Wood Movement

[Dave Fritz]

I'm trying to make pepper mills similar to the one in the craft supply usa instruction sheet using a shaftless crushgrind mechanism. https://www.woodturnerscatalog.com/p/53/5242/CrushGrind-Click-In-Mill-Mechanism Mine is different in that the top and the bottom flow together in one line. Everything was lined up great until I started putting the finish on and I suspect the wood moved. Now the two pieces don't line up anymore all the way around the mill.

I guess that's why a bead or some other detail at the junction of those two parts is used, to cover up any wood movement?

 

[hockenbery]

If you left the inside of the pepper mills unfinished which is usually done the changes in the RH can cause a change In the wood's dimensions.

I sort of think It could also be that the stock was not quite as dry as you thought.
I usually give my small "dry" pieces a microwaving zap before final turning.
A,microwave zap after drilling might do wonders.

The detail at the joint will hide a mismatch in the joint as well as a slight movement of the wood.

Be sure to use straight trained wood. Figured wood will move unevenly.
Regardless The wood should line up when the grain is lined up. Most of us have boxes where the lids only fit when the grain is lined up.
Be sure to have the grain aligned when you turn the two parts together so that they can move together. If you do this a change in dimension will show when the top is turned 90 degrees and not show when the top is aligned.

If you turn the mills from small limbs driling the pith out, the wood movement would similar in all directs and unlikely to be noticed.

In many of today's the homes the RH is controlled to be near 50% most of the year so wood movement should not be an issue for these customers.

Also an epoxy finish inside and out would make a moisture seal.
But I would rather just have the pieces line up when the grain is lined up