closed end tube gluing question

[Parson]

OK closed end penmakers, I have a question for you:

While I am making closed ended pens successfully, the tubes on my acrylic, PR, and truestone blanks come loose while turning from the heat (I think). I have to very carefully glue them back for assembly and frankly, that freaks me out due to getting CA glue on a finished pen part!

Notes:
• I use denatured alcohol to clean the outside of the tubes after I scratch them up real good with 65 grit sandpaper
• I clean the inside of the blanks real good as well with alcohol.
• I use thick CA glue liberally, and even let the blanks cure overnight... the last one that came loose cured for over a week!

You successful guys need to weigh in and help me solve this issue.

 

[Texatdurango]

OK closed end penmakers, I have a question for you:

While I am making closed ended pens successfully, the tubes on my acrylic, PR, and truestone blanks come loose while turning from the heat (I think). I have to very carefully glue them back for assembly and frankly, that freaks me out due to getting CA glue on a finished pen part!

Notes:
• I use denatured alcohol to clean the outside of the tubes after I scratch them up real good with 65 grit sandpaper
• I clean the inside of the blanks real good as well with alcohol.
• I use thick CA glue liberally, and even let the blanks cure overnight... the last one that came loose cured for over a week!

You successful guys need to weigh in and help me solve this issue.

From your comments above the most important thing I would look into is why you are generating so much heat while turning. I don't think there should be any heat whatsoever when turning a blank even truestone.

If your blank is getting warm while turning I would make sure the tool is sharper and lighten up on the pressure you are applying and see if the blank runs cooler while turning.

 

[Gary Max]

Every blank I have ever turned got warm----heck even hot from sanding.
try 2 part Epoxy----the slow drying type works best.

 

[rjwolfe3]

I would try the 2 part epoxy. I had the same problems with CA. I would also do what George suggested and eliminate as many of the causes of overheating as possible.

 

[ngeb528]

Why would it be a problem on closed end pens? I'm thinking about trying one.

 

[RAdams]

mine also get warm at least. I am notoriously lazy when it comes to sharpening which i am sure contributes.

What technique are you using for closed end? Do you paint your tubes and blank drill holes?

I use the 1/4" hole in the end, with the bushing on the mandrel and the tailstock pushed up. I paint both the tubes, and the inside of the blank. I have also never had a tube come loose (yet). Another possible difference is that i use Medium CA when i glue closed end tubes. I think it is thin enough to fill the cracks, but thick enough to not drip straight to the mandrel hole. I put a little bit inside the blank, and quite a bit in the outside of the painted tube.

I would start with examining my techniques to reduce as much heat as possible, and if that doesn't work, then buy some two part!

 

[CaptG]

Sounds like dull tools. Dull tool takes more pressure, causing much more heat and heat will soften up the glue. This also puts more torque on the blank making it want to twist more on the arbor that is gripping the tube. Heat softened glue with extra torque twisting the blank from the tube. My .02 cents.

 

[skiprat]

Perhaps the heat is coming from what ever type of closed end mandrel you are using and the blank is spinning on it?

 

[wb7whi]

could it be that when drilling the blank the heat opened up the hole just a bit so the tube does not make good contact? For acrylics I tend to use that foamy stuff with the gorilla on it.

 

[mickr]

ca cracks easily..are you attacking with a dull tool.? a catch will crack the ca... and how old is the ca?

 

[seamus7227]

I think anytime you're dealing with acrylics, pr, tru stone, plastics, etc, you should use 2 part epoxy. I use 5 min, and have NEVER had one come loose.