advice on wood slice drying

[Time-to burn]

hi there im looking on some advice please, i make sign out of wooden slices, and i needing info on types of wood that dont crack as much as others and how can i prevent them cracking. am i best leaving it to dry in wood round then slice, or slice while wet at an angle and dry slowly. also what wood keeps its bark on best, im using lime just now but the bark falls off when dry.

[morten]

hi there im looking on some advice please, i make sign out of wooden slices, and i needing info on types of wood that dont crack as much as others and how can i prevent them cracking. am i best leaving it to dry in wood round then slice, or slice while wet at an angle and dry slowly. also what wood keeps its bark on best, im using lime just now but the bark falls off when dry.

 

Slice when wet, and dry slowly is best for preventing cracking. You don't want the surface or edges to be much dryer than the core, as the wood shrinks when drying.

 

In general, shrinkage is:

• Very little longitudinal (<0.1% along the grain)
  
• Greater radially (3 - 7% at right angles to the growth rings)
  
• Greatest tangentially (7 - 12% along the growth rings)
  

 

This will mean that, depending on how you cut the wood, it is likely to bow. Allow for this by cutting thicker slabs.

 

To prevent cracking near the end-grain, due to moisture escaping faster through the end-grain, you can paint it (before or after you cut it) with wax or PVA glue.

 

You can read more about shrinkage, including guidelines of species using these links:

• Wood Movement
  
• Measuring seasonal wood shrinkage
  
• WoodCentral's BP Archives: Wood Shrinkage Values
  

 

Good stable wood for carving is Alder.

 

Finally, the trees should be felled between october and march for two reasons. Firstly, the moisture content is lower during that period, secondly, the sapwood does not contain high levels of suger, which will attract fungus that may discolour the wood (worst in pine/spruce)

Edited June 5, 2012 by morten

[Tinker]

In addition to the above from Morton. When I cut small section discs which are a faff to seal, I just put them in a sack of sawdust, making sure the surfaces are separated by sawdust and leave them somewhere cool. I agitate the contents once a week until the wood is dry enough to be stable.

 

Larger pieces will take longer depending on their size.

[Time-to burn]

thanks very much, great information, i shall try the sack idea.