30 Minute Epoxy Broke Loose

[Aeternyx]

Has anyone had this happen? After almost getting a tube stuck half-way into an antler blank with CA glue, I switched to epoxy. I went with 30 minute Bob Smith Industries epoxy rather than 5 minute just so I could do several blanks at a time if I wanted to and not have to worry about it curing too quick.

On this particular occasion, I glued a tube into an antler blank and then forgot about it for about a week - so it had plenty of time to cure. When turning it, I noticed that I was having an awful time keeping it moving. The tools kept stopping the blank. Usually when this has happened to me, it's because the tail stock is too loose (I use a mandrel saver, not the knurled nut) - so I kept cranking it tighter, but in retrospect I should have realized something was wrong.

When I finished turning the pen, I went to pull it off the mandrel and the antler came right off without the brass. I was dumbfounded.

I used some CA glue to stick the brass back in the blank and finished up the pen, none the worse for wear, but what on earth?! Have you ever seen this?

I'm new at turning and this is only my 4th pen. I'd appreciate any insight you might have. The only thing I can think is maybe I didn't get it mixed well enough? I know the tube was covered thoroughly.

 

[TonyL]

I use the same epoxy (as well as others) - the 5 minute and the 30 minute. And yes, it happened to me, but very, very infrequently.
The 5 and 30 refer to "working or setting" times; not full cure times. I believe the 5 minute fully cures in 2 hours (I wait 4 though) . The 30 minute requires 24 hours to achieve full strength.

If you waited the full curing time, then maybe it was a mixing or other issue. I hope this helps.

 

[jttheclockman]

You let cure for enough time so it had to be one of 2 things because That is a good epoxy. You either did not mix well enough or you did not mix equal parts. Just my opinion.

 

[KenB259]

May I ask what method you used to square the blank, after gluing in the tube? The reason I ask is simple. When I first started this hobby, before I knew any better, I used a pen mill to square up the ends. I bought a pen vice and was squaring with that on my drill press. On occasion, when the hole wasn't exactly square with blank, my pen mill would grab ahold of the tube, sometimes breaking the adhesion completely, sometimes just weakening the glue. I would have failures that I eventually figured out the cause. Could something like this be the culprit? My experience, since switching to a sanding method to square blanks has resulted in no more failures from glue failures. I feel the only reason glue fails, any glue you choose, is because of some kind of excessive stress, other than obvious things like old glue, poor coverage etc. My 2 cents only.


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[Aeternyx]

May I ask what method you used to square the blank, after gluing in the tube? The reason I ask is simple. When I first started this hobby, before I knew any better, I used a pen mill to square up the ends. I bought a pen vice and was squaring with that on my drill press. On occasion, when the hole wasn't exactly square with blank, my pen mill would grab ahold of the tube, sometimes breaking the adhesion completely, sometimes just weakening the glue. I would have failures that I eventually figured out the cause. Could something like this be the culprit? My experience, since switching to a sanding method to square blanks has resulted in no more failures from glue failures. I feel the only reason glue fails, any glue you choose, is because of some kind of excessive stress, other than obvious things like old glue, poor coverage etc. My 2 cents only.


Sent from my iPhone using Penturners.org mobile app

This definitely could be the issue. I did use a pen mill with a hand drill and I've had issues with it grabbing brass in the past. I just invested in a disc sander though which will be here next week so hopefully that will help.

 

[Kenny Durrant]

One other thing is that heat will break down all glue. If while trimming the ends or too aggressive with the tool may have built up heat causing the glue to let loose.

 

[egnald]

Greetings from Nebraska - just adding in my 2 cents worth. I have learned to clean the inside of my blanks very well after drilling before applying glue. I use a small brush on a wire (designed to clean re-usable straws) and compressed air to clean them so there is no powdery residue that can interfere with adhesion. On some wood blanks depending on how oily they are, like Olive and Cocobolo, I also use a swab and Denatured Alcohol and compressed air to clean out any surface oils before gluing in the tubes. I don't know if it is necessary, but I consider it an ounce of prevention.
Regards,
Dave