# Cracks on African Blackwood?



## kkwall (Sep 8, 2006)

Hi All,


I have made 3 pens with African Balckwood, and 2 of the three have cracked at the top of the bottom blank, at the twist mechanism join?


I dont have a pen press to join parts together, and use a wooden mallet and cloth to gently assemble the parts. Could this cause the cracking or is there another reason.


Obviously AB is hard, and very dense, and even drilling can crack it, so you need to take things slow.


Does anyone have any tips. advise on how to prevent/minimise this cracking from occurring?


Thanks for any advise you may have in advance.


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## OSCAR15 (Sep 8, 2006)

THIS CAN CAUSE CRACKING....
Certain woods are prone to cracking, e.g snakewood and pink ivory. Blackwood usually doesn't. I have done several with no problems.
Did it crack after you assemled it? Or during assembly?
Forget pen press (overpriced).  Get a half ton arbor press.  I got one from harbor freight on sale for about 20 dollars.  works great.


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## alamocdc (Sep 8, 2006)

Kenny, beating the parts in could definitely cause the cracking you describe. Especially if the parts aren't lined up exactly right. Since you don't have a pen press, do you have a drill press? You can take two scraps of hardwood and make "stops" so that you can use the DP as a pen press. Just leave one sitting on the table and drill the other out so that it fits on to the lower most part of the chuck. Use this to "gently" press your parts. 

You can also drill each piece so they fit onto the head and tailstock spindles and use your lathe as a pen press.


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## Rifleman1776 (Sep 8, 2006)

Mallet? [:0]
I think you have answered your own question.
Normally, African Blackwood is nice to work with. I haven't experienced any cracking problems and use it in place of ebony for just that reason.


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## JimGo (Sep 8, 2006)

I agree with Billy and Oscar.  Also, you haven't discussed your sanding technique; it is possible that you overheated the wood and dried it out.  When it returned to ambient temperature, it may have absorbed more moisture, also causing it to crack.  I did this on a Cocobolo (same genus - dalbergia - as the African Blackwood) pen recently.


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## smoky10 (Sep 8, 2006)

Kenny, I used my drill press to assemble my pens until I got an arbor press. You could also use a bar clamp or a big vise, just don't use a mallet or hammer.


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## kkwall (Sep 8, 2006)

Hi All,

Very helpful feedback everyone.


Noted that I need to stay away from the mallet![xx(]



OSCAR - it cracked after assembly.



Jim - may be some truth in the sanding !!!! I didn't think about it until you mentioned it. Will hold back a little, and use slower speeds.


Will start to lok at pen presses also!


Thanks again. Will keep you posted on developments, I have around 90 AB blanks to play with, so will try some new ones.
[]


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## chigdon (Sep 8, 2006)

While it could be your assembly that is a/the problem it could be that the wood is green.  It would be hard to tell with Blackwood.  As mentioned, despite being such a heavy wood it is a very stable wood and should not be cracking.  I would be more inclined to lean towards the wood being green and moving on you once turned thin than the assembly.  Otherwise you would have more pens in less stable woods cracking also.

That being said, get some kind of press.  A worthy investment regardless of your method.


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## Joe Melton (Sep 8, 2006)

Obviously, some woods are more fragile than others, and need to be treated with different methods. Snakewood is the most commonly mentioned example.
No one has mentioned the glue as a suspect. When you "press" parts together, something is moving. This will be the tube stretching rather than the part going into its interior being compressed. If the glue is hard and doesn't have any give, the stresses as the tube is being stretched are being directly imparted to the wood sleeve and, if the wood doesn't "stretch", also, it will crack. It may not crack instantaneously, but there will be stresses in the wood that relieve themselves later.
You need a way to prevent the stresses from reaching the wood. You might try some epoxy or poly glue (I am assuming you're using CA). Maybe another list member has a suggestion for another type of glue that isn't as hard.
Also, with these fragile woods, you should be extra careful about cleaning out the tubes prior to pressing in the parts.
Just my opinions.
Joe


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## ctEaglesc (Sep 8, 2006)

If you are using a mill to square your blanks is it possible you are "peening" the ends of the tube enough to change the inside diameter?
This would be enough to cause cracking.
I use a  lot of AFB and cannot recall any cracking.
I think the "gentle mallet" may have been your problem.
("gentle mallet" that's a good one!)


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## woodbutcher (Sep 8, 2006)

I'd try selling the mallet and buy a pen press.
Jim[]


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## kkwall (Sep 9, 2006)

Hi All,


Thanks again!


I will throw away my mallet as this appears to be the most likely suspect!


Will also take greater care during sanding, and trimming.


