Hardline possibly off-spec, advice/ideas wanted

[Salticid]

Update to add:

Just bought a chamfer tool to see if it's better than sanding.

Turns out MicroCenter also has silicon oil, so I grabbed some of that too.

Talked to the sales guy about the tubing issue and he verified it on site that one of the tubes from the stock I bought wouldn't go into the fitting no matter how hard he tried, but the manager seemed pretty unconcerned...  kinda disappointed in that.

We'll see tonight if any of this or potentially heating the tube end helps.  Any thoughts or advice on this issue is still more than welcome though.

 

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I finally signed up to ask for help with the first big snag I've hit and am having trouble solving for... 

 

I've looked around online and not found a whole lot, though there are some ideas I haven't tried yet and will tonight.  That said what I have seen seems to suggest my issue is not too uncommon, and I'm wondering if there is more wisdom or more ideas out there.

 

Problem:

My PETG tubing is just NOT fitting into the compression fittings. 

The amount of pressure I need to exert to even wedge the tube in a hair would break the components on my machine.

I am starting to believe the problem is the tubing is very slightly out of spec on the OD.  My own calipers are just not precise enough to really catch it, but even 0.2 mm could cause this problem, and it seems to not be too uncommon...

 

The runs I have bent took several tries and are very nearly perfect now... I sincerely do not want to have to try and do them yet again, after waiting for more tubing - because I'm pretty sure it would have to be special ordered.  I bought it at MicroCenter and so would have to return it to them and they will have to send it back to Bitspower and get replacement tubing....   >_< 

(yes I am going to let them know anyway, this afternoon.  They shouldn't be selling off-spec tubing.)

If I can manage to use these tubes at all, I'd like to.  If I absolutely have to deal with waiting for new tubing and re-bending, then I will deal with that when i have to.  But in the meantime I have a few days before I can drive in my out-of-spec tubes and show proof to MicroCenter to return them for a re-order, so it seems worth it to me to try to troubleshoot and see if I can make it work.

 

Details:

Tubing:  Bitspower PETG 16 mm OD, 12 mm ID

Fittings:  Bitspower compression, 16 mm OD

 

Things I am doing/have tried:

I am removing the compression cap and its o-ring completely and putting them onto the tube separately before trying to slot the end of the tube into the base section of the fitting.  These fit just fine over the tube, though the top o-ring is arguably a bit tight.

 

The tube fits into the base of the fitting fine if there is no o-ring in it.  It's the pressure/resistance of the o-ring not allowing the tube to pass.  Not even when I put the base on a counter and shove the tube end down into it with all my strength.  It's that bad.

 

Sanded/beveled the edges of the tube at insert point to 45 degrees. (I don't have a reaming (chamfer) tool though)

 

Lubricated with a bit of soapy water, both the tube and the fitting

 

Ideas I haven't tried (yet):

After much work last night  I did eventually get the tube into the base of one fitting, at least it felt and looked like it.  That one fitting has become a bit easier to insert the tube into now, though it's still far too difficult.  This suggests that with time and repeat action, it should get easier?  So perhaps pre-fitting each tube into each fitting repeatedly to prep them prior to putting together the loop?

 

I could buy a Chamfer tool, but does it make that much difference over sanding?  I hear varying opinions on this.

 

Lubricaton other than soap....   There has also been some speculation in at least one thread that I read that the o-rings may be stiff from storage/cold/age and may need lubricant or even to be replaced, in order to better allow the tube to pass. 

I had read someone on reddit suggest silicon oil, though I have no easy access to that.  What other lubricants other than that would be safe for a loop and potentially more effective?  Basically I need a lubricant that is easy to buy where I live.

Vaseline?  Has anyone tried this?  Is is a super effective lubricant and according to the o-ring handbook, (http://www.parker.com/Literature/O-Ring Division Literature/ORD 5700.pdf), it should be safe.  But I worry if any somehow got into the loop how it might cause problems in the block channels.

Which brings me to a water based lube...  I am not trying to be funny or weird here, water based means it is likely to not cause issues in a water loop if any got in, and it's sterile - at least when new.

Any thoughts and ideas are appreciated.

 

Heat:

Potentially warming the fittings and their o-rings in hot water before attempting to slot in the tubes....  to allow for more flex?

