Over the years, I have noticed on many of my pieces, that I can feel the glue line on some of the panel joints,i.e. boards glued together edge to edge. Its is the slightest of ridge that your fingernail will detect if you go back and forth over the joint. I am wondering how common this problem is and what is the resolution. I am using yellow glue, either titebond or elmers. I typically use kiln dried wood in the 6 – 8% MC range and I live in New England in a house with baseboard heat (not hot air).
Dan Santos
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This is a very typical occurrence. If you average the shrinkage from 28%(fiber saturation) to ambient of all woods world wide, they shrink a little less than 8% tangentially and a little less than 4% radially. Thereafter they swell and shrink in proportion to these amounts with changes in retaliative humidity because wood is hygroscopic. The chances that any two boards would have edges in the same plane is remote to say the least. Therefore differentials in there thickness with changes in humidity is almost assured, hence the edge your fingernail encounters. Fortunately the causal observer cannot see this unless they are one of your critics.
Ernie, Thanks for the reply. My first thought is that it was differential shrinkage between two adjacent boards from different trees. Than I wondered if it would occur in boards from the same tree. I have also thought that it was the glue not shrinking with the boards around it. Would hide glue result in the same phenomenon? Why do I never see it in antiques or the work be other cabinetmakers?
Dan
It is not the glue, it is the differential in change between the adjacent boards. (Hide will not help.) You do see it in antiques but it is dependent on the humidly so you don't see it all the time. If the piece was glued up in dry weather you will notice it in wet weather and vice versa. What is more you do not so much see it as feel it. You finger nail is much more sensitive that your eye in such matters.
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