Have ordered a pen press, so perhaps this will solve the problem???? Will keep you posted!


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## Ligget (Sep 9, 2006)

Mallet[:0][:0][]


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## kkwall (Sep 14, 2006)

Hi All,


Further to my earlier post, I am now having no problems with cracking!


I took all the advice given, and they certainly have made a big difference.


I cannot take full credit, as whilst waiting for my pen press to arrive, I was walking around my local hardware store with my wife, and "she" was inspired!

(I would like to take credit for this, but she does sometimes read my posts so i'd beter play safe!)

She asked the quetion why a silicon sealant gun wouldn't work to press the parts of a pen together????


As I didn't know, I decided to try it,,,,,and it works a dream! See photo's below!

If anyone can think of any drawbacks to using this, please let me know???





<br />




<br />





<br />


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## Rob (Sep 14, 2006)

Kenny,

Can't say as I've thought of this one, but necessity IS the Mother of Invention.  Seems to me that as long as you can keep everything lined up and apply steady pressure you've got a solution.  Absolutely has to work better than the "beatin' tool".  Stuff like this is why I keep coming back to this site.  The ingenuity of the membership is terrific.  Caulk away...

Rob


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## ctEaglesc (Sep 14, 2006)

The only draw back I  can see is  There may be times when you will not have the "esactness" of control as in when the clutch engages into one of the "cogs"(?)
It may get some kind of a memory built in.
I used a quick grip clap till I wore it out which is the same principle you are using.Hey if it works go for it.


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## kkwall (Sep 15, 2006)

Thanks Rob and Eagle,


I will give it a try amd see how it works out.

As you say Eagle, I have noticed some scoring on the centre bar from use already!!!! So perhaps it wont last a long time before wear and tear make it redundant!


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## Russb (Sep 15, 2006)

Like Eagle said, the tube gun may not give you the exactness you need especially on some pen kits where the mechanism must be pressed in a specific distance, such as slimlines. I would also second the use of an arbor press instead of a pen press. The arbor press may be had cheaper and can serve other functions around the shop other than just pressing pens together. 

Sounds like you have solved you cracking problems. I was also going to suggest the inside of the tubes are clean of excess glue before pressing the parts together. The excess glue can cause the brass to expand more than it should. So when the brass expands too much it cracks the wood usually at the ends.


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## kkwall (Sep 15, 2006)

Hi Russ,


Noted the comment regarding the glue! Will ensure that I am not using too much on the tubes prior to insertion.


The sealant gun can make very fine adjustments to the pressing of parts, and I am currently using it on slimlines, checking on the mechanism insertion to ensure the correct depth is achieved.


That said, I am not sure if this will be a lasting answer! Wear and tear will be it's downfall.


Will look at an arbor press for the longterm!


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## Sylvanite (Sep 15, 2006)

> _Originally posted by kkwall_
> <br />Will look at an arbor press for the longterm


For what it's worth, Harbor Freight has their 1-ton arbor press on sale for $24.99 (regularly $43.99) - item # 03552-3FRA.  The online ordering doesn't work, but you can still buy it over the phone.  There's also a $5.00 off coupon you can use if your order is $50.00 or more.  Just tell the salesperson that you have coupon # 816-986-139 (good until 12/01/06)

I got one and assembly with the arbor press is a breeze compared to a bench vise (which is what I used previously).

Regards,
Eric


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## Randy_ (Sep 16, 2006)

Those puppies are pretty heavy.  What did shipping cost you??


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## Sylvanite (Sep 16, 2006)

> _Originally posted by Randy__
> <br />Those puppies are pretty heavy.  What did shipping cost you??


Harbor Freight charges shipping by order total, not by weight, so shipping turns out to be fairly reasonable, especially if your order is enough to use the $5 off coupon.


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## Thumbs (Sep 16, 2006)

Kenny, I like your idea of using a caulking gun as a pen press and had considered it myself once before I got too fancy.  

I didn't use it because of the question of the latching mechanism being inexact as eagle and others said.  That was before I'd seen the use of a block being used as a stop and as a measure for pen presses.  I think this now deserves more consideration!  

It may even work better than using a stop block with a regular pen press for getting consistent, same measures.  The pressing mechanism here is a bit larger than a normal press and can be rigid enough that you can just drop the measuring block into the tube holder without having to hold the pen parts and block all together which can be quite a handful!  As the pressure can be immediately released by turning the driving push rod around and the mechanism latching spacing is no longer a problem.  This could be used vertically or horizontaly as space permits.  It's just too bad that the handle assembly can't be turned to the side as well so you you could better face the open working area.  This could still be a good and cheap solution for folks with a limited amount to invest. []


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