Duotight fittings disintegrated

[Summa_Brewologica]

I’m hoping to find a solution. I build a kegerator using all duotight fittings and the white duotight regulators. All the grey duotight fittings have disintegrated over the course of a year as shown in the images. Only the fittings that were inside the fridge have deteriorated meaning it’s either a moisture issue or a temperature issue.

Funny enough, the regulators are perfectly fine. I guess the plastic is different on those?

Anyone have any thoughts? I liked this setup because it was a cheap way to get inline regulators for each keg. Im happy to just keep everything outside the fridge but that still means that the fittings attached to the disconnects on the kegs will still be subject to damage.

 

[McMullan]

I'd recommend replacing them with John Guest fittings, which are much better quality. The Duotight fittings suffer chemical fracturing if exposed to starsan for too long. I do wonder how suitable they are for CO2 and beer, tbh. The plastic and finish on mine seems to vary quite a lot. Zero QC. Cheap crap really.

 

[Summa_Brewologica]

I'd recommend replacing them with John Guest fittings, which are much better quality. The Duotight fittings suffer chemical fracturing if exposed to starsan for too long. I do wonder how suitable they are for CO2 and beer, tbh. The plastic and finish on mine seems to vary quite a lot. Zero QC. Cheap crap really.

Thanks for the reply. Do you know what size JG fitting would replace the 8mm duotight fittings?

 

[McMullan]

5/16

 

[Unicorn_Platypus]

well, that's not very reassuring considering I am heavily invested in duotights & eva barrier

I've never had an issue with mine. However, I only hookup my lines when serving or carbonating. So, I'm not leaving them in the keezer for very long periods of time. I've found that disconnecting lines between servings increases the shelf life of my beer dramatically.

Are you soaking your fittings in starsan for extended periods of time?

 

[Ayzala]

I've had the same issue, it's the StarSan. I left one soaking in it for a week (call me lazy) and hooked it up. Once the keg was kicked, I went to pull the line and nothing but tiny pieces of plastic fell out. I'm not using StarSan any more, replaced with Iodophor (and for only two minutes).

For what it's worth. When I need replacements, it will be John Guest.

 

[Unicorn_Platypus]

I wash all of my duotight stuff including the QDs throughly with fragrance feee dish soap and warm water for cleaning. I don't use PBW or anything caustic.

(no issues with head retention from the use of dish soap as long as its washed thoroughly)

I do use starsan and saniclean to sanitize the lines, but don't leave them soaking for extended periods of time

I've never really had an issue with any of my duotight stuff, but this thread does scare me a bit LOL

Overtightening one of the FFL adapter caused a leak one time, but it was my fault for overtightening

I'll still be purchasing duotight stuff because of all the accessories its capable of, spunding valves, duotight QDs, etc.

 

[tracer bullet]

Mcmaster-Carr sells a variety of push-connect fittings including Metric sizes. Just FYI as an alternative if folks wanted to stay Metric.

 

[McMullan]

Just to be clear, the EVABarrier tubing, 2ry regulators, Blowtie valves, and other things are absolutely fine, but the grey fittings are sh*t. Hands down.

 

[Deadalus]

Mcmaster-Carr sells a variety of push-connect fittings including Metric sizes. Just FYI as an alternative if folks wanted to stay Metric.

The common choices for fitting sizes for these homebrewing types of ptc fittings and tubing are based on the Imperial sizes of 1/4", 5/16", and 3/8". The respective metric sizes are 6.35mm, 8mm, and 9.5mm but those are really designed for 1/4", 5/16", and 3/8" outer diameter tubing. It might warrant being careful at McMaster-Carr because they have such an extensive inventory. They might actually have a 6mm that is 6mm.

 

[tracer bullet]

The common choices for fitting sizes for these homebrewing types of ptc fittings and tubing are based on the Imperial sizes of 1/4", 5/16", and 3/8". The respective metric sizes are 6.35mm, 8mm, and 9.5mm but those are really designed for 1/4", 5/16", and 3/8" outer diameter tubing. It might warrant being careful at McMaster-Carr because they have such an extensive inventory. They might actually have a 6mm that is 6mm.

Their metric fittings will definitely be metric.

