Antler Pen Cracks

[Mainebowlman]

I made my first and only antler pen for my son-in-law for Christmas. He doesn't seem to use it much and keeps it in its hardwood box.

I was saddened last night when he showed me that it had three cracks. It's a Designer MBlanc style with a crack starting at the cap and one at either extreme of the lower portion. Wherever I inserted a part, the stress cracked the antler.

When I made the pen, it had such a high 12K MM polish, I didn't do anything to it. Just thought I'd let it "age" with its own patina. Was that my mistake? Or was it something else (Murphy?)?

Jack

 

[Fred in NC]

Jack, you said it: "Wherever I inserted a part, the stress cracked the antler."

The press-fit parts expand the tubes when they are inserted. This expansion can be worsened then there is glue inside the tube, or the part is not perfectly straight going in. When the tube is a tight fit in the blank the problem gets worse.

I have solved the problem for my pens that use the 7 mm tube. I use a size "D" (.246") drill bit as a reamer. I just put a turned handle on the bit. It will clean the end of the tube, and make insertion easier.

If you need to use glue to hold the cap or tip to the tube, use a toothpick to put a SMALL drop of the glue INSIDE the tube. The part will push the glue in. Don't put it on the cap or tip, it can squeeze out. I would not use glue on the transmission.

 

[ctEaglesc]

There can be a number of reasons for this.
Freds explanation is one of these.
Heat while drilling, sanding or finishing could be the culprit.
The part of the antler itself may be part of the problem.
I have made quite a few antler pens and am constantly perfecting my finishing technique.
What kind of stabilizaton method did you use if any?
How much "pith" made up the blank?
Was the pen "sealed" in any way?
IF you didn't glue the components it may be possible to make an invisible repair.( or "showcases" the damage)
Could you post a picture of the pen?
I'm sure the pen is a prized posession to your son and would love to use it.
I can only imagine how heartsick he was when he discovered the cracks.
All may not be lost.

 

[J. Fred Muggs]

One other possibility: Antler will shrink some as it dries just as wood does. If the pen was turned from a freshly killed deer, that could be your problem. The Boone and Crockett scoring system for ranking of really big deer racks requires a drying time of something like 60 - 90 days before they will score a rack. I make sure the ones I turn have cured for about three months before turning. Haven't had one crack yet(knock on wood, or antler, or something).

The other Fred hit on a really good point also: If you use a pen mill for squaring the blank, it will raise a burr on the end of the tube. Sometimes it's big enough to cause too much outward stress on the blank when you insert the parts. Always chamfer the inside of the tubes slightly. You can do this with a countersink, a larger drill bit, as Fred describes, or something like a "Rota-bur" deburring tool which I find easiest to use. Makes the parts easier to start as well.

 

[Mainebowlman]

I knew I'd get great feedback. Thanks!

Reemer is a great idea I'll use on ALL my pens from now on.

Answers to some of your questions.

Antler was aged and dried.
Very little pith that I can remember.
No stabilization or finish (au naturale)
Only glue I ever use is CA on tubes.
Will try to get pen and post pic.

Thanks again, Guys.

Jack

 

[KKingery]

All the above reasons could be the culprit - it is a shame, especially as it was a present.

 

[ctEaglesc]

I see you use CA on the tubes.
That's what I like to use also.
Are the cracks so wide that the tubes are visable?
If not a repair that is almost invisable is possible.
Any chance you could post a picture of the damaged sections?

 

[Rifleman1776]

Once you have (hopefully) repaired the crack with CA or whatever, remove the ink and soak the pen in mineral oil. A week should do it. This is an old trick of knife makers. The mineral oil will not discolor the antler but will keep it from shrinking and cracking. For larger items, like knife handles, a month in the mineral oil is not too long.

 

[ctEaglesc]

RIfleman
I have experimented with MO and CA and to me it seems that Mo will dissolve CA.
I checked this out with Lou(chemistry backgound) and he told me he wouldn't be surprised if MO had acetone in it.
I have since stopped using any MO wher I have used CA and since all my pens have CA glued tubes, I am very leery of it.
(your mileage may vary)

 

[J. Fred Muggs]

Dadgummit, Eagle! I was plumb tickled pink to find Rifleman's mineral oil post. Then you had to go and shoot it full of holes. (maybe you're making too many of hose bullet pens)[][][]

Seriously, I appreciate both comments. That's what makes this forum great.

Sounds like I need to do a little experimentation with leftover bits of antler and both MO and CA.

 

[DCBluesman]

Originally posted by cteaglesc
<br />I checked this out with Lou(chemistry backgound) and he told me he wouldn't be surprised if MO had acetone in it.

The key here is that I <b>would not be surprised</b>. There is no standard chemical composition for mineral oil (or mineral spirits, which is a totally different beast).

 

[Mainebowlman]

Still waiting to get the pen from my son-in-law. Will post photos ASAP.

He plows us out and a storm's a commin' tonite. So if I can catch him when he comes, I'll get the pen and photograph it.

Jack (with the crack)

 

[ctEaglesc]

Originally posted by DCBluesman
<br />

Originally posted by cteaglesc
<br />I checked this out with Lou(chemistry backgound) and he told me he wouldn't be surprised if MO had acetone in it.

The key here is that I <b>would not be surprised</b>. There is no standard chemical composition for mineral oil (or mineral spirits, which is a totally different beast).

I have done this "test"
Iput a drop of thin CA in a cap ful of both BLO and MO(not haleys)
I left them overnite.
THe next morning the CA/blo had solidifed
The CA/MO(not Haleys) was more or less"plasicticly flexible" no where near as hrad as the CA/BLO.
take it for what it;s worth.
(There does that count for todays contribution?did I "share enough"?)
(Your mileage may vary)

 

[Rifleman1776]

But that possibility does surprise me. That tip was given to me by an Arkansas Master member of the Knifemakers Guild. And, believe me, in Arkansas, knife making is taken quite seriously (home of Jim Bowie and James Black) and a 'Master' designation is powerful medicine. I don't know what kind of adhesives most knifemakers use on their scales (handles) but, like I say, it would/does surprise me that mineral oil might do damage. The one knife he reccomended I do this with was made by one of Arkansas', and the U.S.s most revered knife makers, now deceased, Jimmy Lile. It is a one-of-one Bicentennial commerative, estimated to have a value in excess of $5,000.00. (I won in a raffle, could never afford anything like that). I am confident he would not have given that advice if he thought it might harm the knife. But, you say you have experimented, so, I'm confused. Dunno what to do. [?] Might do my own experimenting.

Originally posted by cteaglesc
<br />RIfleman
I have experimented with MO and CA and to me it seems that Mo will dissolve CA.
I checked this out with Lou(chemistry backgound) and he told me he wouldn't be surprised if MO had acetone in it.
I have since stopped using any MO wher I have used CA and since all my pens have CA glued tubes, I am very leery of it.
(your mileage may vary)

 

[ctEaglesc]

Frank=
My findings pertained to CA, I imagine that knife makers use an epoxy.
I know acetone will dissolve some epoxies I use, don't know about knife makers.

 

[Rifleman1776]

"I know acetone will dissolve some epoxies I use, don't know about knife makers."
Yes, acetone will dissolve knife makers. []