Finally a Tambotie pen without cracks

Signed-In Members Don't See This Ad
See more from Chrisjan

Chrisjan

Chrisjan

Member
Joined
Mar 23, 2012
Messages
111
Location
Pretoria, South Africa
I folks, I have been promising a lot of people to post a Tambotie pen... Up till now, all the Tambotie finishes have cracked (done with CA) within 24 hours of completion... This one has made it to 48 hours without blemishes (so far)
Secret: I used a base coat of Woodturners Finish before applying CA - now lets see if it stays!
Chrome Continental RB - enjoy!
 

Attachments

  • image-1914973911.jpg
    image-1914973911.jpg
    326.2 KB · Views: 499
Signed-In Members Don't See This Ad
Terrific Pen, Chris.
Glorious Blank, Superb choice of the Continental Roller Ball.
Excellent Fit and (fingers crossed) Finish.
I can see why you persisted with the Tambotie Blank,
Congratulations,
Brian.
 
Your pen looks fantastic. I love the smell of Tambooti when you turn it!!

I have a couple of Tambooti pens, and none of them have cracked...

I would agree with Wayne, that your CA or something else should be suspect if the wood is not cracking or otherwise showing signs of movement..
 
Chris - I agree with the other comments above, esp those that suggest the CA being the culprit. "Old" CA can do several things, most of them bad. Among them is developing cracks that look like a crackle finish. Not a bad look but it will eventually disbond and scale off. If this one eventually cracks, suggest you remove the bad CA and refinish with fresh CA.

Super nice pen, by the way. Well done. Great wood, isn't it?
 
There's actually two wood types that gives me the same problem; one being this tambotie (Spirostachys africana) and the second being kameeldoring (Vachellia erioloba syn. Acacia e.)

The blanks are fairly fresh, collected recently from the wild and very oily. The moisture content is very low (generally around 11%) meaning its dry or seasoned, right?

I have been at this for about 15 months now... tried several bottles and types and viscosities and the results are similar. I'll finish the blanks with or without accelerant to a beautiful shine, assemble the pen after cleaning the tube insides and wait... Sure as Hell within 24 hours there are hairline cracks; longitudinal and radial! Then the CA turns turns whitish an after a while a soft pry with your fingernail will send the flakes flying... No damage to the wood though - not even rough, still as smooth as I sanded it! Even when I wiped it with acetone (denatured alc.)

CONCLUSION:
The oil starts to dissolve the CA from the inside until it breaks of.

MY SOLUTION:
Put on a non oil based sealer - Woodturners Finish, but it doesn't build up and shine with the same brilliance as CA.
Put CA over the WTF and polish - only time will tell if it works... It's been 80 odd hours and counting while I'm carrying and using it - so far so good...
 
Fantastic looking pen; great fit & finish. I've done a fair number of Tamboti pens and never experienced any trouble with cracking, so maybe it is the age of your CA. Here's hoping that this one will be OK.
 
Chrisjan said:
There's actually two wood types that gives me the same problem; one being this tambotie (Spirostachys africana) and the second being kameeldoring (Vachellia erioloba syn. Acacia e.)

The blanks are fairly fresh, collected recently from the wild and very oily. The moisture content is very low (generally around 11%) meaning its dry or seasoned, right?

I have been at this for about 15 months now... tried several bottles and types and viscosities and the results are similar. I'll finish the blanks with or without accelerant to a beautiful shine, assemble the pen after cleaning the tube insides and wait... Sure as Hell within 24 hours there are hairline cracks; longitudinal and radial! Then the CA turns turns whitish an after a while a soft pry with your fingernail will send the flakes flying... No damage to the wood though - not even rough, still as smooth as I sanded it! Even when I wiped it with acetone (denatured alc.)

CONCLUSION:
The oil starts to dissolve the CA from the inside until it breaks of.

MY SOLUTION:
Put on a non oil based sealer - Woodturners Finish, but it doesn't build up and shine with the same brilliance as CA.
Put CA over the WTF and polish - only time will tell if it works... It's been 80 odd hours and counting while I'm carrying and using it - so far so good...
Click to expand...


`Fairly fresh`may mean that moisture content within a dense wood is not totally uniform . 11% is a long way from dry under my temp/RH conditions and may be okay for you , BUT `whitish`areas are classic symptoms of trapped moisture . Although I have never tried tambotie , the fact that others who have , have not experienced your problem leads me to think moisture is at least part of it . Turn and sand your blank , let it sit for a week , then finish , and I don`t think you will have any more problems .

If WTF is water based it may allow trapped moisture to breathe out . Overcoating with CA will trap it in , unless it has gone before the CA is applied .
 
Chris - could possibly have to do with the oily nature of some "exotics". Perhaps a wipe down with acetone before applying the CA?

But my intuition still says old/bad CA. Btw, 11% is low but might still be a wee bit "damp". I generally run less than 10%.
 
I have never worked with Tambotie, it is pretty. If it is oily, then I would also highly suggest wiping down with acetone or DNA before applying CA. I have found that I need to do this with many exotic woods such as African Blackwood, Bloodwood, Cocobola and others, to prevent the exact problems your describing.

When I'm ready to apply the finish I will use a clean piece of shop towel with some acetone. I will clean it a few times until there is very little color coming off the blank. Let it sit for a minute, to ensure all the acetone is evaporated, then I apply CA as normal. Two coats of thin, to soak in,then about six coats of med. I use a quick spritz of accelerator and 30-60 second wait between each coat. I have not had a lifted or cracked finish since I started this.

I figure the acetone is drawing out sufficient oil to let the CA fully cure before the oil leeches back to the surface. Once the CA is well cured, then all is well. This is why you need to apply the CA right after the acetone. If you leave it for a day, or even a couple of hours sometimes, your right back where you started.

I personally don't use BLO because I found it sometimes caused similar problems.

Hope you get this working.
 
You must log in or register to reply here.
Back
Top Bottom