In case anyone cares, I have used all of these glues for gluing pen tubes into pen blanks:
- Polyurethane: Original Gorilla Glue, White Gorilla Glue
- Epoxy: 5 minute syringe (various brands), West Systems G-Flex
- CA: Various thicknesses and brands, including StickFast "Flexible"
- Silane: Gorilla Clear
Not Tried, Because It Does Not Work:
- Wood glue (e.g., Titebond I, II, III)
- Other white glues, household glues
- School paste
- Whatever stuff ends up on childrens' fingers after they eat candy
What I use:
- Polyurethane: Most of the time for general pen making. I use it on wood and opaque plastic blanks.
- I have this down to a science. It just works. I let the glue cure overnight at least, 24 hours preferred.
- Epoxy: Translucent plastic (acrylic) blanks and "special" pens.
- Works well and reliably, but mixing two-part adhesives is annoying, messy, and expensive.
- Syringe types are almost like CA for quality. Not very good.
- Based on my experience, "5 minute epoxy" is not ready in 5 minutes. Give it a couple hours to cure for better results.
- I like the West Systems G-Flex epoxy for high quality and good results. There are many "quality" epoxies to choose from.
- CA: Pen making demos and classes, when the pen must be ready to turn in a few minutes.
- Brittle
- Useful for quick demos and classes, but not for "production" pens, in my opinion.
- The vast majority of blank separation turning failures that I have witnessed happened when pen tubes were glued with CA.
- If you must use CA, consider a flexible CA to reduce brittleness and potential failures.
- I have done this, but all I can say is that it worked okay. Personally I would not use flexible CA for production pens.
- Silane (Gorilla Clear): I have tried it on a few pens.
- It works like epoxy without mixing. It takes 24 hours to cure.This is a potential replacement for epoxy. I have not glued enough pen tubes with it to say much. It is pricey, and must be stored in the light to stay clear, but away from heat.
I am with Hank (
@leehljp) regarding polyurethane (sorry, John) - it expands to fill the gaps. I agree that it is brittle when cured, which is not desirable for gluing pen tubes, but it does not seem to be an issue for me. I have yet to see a polyurethane glue failure.
I use polyurethane for the vast majority of the pens I make. I use it because it is cheap, easy, and convenient. You can glue a lot of pen tubes with the smallest 2 oz Gorilla Glue (original) bottle for around $6. It is messy - there is definitely a technique to glueing pen tubes with it, but you have similar issues with epoxy.
Another side note:
Do not use those silicone brushes, trays, and mats with Epoxy, CA, or Silane glues. Epoxy will leave a permanent tarry, sticky residue wherever the mix was not perfect. The CA and silane glues stick permanently. The silicone brush bristles will break off before they release CA or silane glue.
-> Some people say that those silicone gluing accessories do not work with polyurethane glue, but I have been using the Rockler branded products with original Gorilla Glue for years with no problems. When I glue pen tubes in a bunch of blanks, I lay them out on one of those Rockler silicone work mats. The polyurethane glue foams, cures, and comes off the brushes, trays, and mat as expected. I assume that other brands of silicone gluing accessories work equally well with polyurethane. Just my experience.