tight wood joints

[Evon]

When ever I can I like to pick old broken furniture. Chairs, Bureau's, tables, etc. I've notice that in the real old pieces the joint were tight w/o any sign of glue. One day I was talking to an old chair maker and he said that he never used glue or any other fasteners in any of his chairs. Ones he and his grandfather built 60 years ago are still tight.?!

The secret - get a pan of sand - a propane burner and heat the sand until it is hot. Put the tendon end into the sand for about 5 minutes. Then slip it into the mortise ( drill mortise 1/16" - 1/8" smaller than tendon). Within

30 minutes you will never get the joint apart and it will stay tight. Try it you'll be surprised. I've never had the wood split.

[loutent]

Hi Evon,

Thanks for your post, but I don't think it makes any sense - at least to me.

If you heat a tenon, it will expand, so how can you slip it into a mortise that is 1/8" or so smaller?

Maybe you mean to heat the mortise to get it to expand and then slip it over the tenon and as it cools, it would contract around the tenon.

Whew...is it gettin' hot around here or is it just me?

;-)

Lou

[Scott Lurndal]

I would hazard a guess that the hot dry sand draws down the moisture content of the tenon, thus making it smaller.

scott

[bridger]

if it was metal, you'd be right. but it's wood. heat drives the moisture out, and it shrinks.

[George E. Cawthon]

Made perfect sense to me and sounds like a neat trick.

Uhh,,, you're talking about wood not metal. The hot sand will suck the moisture out real quick. The shrink from loss of moisture will be great compared to any thermal expansion. Somebody posted the thermal expansion of wood recently and it is tiny, would be nothing in a small piece.