I read someone here - the one post here I could find with this problem - had been heating the ends of the tubes to soften them first, thus creating a custom fit into the fitting.  This seems like last ditch to me, but has anyone had actual success with this and no issues cause by doing so?

 

[W-L]

7 hours ago, Salticid said:

-SNIP-

Take a pair of calipers and measure the OD of the tubing if they are out by +/-0.3mm it won't fit as the Bitspower fittings have a tolerance of something like +/-0.1mm or +/-0.2mm.. It could be that the tubing so happens to be at the upper limit and the fitting at the lower causing the interference. 

 

The best way to find out is to take out the o-rings to get a measurement of the fitting if it's smaller than the tubing then we have a problem. 

[Salticid]

Thank you so much for taking the time to reply, I appreciate it

However, I did address exactly what you just said in my original post, if you read it.

Under "Things I've tried" you will see I did in fact take out the o-ring and try and insert the tube without it.  The tube did clear.

 

I have calipers.  I have measured the tube with them.  But my calipers are not made to be that precise so I can't exactly tell how far over the tube is, and frankly I have already spent so much on this I don't want to go and spend more on a pair of more precise calipers that I will only ever need for this one purpose.

 

I have done a lot of reading to troubleshoot and ran across these things already.  I know my OP is a bit of wall of text, but I provided that information to help defer advice or information I have already tried.. 

 

I've covered a lot of the basic knowledge already. 

I've pretty much confirmed with MicroCenter that the tubing is indeed very slightly out of spec.

 

What I am looking for is, short of buying all new tubing, how I might be able to work with what I have or make it work as best I can.  Ideas.  Information of if warming the end of the tube might actually help or do more harm.

 

I was also curious if anyone has tried or has thoughts about lubricants other than silicon oil, since I didn't think I could get any of that at the time of the post.  Honestly, I am still interested in the answer to that.

 

If I absolutely must buy new tubing, then I'll bite that bullet when I come to it. 

 

An update:

*  The chamfer tool did help a little over sanding.  Possibly because the edges seem smoother and the angle is probably more exact.  Still, alone it wasn't enough.

 

*  Removing the inner o-rings from the base of the fittings and soaking them in hot, soapy water, replacing them, and then using soap with a bit of water on both the tube and the fittings worked well enough that after some work I was able to get the pipe seated in the fitting base properly outside of the machine (on my bench). 

 

Once there I removed and replaced the pipe several times, until eventually it is workable.  They're still very tight, but I don't have to worry about breaking something with the pressure I put on them while mounted on a component.

 

If someone comes across this thread and tried this, wear gloves doing this.  The fittings can be quite sharp when doing this, and I inadvertently tore the heck out of my fingers against them.

 

I was able to use 2 of the 3 pipes I bent so far.  The third is proving to be especially tough, though I may have just started to get tired.  Once I finally got the fitting on, I left it there in the hopes it kind of normalizes against the tube until this evening.

 

I have not yet opened the silicon oil in the hopes I won't have to, but I may just give it a try tonight.

[W-L]

9 hours ago, Salticid said:

-SNIP-

If they are physically too large for the fitting itself and not the o-ring they won'y work, you can try warming the ends but for the cost of the tubing it's not worth the hassle. For lubricating the orings that's pretty standard practice in industry when installing seals to prevent the oring from being extruded or damaged. I've used Molykote III and it works great for sealing the orings in waterblocks. 

[Salticid]

15 hours ago, W-L said:

If they are physically too large for the fitting itself and not the o-ring they won'y work...

Yes, I get that.  As I said, the tube is not too big for the fitting.  It's slightly too big only when the o-rings are in.  That would put it about 0.1 or a touch more off spec, but not too big for the fitting itself.

 

If it were too big for the fitting itself, the tops of the compression wouldn't fit the tube, and as I also said in my OP, they do.

 

I don't know where you're buying your tube, but it's not actually cheap where I am. At least not the Bitspower tubes.  Add to that, I put in a LOT of work to get the runs I have bent just right, and I don't know if I can replicate that even if I wanted to... the hassle is worth it to me and my time.  Also, there is still nothing I can do about getting more tubing or returning what I have until tomorrow, so I may as well try.

 

As far as lubricants, in all my reading and research prior to starting this I've only seen one or two mentions of using a lubricant, and those only after running into this issue.  Which is funny, because you're absolutely right it's pretty standard in plumbing and piping so it makes sense. 

