I am currently working on a wood extension and am having a problem.
I used a scrap piece of walnut off another gun that matches the stock well, attached it with 3/8" wooden dowels, wood glued it in place and then clamped the extension down so it was tight. After it dried, I reshaped the extension, sanding it down to an exact fit. I then wiskered the stock, stained it, sealed it, and filled the pore just and any minute gaps in the extension just as I would if I were filling the pores (using the sand in method).
Here is my problem. As I began to apply the final coats of finish (Tru-oil) everything looked perfect. The separation between the two pieces of wood looked like a thin line under a thin coat of glass -simply beautiful. But then, on the last coat, for some reason the stock swelled just enough to break the finish and I can barely catch a finger nail on it as I rub my finger across it. I re-sanded this side and started to apply the finish again, when this also began to happen on the other side (to a lesser degree, but still there nonetheless). The strange thing is, this is only happening on the sides of the stock. The heal and toe are still as smooth as silk.
I assume this is happening due to moisture in the air, the moisture in the stock, and the difference in density between the two woods, although both pieces are walnut. The swelling is almost unnoticeable unless you run your finger over it. You can barely feel it.
So, where did I go wrong?
