Tube glue failure

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Ray-CA

Ray-CA

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I am starting to have some trouble with the glue/tube/blank adhesion process. I've used the CA that came in the Rockler starter kit, CA (medium) that I bought at a local hardware store as well as some Gorilla superglue. About 30% of my tubes don't fully adhere to the blanks. I've tried putting some glue inside the blanks, glue on the tubes after roughing them with sandpaper, and I twist the tube while inserting it into the blank.

Any help and/or advice would be welcome.

Thanks

Ray
 
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Your process involves two brands of CA (including some that was provided as part of a 'starter kit' which means that the age is unknown), and with different application methods, and with and without scuffing the tubes with sandpaper. Its hard to figure out what is going wrong when you can't correlate failures with specific materials and methods.

One approach to diagnosing what is happening here is to embark on a careful series of experiments in which you record the materials and methods, and then correlate those with the outcome. to determine which combinations aren't working. Unfortunately, that approach will likely cost a lot of money and frustration. Instead, I may make more sense to adopt a set of materials and methods that are known to work.

My experience suggests the following:
1. CA is not the best option for gluing tubes. Instead, I prefer to use polyurethane glue (such as the original Gorilla Glue) because it expands to fill the gap between the blank and the tube, and because it sticks very well to the tube (and it seems to always get on your hands - an obvious negative - so wear rubber gloves). Two-part epoxy is also good, but having to mix it is a PITA. It's almost like having to decide between two bad choices! CA is brittle when it is cured, while PU and epoxy both remain a bit resilient, so they are better able to withstand the stress of milling the end of the blanks and turning the pen.
2. CA glue does age, especially if the storage conditions aren't controlled. The best way to store CA is to refrigerate it. If you don't know how old the CA is, or how it was stored, it probably should not be relied upon for critical applications. I would be very suspicious of CA that came in a starter kit purchased from a hardware store because you don't know its heritage.
3. Polyurethane glue cures better and faster in the presence of moisture. I have found that when gluing tubes in wood blanks, the best way to add moisture is to run a little water through the hole in the blank. The water will quickly soak into the raw wood inside the hole through the blank to accelerate curing, and also encourage the glue to migrate into the fibers of the wood making the joint stronger.
4. You can either apply glue to the tube, or to the hole in the blank. Because I wet the inside of the hole, I prefer to apply glue to the tube and then rotate it as I push it into the hole. But I also put a little glue inside the end of the hole through which I push the tube. Remember the general rule that when you push a tenon into a round mortise, the edge of the mortise will act a bit like a squeegee to scrape the glue off the mortise, leaving a starved joint. Polyurethane glue is VERY sticky, so it doesn't peel off of tenons as easily as CA or PVA glue (and when gluing brass tubes in blanks, PVA is absolutely the wrong glue because it won't adhere to brass). And the recommended drill size generally allows a small gap between the tube and the blank for glue. But applying glue on both the tube and the blank increases the chances that glue will be spread deeply into the hole.
5. It is critical that the tubes be scuffed to create a rough surface. Either PU or epoxy will stick to brass, but scuffing the surface means that when the glue in the gap between the wood blank and the tube cures, it will harden in the scratches which then mechanically locks the tube in the hole in the blank. In addition, scuffing the tube removes any corrosion which helps the adhesion between the glue and the tube.
 
I've been using Loctite 5 min epoxy general use for ten years now with no problems. Just make sure it's warm before mixing. I place it in the sun light or under hot water for a bit. Mixes real easy and holds great.
 

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I've been using 5 minute epoxy for well over 10 years with no failures. Early on I tried CA with limited success. I even had a couple of tubes get stuck halfway into the blanks. I also tried polyurethane glue, but it was messy and had limited adhesion. I switched to epoxy then and haven't used anything else since.
 
Thanks to all. I'll pick some up Tuesday.

I appreciate all the support that you are sharing. I moderate two forums and it's tough to get members to treat "newbies" well.

Ray
 
Ray-CA said:
Thanks to all. I'll pick some up Tuesday.

I appreciate all the support that you are sharing. I moderate two forums and it's tough to get members to treat "newbies" well.

Ray
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Hey, we were all newbies once. There's a great group of people here, whom I have learned a lot from.
 
