Turned my first pens and pencils this past week and had a glue failure. I used thick CA glue and accelerator to glue the brass tubes inside the wood blanks as per the instructions that came with the pen kits. Waited maybe five to ten minutes then tried to ream and square the wood blank ends. Brass tube came out.
So my questions are: Is polyurethane glue better to use than thick CA glue? Does using accelerator lead to more failure than just CA glue and time to cure? If I use just thick CA glue how long should I let the CA glue cure before attempting any reaming, etc.? I am under no time constraints.
Thanks in advance for any advice as I am making these as gifts for my family and would like them to last a long time. Doug
...I recommend against using CA glue for much anything. Others will (strongly) disagree.
1) CA is very unhealthy if you breath it, and you will
2) It is well known that CA turns to a worthless powder in a few years in most applications.
3) In use, CA may trick you into thinking it has cured, when it is only solid on the outsides, and the insides are still liquid -- ask my face shield!
4) When you accelerate CA, you substantially weaken it -- that's what the white business is all about.
About the only things I still use CA for are:
a) temporary glue blocks -- it works great for that, but bearing all the above in mind;
b) temporarily stopping pith cracking in green wood so I have more time to use the blank before the cracking progresses farther; I always cut off the cracked part before using the piece. I store my wood in a cool, dark, humidity controlled environment, and sometimes the cracking never starts again. I've got a nice little holly log right now, about 6" in diameter, that this seems to be the case for; and
c) I used to use it as a pen finish, but I started having problems with it cracking, so I quit. I know a lot of people do it successfully, but it doesn't work for me any more.
FOR PEN TUBES, I strongly recommend 5-minute epoxy. And make sure to scratch your tubes with 100-grit sandpaper before applying the glue.
I use medium CA qlue for pen tubes. I keep a fan blowing across to keep the fumes away from me. I sand the tubes and rotate them while inserting in the pen blank. I have never had one fail and I have been making pens for 3 years. I am in no hurry to true the ends or turn the stock so I generally let them set overnight. I did rush one and squared the ends after about 10 minutes and the CA glue held.
The problem with CA is it isn't archival. After some period (6 months, 2 years?) you don't know what could happen. The main reason is it has no shear strength. So as wood moves, it can't and the bond breaks. But even with glass, it doesn't work well.
Makes a good bond for temporary use though. 5 minute epoxy is best here, as poly glue fills the bond, but isn't strong in the gaps
Have used medium CA, 5 min epoxy, & polyurethane glue on pen barrels. Only use the epoxy these days but do my end milling the next day. All three glues take 24 hours to reach full strength.
Had too many glue failures with CA, and became sensitized to the stuff.
Never had a glue failure with either epoxy or polyurethane. Only draw back found with polyurethane is stuff going bad in the bottle and cleaning away the foam from ends of tubes. Never had tube push out using poly. Think can buy smaller bottles of the stuff now.
Prefer the separate tube epoxy if can find it, but have used two tube injector product without a problem.
I do more than couple kits at time so found drilling & glue up one day; end milling & turning day later let me work smater than harder.
Five minute epoxy does not get really hard. It forms a stiff gum. Polyurethane makes such a MESS. You can't get poly off your fingers. I use medium CA. Sand the tubes. I put a ring of glue around the first end to be inserted and then some up the tube. I insert it half way, twist the tube and pull it back a 1/4" and then insert to proper length. This method spreads the glue to 100% coverage. Allow glue to cure for at least 15 seconds, then spray both ends of blank with accelerator. Always cap your CA before spraying the accelerator. Allow to cure over night! This method has worked for 100s of pens. I have a customer that has bought pens for 8 years, if they were failing, I would know it. There are pluses and minsuses with all three glues. I learned this method at a class at Woodcraft, Johnson City, TN on my very first pen.
Many will tell you to sand only to 220. I sand to 600 and then MicroMesh. The pens start to shine without finish about half way between 400 and 600. YMMV.
Clean hands, blanks, and sandpaper between each grit. Between each grit, stop the lathe, and sand by hand along the length of blank. Each new grit will leave a grey haze in the wood. If you see any scratches thru this haze go back up one grit. Our finishes protect the wood, they do not provide the shine!
I have been turning pens for about 1 1/2 years now, and my brass tube procedures have evolved during that time. I realize I am certainly not an expert, but am happy to be of help if I can.
