Duotight fittings disintegrated

[Summa_Brewologica]

Popping in here to share my similar experience. Full Duotight setup, from William's. I've only had them for a couple of months, maybe 2.5 kegs' worth. I've had about 4 flares and at least one checkvalve have their collars disintegrate as well. Both inside and outside the fridge. Gas and liquid.
I'm chalking this up to Star San as well because I definitely soaked some of them for an extended period of time. My two regulators seem fine so far. I had no idea Star San was a problem until finding threads like this out of frustration. Debating whether to replace >$50 of new duotight or go back to more reliable equipment. What a waste.

I also just invested in Value Brew's "Locking Clips." These were definitely not introduced to any StarSan and are also prone to snapping. I'm really turned off the entire Duotight concept.

I’m curious, did you by chance notice a “musty” smell from the affected fittings?

 

[DuncB]

I would say that starsan is not bleach, bleach is sodium hypochlorite wheras starsan is phosphoric acid and other chemicals it is acidic. Bleach is alkali.

I think a spray with starsan and then a spray with water to wash it off the surface would work well.
Use soapy water to check for leaks is perhaps the moral of the story.

 

[dmnota]

did you by chance notice a “musty” smell from the affected fittings?

Hmm. I didn't notice anything especially unique about the smell. Though, on many of them is a dark brown - almost like a burn - discoloration on the outside where the collar meets the body (if that makes sense). Originally I thought it was probably beer stain but I'm guessing not, now

I'd like to try a fresh set but my LHBS doesn't have them, and all others have a minimum for free shipping. Anyone aware of the most economical place to get a few to try them StarSan-free?

 

[Summa_Brewologica]

I would say that starsan is not bleach, bleach is sodium hypochlorite wheras starsan is phosphoric acid and other chemicals it is acidic. Bleach is alkali.

I think a spray with starsan and then a spray with water to wash it off the surface would work well.
Use soapy water to check for leaks is perhaps the moral of the story.

It may not be bleach but concentrated star San absolutely bleaches.

 

[Summa_Brewologica]

Hmm. I didn't notice anything especially unique about the smell. Though, on many of them is a dark brown - almost like a burn - discoloration on the outside where the collar meets the body (if that makes sense). Originally I thought it was probably beer stain but I'm guessing not, now

I'd like to try a fresh set but my LHBS doesn't have them, and all others have a minimum for free shipping. Anyone aware of the most economical place to get a few to try them StarSan-free?

I had the same “burn” look on mine. I’m just gonna order through Williams, again.

 

[IslandLizard]

on many of them is a dark brown - almost like a burn - discoloration on the outside where the collar meets the body (if that makes sense).

Could you post a (closeup) picture of those fittings showing the discoloration? Have any of them broken into pieces?

Another thing Starsan does is make clear vinyl hoses opaque, they turn white, when soaked/immersed for extended time, say a week or so.
When hung up to dry they return to clear after a few days to a week.

 

[Summa_Brewologica]

Could you post a (closeup) picture of those fittings showing the discoloration? Have any of them broken into pieces?

Another thing Starsan does is make clear vinyl hoses opaque, they turn white, when soaked/immersed for extended time, say a week or so.
When hung up to dry they return to clear after a few days to a week.

I’ve noticed this with my silicone tubing, as well. The part submerged turned completely white like it was dipped in white paint.

 

[scrap iron]

After reading this very informative thread I checked all my Duotight fittings. I bought them from my LHBS less than a year ago and they are all the newer version that Deadalus posted in #24. Thanks for the PDF. I have had no leaks or breakdowns; I did spray them with starsan but I spray rinsed them with water after assembly. I suggest using a spray bottle from a farm and home store that are made to use with chemicals. I've had one from Tractor supply for several years.

 

[Craiginthecorn]

I’ve noticed this with my silicone tubing, as well. The part submerged turned completely white like it was dipped in white paint.

That's a different issue. According to Charlie Talley of Five Star Chemicals in an old podcast interview, that's a component of Starsan binding to the hose. He said that cleaning with PBW would remove it.

