Glue for carbon fiber tubes

[Ken Thompson]

Looking to glue in some cf ferrules in cf tubing. What works best?

[Link .]

.

[Link .]

.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Sam Farrington]

K T,
Began long ago using epoxy glue. Sometimes though, epoxy glue can break down the resin and hardener in carbon fiber tubing. When this happens, the joint just kind of goes squish. Happened many times.

So switched to contractor grade (NOT ‘Gorilla’ glue) urethane glue. Elmer’s glue-all max is one, Lepage make one. It has the added advantage of expanding and foaming when drying, thus holding the ferrule more tightly in the joint. The 2-part urethane glues are more difficult to use, but adhere the best. Much discussion about those is in the threads on bonding Cuben fiber.

However, even with Elmer’s, there were a few times when the glue around the ferrule hardened to a shiny surface, and the ferrule separated. The now defunct ‘ProBond’ urethane glue was better. Usually, if the bond fails, the ferrule slips all the way into the glued tube when the poles are folded up, making it impossible to join the pole tubes. Without taking out the shock cord for a full repair, not much fun on trip, an over-sleeve in the answer.
I carry a couple that slide snugly over the carbon poles for that purpose, and also for breakage. Because they are snug, there must be at least one end of the tent pole with an internal fitting that does not project more than the diameter of the tent pole. But I’ve never used them since beginning to use better quality arrow shafts for poles. Some prefer to carry a whole extra pole section if the pole can be designed with identical sections. It is better to do that anyway, to when the poles are folded, none will stick out and be more subject to breakage.

I try to concentrate the bond closest the end of the ferrule inside the tube, so at least half the ferrule closest to the exit, is free to slide as the tube bends. The opposite, or concentrating the glue where the glue exits the tube, might have the same effect, but is messier. If glue is placed where the ferrule enters the tube, no matter how well you clean the end of the joint with 91% Isopropyl alcohol, the glue will bubble up around the outside of the joint when it dries, and must be removed to allow the poles to join tightly together over the ferrule.

For ferrule connections there are very light alloy rings, called ‘bull dog nock collars’ that can be fitted over the end of the open tube that slides freely over the ferrule. They come in a number of sizes, and from several archery sources. They are good for joints exposed to the greatest stress, like those at the high point on the hoop or arch, but I never put a ferrule at or near the center of a hoop pole. I’ve been able to find the right sizes of collars that press fit over the pole ends without having to drill the rings out and thus weaken them, but use them only where an arch pole slides over an elbow at the apex of the tent.

Also, for a good bond, a low vicosity glue, not a high V one, works best.

It might be worth testing some of the best epoxies, like West System, on the carbon tube and ferrules you have in mind. Things may have changed. Incidentally, there was an airline accident some years ago that resulted from a solvent getting on a carbon fiber rudder. So … care must be taken to keep solvents off. Perhaps like DEET, for example, but this is just guessing.

Hope this is helpful. Good luck.

[Ken Thompson]

Thanks all. It’s for a mid pole. Didn’t look at glue for grips, because, well I am not glueing dissimilar materials.

Sam, Thanks especially.

[Roger Caffin]

Loctite Black Max (480) is excellent. Lasts ‘for ever’, with no damage to the CF tubing.

Cheers

[Sam Farrington]

Thanks, Roger.
Will see if I can get some.
Sam

[Ken Thompson]

It’s pricey. Hysol seems to be a favorite too. I’m using it for a fairly non critical application I just need the ferrule to stay in place.

[Roger Caffin]

Yeah, not cheap. But my UL pack frames are held together with it.
The price is less in the middle of a bad storm.

Cheers

[Sam Farrington]

Roger,
Googled and found it is a cyanocrylic (‘krazy’) type glue. Not a fan because it often sticks more of me than the work.
But it sounds like that might be offset by the high strength. It is ~$44 from Amazon for a one oz bottle with free shipping, but can be bought in much smaller tubes to try out.
The rubber content appears to add some flexibility to avoid cracking like many cyanocrylics do. If it can hold your pack frames together while being exposed to warping forces, that is quite unique. Should have tried it for the reinforcements on my alloy camp chair. Will do so when they start to come loose.
It may also help to focus a ferrule bond to a smaller point, allowing more of the ferrule to bend freely, a deterrent to breakage.
Thanks for the tip.