Epoxy or polyurethane glue. For delicate blanks - only poly glue. Poly expands. Epoxy does hold better than CA overall, but epoxy can have gaps in it as much as CA does. This is learned when you have a blowout from a blank in which you can tell how much adhesion you had and how much you did not have. This is the area that poly glue shines over the other two - it expands and fills up any "spaces" and gives full 100% adhesion, which in turn adds structural strength.

Epoxy does take about 8 to 12 hours before it sets. It sets before that but curing takes longer.
 
leehljp said:
Epoxy or polyurethane glue. For delicate blanks - only poly glue. Poly expands. Epoxy does hold better than CA overall, but epoxy can have gaps in it as much as CA does. This is learned when you have a blowout from a blank in which you can tell how much adhesion you had and how much you did not have. This is the area that poly glue shines over the other two - it expands and fills up any "spaces" and gives full 100% adhesion, which in turn adds structural strength.

Epoxy does take about 8 to 12 hours before it sets. It sets before that but curing takes longer.
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I noticed an error AFTER posting and after edit allowance.
CORRECTED: Epoxy POLYURETHANE (glue) does take about 8 to 12 hours before it sets. It sets before that but curing takes longer.
 
leehljp said:
I noticed an error AFTER posting and after edit allowance.
CORRECTED: Epoxy POLYURETHANE (glue) does take about 8 to 12 hours before it sets. It sets before that but curing takes longer.
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Agree fully, but I will add that my experience is that the newer WHITE polyurethane from Gorilla seems to set much faster than the original version.

But a corollary is that one of the things that I keep reminding myself is that I need to be more patient - I'm retired and can afford to wait until tomorrow. Actually, I do that all the time on my wife's 'honey do' projects, so why not in the shop also?
 
monophoto said:
Agree fully, but I will add that my experience is that the newer WHITE polyurethane from Gorilla seems to set much faster than the original version.

But a corollary is that one of the things that I keep reminding myself is that I need to be more patient - I'm retired and can afford to wait until tomorrow. Actually, I do that all the time on my wife's 'honey do' projects, so why not in the shop also?
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I dont think the white gorilla glue is a true poly urethane glue. It doesnt foam like traditional gorilla glue, therefore it doesnt have the self centering property of the original. Im sure it is pretty strong, but epoxy and original gorilla glue are tried and true.

Personally, I use 2 part epoxy when I want to tint the glue, either with alumilyte dye or mica resin and reserve traditional gorilla glue for wood blanks where i can wet the inside of the hole before inserting the tube. The water needs to be absorbed into the blank so the gorilla glue can react with it, creating the bond. If the blank wont absorb water, i.e. a resin impregnated one, or an acrylic / alumilyte one, what is the point of using a water activated expanding glue? Just use 2 part epoxy, tint as needed and give yourself the extra open time to precisely place the tube just as you want it.
 
I like the polyurethane glue (gorilla white - note that gorilla started out as polyurethane glue but now has various formulations that includes CA and epoxy, the branding is kind of confusing IMHO). The only problem that I have had is sometimes the foaming action will force the tube slightly out of the hole, this can be problematic depending on the kit. Make sure to lay the blank flat after applying the glue.
 
Jarod888 said:
I dont think the white gorilla glue is a true poly urethane glue. It doesnt foam like traditional gorilla glue, therefore it doesnt have the self centering property of the original. Im sure it is pretty strong, but epoxy and original gorilla glue are tried and true.
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One of the problems is that Gorilla has expanded their product offerings so much that its difficult to tell what each product is and how it differs from others. They now offer low-foam polyurethane, white polyurethane, PVA glue, two-part epoxy, and even duct tape (which, for some folks, is a form of glue).

My experience is that the so-called white polyurethane Gorilla-brand glue does foam out like the original - but not as much as the Gorilla product sold as low-foaming polyurethane glue. That said, I think I prefer the longer-working time of the original product.
 
Gorilla Glue - clear would be my recommendation. I started out with CA (thin and medium) and had occasional failures. Since using Gorilla Glue clear I have had zero failures on the latest couple of hundred pens. This version of Gorilla Glue does not foam. I also watched Mr. Dreyer's 10-minute video on gluing (as well as the others he has produced) and use much of his process. Good luck on your process improvement.
 
JohnU said:
I've been using Loctite 5 min epoxy general use for ten years now with no problems. Just make sure it's warm before mixing. I place it in the sun light or under hot water for a bit. Mixes real easy and holds great.
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Plus you are able to tint it easily without affecting the cure.
 