 

[matt_m]

I suggest using a spray bottle from a farm and home store that are made to use with chemicals. I've had one from Tractor supply for several years.

The Zep branded ones at Lowes seem to hold up well too. I would assume they are made for cleaning products since that's what Zep does. The cheaper ones at Lowes aren't worth it.

 

[Bobby_M]

That's a different issue. According to Charlie Talley of Five Star Chemicals in an old podcast interview, that's a component of Starsan binding to the hose. He said that cleaning with PBW would remove it.

I don't know about the binding theory because silicone hose that sits in starsan for 1-2 weeks can be snapped in half. It would seem it's taking something away rather than adding it if it becomes that brittle, but maybe that's one of those counterintuitive scenarios.

 

[IslandLizard]

silicone hose that sits in starsan for 1-2 weeks can be snapped in half.

I've never seen that happen, and I'm sure I've occasionally (and unintentionally) left 1/2" thick-walled silicone brew hoses in a Starsan working solution for several weeks. No brittleness experienced either.

 

[dmnota]

Could you post a (closeup) picture of those fittings showing the discoloration? Have any of them broken into pieces?

The Flare has totally failed, the inside pieces coming apart.
The Checkvalve has not broken apart. It was leaking from behind the collar, though.

Another Flare (not pictured) which just failed on my CO2 tank only has slight discoloration on the face.


RE: storing StarSan- I've had this for 3 years. So far so good! https://www.amazon.com/gp/product/B00BCH4WTA

 

[Bobby_M]

I've never seen that happen, and I'm sure I've occasionally (and unintentionally) left 1/2" thick-walled silicone brew hoses in a Starsan working solution for several weeks. No brittleness experienced either.

It doesn't seem to be isolated either. I had several customers over the years order 25 feet of silicone to replace stuff that's old and stained and think, "hey, I'll just get this soaking in some starsan" then forget about it for a couple weeks and then call me to ask why the tubing can be easily snapped in half. Then there's a brewery I won't name that ordered 20 brand new butterfly valves and called a month later to tell me that they are all defective. They were leaking like sieves on both the dump and racking ports on a 20 BBL fermenter. We later discovered that all the seats receded about 1/4" due to a well intentioned month long soak in starsan.

 

[Off Balance Brewing]

I only use duo tight so far for my spunding valve setup, but seems like my QD fitting starts to leak after 6 to 9 months. I guess from the starsan but they are the new versions. I tried adding more tubing to put less stress on the end of the fittings this time. We'll see if they last longer.

 

[Ayzala]

Here is what happened to my cutoff valve, soaked too long in Starsan, and I sprayed Starsan to check for leaks. There was discoloring on the collar.

 

[balrog]

Another thing Starsan does is make clear vinyl hoses opaque, they turn white, when soaked/immersed for extended time, say a week or so.
When hung up to dry they return to clear after a few days to a week.

I've started piping fermenting CO2 through keg to jar of tapwater. THe vinyl hose from the keg's gas out turns white in the water (CO2 bubbling through no doubt making it acidic). But it also returns to clear when dried.

 

[DuncB]

@dmnota
THe flares shouldn't be overtightened, definitely increases failure rate. Something about hand tight and then another quarter turn is only needed, think that was on a kegland or home brew network video.
@Ayzala That collar shows dried out starsan which will be a much lower pH than straight out of the bottle and the video suggest that is the issue, David Heath video I think.

Their is likely to be a chemical reaction between the phosphoric acid and the silicone in the tube to turn it into a more rigid form. I'll look up the chemical formula for some clues.

Maybe a quick dunk of the connectors with Ethyl alchohol is the answer to sanitise them, after all the outside doesn't need to be sterile at all and similarly dip the tube end before inserting in alchohol.

 

[dmnota]

THe flares shouldn't be overtightened, definitely increases failure rate. Something about hand tight and then another quarter turn is only needed, think that was on a kegland or home brew network video.

