Acrylic Problem

[Jyd]

Ok I had an Apollo Infinity Gold TN kit laying here and I purchased a Copper Lightning blank from BearTooth Woods to build this pen.

I have to say this is one of the best acrylic blanks I have used it drilled nice and turned very nice without chunks coming out. Turned the lower tube with no problem polished out and look fantastic. Turning the upper and getting close to bushing diameter and all at once the blank stops turning. I shut down and look things over and the blank has come loose from the tube and has two cracks on one end.

I did not think it was getting to hot, I have read here that it could cause my problem. It just looks like the epoxy never stuck to the blank, the tube is covered and it is bonded tight to it but the blank is smooth as a babies butt.
I have had problems with my last 3 pens when turning the blanks as I get close to final dimension. The first one was Spalted Maple and a piece popped off at the end. The second was a segmented blank from Woodcraft and I had the same problem a segmented piece came out, and the third is the acrylic above.

I am wondering if my epoxy has reached its shelf life or if I am just not doing my gluing process correctly. It is PSI 15 minute Mid Cure that was purchased with my starter kit in Oct. 2012.

Also has anyone tried polyurethane glue for building pens I thought maybe I could get better coverage as it foams up.
Any help is appreciated I am frustrated at this point and I don't need to toss anymore cash in the trash can.:frown:

 

[longbeard]

I use gorilla glue 5 min epoxy for over a year and half now, not had any problems or issues. Not sure what is causing your problem, could be that the glue is old. You may want to try some new glue and see if you have any problems with it.



Harry

 

[gbpens]

18 months for glue is getting a bit old. New glue may or may not help. When I have encountered the material separating from the tube it is usually not getting an even coating of glue on one end of the tube of the tube. This was the result of a tight fit at that end of the tube. Make sure your tube slides in and out of the blank easily. Except for cross cut blanks I do not have blanks blowing out at the start of turning. As we get nearer to the finished diameter the material gets thinner and can take less stress. Near the end ease up and take lighter cuts and keep the tool sharp. Depending on the density of the material being turned tools can dull quicker than we think.

 

[fisher]

Turn the rest of the acrylic off the tube.Make another blank.
I use 5 minute epoxy .Never had a problem with it so far.
Tool's need to be crazy sharp for acrylic and any man made material.

 

[Jyd]

Turn the rest of the acrylic off the tube.Make another blank.
I use 5 minute epoxy .Never had a problem with it so far.
Tool's need to be crazy sharp for acrylic and any man made material.

The acrylic was cutting like butter so I am pretty sure my tool was sharp, I have a feeling my glue is a bit old and that I might have had the blank hotter than I thought but I will take everyone's comments and some new epoxy and see what happens.

Thank you all this is a great group!