Ray-CA said:
I am starting to have some trouble with the glue/tube/blank adhesion process. I've used the CA that came in the Rockler starter kit, CA (medium) that I bought at a local hardware store as well as some Gorilla superglue. About 30% of my tubes don't fully adhere to the blanks. I've tried putting some glue inside the blanks, glue on the tubes after roughing them with sandpaper, and I twist the tube while inserting it into the blank.

Any help and/or advice would be welcome.

Thanks

Ray
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Hi I've only ever used CA glue Thick version and never had a problem with adhesion. Do you lightly sand the tube before gluing this I find is important for adhesion.
 
Tube gluing failure is a common concern here. Here's a recent thread that discusses it in length: https://www.penturners.org/threads/poly-glue-what-went-wrong.167954/

This application calls for a glue that has two properties:
- gap filling - so that it will fill the gap between the brass tube and the hole in the blank
- will adhere to brass
Practically, this pretty much limits the choice to CA (medium, or better yet, thick), epoxy, and polyurethane.

I haven't done an exhaustive survey, but my intuitive sense is that there have been more reports of failures involving CA than with other types of glue. I know that one hypothesis that has been put forward is that old CA is more prone to failure; my experience, however, is that as CA gets old, it gets thicker, and glue that is too old to use won't even come out of the bottle! So I suspect that there is some other factor involved, but I don't use CA for this purpose so I can't really comment further.

That leaves epoxy and polyurethane - both have the two required properties, and both are messy to use. But epoxy has the further requirement that it must be mixed, while polyurethane is used straight from the bottle. However, polyurethane foams and expands and typically overflows the ends of the blank, but that's OK since the ends have to be trimmed anyway.

Other than using the wrong glue, my sense is that the three most likely causes of glue-up failures are failing to scuff the brass tube, failing to apply the glue properly so that it is not uniformly distributed throughout the joint, and drilling a hole that is the wrong size - too large, and the glue can't fill the gap, whereas inserting the tube into the hole will scrape away the glue if the hole is too small, leaving a starved joint.
 
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qquake said:
I use acrylic artist paint for coloring epoxy. 50 cents at Walmart.
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Not to hijack this, but I've wondered about tinting like this and haven't asked about it yet since I don't work with a lot of "plastic" blanks. I would guess it's still recommended to paint the tubes, too? Does the acrylic paint work well for the tubes and stay put when glueing?
 
sorcerertd said:
Not to hijack this, but I've wondered about tinting like this and haven't asked about it yet since I don't work with a lot of "plastic" blanks. I would guess it's still recommended to paint the tubes, too? Does the acrylic paint work well for the tubes and stay put when glueing?
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I use spray enamel for the tubes.
 

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Too tired to read all of the previous posts but I'm sure someone has said, CA has very poor shear strength. You'll notice that when the glue fails it's because there is no glue on the tube. If you want to use CA make sure the tube AND THE BLANK are well scuffed and you use copious amounts of it. Depending on the wood and the drill bit the interior of the blank can be slick and smooth as snot so there is nothing for the CA to hold on to. Never had that problem since switching to Gorilla Glue.
 
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I've started wetting the inside of the blanks before inserting the Gorilla glue coated tube. Give it 24-hrs to cure and then turn. Haven't had a failure since changing to this method.
 
Ray-CA said:
I've started wetting the inside of the blanks before inserting the Gorilla glue coated tube. Give it 24-hrs to cure and then turn. Haven't had a failure since changing to this method.
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Yes, You must do that. The water activates the glue and causes it to foam and cure.
 
I have read the comments and can only say I have been making Pens for 10 years and have never used anything but CA Glue.
It is obviously important to rough up the tubes use a good quality Thick CA Glue , I don't use accelerator sprays.
It is also obvious that the drill size is correct . I drill all my Blanks on the Lathe do not possess a Pillar Drill. Drill on slow speed to avoid run off.
Having Glued and spot faced my Blank I turn straight away never found it necessary to wait for the glue to cure.
Once you expel the air between the tube CA glue its cured that's the way CA Glue works.

Hope these comments help.
 
Sorry but I thought that's how it works. If you put CA Glue onto two surfaces the glue does not go off but squeeze them together and you have Bond.
 