These failures are unrelated to over-tightening. The checkvalves don't have that as an option and the flares' failures are inside the collar, not on the screw fittings.
No doubt a different cleaning/sanitizing method than I used seems to be in order, though!

 

[DuncB]

I thought the first picture was of a flare fitting as I can see the flat parts for tightening. Agree the check valves and other connectors aren't tightened on.

 

[dmnota]

Ah, yeah I gotcha. Don't get me wrong, I had some separate failures from over-tightening. That was a quick remedy though .

But those pictures were specifically for someone who asked to see the brown/"burned" marks. I had a few others which have since been thrown out, but they always appeared in that "half moon" shape. I (wrongly) assumed that was a result of dried liquid pooling from gravity. Guess not.

I appreciate this thread though; isolating the variables is giving me confidence to try them again. Better informed this time.

 

[balrog]

The three of mine only failed with the interior flanges holding the metal teeth, which broke off. None discolored. None have ever been soaked long term in StarSan, just dunked, shaken, then used. Guess it means StarSan dried on them though.

 

[IslandLizard]

The three of mine only failed with the interior flanges holding the metal teeth, which broke off.

"Only" failed? That's utter and complete failure!
That kind of unexpected failure can cause significant damage, aside from being a nuisance, loss of beer, gas, etc.

Were those the gray Acetal?

I just saw they sell "half cartridges," but all are Acetal, in different colors, white, gray, and black:

John Guest Plastic Half Cartridge - 1/4

The John Guest plastic half cartridges are an easy and cost-effective way of incorporating a push-fit connection into a wide range of OEM equipment. Easy to assemble and compact, push in connections avoid the need for threaded ports, offer improved product appearance and easy tube connection...

www.freshwatersystems.com

 

[balrog]

"Only" failed? That's utter and complete failure!
That kind of unexpected failure can cause significant damage, aside from being a nuisance, loss of beer, gas, etc.

Were those the gray Acetal?

I just saw they sell "half cartridges," but all are Acetal, in different colors, white, gray, and black:

John Guest Plastic Half Cartridge - 1/4

The John Guest plastic half cartridges are an easy and cost-effective way of incorporating a push-fit connection into a wide range of OEM equipment. Easy to assemble and compact, push in connections avoid the need for threaded ports, offer improved product appearance and easy tube connection...

www.freshwatersystems.com

Well, I be an idiot. Mine were John Guest. It does however appear to me that the failure was on a gray plastic part however...

Apologies for adding to a Duotight thread with John Guest issues.

 

[McMullan]

I've had a JG collet disintegrate like that. One out of dozens, mind. I thought it was due to being left overnight in Iodophor solution.

 

[balrog]

I thought it was due to being left overnight in Iodophor solution.

I thought my three failing the same way was due to repeated switching; I thought there was a mean time between failure about which I was unaware.

 

[Deadalus]

Well, I be an idiot. Mine were John Guest. It does however appear to me that the failure was on a gray plastic part however...
View attachment 781455
View attachment 781456

Apologies for adding to a Duotight thread with John Guest issues.

Sorry I kind of roped you in earlier...the John Guest are made of gray acetal copolymer which the Duotights were made of previously but the Duotight collars are now made of polyketone (POK) per their pdf.

 

[McMullan]

I thought my three failing the same way was due to repeated switching; I thought there was a mean time between failure about which I was unaware.

Yes, I don't think push fittings are supposed to be disconnected repeatedly. The collets look like potential weak points regardless.

 

[superiorsat]

Out of curiosity could a person just use normal barb type fittings/valves/regulators with EVA tubing? Shark Bite push to connect plumbing fittings are a none professionals way of doing plumbing IMO and I've always looked at these fittings with the same negativity.

 

[IslandLizard]

Shark Bite push to connect plumbing fittings are a none professionals way of doing plumbing IMO and I've always looked at these fittings with the same negativity.

Wow, I too have always felt that way about Sharkbite type "push to connect" fittings, especially on copper connections. I can see it work on plastic tubing, especially when they're exposed and can be inspected periodically.

