Hello I am in the process of milling up some Blackwood slabs. Am I right in thinking the thinner the slab the easier it will warp? How thick should I go? They will range from 300mm to 550mm wide.
Thanks for your advice
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Hello I am in the process of milling up some Blackwood slabs. Am I right in thinking the thinner the slab the easier it will warp? How thick should I go? They will range from 300mm to 550mm wide.
Thanks for your advice
Thinner slabs does mean more warping especially if they are poorly stored - see belowQuote:
Originally Posted by Zac320
But thickness should depend in part on potential use.
If you want boards then 50 or 55 mm mm will shrink by about 10% in thickness which can be resawn later to 20 mm thick boards.
If you want to be able to use then for furniture legs etc then 75 or 100 mm thick is the way to go for at least a couple of the slabs.
If you want just slabs I wouldn't mill them any thinner than 40 mm, unless you have a really good way of storing them, ie concrete floor and serious way of camping then down like a steel strapping machine of some half ton concrete weights.
For small logs the following is worth considering but the wing nuts do nee to be regularly tightened as the wood dries out.
Attachment 467872
Full length stickers spaced directly above each other and no more than 450mm apart is also important.
By milling slabs at 58mm you allow enough for drying, jointing, splitting and surface planning. This gives you a pair of flat, book matched boards of 25mm dressed thickness. If you are happy to work with "thin inch" boards ie 22mm dressed, you can saw at 55mm. If flat sawing, it is best to err on the side of extra thickness as backsawn boards are more susceptible to cupping.
Rustynail is on the money at 58mm. We have milled all ours at 60mm for the past 20 years, unless in super stable huon pine or kingbilly. 60mm gives you some a bit to play with hardwoods for cupping, surface checking, etc. Blackwood is particularly susceptible to cupping with anything backsawn over 300mm wide.
As Bob metioned, racking them out is just as important as milling them will. Milling slabs at this time of year can be risky too, lots of surface checking with the hot weather. A lot depends on your end use for the timber also.
I have attached a photo of how we build and stack our racks.
Attachment 467984Attachment 467983Attachment 467982
Cheers,
James.:2tsup:
PS I also PM'd you for the blackwood photos but nothing has showed up.