When Cutting 1/8" Veneers Does Grain Orientation Matter?

Discussion in 'Wooden Boat Building and Restoration' started by mcm, Aug 15, 2011.

  1. mcm
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    mcm Senior Member

    If not, then only one of the two flat surfaces of each of my quarter sawn WRC logs has to be 6" to fit the height of my band-saw.

    I would be able to cut the entire quarter-log without alternating each cut between the two flat surfaces of the quarter-sawn timber.

    But if the grain orientation matters in 1/8" veneers, then i'll have to cut each quarter of the quarter-sawn log down to 6"x6", and that will leave a lot of wood along the edges of the quarter-sawn timber wasted.

    Any suggestions?
     
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  2. mcm
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    mcm Senior Member

    By grain orientation I mean edge-grain or flat-grain.

    Stringers and frames demand edge-grain material from quarter-sawn timber.

    But if grain orientation doesn't matter for 1/8" veneers as used in cold-molding, then I can use flat-grain material as well.
     
  3. Corley
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    Corley epoxy coated

    I'm not a professional but I'd say it depends on a few things the main thing is with cold molding that the grains are running in the correct direction dimensional stability is promoted by the thin veneer and lamination with other opposed veneers. If your trying to bend the veneer around a strongly curved bilge I've found the quarter sawn is easier to bend and twist without steaming into shape but then my boat has some fairly extreme turn to the bilge around the stern.
     

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  4. alan white
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    alan white Senior Member

    I don't know if quarter-sawn bends easier--- I thought the opposite was true, that flat-sawn bent best. In any case, regarding which orientation is most stable, that's not relevant at least where epoxy is used to create a multi-layer hull.
    The epoxy in cold molding "fixes" the wood of one layer by running the next layer against it at close to right angles. I wouldn't worry about grain orientation, except to say buy straight-grained stock to start with.
     
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  5. Corley
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    Corley epoxy coated

    I'm not sure that the timber I'm using (Paulownia) is equivalent to Western Red Cedar in its properties the biggest challenge I find is that Paulownia tends to fail in a clean break when twisted and curved, the quarter sawn stock seems to have less tendency to break in that manner, having said that every veneer seems to have its own quirks which you get a feel for by twisting and curving the veneer over the mold.

    I've found that steaming thin veneers with a simple clothes steamer does the trick nicely you dont really need a steam box as long as you work on one veneer at a time.
     
  6. alan white
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    alan white Senior Member

    Also try dry heat--- a heated cylinder (steel pipe) for bending. That's how guitars are formed, very similar in thickness too.
     
  7. rwatson
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    rwatson Senior Member

    A lot depends on the age of the Pawlonia. Timber under ten yo is much more brittle than WRC in general.
     

  8. Corley
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    Corley epoxy coated

    Once the lamination is glued together though it does seem quite strong the hull shell on this boat is a bit of an experiment I'm keeping my mold in case the whole thing goes pear shaped and I have to lay up a new hull but the light weight of the structure so far is impressive. If I had a real gripe about the timber it would be the ease with which it crushes. I've switched to using packing strap to staple through to reduce the damage the staple does to the veneer and make getting the staples out without damage easier.
     
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