Brass tube delamination

[donnalleyd]

Hello from NC,

This is my first post and I am excited to get into the world of pen turning. I have been reading on the forum for a while and the wealth of knowledge is great on here. I have turned about 20 pens for friends and family.

I am coming to you because my first pen I turned (not exactly pretty but sentimental) has broken away from the brass tube. It is a slimline pen made with Cocobola finished with EEE and shellawax. The tube was glued in with CA glue. I was wondering what the suggested procedure for repairing it or is it a lost cause? Going forward does 5 min epoxy offer better adhesion? What is the recommended cure time for CA on the tube? Any advise is highly welcome.

Thanks

 

[rblakemore]

This has happened to me also!

I have had several tubes glued with CA come loose. I have switched to epoxy, I do not fully trust the timing though. Look closely, 5 minute epoxies may set in 5 minutes, but may need 8 - 24 hours to fully harden. Read the label closely. I made a pen Monday, Tuesday; I place the glued tubes in the sun (85 here yesterday) and they were workable in 3 hours. I have not yet tried as soon as the glue sets.​

 

[Jim Burr]

In last weeks discussion of this same topic...what viscosity CA...what blank prep...how long to cure...so on and so on. There is no right answer, the answer is what do you do correctly? There are dozens of YouTube videos that demonstrate the process.

 

[donnalleyd]

Is there a better Epoxy to use? I know 5 min epoxy is usually longer to cure than 5 minutes. My workflow would likely change such that I would let the epoxy cure overnight.

 

[donnalleyd]

My process I currently use:

Center hole drilled on lathe using pen blank chuck from PSI
Lathe has been centered and is only a few thousands off with a slight downward angle. In the short distance of the pen blank it is unnoticeable except with calipers (only reason I notice is experience with industrial metal lathe at work).
Tubes are scuffed thoroughly with 150 grit sandpaper and wiped of all shavings
Pen Makers CA Super glue from PSI is added to 2 sides and pushed into the blank with a rotating motion.
Left to cure for 30 minutes no accelerator
Barrel trimmed and edges faced

This seems to be on par with most techniques I have seen. My bigger question is can anything be done to save the pen for sentimental purposes? Is the CA adhesion a problem because of the Cocobola and its oily nature?

 

[southernclay]

I have used CA and Epoxy, usually CA, I let both dry overnight for the most part. The only problem I have ever had was a acrylic blank that had been reverse painted, dried overnight, glued in with epoxy, dried overnight. Came loose during turning, no idea what happened but isolated so have kept on trucking. I use glue/epoxy fairly liberally and really try to work it in the blank to get good coverage. Like Jim said, there are some great YouTube vids for this as well, I'm a very visual learner so spent many hours on youtube as well as the library when I got started......still spend a good bit of time in both. Welcome to the forum!

 

[kovalcik]

Epoxy vs. CA vs. Gorilla Glue vs. ??? is definitely a subject that is debated. In my opinion (take it for whats it is worth) I think technique matters more than the glue used. I have used Thick CA and 5 min epoxy without any problems either way. I have not tried Polyurethane glue (ie. Gorilla glue).

I do like the longer working time of the epoxy at times, but thick CA also works well. I find that I end up with more of a mess when I use epoxy and there is usually some waste. On the other hand it is also cheaper than CA. The key is to have your hole drilled so you do not have large voids to fill, and to make sure the tube is fully covered with glue. I usually let the tubes set up overnight, but have turned CA a couple of hours after gluing with no problems.

As far as how to fix your pen, I have never had good luck disassembling a transmission from a slim. I would get a new tube and transmission. You can reuse the old nib or get a new one. Make sure the new tube is the same length as the old one. You can sand it down a little if necessary. I would put masking tape over the wood barrel to protect the finish. Block the tube ends with some play-doh to keep glue out of the tube, slather it with thick CA or Epoxy and put it back in in the barrel until it is flush with the ends. Clean up the glue and remove the masking tape. You can put the barrel back on the lathe to touch up the finish if necessary. Reassemble and you are ready to go.

You can try using the old tube by knocking the nib out and masking the transmission off, but any glue in the transmission will keep it from working.

If the top barrel came loose same procedure, but you can reuse the old tube. You may not even have to remove the hardware if you are careful and mask it off. A 15 minute epoxy will give you more time to clean it up.

 

[donnalleyd]

Thanks all for your help! Upon closer inspection I think I know what the real cause might be. Being that it was my first pen I likely didn't wait long enough for the CA to cure. Also, at the very tip of the pen it appears as if it has many micro fractures in the wood. My guess is this caused some lateral forces to be applied to the tube (like wiggling a tooth). I also bear down on a pen quite hard which I am sure doesn't help. The tube actually still has some wood bonded to it around the tip of the brass tube. I think the wood gave way not the CA glue. Just a guess but it also looks like the repair might not work. Oh well maybe I can find something else to do with it.

