Help needed with sealing assembled pipe

In Washington State recent laws now allow micro distilleries. One is opening up near me and I have done some welding on the stainless steel
stills. Someone goofed and a 3/4 pipe coupler was threaded to the drain on the bottom of the still. It is apparently leaking. I am pretty sure it galled up during assembly. There is not enough room to weld around the threaded joint. So I'm thinking about using a wicking sealer. Loctite makes one, 290, but it is only good up to 1/2 inch diameter threads. Does anybody here know if I can get it to work on the 3/4 pipe? I just need sealing, not retention of the fitting. I will consider other methods too. I doubt that taking the coupler off without destroying the threads is possible. I am willing to try using Kroil or similar but if that doesn't work I will need to somehow clean it out of the threads if I intend to use a wicking sealer. HELP! Thanks, Eric
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On Sat, 19 Mar 2016 15:43:53 -0700, snipped-for-privacy@whidbey.com wrote:

Is the outlet of the still male? If not, I'd just unscrew and replace. If the nipple is bunged, replace that too.
I'm surprised the outlet is not a sanitary flange. I wouldn't want leftover mash stuck in the threads, although the product does go overhead.
Pete Keillor
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wrote:

Cleaning up pipe threads with a die is much easier than cutting them initially. My collection of larger pipe taps and dies is mostly second hand and too dull to thread solid metal, but they fix rusty or damaged threads well enough. --jsw
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On Sun, 20 Mar 2016 06:55:01 -0500, Pete Keillor

The outlet is a nipple welded to the still. Can't be replaced without much trouble. I convinced them to not use threaded fittings anymore for drainage but I still need to fix the one. I need a solution that doesn't involve unscrewing anything. I thought I made that clear in my first post but once again I didn't. Eric
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On Mon, 21 Mar 2016 09:22:03 -0700, snipped-for-privacy@whidbey.com wrote:

I have used "silver solder" (actually silver brazing) with a flux for stainless with good results and it will flow into pretty small places. I was building a bicycle frame with steel tubes and stainless lugs but you can read http://www.morebeer.com/brewingtechniques/library/backissues/issue2.6/palmer.html for use in brewing
--
cheers,

John B.
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On Mon, 21 Mar 2016 09:22:03 -0700, snipped-for-privacy@whidbey.com wrote:

I understood your post, I thought is was galled, but maybe would still come off, guess not. I'm mostly concerned about using threaded fittings in "food" application. Maybe it's ok on a still. Same for the silver solder, is it ok in that service, and how do you flux? It'll wick if everything is very clean and fluxed, but you have to make damned sure you get residual flux out. Some of that stuff has hydrofluoric acid in it.
Might be better to bite the bullet, cut that sucker off, and weld on the proper fitting. They'd avoid trouble (and potential fines) down the road.
Pete Keillor
Pete Keillor
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On Tue, 22 Mar 2016 07:22:55 -0500, Pete Keillor

The way the thing is now welding on a different fitting would be really expensive. So the solution will be as it looks now is a phosphoric acid based flux which is safe for food service as well as a silver solder alloy that is made for food service. The still will not be distilling the beer but will instead be distilling the distillate from the beer, so mainly alcohol and water. It is a vodka still. It's odd to think about when we hear about all the poisons in moonshine, like lead and cadmium from solder, but these poisons only get into the condensate. The vapor doesn't carry any poisons that won't vaporise during the process. And pathogens are killed by the temp and eventually the high alcohol concentration. So even though I'm pretty sure some stuff will collect in the threads in the drain for this still it won't cause any harm. Nevertheless I have convinced them to do away with the threaded fittings and go with welded fittings and sanitary flanges, which they have have done with subsequent stills. Eric
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On Saturday, March 19, 2016 at 3:39:58 PM UTC-7, snipped-for-privacy@whidbey.com wrote:

My first thought is teflon pipe tape; it's safe for consumable contact, and should take autoclaving temperatures and contact with organic solvents...
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wrote:

I can't unscrew the fitting. That's why I'm looking at wicking sealers. I think I found a solution over the weekend. Apparently Sil-Phos will braze SS nicely and wicks very well. So I will try it out on some SS fittings and if it works I'll do the still. Eric
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On Mon, 21 Mar 2016 09:25:14 -0700, snipped-for-privacy@whidbey.com wrote:

I was going to say solder or braze with the appropriate flux.
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On Mon, 21 Mar 2016 09:25:14 -0700 snipped-for-privacy@whidbey.com wrote:

Something off the wall... I've used electric tape in the past for odd leaks. Not sure if you have room to work with it or not... I would splurge and get some nice 3M tape and then make some really tight wraps, twice over the area. Then apply something like Scotchkote over the tape. While it is still tacky make two more wraps with the tape. Then apply another covering of Scotchkote.
(Amazon.com product link shortened)
The Scotchkote is key to the fix. It keeps the tape from unwrapping and kind of binds it all together. Liquid Electrical Tape is similar, maybe the same but I've not tried using it...
--
Leon Fisk
Grand Rapids MI/Zone 5b
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Really? On food-grade equipment? They'd sue you off the face of the earth!
Although it might _work_, to use it on a food processing device would be tantamount to deliberate sabotage!
Lloyd
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Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:

It's no different than leaving on a busted up theaded fitting that leaks because it costs too much to replace.
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BS... the latter one is a maintenance issue (and must be corrected). The other is "deliberate contamination".
C'mon... think.
Lloyd
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On Tue, 22 Mar 2016 20:11:34 +0000 (UTC), Cydrome Leader

If you are alluding to the fitting I needed to seal, it was not busted up, it was galled. Full thread engagement. Assembled dry the pipe joint leaked. Wicking Loctite 290 is an industry accepted practice for this type of leak, even for food contact. As is the particular silver solder alloy slated for the job. The finished assembly is now stronger than if it was assembled with teflon tape, which is also acceptable for food contact. So there. Eric
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snipped-for-privacy@whidbey.com fired this volley in

I think you mis-attributed your "so there" to me. I was NOT the person suggesting bad things. I said that black electrician's tape was an illegal deliberate contaminant. I agree that wicking sealer approved for food contact OR brazing/silver soldering is the right way to go.
Lloyd
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On 03/21/2016 11:25 AM, snipped-for-privacy@whidbey.com wrote:

I'd wonder about whether is approved for the application or not...don't want to leave the vendor with an unusable production vessel or get 'em fined big time or the like...
--



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