As for the tubing, I may have made a bad assumption that the tubing diameters were actually metric, given that the EVA barrier stuff is sold as such. But I could be wrong. And sure, not everyone is using the EVA barrier either - seems somewhat common when the duotight fittings are mentioned but certainly not guaranteed.

 

[DuncB]

Apparently it's worst for the old duotight if they get starsan on them and then dry as this increases the concentration of the acid. Recommendation was to wash it off and not long soak.
I believe plastic has been reformulated on genuine duotight fittings.
@McMullan
I think I saw this info on the he who should not be named website, or perhaps kegland.
Not had that grey plastic but fail on any duotight fitting only on a John guest into top of Williams warn bottle filler.

 

[Summa_Brewologica]

well, that's not very reassuring considering I am heavily invested in duotights & eva barrier

I've never had an issue with mine. However, I only hookup my lines when serving or carbonating. So, I'm not leaving them in the keezer for very long periods of time. I've found that disconnecting lines between servings increases the shelf life of my beer dramatically.

Are you soaking your fittings in starsan for extended periods of time?

No I’ve never soaked these in starsan ever. It has to be something with the co2 because the fittings on the liquid side are completely fine.

 

[Unicorn_Platypus]

No I’ve never soaked these in starsan ever. It has to be something with the co2 because the fittings on the liquid side are completely fine.

So wierd! My gas side stuff hasn't had an issue

How long ago did you purchase the duotights and from what vendor?

I buy mine from morebeer or Bobby at brewhardware.com

 

[Summa_Brewologica]

So wierd! My gas side stuff hasn't had an issue

How long ago did you purchase the duotights and from what vendor?

I buy mine from morebeer or Bobby at brewhardware.com

I got them from Williams brewing almost exactly a year ago.

 

[Summa_Brewologica]

So wierd! My gas side stuff hasn't had an issue

How long ago did you purchase the duotights and from what vendor?

I buy mine from morebeer or Bobby at brewhardware.com

It is possible that starsan did it though because now that I think of it I did leak tests with starsan in a spray bottle. Maybe that did it. I didn’t have to leak test the liquid line with starsan, obviously.

Idk I’m hesitant to buy more but if it’s something simple like starsan I can just avoid using starsan for leak testing.

 

[Unicorn_Platypus]

Ibl

It is possible that starsan did it though because now that I think of it I did leak tests with starsan in a spray bottle. Maybe that did it. I didn’t have to leak test the liquid line with starsan, obviously.

Idk I’m hesitant to buy more but if it’s something simple like starsan I can just avoid using starsan for leak testing.

I leak tested mine in starsan too

 

[Summa_Brewologica]

Ibl

I leak tested mine in starsan too

Maybe I made it too concentrated? Who knows. It sucks, though. They are pretty cheap fittings but if I have to do it every year that will add up.

 

[Unicorn_Platypus]

Maybe I made it too concentrated? Who knows. It sucks, though. They are pretty cheap fittings but if I have to do it every year that will add up.

I usually mix up 1ml per 24oz of water in a spray bottle. I use a syringe to measure it out. If you scale it down from the per gallon dosage technically the concentration I'm supposed to use per manufacturer is 1.125ml

So I'm on the lower end of the range in terms of concentration

 

[McMullan]

I've had some of my John Guest fittings in continuous use for 8-9 years. Duotight fittings won't last anywhere near that long. Feel free to sacrifice a couple fittings for a meaningful direct comparison.

 

[DuncB]

All of the fittings hate tight bends at the point where the tube comes out. Also important that your tubes don't move around for example when fridge or keeper door opens and closes.
The fittings that have most failures are the ball lock connectors on tubes that get used and moved a lot. The ones for liquid or gas transfers during purging and closed transfers.

 

[Deadalus]

Their metric fittings will definitely be metric.

As for the tubing, I may have made a bad assumption that the tubing diameters were actually metric, given that the EVA barrier stuff is sold as such. But I could be wrong. And sure, not everyone is using the EVA barrier either - seems somewhat common when the duotight fittings are mentioned but certainly not guaranteed.

Evabarrier is sold as metric because it is coming from Kegland but it's sized on fractional inches.

I had one duotight crack on the interior tabs and that fitting was barely used. It was a tubing by flare connector but I can't say whether it was on the beer or CO2 side. It didn't disintegrate but I definitely sprayed it with Starsan. I don't usually soak for long in Starsan when I do. I've since bought 1-2 extra just to have around. They're fairly cheap and no sense waiting around for one like I had to when I replaced the one that broke.