[Roger Caffin]

The rubber content appears to add some flexibility 

Exactly. I find it is much superior to the cheaper rigid superglues. As for sticking to me – I try to avoid that :-) However, it does come off skin after a while.

Cheers

[Ken Thompson]

I’m using it on 1/2″ id tubing, so not much flex.

[JCH]

Sam,

re: your statements about using epoxy…What brand/type (5min etc.) of epoxy did you use? How long does it take before the “joint just kind of goes squish”?

I’m not concerned with the effects of bending forces as I am making “trekking pole replacements” for when I don’t need/want to take poles.

[Sam Farrington]

JCH,
It was over a decade ago. The arrow shafts were Cabela’s house brand, and supposedly contained layers of CF. Not so. Could tell just from the weakness of the shafts.
The ‘squish’ was like the firmness of the tube just dissolved. Was using pultruded tube in those days for the ferrules. Both the ferrules and tubes went soft where the epoxy was applied, were useless, and had to be replaced with extras carried in the field. The epoxy was a common store brand then that began with the letter “D.” But don’t remember the full name, though it was the regular epoxy, not the fast drying.

I recently replaced the grip and extension on Yukon Charlie ‘flick-lock’ poles because liked the quality of the locks, use of alloy for the lower 2 sections, and CF for the top section; but the grip the pole came with was junk, and I had another much better grip and extension from a Scott pole that had exceeded its life when the pushbutton for the bottom section wore out the hole and made the bottom section loose. (Used to happen all the time with cheap pushbutton poles from Campmor).

Did the whole boiling thing to get the grips off. No problem getting the the grips off, but the foam extensions were difficult to remove, and were weakened by the boiling. But did get the job done. Used West System lower viscosity epoxy, from alphaknifesupply.com. When the epoxy dried, the grip stiffened up, and the pole has worked fine for several hikes. It is 7.5 oz with the heavier grip, strap and extension, mud basket and rubber tip. Like it, and take comfort that the lower alloy pole sections are not going to crack and break as CF ones are prone to do.

Looked at the three CF tube companies that come up on Google, and note that only one sells filament wound CF tube larger than tent pole tube. That’s a fair bet the others are pultruded, and therefore much weaker.

Don’t know what your trekking pole replacements are, so not sure how to respond to that. Hope this is of some help.

[JCH]

Sam, thanks for the (very complete) info.  If I may, it sounds like the culprit was likely low(er) quality pultruded tubes from a decade ago…at least that is what I would like to believe :)

Bob Moulder has posted extensively on his MYOG trekking poles and posted this link to a Chinese eBay supplier of “high quality 3K roll wrapped CF tubes”. I recently built some 45″ 3-section poles for my Duplex using 12mm x 10mm tubes for the main pole sections and 10mm x 8mm tubing for the ferrules with material from that supplier. I’m no CF tubing expert, but the product I received looked as good as any CF tubing I have seen.  Working with it was very easy and I glued the ferrules in using Gorilla Glue 5-min epoxy from Lowes. While there I grabbed a few vinyl bolt thread protectors to use as end caps and strung it all together with 1/16″ shock cord from the local sewing supply store. Total cost ~$45 and the satisfaction of building them myself :)

They turned out better than I would have imagined.  VERY stiff, and only 2.5 oz each.  This is only 0.5 oz per pole more than the “noodly” little aluminum poles I got from Tarptent (not saying anything bad about their product…even TT says they are not heavy duty.  I bought them because they were light and cheap).  TT also sells a 0.49 pole for $32 + shipping a pair that are likely closer in stiffness to my CF poles, but they weigh 4 oz each and I doubt they are *as* stiff.

Bob has had good luck with JBWeld 5-min epoxy on these tubes so I expect my poles will prove to be very sturdy and long lived…time will tell.

 

Edit: HA! I see Bob chimed in moments after I hit “submit” :)

[Bob Moulder]

Probably Devcon.

Hysol (previous mention) also works well, as do JB Weld and JB Quick, although with JB Quick it sets so quickly that you’d better be damn sure you’ve got it all figured out and stick your parts together right now. The nice thing about the JB epoxies is that they don’t shrink like others, including Hysol.