One thing I always do is clean out the hole in the blank with a round brush. I don't want any sawdust or other issues inside the hole. I used to use medium CA, but I had a couple of failures like you described. I went to 5-minute epoxy, but had a problem when I was doing more than 2 or three pens; the epoxy would start to set up. I went to System Three T-88, which has a 30-45 minute work time, and I believe a much stronger bond. I always let it alone for about 24 hours before I clean the blank/tube from any left over residue. So far, I have not had a single failure after about 30 or so pens.
I also put the blanks on a mandrel and scuff them with some 150 sandpaper, and then plug the ends with plumber's putty before they are inserted.
>>I also put the blanks on a mandrel and scuff them with some 150 sandpaper,
>>and then plug the ends with plumber's putty before they are inserted.
I scuff with 80 grit, about the only use I find for it besides cleaning brake drums. I like the idea of the plumber's putty.
Just saying CA didn't work raises questions about the other variables in the process. I have always used Stickfast or Hotstuff medium CA and have not had a failure. I generally finish pens with CA glue.
The some people have failures and others not makes me wonder if all other things are the same. For example how about the types of tubes and the types of wood used? How about the type and freshness of the glue, the type of finish??
Someone gave me some aluminum pen tubes that I've been afraid to try. I've always used brass, scuff them severely before applying glue, and clean with alcohol. I do not want any oils or even fingerprints on the tubes. Were the failures made with brass tubes and processed the same way?
As for wood, I almost always use very dense exotics. Some of these (like cocobolo) are so full of resins and such that wood movement from seasonal moisture doesn't seem to be that much of a problem. For example, my turned boxes from cocobolo haven't had seasonal lid issues. Are the pens that others have had come apart made with similar dense woods or something more porous? Could there still be moisture in the wood when used?
As for the CA setting up slowly, some of the exotics seem to act as accelerators. I've learned to put glue on both the tube and in the hole and insert the tube quickly while twisting. Be too slow about it and the glue may set up before the tube is seated properly.
Five minute epoxy does not get really hard. It forms a stiff gum. ...
There are different types of epoxies, so I'm sure that there are some types that don't get hard. However, for most of the 5 minute epoxies that are sold at local hardware stores, the epoxy will cure to a hard plastic that can be sanded and finished. If it remains gummy, either not enough hardener was used or part A and part B weren't mixed thoroughly.
Doug -- I suspect the reason for the glue failure is that you didn't allow sufficient time for the glue to cure. Medium CA doesn't set up as quickly as thin CA and, sealed inside a deep hole, the conditions might be very similar to those inside the glue bottle. There's nothing to set-off the glue. Unless there's moisture in the wood, it can take a while for medium CA to set up.
Another possible problem: Be sure to paint the inside of the blank and the outside of the tube with glue. The tube tends to act like a squeegee. If you simply coat the tube and insert it into the hole, the glue may "roll up" and follow the tube -- leaving behind mostly dry walls just as a squeegee leaves behind dry glass.
I don't turn many pens. Only by order. But I have found a epoxy glue that I think would work well on pens. Lowe's sells not sure about any stores. It's call Jell Epoxy. I have used it to glue small pieces to a waste blocks and have never had one come off.
I have used 5 minute epoxy for some 40+years. Multiple brands, conditions, mixes, temperatures, etc none of it has ever gotten really hard. Two days later you can still leave tracks in it with your thumb nail. It is wonderful stuff for proper uses, just don't expect HARD.
One other thing I always do is to pass the unglued tube thru the hole in the blank. It needs to drop thru. Some blanks, especially oily exotics, will develop a "raised grain" on the inside of the hole. If your technique is a little slow this can block insertion of the tube. The longer the drilled blanks sit the more problems. A batch of Beth olive sat for a week after drilling, they had to be re-drilled.
Overheating of blanks while drilling causes all kinds of problems. Cracking, increased raised grain in the hole, etc. I drill the blanks on the lathe, with a constant air blast on the drill bit at the point where it enters the blank. One hand on the tailstock and one on the air gun. This cools the bit and cleans off the chaff.
I have used Gorilla for years and never had a failure. I scratch the brass, rinse the wood with water and stick the tube in slightly negative to the wood. The water accelerates the glue by hours so within an hour or two it is hard as a rock. Philip