Kcimdrib said:
I have read the comments and can only say I have been making Pens for 10 years and have never used anything but CA Glue.
It is obviously important to rough up the tubes use a good quality Thick CA Glue , I don't use accelerator sprays.
It is also obvious that the drill size is correct . I drill all my Blanks on the Lathe do not possess a Pillar Drill. Drill on slow speed to avoid run off.
Having Glued and spot faced my Blank I turn straight away never found it necessary to wait for the glue to cure.
Once you expel the air between the tube CA glue its cured that's the way CA Glue works.

Hope these comments help.
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Again and again not to dispute the use of CA as an adhesive but there is alot more that goes into using CA then there is epoxy or even Gorilla glue. Now you have been lucky for 10 years but that is not to say you probably take enough care when using it. A couple things with CA, it it this and it becomes brittle as cured. Drilling close tolerance holes is a must because the bigger the gaps then the more CA and thicker CA is needed. This error gets made up for with epoxy and Gorilla glues. I mentioned this in another thread, depending on the type of kits you use will determine how much outside force is applied to that blank after assembled. Many kits there is none after they are put together. Such as rollerballs and fountain pens that are caped. But kits like cigar and sierras and many other ballpoint pens require twisting motion to expel the refill and this puts strain on the barrels because that is what you twist with. Constant doing of this can break the adhesion of your glues and with CA being brittle it can easily happen. Epoxy will stay flexible even when cured as well as gorilla glue. Just some of my thoughts on this subject that keeps getting brought up. To each their own as to what to use. But for failures there is more with CA than other adhesives. Good luck.
 
Kcimdrib said:
Sorry but I thought that's how it works. If you put CA Glue onto two surfaces the glue does not go off but squeeze them together and you have Bond.
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I'm by no means a CA expert, but have spent probably more time than I should have trying to understand it. The hardening of CA is a polymerization reaction that must be initiated. Moisture (water) is often cited as the initiator, but this is not technically correct as it is actually the hydroxide in the moisture that initiates the reaction. This is why baking soda is often suggested as an accelerator, it has a lot of hydroxide ions. Anyway, not to get too far in the weeds, the materials that you are gluing together can really impact the speed at which CA cures. Unfinished wood has a lot of moisture and therefore CA will cure quite quickly, metals and plastics not so much. Ambient humidity plays a role. The CA rabbit hole is a deep one, this only scratches the surface...

As JT already touched on, there is actually scientific evidence that shows that CA will become more brittle in the weeks/months after initial cure. Also, thin is more brittle than thick and flex is less brittle than thick.
 
ramaroodle said:
Too tired to read all of the previous posts but I'm sure someone has said, CA has very poor shear strength. You'll notice that when the glue fails it's because there is no glue on the tube. If you want to use CA make sure the tube AND THE BLANK are well scuffed and you use copious amounts of it. Depending on the wood and the drill bit the interior of the blank can be slick and smooth as snot so there is nothing for the CA to hold on to. Never had that problem since switching to Gorilla Glue.
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That's interesting about using copious amounts of CA; I had a couple of failures, talked to my woodworking coach, and backed off on the amount of CA glue I put on the brass. Now I only use a single drop every inch or so, and spiral it around the tube. Haven't had a problem since. But, now that I'm reading all of these great posts about glues, I'm going to try some of the other recommendations. I hate using CA glue; I often end up with my fingers glued together.
 
I typically use epoxy for gluing my tubes up. It's a little inconvenient to wait but even five minute epoxies dry fairly quickly. It gives me time to work on other projects or clean up the shop a little bit.
 
doctormarje said:
That's interesting about using copious amounts of CA; I had a couple of failures, talked to my woodworking coach, and backed off on the amount of CA glue I put on the brass. Now I only use a single drop every inch or so, and spiral it around the tube. Haven't had a problem since. But, now that I'm reading all of these great posts about glues, I'm going to try some of the other recommendations. I hate using CA glue; I often end up with my fingers glued together.
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You run the risk of not getting good contact using that little. There is no way to get the hole drill exactly especially in wood because it expands and contracts and could expand as you drill because of heat. You are then relying on certain contact points on the tube as the tube sets in the hole. Again stress on those contact points can become a problem but maybe not. All we are doing here is bringing out points that could lead to failures. But if you never had any then keep doing what you think is best and works for you. No right or wrong way of doing this just multiple ways as with many aspects of pen turning.
 
jttheclockman said:
You run the risk of not getting good contact using that little. There is no way to get the hole drill exactly especially in wood because it expands and contracts and could expand as you drill because of heat. You are then relying on certain contact points on the tube as the tube sets in the hole. Again stress on those contact points can become a problem but maybe not. All we are doing here is bringing out points that could lead to failures. But if you never had any then keep doing what you think is best and works for you. No right or wrong way of doing this just multiple ways as with many aspects of pen turning.
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I never imagined that glueing a brass tube into a pen could prompt so much reaction. Its a simple pen with hardly any torque applied to it so hardening with age seems irevelent. I make pens for fun I give them away and raise some money for charity. I like most hate using CA glue it sticks to everything you don't want it to stick to. But for me does a good job.
 
