by 48Rob » Tue Mar 31, 2009 9:09 am
Tapered.
Preferrably of the same or similar density wood, with the grain of the plug oriented the same as the plugged piece.
The tight fit of the taper compresses the wood of both the plug, and the plugged piece, so when the piece expands and contacts, the plug doesn't show a visible gap.
Both types, straight and tapered are glued in.
Either will do the job and done correctly won't "come loose", though straight has a greater chance of failing.
Since wood expands much more across the grain, the edges of either style make, and maintain good glue contact on two sides, the length of the grain.
It is the other two sides, the width of the grain, that present the potential for expanding beyond what the plug can maintain.
By using tapered, you compress the grain across the width, allowing more potential for expansion without visible results.
There are other methods that use green wood and dry dowels to "lock" the parts together.
That is starting to get away from the basic plug the hole concept, though the results are similar, the parts compress around the pin or plug.
Rob
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...
