Messed up finish.

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fitzman163

fitzman163

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Joined
Apr 1, 2005
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390
Location
Middletown,PA via The Coal Region,Pittston, PA, US
Saturday night I made a very nice Panache pen from Bocote wood. I sanded as I always do, cleaned the wood with denatured alcohol, added two coats of thin CA glue, then 6 coats of med. CA. The final result beautiful. The next night I show the pen to my sweetheart under a incandescent light not the florescent light in the shop, and oh boy what a mess. The finish looks like a shattered windshield. You can't feel it but you sure can see it. It must be in one of the early coats I applied. Any thoughts, or ideas what happened?
 
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fitzman163 said:
Saturday night I made a very nice Panache pen from Bocote wood. I sanded as I always do, cleaned the wood with denatured alcohol, added two coats of thin CA glue, then 6 coats of med. CA. The final result beautiful. The next night I show the pen to my sweetheart under a incandescent light not the florescent light in the shop, and oh boy what a mess. The finish looks like a shattered windshield. You can't feel it but you sure can see it. It must be in one of the early coats I applied. Any thoughts, or ideas what happened?
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I have heard of this issue when the ends were not sealed and water soaked in and expanded the wood while sanding/finishing and causing the finish to stress and crack as you described. Or the temp change cause the wood to swell up.. Someone else may have other input
 
I started a thread no long ago with this, and in my case was using an old med CA with accelerator, I stopped using accelerator and letting 30 sec between coats, no cracks after that
 
Thanks ALexG I did use accelerator between all coats. This is what I have done in the past and the med. is new to me don't know how long it may have sat on the shelf. I was thinking it had something to do with the type of wood. I wil try your way when I refinish it. thanks again.
 
There has been a plague of the cracked CA finish lately. It is happening to lots of experienced turners and so far no one has come up with a consistent explanation. I don't know if there are some "bad batches" of CA out there or if it some other fundamental flaw that is yet to be discovered.
 
Marc said:
There has been a plague of the cracked CA finish lately. It is happening to lots of experienced turners and so far no one has come up with a consistent explanation. I don't know if there are some "bad batches" of CA out there or if it some other fundamental flaw that is yet to be discovered.
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Interesting Marc I just did 5 pens last week with the same CA and accelerator no problems but it was Cherry not Bocote. Still has me guessing.
 
It really puzzles me as well . To my eye , it looks like stress cracking . I don`t know what , if any , chemical agents induce stress cracking in CA , but I do wonder if perhaps another secret ingredient has been added to some accelerators .


Marc said:
There has been a plague of the cracked CA finish lately. It is happening to lots of experienced turners and so far no one has come up with a consistent explanation. I don't know if there are some "bad batches" of CA out there or if it some other fundamental flaw that is yet to be discovered.
Click to expand...
 
I had originally thought it was stress cracking also. I thought that perhaps that little bit of CA that sometimes hangs over the end was not sanded off good enough and that when I pressed the blank to the hardware, the pressure caused the cracking. I called our vendor (WDZ) who thought the CA coats were being applied to thickly and that the accelerator was only curing the top part of the coat while the underneath part was not cured. If that happened with all the coats then you can get that crazy, uneven cracking because of all the different curing going on underneath each coat.

I don't know if that is all or part of the issue but when I see others basically finishing pens in the same manner that they have always done it and then getting some of them crackling and others are fine, I just don't know if that is it.

Others think some woods are oily and that is causing it. Even with cleaning the finished blank with DNA prior to the CA finish, I have still experienced the crackling.

I am mystified.
 
I have had a couple recently also - fortunately I was able to repair. Both cases only required light -moderate sanding with 400 grit and reapplied two coats of medium and no more problems
 
The one thing that always gets my attention is the use of denatured alcohol to clean pen blanks prior to starting a finish. Water in the air will dissolve into alcohol. Always mentioned is water getting in through the ends. Maybe the water is being added by the use of denatured alcohol. Many of the posts about CA finishes going bad mention the use of denatured alcohol for cleaning the blank. My suggestion is to clean the blank with accelerator. Accelerator in the plastic bottles is perfect for this. Put a little on a cloth and wipe down the blank.
Do a good turn daily!
Don

fitzman163 said:
Saturday night I made a very nice Panache pen from Bocote wood. I sanded as I always do, cleaned the wood with denatured alcohol...
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Thank you for all the help. I did what virgil recommended. I took the tools to the finished pen a lot of CA came off but when I got to the bottom it looked as if the issue was with the first coat as virgil suggested.I cleaned the pen with my accelerator put 2 thin coats and 6 medium as before and it came out very nice. Thanks again everyone.
 
I've had the same issue....I was using a good number of thin coats of CA..with accelerator in between (got anxious to finish the projects)...the next day the cracking all occurred. In the last two weeks I've stopped using the accelerator..using the same thin CA bottle I had...with about half the coats and waiting several minutes between each coat...and the problem looks to have gone away.
 
UPDATE: As stated above I redid the pen no DNA used thought I had it figured out all looked good. Pen has been sitting for two weeks waiting to be delivered I looked at it yesterday in the sun light and there it is again. More cracking not as bad as before but it's back. I give up! Could it be the Bocote wood does not like CA glue??? It's the only think I can figure at this point.
 
fitzman163 said:
UPDATE: As stated above I redid the pen no DNA used thought I had it figured out all looked good. Pen has been sitting for two weeks waiting to be delivered I looked at it yesterday in the sun light and there it is again. More cracking not as bad as before but it's back. I give up! Could it be the Bocote wood does not like CA glue??? It's the only think I can figure at this point.
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Diverse known issues have been reported with the brand of CA glue (batches) as with accelerator. also excessive accelerator has seen cause like this.
 
I believe that no one has an answer.

We have speculated about many things---one fact, CA was made to be an adhesive, NOT a finishing product.

Truth be told we have NO IDEA what is making this happen and there is NO GUARANTEE your customer will not have this problem AFTER he buys the pen. He will deduce that your workmanship is shoddy.

My solution: Use finishes to finish (I like Woodturners Finish) and CA to glue the tubes in!!

FWIW,
ED
 
For what it's worth....I've resolved myself to a few methods that work for me so I stick with them
- I never use anything on the wood other than what I am finishing it with (CA, oil, etc.). Maybe a sanding sealer for very oily woods, but nothing else. Why add more chemicals to a natural wood than you have to?
- I keep my blanks stored in the house, not the shop. This way they sit in a consistent environment. Severe temperature swings - especially cold - are an enemy of small pieces of wood like pen blanks.
- I have enough blanks on hand that they usually sit for a few months before they get used. Sadly, far more than I will ever use...err! By then, they have dried out completely and are pretty stable, not too much movement left in them. Often I will drill the blank and let it sit for a day or two just to give it one last chance.
- I never use accelerator. Never. To me, that's like stretching a balloon back and forth across the wood. Thin CA dries fast enough for my use. Medium gives me a chance to re-fill my coffee.

This has helped me avoid a few problems. I didn't figure this out because I'm smart, I did it because I have had more than my fair share of "learning opportunities".
 
ed4copies said:
I believe that no one has an answer.

We have speculated about many things---one fact, CA was made to be an adhesive, NOT a finishing product.

Truth be told we have NO IDEA what is making this happen and there is NO GUARANTEE your customer will not have this problem AFTER he buys the pen. He will deduce that your workmanship is shoddy.

My solution: Use finishes to finish (I like Woodturners Finish) and CA to glue the tubes in!!

FWIW,
ED
Click to expand...


I tend to agree in most cases. What is your recommendation for projects that involve putting on decals?
 
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