Resawing veneers for cold-molding ?

I see little problem with the swelling of wood in this method of construction. Rarely if ever when a person builds a cold moulded hull do they finish the boat without some form of glass or resin satuated wood to the extent that the issue of swelling or contracting comes into play. So the issue in most cases becomes a non issue. IMO.

On the other side of the fense, many of the wooden runabouts that gets solid hardwood veneers on the outside in most cases also forgo any fabric and the boats are finished with varnish. If they was any real movement these style boats would not be built either using this style building technique.

If a person takes several years to build a boat using solid wood veneers and do so so in semi exposed areas to the weather, I could see that you may experience some problems with the wrong grains and too wide of planks.

 

Good point Oyster,

But they didn't mention if the excessive expansion and contraction of rotary peeled veneers was due to water ingress or simply natural temperature variations.

 

The key to cold moulding using solid lumber veneers is to choose stable lumber in regards to air or even kiln dried materials. Of course there are some types of wood thats better than others for minimum expansion and contraction such as the cedars.

But even with the wide variety of cedars avaliable there is still differences in how much each flavor will move. But another factor is how thin or thick you resaw and how long before you glue the veneers up, which will also allow dry lumber to further dry. This will also change the amount of resin or even a prewetting of the veneers in the inner layers.


What I normally do is as I resaw i stack the veneers as i saw them right back in line with each other. You will need to be mindfull of the edge fits too depending on the flare and location along the sides and even the bottom.


But you still need to be mindfull of not using green lumber or fresh cut lumber if you plan on cold moulding because of the need for proper bonding. The rotary grain does lend itself to more precoating and even additonal thickening agents too.

 

Oyster, thanks for the insights.

I just got a moisture meter, but i haven't used it yet - i hope they're accurate.
The quarter sawn timbers have been drying for the better part of a year, and then i plan on kiln drying each filch (500'-1000') of 1/8" veneers the day before i laminate 'em.

Do you think that'll work ?

 

I think you have a good plan. By the way I may have missed it. What boat are you planning on doing? One point of note, if the boards are truely quarter sawn they can be a bit weaker and more prone to splitting if the cedar gets too dry. Can you take a picture of the end grains of your flitches? Clean cut and wet it with some mineral spirits.

 

A long lean catamaran with sitting headroom only, but i don't have a set of plans yet, only some conceptual drawings of my own that are starting to look like "Crossbow 2" from 1980.

I've only just started ripping my quarter-sawn timbers into 6"x6"s, then its on to the bandsaw for resawing of the veneers.

 

Two points about resaws:
Many resaws have an oil drip feed to lubricate the blade and prevent wear on the wheels, naturally a lot of this oil ends up on the cut surfaces.
The quality of the cut depends very much on the sharpness of the blade. Most shops will probably be using disposable blades and so will hang on to them until the blade dies as the cut quality doesn't matter if you are going to machine it all off anyway. Might be worth offering to buy a new blade.
Nick