My previous posting on bushings turned into a discussion of dimensions and tolerance, and what we can see and feel. I am starting another topic because I am interested in how others handle the problems of wood movement with changes in humidity, moisture content, and temperature.
I have always believed that we have to keep the dimensions and tolerances in perspective and within reasonable limits when working with wood. One problem is that is that everything changes with changes in humidity and the resulting change in the moisture content of the wood. Finishes retard the rate of moisture and dimensional change, but they don't stop it. The pen whose joints I made to a perfect fit in January doesn't look and feel as good this summer.
The other problem is changes in dimension with temperature. Wood expands when it gets warmer and it shrinks as it cools, and some wood species move a lot. Sometimes that perfect fit I made while the wood was warm isn't as good the next day after the pen barrels have cooled back to room temperature.
Acrylics and stabilized wood don't solve the problems. While I have never detected any dimensional change with changes in humidity, they can move a lot with changes in temperature.
I do the things that have been suggested, like soften the edges of the wood, to make the dimensional differences between the wood and fittings less abrupt, and less noticeable. Even though I do this, I still have a problem when the wood shrinks to a smaller diameter than the metal fitting. I try to make an allowance for shrinkage, and sometimes I succeed and sometimes I don't. Either way, I seem to be the only person who knows the difference.
I solved the problem of fit at the tip by burying the metal tip fitting inside of the wood. Not only does it have a different appearance and "feel" good in the hand, it triples the price I can get from a SlimLine pen. I still have to measure the diameter of the wood at a couple critical locations to keep the pen from getting too large and still not cut through the wood at the tip. I have been surprized by how many people will tell me that a pen feels too large when it is only 1/32" larger.
Does anyone else consider the wood movement when making a pen, or is it inconsequential and not worth worrying about?
I have always believed that we have to keep the dimensions and tolerances in perspective and within reasonable limits when working with wood. One problem is that is that everything changes with changes in humidity and the resulting change in the moisture content of the wood. Finishes retard the rate of moisture and dimensional change, but they don't stop it. The pen whose joints I made to a perfect fit in January doesn't look and feel as good this summer.
The other problem is changes in dimension with temperature. Wood expands when it gets warmer and it shrinks as it cools, and some wood species move a lot. Sometimes that perfect fit I made while the wood was warm isn't as good the next day after the pen barrels have cooled back to room temperature.
Acrylics and stabilized wood don't solve the problems. While I have never detected any dimensional change with changes in humidity, they can move a lot with changes in temperature.
I do the things that have been suggested, like soften the edges of the wood, to make the dimensional differences between the wood and fittings less abrupt, and less noticeable. Even though I do this, I still have a problem when the wood shrinks to a smaller diameter than the metal fitting. I try to make an allowance for shrinkage, and sometimes I succeed and sometimes I don't. Either way, I seem to be the only person who knows the difference.
I solved the problem of fit at the tip by burying the metal tip fitting inside of the wood. Not only does it have a different appearance and "feel" good in the hand, it triples the price I can get from a SlimLine pen. I still have to measure the diameter of the wood at a couple critical locations to keep the pen from getting too large and still not cut through the wood at the tip. I have been surprized by how many people will tell me that a pen feels too large when it is only 1/32" larger.
Does anyone else consider the wood movement when making a pen, or is it inconsequential and not worth worrying about?