CA finish shrinking?

[MPVic]

I searched a couple forums but could not find anything about my problem so I hope I am not guilty of doing an incorrect search.

My problem is that while applying 10 - 12 coats of CA, and waiting 10 minutes between coats for curing (no accelerator), I come back in the morning only to find that the diameter of my pen has shrunk. Would appreciate your feedback. Thanks.

 

[Charlie_W]

I searched a couple forums but could not find anything about my problem so I hope I am not guilty of doing an incorrect search.

My problem is that while applying 10 - 12 coats of CA, and waiting 10 minutes between coats for curing (no accelerator), I come back in the morning only to find that the diameter of my pen has shrunk. Would appreciate your feedback. Thanks.

Odd.......did you confirm your wood blank was dry before turning and applying the CA?
How many thousandths in diameter are we talking about?
Did you seal the ends of the blank with CA?
What type of wood were you using?
Did the CA separate from the wood neat the ends?

Maybe an answer to these questions may give a clue so we could have an answer.

 

[Charlie_W]

Mark, if you introduce yourself to the IAP community on the Introductions tab, you may win a new member prize!
Welcome!

 

[magpens]

Welcome to IAP, Mark !!!!!

Say a word or two about yourself in Introductions and perhaps you'll win a prize in the newcomers' draw.

 

[JimB]

Maybe you just measured in incorrectly the first time. How did you measure it?

 

[MPVic]

I measured using a digital set of calipers.

 

[MPVic]

Hi Charlie - thanks for responding.
I was using stabilized oak burl.
The shrinkage was about .008".
I did seal the ends of the blank with CA before starting to apply the finish.
The CA did not separate from the wood near the ends.

 

[leehljp]

Measure it, move about 1/8 turn, measure again, move another 1/8 turn and measure again.

This "may" give different results and have a couple of possibilities if it does have different measurements.

 

[MPVic]

Hi Lee:
I did what you suggested, i.e. measure the diameter again several times while rotating the blank and I DID get different measurements!!! Which indicates I am not getting the CA on evenly - thanks so much for the input.

 

[KenV]

Hi Lee:
I did what you suggested, i.e. measure the diameter again several times while rotating the blank and I DID get different measurements!!! Which indicates I am not getting the CA on evenly - thanks so much for the input.

Or you may have caught the dreaded "out of round" virus. Is there a pattern to the different measurements?

 

[MPVic]

No pattern detected, but to be sure the virus you speak of "infected" this pen. I'm wondering if the speed of the lathe while applying the CA is too slow leading to uneven application - will test that theory.

 

[leehljp]

"Out Of Round" (OOR) virus as Ken wrote - That is what I suspected but wasn't sure until you measured it.

There are two or three things that come to mind for this. First, you said that it was stabilized. Generally that will work but on a rare occasion it does not. If not, then you may have had wood movement. Oak will move more in one direction than the other - when looking at the end - depending on the cut.
HOWEVER, while it could have been the problem - I don't think this is your problem.

The next two things are more likely the culprit:
1. a. ever so slightly bent mandrel, OR b. too much pressure from the tool on the wood will or can - cause a slight flex in the mandrel. Either of these can cause the OOR, which some will say is not technically the correct term, but the term that I like to use for simplicity sake.

2. Sanding with slightly heavy pressure will remove the softer grain and leave the harder grain. The sides with the hard grain exposed will sand off less than the soft grain. But you said it was stabilized. This shouldn't be the problem in this case, but does happen probably 1 it 50 or 1 in 100 times.

 

[MPVic]

Thanks very much - I really appreciate your response. Will keep these points in mind for the next time!