Kcimdrib said:
I never imagined that glueing a brass tube into a pen could prompt so much reaction. Its a simple pen with hardly any torque applied to it so hardening with age seems irevelent. I make pens for fun I give them away and raise some money for charity. I like most hate using CA glue it sticks to everything you don't want it to stick to. But for me does a good job.
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Michael let me tell you. Look through past threads here and you will hundreds of them that deal with this same topic along with finishing. That is basically that all that gets discussed here over and over and new people such as yourself bring them up over and over and there is nothing wrong with that. But you need to understand there are always different ways to do everything we do in making a pen. That includes gluing in the tube. I laid out things that can happen not saying they will happen but again I have been here a long time and seen responses that tell me they can happen. What happens to one pen kit may not be the cae with the next one you try and now you have some info. File everything you read here away because believe me and I say this with all the conviction in the world you will run into them. Ask anyone here. If you ever get to the point of making pens and selling them you do not want your name dragged through the mud because you make an inferior product. You are competing with a whole lot of more pen makers than you realize and a ton of them do not even belong to this site. If something works continue until it stops. Good luck.

By the way you do not say what kit and to further your knowledge, if it is a twist pen you have nooooo idea what the recipient does with the pen and how they treat it. You may know not to twist too hard but do they?? Always ask yourself how can I protect myself from getting a return on my product for nonworkable craftsmanship.
 
Kcimdrib said:
I never imagined that glueing a brass tube into a pen could prompt so much reaction. Its a simple pen with hardly any torque applied to it so hardening with age seems irevelent. I make pens for fun I give them away and raise some money for charity. I like most hate using CA glue it sticks to everything you don't want it to stick to. But for me does a good job.
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IN addition to what John said above . . . You understand the work that you do and that is good. But we have 30,000 members, most come and go after learning basics. But what you are not seeing is that many people do not understand at the beginning - the basics of tube, CA glue, 3000 RPM, inexperience with a tool and WHAM, a catch, weak spots between the tube and blank due to inefficient gluing - it explodes. A combination of things, one of which is not enough glue to hold the tube and glue together. The blank, after being turned to "round" is very thin and the integrity of the thin blank is in its relationship to the tube with full dependency on enough CA or epoxy to hold it.

It is not about a matter of sticking the blank to the tube, it is about making the tube and blank be as one - to withstand the forces of 3000 rpm and a chisel chipping away. Just do a search here for "blowouts" and you will see how many times this has occurred. 17 pages to 2015 of that alone and for some reason, I couldn't it get it to search back before that.
 
Well gentlemen I appreciate your responses and if ever I make Pen Making a business I will remember your words of wisdom.
For know I will continue with it as a very pleasing hobby. I turn many items not just pens.
I have been retired some 13 years now and enjoy a game of Golf and have played for nearly 50 years and have still not mastered it, perhaps making pens will be the same.
I look forward to more conversations with like minded members.
Stay safe under these difficult time,
 
Ray-CA said:
I am starting to have some trouble with the glue/tube/blank adhesion process. I've used the CA that came in the Rockler starter kit, CA (medium) that I bought at a local hardware store as well as some Gorilla superglue. About 30% of my tubes don't fully adhere to the blanks. I've tried putting some glue inside the blanks, glue on the tubes after roughing them with sandpaper, and I twist the tube while inserting it into the blank.

Any help and/or advice would be welcome.

Thanks

Ray
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I use the small tubes of epoxy from harbor freight. Since I switched to epoxy I have not had any problems. I am sure there is better epoxy but it works for me.
 
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How do you drill your blanks. The tube should be a good fit in the blank. Do you drill on a slow speed and back off the drill and clean the flutes of the drill.
If you generate heat when drilling you get an oversized hole.
I drill on the Lathe and use a centre drill just give the drill a good start,
Also I use thick CA glue.
 
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