soldering stainless and copper is to have both surfaces spotlessly clean and keep applying the flux with a hog Bristle brush . And heat the copper not the stainless steal . When you hear the flux starting to sizzle , paint on some more and apply the solder . Don't get it too hot to quickly as its easy to cook the flux and staino and then the solder won't take .
If you are using a Mapp torch you will need to back the flame right off .

[zapata]

Hmm. Interesting. I didn't think copper and stainless would stick together at that low

Harris or radnor stay brite or stay brite 8 solder, stay clean liquid flux. 430*F, easy peasy, can do with butane if thats all ya got. Good for cu, brass, steel and stainless.

[JeremiahJohnson]

For my 2.5" column I used a coupler cut in half and brazed a hammered 6gauge wire to it then soldered that onto the pipe. Makes for a wide sealing surface. 2.5" tri clamps fit them well. I also acquired a good bit of 2.5" copper for next to nothing and it was new stuff. I have lots of 2.5" ss tri clamp parts for everything other than the column.