 

[commercialbuilder]

I use epoxy with great results, you can add color to the mix if needed.
The tube ends are sealed with dentist wax to keep the epoxy out then I use a 1/8" dowel to coat the inside of the blank first then I twirl the tube in the mix to get a good coating about halfway up the tube. Insert the tube in the blank using a twirling motion slowly being sure that the excess epoxy on the tube stays completely around the the tube as it goes into the tube. I have used several different brands of epoxy and they all worked, you can buy the smallest size and try several until you find a brand that works best for you.
I have found that once the epoxy begins to set you can take a dental pick and get most of the epoxy out of the tube before it sets completely.
I have turned lots of pens an hour after the glue up with no failures to date.
Good luck
Mike

 

[sbell111]

I am coming to you because my first pen I turned (not exactly pretty but sentimental) has broken away from the brass tube. It is a slimline pen made with Cocobola finished with EEE and shellawax. The tube was glued in with CA glue. I was wondering what the suggested procedure for repairing it or is it a lost cause? Going forward does 5 min epoxy offer better adhesion? What is the recommended cure time for CA on the tube? Any advise is highly welcome.

How are you preparing the tubes prior to gluing them in? Upon receipt, tubes are smooth and likely have some trace oils on them from the manufacturing process. Both of these conditions can interfere with glue adhesion.

What I do to prepare my tubes is rough them up with a tiny sandpaper drum chucked into my foredom's handpiece. This gives the tube quite a bit of texture for the glue to bite.

I glue my tubes with thick CA and allow a day for them to cure.

It is also important to ensure that your holes are the correct size. Some of the hole sizes listed in kit instructions are considerably off, in my opinion. You might consider drilling some holes in blank cutoffs to ensure that the drill bit size for each kit is to your liking.

 

[Smitty37]

Hello from NC,

This is my first post and I am excited to get into the world of pen turning. I have been reading on the forum for a while and the wealth of knowledge is great on here. I have turned about 20 pens for friends and family.

I am coming to you because my first pen I turned (not exactly pretty but sentimental) has broken away from the brass tube. It is a slimline pen made with Cocobola finished with EEE and shellawax. The tube was glued in with CA glue. I was wondering what the suggested procedure for repairing it or is it a lost cause? Going forward does 5 min epoxy offer better adhesion? What is the recommended cure time for CA on the tube? Any advise is highly welcome.

Thanks

I would never use CA of any stripe to glue in tubes. CA by it's very nature does not provide good shear strength - it is great on pull strength but very weak on shear. Shear strength is what you want on tubes - all of the forces you apply in turning and assembling pens are shear forces.

Epoxy is much better and I think even something like polyurethane is better than CA.

That being said You can probably disassemble the barrel and reglue the tube if you are careful enough. Depending on which barrel it is you might have to replace the transmission.

 

[ed4copies]

I would never use CA of any stripe to glue in tubes. CA by it's very nature does not provide good shear strength - it is great on pull strength but very weak on shear. Shear strength is what you want on tubes - all of the forces you apply in turning and assembling pens are shear forces.

IF you turn pens properly (sharp tool, correct angles, etc), there is little stress put on the adhesive. Once the pen is made, there should be NO stress on the adhesive. I have made several thousand pens with CA and know many other prolific pen turners who have done the same. If your tubes are separating from your pen material, you did a lousy job of spreading the glue or you could use some refinement of your turning or sharpening techniques.

 

[Woodkiller]

I had some "oopses" early on, (and still do)as did most of us here, I'd expect. I just set them aside till I got better at everything and more experienced and found that I was able to fix and use all but one if them not too far down the road. Just try and learn from what you think happened, and go on. There are many ways to do the same thing. Trial and error is a pain, but it gives you valuable experience.

 

[low_48]

The fit of the brass tube in the wood, and how you apply the adhesive seems to be more important than what type of glue you use. Because you are going to get success stories and horror stories about gluing in with CA. For CA to work, you need to size the wood hole so the tube slides in easily with adhesive on it. It can't be so tight that it wipes off the glue as you insert it. If you oversize the hole, epoxy may be a better choice at it can bridge a gap and retain strength. I never just slide the wet tube into the blank. I put on (I prefer epoxy) on the tube, and a little inside the blank. Then I rotate and push the blank in so it can get the best coverage. Plug the brass tube with a little Play doh if you want to keep the inside of the tube cleaner. I also let the epoxy set overnight.

 

[knowltoh]

I think the fact that the wood was Cocobolo added to the problem. The oils in the wood can cause issues in finishing also.

