cracks appearing when pen is assembled

[springtime]

Hi any tips for avoiding cracks at ends of tubes on assembly, must have made 50 snakewood pens, no give on assembly
just done Madagascar rosewood and on assembly minute cracks appeared at clip end of Seara tube,
I sand the inside of lots of tubes after turning so parts not as tight but still have disasters often. any advice?

 

[jttheclockman]

File the inside of tube so components are slip fit by hand. Then use either red or blue locktite depending if you want to take apart in the future or not. (red less aggressive) Snakewood is one of those woods that just will crack no matter what you do. Many times it has minute cracks in already and the heat from turning and sanding just expands them.

 

[Dehn0045]

+1 for what JT said. For less crack-prone materials I don't go all the way to slip fit, but remove enough of the tube so there is a but less force required for assembly. Also, I use gorilla glue (white or original - polyurethane foaming), I believe the expanding/foaming both holds the material to the tube better and allows for a small amount of expansion of the tube without putting a lot of pressure on the blank material.

 

[MRDucks2]

Both are woods mentioned can be crack prone regardless of what you do.

 

[DrD]

In addition to the above excellent advice, pay close attention to HOW you assemble your pens. Oft times we just place a component on the tube and push it in - FAIL. I suggest using an Arbor press for assembly. Carefully aline component so that it is straight - not catewhompas in the least - then slowly and carefully press it into the tube. Snakewood - good luck! Watching how you assemble things will go a long way in reducing cracks around the ends of the tubes.

 

[egnald]

There is nothing worse than spending all of that time making a prized blank and cracking it when pressing the parts in.

In addition to using a round file, a tapered hand reamer, and a hand chamfer tool, I use a pipe cleaner brush and compressed air to clear out any dust or debris in the tube just prior to assembly. I test fit often to determine how aggressive to get with the tools. Then when I think I have just the right amount of snugness, before pressing, I smear just a tiny bit of Renaissance Wax on the parts that I will be pressing in as a lubricant.

I'm sure if it becomes a problem I will most likely go the route of doing a loose slip fit with some kind of adhesive to glue the hardware in. So far though the extra precautions are working Ok for me.

Good Luck and Best Regards,
Dave

 

[springtime]

Thanks for the replies, most helpfull, I do use gorilla glue , butdont do enough work to makefit slack enough it seems
dont know why the fit is made so tight. will take more time sanding etc before assembly. thanks again
Roy

 

[1080Wayne]

I suspect the reason the manufacturer makes the fit very tight is to ensure the clip end stays in the tube . That interference fit expands the brass tube enough to create the cracking problems with hard dense woods . Hence the need to ream /sand out the tube for those woods , and the use of Loctite to anchor the clip end back in . Red for permanency , blue for removability .

One other thing needs to be remembered . Every time the clip is raised and lowered to pocket the pen , a very small force is exerted which tries to wiggle the insert in the tube . The looser the the insert , the greater the potential wiggle , and the greater the need for a strong adhesive to resist . Too many successful wiggles will walk the clip insert right out of the tube . That is why I stick with using red Loctite , and why I would not use wax . Sorry Dave .

 

[jttheclockman]

This is also a good reason when drilling the blank for the tube it is not a bad thing to have a larger hole and the use of epoxy that is flexible as opposed to CA is a method I like to adhere to. Any help you can do will pay off. I also use vaseline many times when pushing in components especially ones that have that long black plastic tube.

 

[Wayne]

Here's my reply on another post.

I'll track it down and link it below my reply.

:
I've been successful with snakewood, pink ivory and some ebony wood. They are all troublesome.

Here's my solution. When drilling, yes drill shallow cuts. Then let it cool.
Here's the key.
After drilling put it aside for at least a week. Then check to see if drill slides through, probably not. Redial and once again set it aside for a week... When you finally can push the drill through its ready. These woods need rest time to stabilize.
Remember to clean the hole in blank with DNA or other, and glue immediately.
Turning these wood also require careful slow cutting/turning, heat is the enemy. Let it rest and cool down while turning. I often apply thin CA between turning and sanding.

Sanding, same concerns, keep it cool.
:

Cracks after turning

Hi All, I'm brand new to the site and also brand new to pen turning. I've turned 3 blanks so far with decent results but this last one I did has a crack that I can't seem to fix. Any ideas on what causes this and how to fix it? This particular blank is snake wood. I've sanded it down with...

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