I am a crack king....

[Tullyamo]

I have had many friends come back within 1-2 weeks on pens that I have made ALL having the same thing to say about their pen. "It was very nice...blah blah.. I've noticed the wood has split on it..." Yeah, the first pen, I thought, hmm.... what happened. The second pen left me thinking, what are they doing with the pens. The third and fourth pen left me thinking, OMG what am I doing. The fifth, sixth, and so on ....

Here are my steps, I am hoping this can be resovled as this has happened to cigar and Majestic style pens. Woods including Cocobolo, African Blackwood, Bloodwood, Osage Orange, Snakewood *yeah I knew that would happen, ligum vitae, and stabilized boxelder. Koa... never cracked.


Measure blank with the tubes and make my cutting marks.

Cut on a bandsaw

place blank on the pen vise tight but not tight enough to hear a crack

pre-drill with an 1/8" bit backing the bit up to not over heat

drill with the 10mm carbide tip bit backing the bit up to avoid clog and over heating*for cigar pens and appropriate bit for majestic

insert appropriate tubes after sanding the outside with 400grit paper and swirling CA thick on the ends before slipping them into the blank.

Spraying the ends with activator to harden the glue that overflows on the outside from putting the tubes in the blank

place blanks back on the pen vise for barrell trimming

trim barrel backing of when I see the slightest bit of smoke

apply blanks to the bushing and place on the lathe.

I have used a brass tight nut to secure the blanks on the mandrel and I have used the mandrel saver, both are yeilding the same result.

I have turned the wood at 1150 and 650 rpm and have yeilded broken the same results.

sand 180, 240, 320, 400, 600 but not to tight to avoid heat build up. Sanding was down at 2250rpm

==================================
from here I have used two different approaches to finish... both yielding the same cracks...

1. using eee ultra two coats on a cotton cloth

Following up with friction polish on a cotton cloth *2 coats

++++++++++++++++++++++++++++++++++++

2. applying CA and Activator... 1 coat CA, 1 spray activator, *8 coats

sanding 1500 to 12,0000 wet

applying plastic polish

BOTH of the finishes have yielded my cracks.. it has gotten to the point I am a bit embarrased to chat with these friends due to the "hey, my pen........" I have nearly sworen off wood pens entirely. Acrylics so far have yielded much better results. How can I correct this problem? I understand that many of you will reply with the "I am not there to see the pressure, speed, etc that you have used so I can't give the best advice." I have documented every step to the dot how I do stuff minus the pressure that is applied with the bandsaw, drill press, barrell trimmer, and sand/eee/polish. I am hoping this will help.

Thanks

Jeremy

 

[hunter-27]

Only variable I can't comment on is activator, I don't use it. I use gorilla glue on the tubes. Other than that I do basically the same.

 

[Parson]

The wood cracking is really puzzling. Do you live in a very dry part of the world?

Just taking a blind stab at it, but I wonder if humidity or lack-thereof may be your culprit.

On other matters....

"Spraying the ends with activator to harden the glue that overflows on the outside from putting the tubes in the blank"

This step is not necessary. Take a paper towel and wipe away the excess after the tube has set up a bit. Then, ream the tube out with a box cutter blade if there is glue buildup. Activator isn't cheap and this is just a waste in my opinion.

 

[low_48]

You didn't mention where you get your wood. Ever checked the moisture content? I use either 5 minute epoxy or Gorilla glue. I don't think you can get good enough glue coverage with CA. With either of the glues I use, I rotate and pull the brass tube back and forth to get full coverage. I also turn at about twice the rpm's you do, but that won't cause or prevent cracking. I suspect the wood may be too wet and needs more drying time.

 

[Tullyamo]

I live in Yakima, Wa. We are kinda the desert of Washington State. We receive on average 290 days of sun per year. It is much dryer here then in Missouri, where I am origionally from.

I have purchased almost all my wood from woodturningz. I got a few pieces here and there off ebay, but 98% of the wood is from woodturningz. Come to think of it.. the wood I have gotten so far from ebay, hasn't cracked..... perhaps just coincidence?