 

[Summa_Brewologica]

Evabarrier is sold as metric because it is coming from Kegland but it's sized on fractional inches.

I had one duotight crack on the interior tabs and that fitting was barely used. It was a tubing by flare connector but I can't say whether it was on the beer or CO2 side. It didn't disintegrate but I definitely sprayed it with Starsan. I don't usually soak for long in Starsan when I do. I've since bought 1-2 extra just to have around. They're fairly cheap and no sense waiting around for one like I had to when I replaced the one that broke.

Yea these literally disintegrated. Like part of it was dust on my fingers. I’m going to assume it was starsan and just avoid it. I am still looking into John guest fittings, though.

 

[Deadalus]

I just found this document from Kegland, it describes some issues with the materials used to make the fittings.

 

[Deadalus]

@balrog had some issues with his John Guest fittings that he posted about in this thread where I had previously noted the breakage on mine. From that document I just posted, it seems my fitting was of the newer type that Kegland produced as my fitting has the raised lettering that indicates it's newer.

 

[balrog]

@balrog had some issues with his John Guest fittings that he posted about in this thread where I had previously noted the breakage on mine. From that document I just posted, it seems my fitting was of the newer type that Kegland produced as my fitting has the raised lettering that indicates it's newer.

I’ve not had any more failures w Duotight. I’ve seen no issues yet w the Kegland QD/PTC fittings. I continue to Starsan w each use, and that means they are sprayed, connected to kegs, typically in ferm chamber for a week or two, then removed, water rinsed, tossed in drying bin.

 

[IslandLizard]

Mcmaster-Carr sells a variety of push-connect fittings including Metric sizes. Just FYI as an alternative if folks wanted to stay Metric.

Another source for John Guest Push-to-Connect fittings is Fresh Water Systems. They also sell 10-packs at a price break. Not sure how things are now, haven't checked there lately.

the grey fittings are sh*t

I was under the impression that the gray fittings are made of Acetal polymer. That could be the issue, maybe superior in some ways but not in every application.

The white ones are Polypropylene.

Now I have another evidence that Starsan attacks plastics. My spray bottle with Starsan self-decapitated:

 

[balrog]

Another source for John Guest Push-to-Connect fittings is Fresh Water Systems. They also sell 10-packs at a price break. Not sure how things are now, haven't checked there lately.


I was under the impression that the gray fittings are made of Acetal polymer. That could be the issue, maybe superior in some ways but not in every application.

The white ones are Polypropylene.

Now I have another evidence that Starsan attacks plastics. My spray bottle with Starsan self-decapitated:
View attachment 780511

My 6 yr old starsan spray bottle is still hanging in there but is having issues -- I have to prime the dang thing, as if the internal "valve" in the pump is failing.

 

[tracer bullet]

https://cdn5-ss5.sharpschool.com/Us...c Schools/COVID-19/starsan hand Sanitizer.pdf
Star San MSDS ^^^, you can see what's in it.

Next question is which plastics are good or not with these acids. Off the top PTFE (teflon) and Polypropylene are good, but that can be case by case. I know that some acids dissolve some plastics, enough to be aware of it, but I don't know specific combos.

 

[balrog]

i knew about the phosphoric acid, not the sulfonic. But my quart of 80% phosphoric came in plastic so I know there exist plastics that will be ok.

Cheap a$$ dollar store spray bottle plastic clearly not so much, I guess.

 

[Summa_Brewologica]

Another source for John Guest Push-to-Connect fittings is Fresh Water Systems. They also sell 10-packs at a price break. Not sure how things are now, haven't checked there lately.


I was under the impression that the gray fittings are made of Acetal polymer. That could be the issue, maybe superior in some ways but not in every application.

The white ones are Polypropylene.

Now I have another evidence that Starsan attacks plastics. My spray bottle with Starsan self-decapitated:
View attachment 780511

Yes I’m leaning toward the starsan being the cause. I also suspect I was loose with the mix and made too strong a batch in my spray bottle at the time.

As far as spray bottles go I’ve always used glass ones and love them. The spray part, however, is obviously plastic but it seems to be holding up. I usually empty everything out after a week or two since that seems to be the shelf life.

