wood cracking when pressing

[mdwilliams999]

I was wondering if anyone had any friendly advice when pressing pen kits together. Not that I have never had a pen crack on other pen kits, but the slimline pens seem to give me the biggest problem. Mostly with certain woods. African Blackwood is probably the worst, though I have had some issues with a few others as weel (Bloodwood for example).

I understand impact of humidity on wood, having parts appropriately aligned, taking your time, making sure the brass tube is clean and free of anything that could create to much pressure (like CA glue on the inside of the tube.

Does anyone have any other helpful tips? I was wondering if for example the fit on the slimlines is just a tad to tight or is there another "trade" secret" I'm not aware of. For the African Blackwood, I probably crack nearly 50% of them. I'm about to take it off the list of options for customers.

Thanks,
Mike

 

[ed4copies]

Hi Mike!!

The slimline has become a staple in every manufacturer's line. So, you have no idea what you are getting when you buy them.

One Christmas I did all Chinese slims (it was an experiment and yes, I knew there would be problems, but I wanted a more affordable pen!!)

Bent several trannies, even a few "nib" ends. The fit was horribly tight on one and loose on the next.

Invested in several round "chain saw" files---so I could take a little brass out of the tubes if they were too tight.

Things are better now, but not for ALL manufacturers.

 

[pensbydesign]

sounds like you have your bases covered
where are you getting your kits, sounds like a manufacturing defect

 

[Daniel]

I have found most slimline kits with any sort of "Extra" finish have to tight of a fit. The Black Enamel for example. It is my impression that the kit was originally made for the micro thin gold plating and never redesigned for the thicker platings. I don't tend to make slimlines out of the more expensive materials due to at least some expectation they will end up less than desirable. Sort of like not putting the silk robes on a pauper idea. I like the slimline, don't get me wrong. But I also recognize for myself that it is what it is and it is not the finest pen I can make.

 

[WWAtty]

This might help a bit: deburr the inside ends of the tubes. A couple twists with a reloader's deburring tool will take off the edge.

 

[KBs Pensnmore]

The deburring tool does help a bit, I've found that I have to run a drill bit (with a lubricant) to ream out the inside a tad. I do this on all my slim lines ( bottom section mainly) and have had no more problems.
Kryn

 

[crabcreekind]

Definetly, take the burrs out. Also, i found that the berea slimline kits are really good. They just seem to be better quality than anywhere else. They can be a little more spendy, but worth it in the end, if you are breaking alot of them and wasting many kits.

 

[jd99]

I am trying an experment right now with some Streamline pens, I make a lot of Corian and it cracks all the time.

Going to drill both ends of my blank a little over size maybe 9/32" down about 1/4" the use the ruberized CA Monty has, it is supposed to give a little: my hope are that when I press in the components the glue will assorb the expansion and not try to expand the corian.

Could work, might solve the wood cracking issue also.

 

[monophoto]

In my admittedly limited experience, there are at least three factors involved here:

1. The interior of the tube has not been thoroughly cleaned prior to assembly. When the parts are pressed together, debris left inside the tube causes distortion in the tube that appears externally as cracks.

2. The wood has been turned down especially thin, making cracks possible. I have an El Grande that my wife purchased for me many years ago and that was made by a very experienced turner. Unfortunately, the very thin wood has acquired a few cracks over the years. I probably know about them because I turn pens - someone observing me using the pen won't notice.

3. And the number one cause - the parts aren't aligned perfectly when they are pressed together. If the alignment is off a bit, pressing causes distortion in the tube that appears externally as cracks.

 

[ed4copies]

I am trying an experment right now with some Streamline pens, I make a lot of Corian and it cracks all the time.

Going to drill both ends of my blank a little over size maybe 9/32" down about 1/4" the use the ruberized CA Monty has, it is supposed to give a little: my hope are that when I press in the components the glue will assorb the expansion and not try to expand the corian.

Could work, might solve the wood cracking issue also.

CAUTION: CA will offgas and make the hardware look "foggy". I don't know about the "rubberized"--but test your plan before doing a "run" one night and seeing all your pens turn ugly!!

 

[jd99]

I am trying an experment right now with some Streamline pens, I make a lot of Corian and it cracks all the time.

Going to drill both ends of my blank a little over size maybe 9/32" down about 1/4" the use the ruberized CA Monty has, it is supposed to give a little: my hope are that when I press in the components the glue will assorb the expansion and not try to expand the corian.

Could work, might solve the wood cracking issue also.

CAUTION: CA will offgas and make the hardware look "foggy". I don't know about the "rubberized"--but test your plan before doing a "run" one night and seeing all your pens turn ugly!!

I'm talking about when I glue the tube in, in other words the two ends of the blank will be a little larger then the 7mm in the middle, so when I press in the components the tube will have space to expand, and the ruberized glue will compress, with out trying to expand the corian.

Its all theory right now.

Not talking about gluing the components in.

 

[okiebugg]

mandrel?

Do you use a mandrel to turn your pens? Over the years, I have found that when tightening the nut to "hold it all together", when the blank sometimes slips. To compensate, I always used to tighten the nut tighter. When you do this, you are compressing and distorting the ends of the tube which deforms them and you run into cracking problems. Not always, but often enough to make you change the way you do things.

African Blackwood is a close relative to ebony. Ebony is the worst wood there is when pressing a pen together because more often that not it will crack or worse, it cracks the following day (s). I've found that this is in part due to getting the wood too hot when sanding, displacing the oil in the blank and in effect 'drying' it out. This in effect changes the characteristics of the wood and it will crack. My $0.02 worth

 

[MattTheHat]

I have a set of chucking readers in 1/16th inch increments. If I thinking might have a problem with splitting, I ream the inside of the tube. I've only done so a few times so far (don't turn that many small diameter thin walled pes), but I've had no splitting since.

A couple of adjustable readers would cover all pen sizes, and the would be, well, adjustable.


-Matt

 

[DestinTurnings]

I would definitely chamfer each end of the tubes after they have been turned. Also ensure the tube interior is completely clean and devoid of adhesive and paint. I haven't cracked a single pen since I started doing this.

To chamfer, you don't need to buy a special tool. I use a sharp exacto knife and just run it around the edge taking off about 1/64" or so material. I will also use the blade to scrape out the inside of the tube before assembly to ensure I don't have any built up glue.

Just my 2¢.