Shape Shifting ~ resaw
17/03/09 13:30 Filed in: Technical
With either method of drying, if you store the timber or put it into use - the timber will change shape as it dries and shrinks.
I left off the article Bustin’ the Myth with a discussion on kiln dried vs air dried timber.
With either method of drying, if you store the timber or put it into use - the timber will change shape as it dries and shrinks.
Also the part of the log that timber came out of during the original sawing process will determine the final shape of the timber.
A timber cut from the center or heart of the log will remain relatively square but will bulge out slightly on all four sides, so that the sides of timber are curved.
If the timber is cut off center in the log (which is a common practice to get 2 timbers from one log) then the timber will bulge on one side and concave on the opposite side.
Quite often the timber cut from off center in the log will shape shift into a parallelogram as the sapwood side of the timber dries at a different rate than the heart wood.
The solution to shape shifting is to saw the timbers oversize, getting the maximum timber size possible from the log then allowing the timbers to dry as long as possible and finally resawing the timbers to the required size.
The resawn timber will remain in the resawn shape because you have allowed the shape shift to happen in the drying process.
This method requires keeping an inventory of oversize timber on hand.
If you use reclaimed timber (previously used in other structures) the shape shift has already occurred.
Resawing reclaimed timbers requires the use of metal detection equipment to find old nails or spikes left in the wood by the salvagers, or alot of extra bandsaw blades!
Whether it is oversize dried timber or reclaimed timber, resawing is the solution to shape shifting.
With either method of drying, if you store the timber or put it into use - the timber will change shape as it dries and shrinks.
Also the part of the log that timber came out of during the original sawing process will determine the final shape of the timber.
A timber cut from the center or heart of the log will remain relatively square but will bulge out slightly on all four sides, so that the sides of timber are curved.
If the timber is cut off center in the log (which is a common practice to get 2 timbers from one log) then the timber will bulge on one side and concave on the opposite side.
Quite often the timber cut from off center in the log will shape shift into a parallelogram as the sapwood side of the timber dries at a different rate than the heart wood.
The solution to shape shifting is to saw the timbers oversize, getting the maximum timber size possible from the log then allowing the timbers to dry as long as possible and finally resawing the timbers to the required size.
The resawn timber will remain in the resawn shape because you have allowed the shape shift to happen in the drying process.
This method requires keeping an inventory of oversize timber on hand.
If you use reclaimed timber (previously used in other structures) the shape shift has already occurred.
Resawing reclaimed timbers requires the use of metal detection equipment to find old nails or spikes left in the wood by the salvagers, or alot of extra bandsaw blades!
Whether it is oversize dried timber or reclaimed timber, resawing is the solution to shape shifting.