I always use RO water for mixing starsan and wonder if the mix should be measured differently depending on the water source. The directions on the bottle don’t mention anything about that which makes me think it should be good but I’m still curious.

 

[McMullan]

Another source for John Guest Push-to-Connect fittings is Fresh Water Systems. They also sell 10-packs at a price break. Not sure how things are now, haven't checked there lately.


I was under the impression that the gray fittings are made of Acetal polymer. That could be the issue, maybe superior in some ways but not in every application.

The white ones are Polypropylene.

Now I have another evidence that Starsan attacks plastics. My spray bottle with Starsan self-decapitated:
View attachment 780511

I've lost count of the number of spray bottles I've gone through. I'm thinking about spending a little extra for a viton one next time.

 

[DuncB]

My spray bottle with polythene bottle is going strong after 4 years. Back part of handle broke when I dropped it on the floor.
I've had the threaded part of coke pet bottles crack up and leak with starsan in bottle and the red ball lock thing screwed on.

 

[Deadalus]

https://cdn5-ss5.sharpschool.com/Us...c Schools/COVID-19/starsan hand Sanitizer.pdf
Star San MSDS ^^^, you can see what's in it.

Next question is which plastics are good or not with these acids. Off the top PTFE (teflon) and Polypropylene are good, but that can be case by case. I know that some acids dissolve some plastics, enough to be aware of it, but I don't know specific combos.

In the pdf I posted, it says the Duotights were made out of Polyoxymethylene (POM) but that the collars were switched to polyketone. The pdf notes that John Guest fittings are also made from POM but probably a good idea to just double check that against information from John Guest.

 

[Deadalus]

I’ve not had any more failures w Duotight. I’ve seen no issues yet w the Kegland QD/PTC fittings. I continue to Starsan w each use, and that means they are sprayed, connected to kegs, typically in ferm chamber for a week or two, then removed, water rinsed, tossed in drying bin.

That one failure I had was the only one myself since, thought I would just link the two threads. I just switched my jockey box over to Duotights too...

Not to gum the discussion up but I just had a poppet in my Kegland ball lock QD melt/deform. I had the material* identified yesterday for the poppet and was investigating and the material is supposed to be good to past boiling. I did overshoot the temp on the PBW I was running through the system but it wasn't boiling. I still want to check sources further on that material to be sure.

*EPDM and PP/EPDM overmoulded poppet

 

[tracer bullet]

Polyoxymethylene

Funny, I hadn't heard of that, but am quite familiar with Acetal. Anyhow:

https://www.calpaclab.com/acetal-polyoxymethylene-chemical-compatibility-chart/
And... drumroll.... acetal doesn't seem to get along with phosphoric acid, or really an acid it seems.

 

[Bobby_M]

The added seal of the second oring isn't insignificant. I setup my whole kegerator with John Guest fittings but they were too prone to leaks if the tubing was stressed just slightly off axis. I switched to Duotight and less problems.

 

[dmnota]

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.

 

[DuncB]

I am puzzled by this outbreak of issues with Duotight, mine as I say have been fine, I don't use those brew locking clips and I've got a mix of connectors bought in Australia, New zealand of varying ages.
I'm not sure I bothered to starsan the gas side at all. But posts and ball locks get sprayed each change of keg / at line washing.

 

[Summa_Brewologica]

I need to be clear: duotight fittings are great products. This issue which I am 99% sure is starsan related, is not really their fault. They have written somewhere not to use bleach to clean their fittings. I don’t think starsan classifies as bleach but maybe they mean for this to be included. Either way, in my case, Im fairly convinced I made too strong a mix. Im happy to spend an extra $3 on a fitting when I order my next set for a spare that I can experiment on if it will help anyone.

I never soaked any fittings gas or liquid. But I did spray everything down and since it was my first experience with duotight I may have been excessive with spraying down the gas fittings (with probably a heavier starsan mix by accident) while looking for leaks. Anyone who first puts these together probably understands the skepticism as they fit together too easily and it almost feels like there is no way that something that simple could seal that well but they do.

So I think the lesson from this really is to just pull back on the starsan. I don’t think they need soaking (gas or liquid) just a spray bottle with a simple spritz before hooking everything up should do.

Edit: starsan in its concentrated form might be considered bleach. If anyone has spilled a bit on a countertop without realizing it or similar probably knows what I mean.