Union joint leak

[Tōtōchtin]

Ok, how do you find a leak?

I've had mixed success with any method unless it makes a drip, that's pretty easy. I smell alcohol anytime the still is running so that's not an alternative. The best results I got with a mirror was when it was cool but not cold enough to fog up from ambient humidity kinda touchy.

Got to find it to fix it.

Add some dish soap to a small glass of water. Use a brush to wet the joint area with the soapy water and look/listen for bubbles.

[Tōtōchtin]

I used to convert buses in a past life and I used dish soap(zero chorine) to check for leaks if my manometer showed one after assembly. If you can hear bubbles popping I would run..
Tōtō

[Chauncey]

Iv'e never found a leak with a mirror yet......maybe it's something that only works well for you cold climate fellas.

Yea I can't get it to work here mirrors usually fog up on me no matter what

[rbsc]

I put it together without Teflon and submerged it, it’s still leaking. Anyone have a one inch tri clamp they recommend?

[NZChris]

I've got some valve grinding paste. Brand isn't important.

[Steve Broady]

I put it together without Teflon and submerged it, it’s still leaking. Anyone have a one inch tri clamp they recommend?

Don’t bother with 1”. If it’s 1” pipe, get a 1.25” tri-clamp ferrule with the same OD as 1.5”. It slide right over. Use liquid flux and plenty of heat, and it should solder nicely.

[rbsc]

I've got some valve grinding paste. Brand isn't important.

Is that what someone was referring to above about finding which faces weren’t lining up, then putting some kind of paste on it? This could save me from having to replace it?

Edit: if I use this I assume I can’t break it all down after every use?

[rbsc]

I put it together without Teflon and submerged it, it’s still leaking. Anyone have a one inch tri clamp they recommend?

Don’t bother with 1”. If it’s 1” pipe, get a 1.25” tri-clamp ferrule with the same OD as 1.5”. It slide right over. Use liquid flux and plenty of heat, and it should solder nicely.

Thank you. I noticed not much comes up when I search for one inch.

[NZChris]

It's not glue. It's an abrasive paste that can be used to grind two surfaces so that they match better. Used for car valves, look it up. It's easy to use, just put it on the joint and rotate one half for a while, wipe it off and check it visually. When you think both faces are clean and shiny, you're probably done.

[shadylane]

Don’t bother with 1”. If it’s 1” pipe, get a 1.25” tri-clamp ferrule with the same OD as 1.5”. It slide right over. Use liquid flux and plenty of heat, and it should solder nicely.

I'm confused as normal.

I can't find any 1.25" tri-clamp fittings.
1/2" and 3/4" are the same, and 1" and 1.5" are the same.
But there's not any 1.25" fittings.

https://www.glaciertanks.com/sizing.html

[shadylane]

It's not glue. It's an abrasive paste that can be used to grind two surfaces so that they match better. Used for car valves, look it up. It's easy to use, just put it on the joint and rotate one half for a while, wipe it off and check it visually. When you think both faces are clean and shiny, you're probably done.

That's how I do it after soldering on a union.
It doesn't take very long to get a tight seal, copper is softer than hardened valves and valve seats.

[Steve Broady]

Don’t bother with 1”. If it’s 1” pipe, get a 1.25” tri-clamp ferrule with the same OD as 1.5”. It slide right over. Use liquid flux and plenty of heat, and it should solder nicely.

I'm confused as normal.

I can't find any 1.25" tri-clamp fittings.
1/2" and 3/4" are the same, and 1" and 1.5" are the same.
But there's not any 1.25" fittings.

https://www.glaciertanks.com/sizing.html

316 Stainless Steel Diameter 32MM 1.25" Sanitary Weld Pipe with 50.5MM Ferrule Flange fits 1.5" Tri Clamp https://a.co/d/aOK9lVV

I have used these successfully.

(Edit to add pictures)

That’s the 1.25” on 1” copper pipe. I’ve also used the 1” on 3/4” pipe:

Having them all fit the same 1.5” tri-clamp has been handy.

[googe]

Epic thread about a union have you got a pic of your still, might help everyone help to rebuild it. Theres some smart people here that will see what you don't.

[rbsc]

It's not glue. It's an abrasive paste that can be used to grind two surfaces so that they match better. Used for car valves, look it up. It's easy to use, just put it on the joint and rotate one half for a while, wipe it off and check it visually. When you think both faces are clean and shiny, you're probably done.

Oh, wow, I’ll definitely try that before I take this apart, then. No concerns about it getting in the vapor path?

[NZChris]

Not if you clean it.

[acfixer69]

It's not glue. It's an abrasive paste that can be used to grind two surfaces so that they match better. Used for car valves, look it up. It's easy to use, just put it on the joint and rotate one half for a while, wipe it off and check it visually. When you think both faces are clean and shiny, you're probably done.

Oh, wow, I’ll definitely try that before I take this apart, then. No concerns about it getting in the vapor path?

It's called lapping compound, and needs to be cleaned off completely before assembly. Then the normal 2 step cleaning as if was flux.

[shadylane]

It's called lapping compound, and needs to be cleaned off completely before assembly. Then the normal 2 step cleaning as if was flux.

Plan B for the lazy and cheap folks.

Use toothpaste and fine sand for the lapping compound.
Then Ya only need to wipe it off with a wet towel.

[acfixer69]

It's called lapping compound, and needs to be cleaned off completely before assembly. Then the normal 2 step cleaning as if was flux.

Plan B for the lazy and cheap folks.

Use toothpaste and fine sand for the lapping compound.
Then Ya only need to wipe it off with a wet towel.

Fine sand is not a finishing compound so Fine to me may not be the same to you.

[acfixer69]

Good unions are not ment to be broken down and refitted over and over. Much like a breaker is not ment to be a on /off switch it will do the job but will break down at some point. I'd buy the ferrules and be done with it.

[shadylane]

Ya got a point, the term "fine sand" isn't very measurable.

That aside, I've used sand and toothpaste to lap the sealing surfaces of copper unions.
It's "food grade" and works without the need for cleaning runs.

As to the debate about unions vs tri-clamp fitting.
That's not what the OP is asking about. He needs it fix a union that has a small leak.

[acfixer69]

When I find a problem I like to fix it and be done as their will be more to come. Quick repair is for emergency shit.

[NZChris]

Grinding a ding or warp out of it should be a permanent fix. It would only take me a few minutes because I already have the paste.

[Steve Broady]

I've used sand and toothpaste to lap the sealing surfaces of copper unions.
It's "food grade" and works without the need for cleaning runs.

If I remember right I used something thing like Ajax or Comet. Whatever mildly abrasive cleaner I had handy, and it worked a treat. I didn’t need to remove much material, and copper is soft.

As to the debate about unions vs tri-clamp fitting.
That's not what the OP is asking about. He needs it fix a union that has a small leak.

True, and he’s been given plenty of helpful ideas on how to deal with the leak. But to be fair, tri-clamps are definitely one way to solve the problem! One of the things I love about this forum and the wealth of knowledge and experience here is that when I ask a question, I not only get an answer (or several) to the question I asked, I also get a whole range of related information that may or may not guide me to a better solution in the end. It’s happened several times I my short tenure here, and I welcome it.

[rbsc]

Very much appreciate all the input, everyone. Have some paste on the way. Next weekend is for mashing anyway, so I’ll give the paste a try and see how the joint does with the vinegar and steam cleaning runs. If it still leaks I’ll just take it apart and try to find the tri clamps. I ruined the big elbow piece on my first attempt because I overheated it while I was trying to take it apart; so I’m going to try anything I can before going that route. Again, really appreciate all the help.