Thread: quatersawing on a lucas?

I guess that different people and mills are going to categorise timber differently but I recall reading one definition being 0-30 degrees backsawn 30-60 degrees rift sawn and 60-90 degrees quartersawn. As different timbers have different characteristics I would reckon that you could only use anything like this as a guide and not make it definitive.

Originally Posted by Burnsy

I guess that different people and mills are going to categorise timber differently but I recall reading one definition being 0-30 degrees backsawn 30-60 degrees rift sawn and 60-90 degrees quartersawn. As different timbers have different characteristics I would reckon that you could only use anything like this as a guide and not make it definitive.

We were selling mainly into Asia - Japan, Taiwan, Korea, Singapore and Hong Kong - and the market required that we then use the Malaysian Grading Rules. MGR's specified a maximum angle across the growth rings for timber to be labelled quartersawn or backsawn - cannot remember what the numbers were but I do not think they were as high as 30*.

It was interesting in that for a decorative species such as red cedar the sawyers would try to maximise the quantity of backsawn which best displayed the grain pattern. For a utilitarian species such as erima they woud try to optimise quartersawing to minimise cupping and twisting.

Cheers

Graeme

PS: We have drifted a long way from Lucas mills.

Carl, your pic of quartersawing on the Lucas shows the centre of the log unused. Is this simply because the centre is usually piped, or the centre contains the pith and is no good, or because it is likely to split down the centre later anyway?? On small logs of some species at least the centre seems quite sound, allowing some of the quartersawn boards to be the full width of the log.

Timbertalk

there is a good Taff course for log grading which will show why the centre of Australian hardwoods is taken out of the milling and useful timber calculations.

The minimum is 100mm square but can take upto 80% of a log full of defects. If there is NO heart showing (mainly on small logs) then the 100mm rule applies but you can normally recover some boards from the area. Its down to grading the boards at that point. best cut them any way unless defects or heartwood is showing.

For 100% backsawn or quartersawn timber we manufacture an Indexing Log Lathe which being independent from the mill can be used on any type of mill, swinger, twinblade, bandsaw or chainsaw.

It is designed for Radial Milling. You need a swinger or single vertical blade to produce quartersawn all other mills will only be able to produce backsawn.

With the swinger you use the vertical possition and take out wedges which then need to be used that way or passed through a dressing process.

With backsawn you either take off the top or side board and then rotate the log and repeat until you have gone all the way round. Then move the mill to the next board depth and do again.

Simple to build one yourself just make sure its stable enough to take the weight of the log. Recovery on 100% quartersawn tends to be lessthan 50% for square boards but backsawn can be in the 80% region.