 

[Smitty37]

I would never use CA of any stripe to glue in tubes. CA by it's very nature does not provide good shear strength - it is great on pull strength but very weak on shear. Shear strength is what you want on tubes - all of the forces you apply in turning and assembling pens are shear forces.

IF you turn pens properly (sharp tool, correct angles, etc), there is little stress put on the adhesive. Once the pen is made, there should be NO stress on the adhesive. I have made several thousand pens with CA and know many other prolific pen turners who have done the same. If your tubes are separating from your pen material, you did a lousy job of spreading the glue or you could use some refinement of your turning or sharpening techniques.

Ed, I've never felt a reason to even try CA....and I've never had a tube break loose. I based what I said on the nature of CA glue. I am sure that if the tube is roughed,the CA covers the entire surface of the tube, the tube fit is tight enough, and you have sharp tools and a skilled turner a person would never have a problem. Under those conditions you could probably almost use Elmer's school glue and get away with it.:biggrin:

 

[donnalleyd]

Just to throw it out there. Everyone seems to say that I would have noticed a problem during turning but the pen delaminated 6 month later. This pen turned well enough I guess. No catches or stops. Is that something normal or is this just a strange case?

 

[randyrls]

Two things come to mind as I read this thread.
Best practices do not guarantee success, but make success more likely
1. Scuff the brass tubes before gluing them in. Block the inserted end of the tube with wax or play dough and put CA into the hole and around the brass tube. When you insert the brass, glue should come out the far end entirely around the tube. If it doesn't, not enough glue was used.
2. Cocobola is a very oily wood. After drilling, wipe the drilled hole with acetone or DNA and allow to dry before gluing in the tubes.

Hope this helps.

 

[sbell111]

Just to throw it out there. Everyone seems to say that I would have noticed a problem during turning but the pen delaminated 6 month later. This pen turned well enough I guess. No catches or stops. Is that something normal or is this just a strange case?

I don't think that I've ever seen one that lets go for no reason, but when we first started making pens, we didn't prep our tubes. There were a number of occasions where we would attempt to dissassemble a pen for one reason or another and the tube would slide on out. Then I would swear and pitch the thing in a trash can.

Since we started prepping our tubes, this doesn't happen.

 

[Smitty37]

Just to throw it out there. Everyone seems to say that I would have noticed a problem during turning but the pen delaminated 6 month later. This pen turned well enough I guess. No catches or stops. Is that something normal or is this just a strange case?

I don't think that I've ever seen one that lets go for no reason, but when we first started making pens, we didn't prep our tubes. There were a number of occasions where we would attempt to dissassemble a pen for one reason or another and the tube would slide on out. Then I would swear and pitch the thing in a trash can.

Since we started prepping our tubes, this doesn't happen.

Just as a side note here - PSI now seems to be doing the prep for us on at least some kits. I fairly recently got some 7mm kits from them that have the tubes already roughed.

 

[donnalleyd]

Just to throw it out there. Everyone seems to say that I would have noticed a problem during turning but the pen delaminated 6 month later. This pen turned well enough I guess. No catches or stops. Is that something normal or is this just a strange case?

I don't think that I've ever seen one that lets go for no reason, but when we first started making pens, we didn't prep our tubes. There were a number of occasions where we would attempt to dissassemble a pen for one reason or another and the tube would slide on out. Then I would swear and pitch the thing in a trash can.

Since we started prepping our tubes, this doesn't happen.

Just as a side note here - PSI now seems to be doing the prep for us on at least some kits. I fairly recently got some 7mm kits from them that have the tubes already roughed.

They were roughed from PSI but I didn't think it was enough and wanted to remove all oxidation just in case.

 

[PenMan1]

I just stay away from CA completely. While CA relies to some extent in changes in humidity to cure, excess heat and humidity like we have with our weather here, can and will cause CA to debond. Additionally, CA does not really appreciate introducing any other type of acid into the mix. With any blank (especially exotics like Cocobolo) that were prepared by someone else, do you REALLY know how the blanks were prepared? Additionally, as Smitty mentioned, CA has less shear strength than many other glues.

Add in the fact that we work primarily with alternative materials that require reverse painting, etc and Epoxy becomes our glue of choice, as we can add acrylic paint directly into the glue to customized colors without causing ill effects.

Because of UV and humidity issues, CA also has a relatively short shelf life, when compared to other types of adhesives. So, we simply choose NOT to use it, except as a finish for the infrequent wood pen.

Finally, epoxy, at least in our experience has been LESS COSTLY to use, accounts for MUCH FEWER GLUE FAILURES and IS MUCH FRIENDLIER TO OUR LUNGS.