I was mystified when a professional plumber in his shop even suggested using those when I was replacing my 1" copper water line, 7 feet underground, from the street shut-off to the water meter inside my basement. I would never use those fittings, especially underground, even at 2 feet. One of those giving out at some point in time could cause a major catastrophe.

Instead, I scored 2 heavy duty brass compression elbows the water department uses (I had a connection there ).

 

[tracer bullet]

https://www.kegland.com.au/media/pdf/duotight%20design%20revision.pdf

Came up in another thread. Newer fittings should theoretically be fine now w/ Star San.

 

[IslandLizard]

https://www.kegland.com.au/media/pdf/duotight%20design%20revision.pdf

Came up in another thread. Newer fittings should theoretically be fine now w/ Star San.

Thank you for the link to the update, that's a worthwhile read!

StellarSan (!) apparently, was indeed the culprit...

Revision:
This "update" by Kegland is from 28/09/2020, not 2022!
So that's over 2 years ago. And all that time they knew Starsan and such were the culprit.

 

[dmnota]

If the "fixed" version of these is identified by the raised branding on the end... then I wouldn't put much stock in this document. I'm keeping my Duotights as far away from StarSan as possible. All of mine have this and have failed when exposed to Star San.
This is a picture of my newest failure: the collar busted and the nut snapped in half. The nut breaking struck me since it's not the usual way caused by "over-tightening."

Kegland's language of "through all testing showed no signs of damage even with very strong acid" and "very few failures have been recorded" feel very insincere to me.

 

[Deadalus]

https://www.kegland.com.au/media/pdf/duotight%20design%20revision.pdf

Came up in another thread. Newer fittings should theoretically be fine now w/ Star San.

No biggie but I posted that pdf earlier in this thread...more noteworthy is that I also posted about a failure with what is described as the newer fittings. At most I can only say with certainty that I sprayed the fitting with Star San. I may have let them sit for a short period in Star San as well but probably not a long soak. If I have a batch of small hardware I usually will have a gallon mixed up in bowl or pot in the sink. I only have the one sink though so I generally just drop them in a colander to move them out of the sink to dry so as to be able to use the sink.

 

[tracer bullet]

No biggie but I posted that pdf earlier in this thread...

Oops! Bad memory, sorry. Maybe I better go kill a few of the weak brain cells

 

[Ayzala]

If the "fixed" version of these is identified by the raised branding on the end... then I wouldn't put much stock in this document. I'm keeping my Duotights as far away from StarSan as possible. All of mine have this and have failed when exposed to Star San.
This is a picture of my newest failure: the collar busted and the nut snapped in half. The nut breaking struck me since it's not the usual way caused by "over-tightening."

Kegland's language of "through all testing showed no signs of damage even with very strong acid" and "very few failures have been recorded" feel very insincere to me.

Agreed! All the Duotights that failed on me were purchased after the "Upgrade". So I'm not convinced the new ones will hold up to Starsan! I'm staying away and using iodophor.

 

[Deadalus]

Agreed! All the Duotights that failed on me were purchased after the "Upgrade". So I'm not convinced the new ones will hold up to Starsan! I'm staying away and using iodophor.

Has the iodophor stained them?

 

[Ayzala]

Has the iodophor stained them?

A little, but if you leave them in for the recommended time it takes a while to discolor.

 

[McMullan]

I just ordered some Duotight fittings for a cask/Caskwidge/cask breather/spunding experiment. John Guest only offer one of the two fittings I need, but I'm sure I could adapt other JG fittings, if it works and the Duotight fittings fail. I really like what Kegland offer home brewers, but they need to sort their 'really awesome' crap out occasionally. Releasing poorly tested prototypes to market is what I expect from small startups, not established businesses.

 

[McMullan]

A little, but if you leave them in for the recommended time it takes a while to discolor.

A no-rinse 12.5ppm iodophor solution is fine on plastics. I try to keep contact time <10min. The white plastic bucket stains a little, but it only seems to be temporary.