Friday 25 May 2012

Stringer Yield

The yield when cutting the stringers was very dissatisfying. I had bought the larch as best quality (for 1,750 /m³) at a boat timber merchant.
After the wood has been cut into batten and the cracks and knots were cut out, I measured, weighed, calculated and the following turned out:
  • Only 31% of the larch was useful to stringers. The rest is good only for the fireplace.
  • The cost for the self-cut and planed 32x32mm ² stringers are  4.70 /m!
Quite expensive!
I am currently looking for alternatives, because I still need about 90m 23x23mm² stringer.

Working time been invested: 220 hours

More Knots, Shakes and Splint than Expected

When sawing the stringers I recognize that the larch has more knots, shakes and splint than expected. I must cut the six meter long battens into pieces. Most of them just one to two meters long.

 Knot to be removed.
 Removed knots, shakes and Splint.

Yield of faultless material. Batten are just one to two meters long and have to be scarfed to 7.5m length later on.

Sunday 13 May 2012


I wonder some time what timber I should choose for the stringer. Dudley Dix  suggests spruce. I decided to take sibirian larch. It has a higher bending strength and durability than spruce.
The larch I bought has a density between 659 kg/m³ and 796 kg/m² (720 kg/m³ in average) at a wood moisture of 12%.