I’ve been using JB Quick for my myog trekking pole tips and it has really impressed me. Many, many times I have used my poles for weed whacking, and several times I’ve swung them with full force into rocks and the glue bonds have not broken yet. I am amazed, quite frankly.

[Bob Moulder]

Heh, great minds working simultaneously, lol! :^)

I’m glad you said Gorilla epoxy because the original Gorilla glue (water-activated polyurethane) is total crap for this application.

[Sam Farrington]

Wow, that is a lot of new info that I hadn’t seen yet.
The wrapped CF tube is not quite as strong as the filament wound, but much better than the pultruded, in my experience with tube that is tent pole size. And filament wound for trekking poles might be quite expensive and overkill. Not so, IMO, if the the poles are being used for dome type tents and need to be flexible without breaking. Fortunately there are filament wound arrow shafts that are mass produced by Gold Tip and maybe Victory
that can be obtained for around the same cost as alloy tent tubes.
Sounds like you have really honed in on min weight with max stiffness for mid and trekking poles.
Will have to check out some of the HaoZhong tubes. Thanks.

[Roger Caffin]

I tried using the pultruded stuff. Utter total disaster: it split full length under light load. It has zero bending strength.
Wrapped tubing is much better, but it is more bendy than 2D filament wound. I only use 2D filament wound.

Victory Archery have suitable arrows, as do Gold Tip (last I looked, anyhow).

Carbon Express do NOT. What looked like ‘good stuff’ turned out to be a pultruded glass core with a light dusting of carbon black paint over the outside. As far as I could see, there was no carbon fibre in them at all, despite the company name. They split as well.

Hao Zhong: some caution needed. As far as I can see, they make wrapped fabric tubing, in a huge range of sizes. It might be quite OK – dinno. They do claim some filament-wound tubing, but the pics are still wrapped fabric. Again, dunno. One would need to get a sample and to pull it to pieces.

Cheers

[JCH]

Bob has reported abusing his MYOG poles quite extensively and the Hao Zhong tubes have held up beautifully. From his description of his adventures, I am certain there were some strong lateral/bending loads applied, but I would expect those loads to be typical (momentary) trekking pole type bending loads, not sustained like a dome-style tent pole. No doubt the filament wound poles are the way to go for dome-style tent poles.

For use as a Mid pole or as poles for trekking pole supported tents, I suspect the Hao Zhong tubes, in the sizes I used, are well suited.  But time will tell and I’ll be certain to report any interesting or unexpected events.

BTW, I’ve ordered some 8×7 and 7×6 tubes (0.5mm wall thickness) to see if they will serve as 26″ panel pull-out poles on the duplex. There is VERY little force applied to those so am hoping these will come out uber light and fit for purpose.

[Bob Moulder]

A few times I’ve put a very large load on my trekking poles and they’ve held up fine.

This past March we were descending Slide Mtn in the Catskills. Virtually (and bizarrely!) no snow except for a few rivers of ice running down the trail. I wasn’t using microspikes because in most places there were ways to easily get around these few sections. At one point I had placed my pole tip in the ice and was leaning over it while keeping my feet on some dry rocks at the edge. Well, the tip slipped out and slid over about a foot and a half to two feet, catching my full body and pack weight with a fair amount of momentum. The pole really flexed and I thought it was a “goner for sure” but there was no damage.

These poles are made with the Hao Zhong 3K tubes, 13x11mm and 11×9 mm, and weigh a little under 5 oz each.

[Daryl and Daryl]

Ken,

For non-critical carbon fiber tent pole ferrules I’ve had good luck with Zap A Gap glue.  It is commonly used by kiters.  I’ve kept a bottle in the frig for years and it still works fine.

I wire brush/sand the inside/outside surfaces to be glued.  I then swab the areas with denatured alcohol and let dry.  One drop of Zap A Gap is sufficient to hold the ferrule in place.

Haven’t had one let go yet.  I always carry a piece of repair tubing and tape just in case, however.

http://www.walmart.com/ip/Zap-A-Gap-Super-Strong-Glue-Bonds-Almost-Anything/30407613

 

 

 

[Author]

Posts