 

When asking people directly the last few days  they usually say just a bit of soapy water, or even direct soap application.  Honestly, I found it to cause more of a headache because when the water dries the soap becomes tacky.  It is a surfactant, after all. 

 

My main worry about lubricants is if any of it somehow makes its way into the system.  Can they in time cause clogs...  I didn't end up opening the oil I have last night.  Instead, I popped open some water based lubricant.  I found it a huge help over soapy water!

 

I originally bought 6 lengths of pipe.  Two of them made the runs I have been working with these last couple of days.  Last night I opened and started working with a third and this one?  Must be perfectly on spec because I had zero issues seating it in the fittings, without chamfering or working with the fitting itself.  A little lubricant and pressure and it seated fine, no struggle.

 

So it was definitely those tubes.

 

For those tubes, a combination of removing the o-rings and soaking them in hot water, putting them back, using a lubricant of your choice (soapy water sucks for this and so far a water based lubricant seems to work great) to seat the pipe, and then either leaving it overnight, working the pipe back into the fitting a few times until its easier after it's had time to sit...  this worked best.

 

I was careful with the o-rings to make sure I didn't tear them up, and anyone else with this issue should be as well.  

[W-L]

@Salticid if the tubes are already made and bent then I give it a go for sure. As for oring lubricants the molykote stuff I used is inert so it doesn’t have any issue for use in a loop as it’s even designed for use in kitchen facet seals and such. Anything of the equalivant applicationshould work well for the seals.  

 

Soap up is acceptable but I would give the loop a quick rinse to ensure there is no chance of foaming just in case. Another is to use petroulm jelly but less ideal as it has other additives in it. 

[Bitter]

Would dunking the end of the tubing into boiling water for a minute and then inserting the fitting then allowing it to cool possibly stretch the tubing while warm and then hold the size once cooled?

[Salticid]

@W-L , Thank you so much for all your feedback and thoughts!

 

I proceeded over the weekend, though I did end up having to re-bend 2 of the 3 original runs I was having issue with - mainly for aesthetics and in once case also to improve fit a bit.  Some of the tube was definitely that little bit out of spec but not all of it was.

 

To get a lubricant like Molykote I would have to order online and wait or be able to make it to a plumbing supply store near me, which is not possible because my commute and their hours just don't mesh.  That said, it sounds like an ideal solution had I planned ahead for that.

 

Petroleum Jelly, or Vaseline, was something I initially considered, but because that's viscous and doesn't dissolve in water, that was a really big concern for me if a little of it somehow got into my loop - those block channels are so tiny, I can imagine it causing an ugly clog.

 

I decided to steer clear of soap/ soapy water.  There's the tacky effect I was getting when bending and fitting my tubes as the soap dried, and yeah, I had a similar thought about suds in the loop if any got in as well.  Sure I could run a rinse, but what a PITA.  Seems less than practical... idk.  Especially when it didn't work as well as alternatives.  Maybe if that's all you have access to?

 

I had great success with the water based lubricant.  To be blunt, I used KY.  Meant to be safe with any plastics, rubber and acrylics, sterile with no growth promoters, and completely water soluble in case of entry into the loop.

 

It seems ironic considering the abundance of bad innuendo jokes liquid cooling, and custom loops in particular, is prone to.  But, it really works, and is a super accessible option in a pinch.

 

@Bitter , I wouldn't use boiling water for that...  It just feels wrong and like it could damage the structure of the tubing, if not over-soften it for such a purpose.  When I have seen people mention heating the end of the tube in order to get it into a to-tight fitting, I have seen people recommend using a hair dryer - not even the heat gun as you run the risk of making it too soft.  You need to maintain almost full rigidity to the tube, making it just pliable enough to constrict on the OD for the tight fitting but staying strong enough to be able to push into the fitting and keep it's shape and ID.

 

The very delicate nature of maintaining that balance so that it's actually effective and doesn't completely backfire is the reason I felt it was a "last ditch" solution and wanted to avoid trying it.  Personally, I thankfully didn't end up having to try it.

 

SO, update:
 

I finished my lines over the weekend and started my fill/leak test last night.

Here are a couple of pics - note the LEDs and fans are plugged into perif sata cables and are the only things plugged in aside from the water pump at this time. I haven't set the LEDs to anything specific yet, they're running in a stock loop right now.  I mainly got them for the UV part of the strip.

 

 

[Bitter]

That looks really nice, great work!