 

[robutacion]

Hi Jeremy,

I may not be able to give you an exact reason for the problem but, I would suggest you get a moisture content gauge and read the MC % on the blanks you got home identical to those you used. Make sure you get the same batch or the same group of blanks you are normally using. Do this test on as many blanks as you can (identical woods used) and let us know...!

Most of the woods you have used are properly kiln dry before they are put for sale (exemptions due apply) but that doesn't mean that they haven't or are exposed to excess humidity or even being in contact with water...!

The test will tell you, they should read between 8 and 12% MC maybe 14% maxi. If you don't have a moisture content gauge, I will suggest that you get one. I have one I purchased on eBay, this unit is cheap but very efficient, I have been using it nearly daily for over 3 years and it never missed a bit!
The Seller is a trustful one, quick and reliable, I've made many purchases from him without any problems. If you want to have a look, here is the link;
http://cgi.ebay.com.au/Moisture-Meter-Foreclosure-Home-Inspection-Tool-2-Pin_W0QQitemZ310207658556QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4839d13a3c#ht_818wt_937

I believe, you have to use the "elimination" method to get to the bottom of the problem, I would suggest you start with this...!:wink:

Cheers
George

 

[1080Wayne]

No problem with acrylic pens plus lots of cracked wood pens equals wet wood . Do you live in Arizona or some other desert ? Any wood you get from the other side of the Mississippi will probably crack , unless it has recently been kiln dried to 6% moisture .

If you have a small postal scale , weigh each blank when you get it , re-weigh after a week . If no change , blank may be dry . If weight has changed , leave another week . This applies to woods with a fairly open pore structure . Very dense woods can take a very long time to stabilise to local conditions .

 

[ssajn]

First off I agree with what's already been mentioned but think I may have a few to add.
Some of the woods your using are known for cracking especially snakewood.
A lot of the pen blanks out there are coated with wax. I've found that most of these have a high moisture content. Scrap off the wax except for the ends and let them dry.
Make sure your drill bits are sharp and drill at a low speed to keep the heat down. You mentioned trimming and seeing a slight smoke. Make sure your trimmer is also sharp and don't use enough pressure to get smoke. After trimming I wipe the end of the blank with a light wipe of ca to seal the end grain.
Make sure you remove any ca from inside the tube and chamfer the inside of the tube.
Sand at a slower speed. I do most of my sanding around 800.
Hope this helps.

 

[emccarthy]

I use CA on the tubes for my pens, but instead of putting it on the ends only, I run a small bead of it almost the entire length of the tube(about 3/16" away from each end). Also, I sand my tubes with 150 grit, which IMO helps by creating deeper grooves for the glue to adhere to.

Beyond that, I have to agree with what else has been posted

GL

 

[jttheclockman]

Alot of the woods you mentioned are very crack prone especially bloodwood, snakewood and blackwood. That could be the first thing. If you suspect a moisture problem then it would probably be wise for you to turn the blank round and maybe leave about 1/8" to 1/16" proud of the bushings and set on the side for 24 hours. You now have exposed the fibers to air and being tight grained woods air has a hard time getting to the center of woods unlike your softer woods. I also would switch to using epoxy as opposed to CA. Ca is a brittle glue and with woods they will move and I don't care what you coat them with. They have little chance to move when held with CA. Not a good thing. Every aspect of the woodworking industry deals with wood movement and just because the pen blank is small does not mean it does not move.

Next thing. when trimming the barrels do not force the barrel trimmer to the point it wants to grab or dig into the wood because now you are destryoying the end grain fibers causing them to weaken the ends. You may laugh at this but I also do other woodworking and these things are a concern in those areas also. You need a good sharp barrel trimmer. I think some of the best money I spent was buy a carbide barrel trimmer from Nolan here.

The final thing is when you put the kit together if there is alot of resistance with parts going together you need to make sure the ends of the tubes have no glue and are reamed because a burr is formed on the ends when using a barrel trimmer. I always use the spacer used with the barrel trimmer to make up the difference in size of tubes as my guide. If this slides in and out with and resistance then I know there is no burr or glue in the tubes.

Other than that good luck.

