Traveller wood... WHY?

[MarkyB]

I think you have answered the WHY?
50 years ago they didn't have the technology we have now, the cars were mass produced and I doubt that Travellers were put together by carpenters, just blokes on an assembly line, hence the wide tolerances.

A better, rain shedding profile, is a great idea, but has the benefit of a lot of hindsight.

What we don't have now is seasoned timber, just kiln dried and maybe pressure treated. Do you know how this may affect it's stability?

[kenshiro]

The trouble is with how the preservative is introduced into the timber. Absorbtion is always better down the end grain and the treatment of assemblies (sides and doors, etc) will be less effective because much of the end grain will be buried in joints, covered with adhesive.

Less penetration into the cell structure comes through the sides and edges, it will always be 2nd place due to the way a tree moves liquids around while it's alive.

Stability shouldn't be a problem if the wood is prepared and brought to the right percentage of moisture content, don't think that the wood will be too dry as it's going to be exposed to a lot of rain and the elements almost straightaway.

I would suppose that dipping assemblies in a tank of heated preservative and letting it drain will be the norm for the present, the other choice (mainly for cost in equipment) will be to manually brush the treatment generously over all surfaces, which takes longer and has more waste along with H&S considerations.

The choice of Ash I believe is due to it's appearance, grain, lack (?) of knots and - I would imagine - the long history of it's use in early motor vehicle frames..
Trouble is that the wood was then protected by a fabric or Aluminium skin, slowing down the rot!

Double vacuum treatment is the best in this case but it needs special equipment, look up the specs & diagrams on google or wikipedia to explain.

I think I'll make my new bits out of white Oak...
k

[MarkyB]

I wonder if the only reason Oak isn't used for coach building is the cost, maybe it doesn't have the right characteristics?

Cart wheels were made with Oak spokes,an elm hub and ash rim because each type of timber has it's strengths and weaknesses.