 

[seawolf]

If the barrel trimmer is the problem drill a scrap blank to the diameter of your mandrel then turn it down to the inside diameter of the tube. Cut or punch a piece of sticky back sand paper to the size of the outside end of your mandrel punch a center hole and stick the paper on the mandrel. Put the bushing in the tube slide it on the mandrel; bring up the tail stock, start lathe low to medium speed. Gently press the blank onto the sandpaper. Slide back to check the tube, when done reverse blank and sand other end. The blank will be square to the tube with little or no heat build up. I also do this with finished blanks to remove any CA that may extend over the end of the blank before assembly.
Mark

 

[Tullyamo]

Trying something tonight... took the smallest sanding head for my dremel, put it inside the barrell, turned the dremel on and gently plunged the dremel half a dozen times to remove any burrs, glue, and debri. Another thing I am trying is to sand from 180-600, steel wool, denature alcohol, let the wood sit for a day, then CA with thin 8 coats. Letting it sit again for 24hrs, then wet sanding 1500-12,000 and applying the plastic polish. Lastly the renisance wax. Does anyone see any problems with the sanding steps?

I APPRECIATE all the thoughts, comments, and ideas from you all. This has been a great learning experience. Normally, I just pound my head against the wall a few times.. try again, if I fail.. well, it's back to the wall. Rinse, wash, repeat until desired outcome.:redface:

 

[fernhills]

I just get glue, burrs, whatnots by hand. Just take a little file, screw anything to get glue out. You don`t have to use a high speed machines to scrape a little glue out. After you grind the inside of your brass tubes the heat must be high,which will cook your wood and melt yor clue. Carl

 

[glycerine]

My first "blame" will be your location. Maybe try some local wood and see if you still have those problems. Then go from there...

 

[Chief Hill]

This may be an assembly issue as well. What are you using to assemble the parts? If everything does not go together in perfect alignment you will be prone to cracks at the ends of the barrels as well. You may not see the cracks initially but will as the wood drys a bit.

 

[gmreeves]

One thing that hasn't been mentioned is where the cracks are forming? Are they down along the ends of the blanks? I have had this happen when the tubes weren't cleaned and the expansion of the brass tube has cracked the wood. Are the cracks in random places along the blank? I have had this happen because of wet wood. I just sand the finish off, let them sit for several days, sand smooth again and reapply the finish. the majority of the times, the cracks dissappear or are filled with CA and don't return.

 

[jaywood1207]

180-600, steel wool, denature alcohol, let the wood sit for a day,

Putting DNA on is like adding water to the wood. I use compressed air to clean wooden blanks.

 

[Tullyamo]

Alright,

I ceased the use of DNA, debrided the inside of the tubes with a coarse mini dremel sanding attachment, only went to 600 on sanding then did 0000 steel wool. I CA last night on 4 pens, all of which at the moment do not have any cracks. This morning I have used the pen press to put the pens together. I have at my despense 3 nurses and a doctor for the day. I gave them all a pen and told them to give it hell. We'll see what they look like at the end of the day.:biggrin:

 

[Tullyamo]

the cracks for the most part appear on the nib end and the pen clip end. It has been rare to see them appear or originate in the middle of the pen. Hopefully that was a glue issue and after taking the preventative steps as I have done, this is eliminated. Some of the cracks of course should be showing up within the first 24 hours. The Operating Room is 58 degree all day, the air is cycled complete 20 times an hour, and the humidity is around 30-40%. I have given 1 of the pen to a doctor who will be in that environment all day, 1 to a nurse that will be in a non controlled environment encluding outside, inside, in the washroom where the temps can be 70-80 degree and humidity up to 80%. 2 of the other pens went to nurses that sitting down all day at a computer with temps of 70 degree and humidity of 60-70%.

 

[glen r]

Like others have stated, turn your wood to the point where all possible sealant on the sides is removed - leave the ends just a little proud of the tubes when using the pen mill for the first time. Let sit for at least a week to allow all moisture to escape and then mill end to the tube length and turn to the bushing diameter. Having a moisture meter would be a great hlep. I use a small chainsaw file to clean out the inside of my tubes.