As you are probably aware, hand sawing veneer out of material wider than 12 inches is a pretty tall order. In fact, it's something I've never done. But, I have hand sawn veneer out of narrower stock, and have a few thoughts which may, or may not, be of any help.
If you are contemplating a one-time episode, then you MAY be able to get by with a "full" rip saw. I.e., a 28 to 30 inch hand saw, possibly with 3 1/2 to 5 ppi. Filed for rip cuts - more on this in a moment.
If, on the other hand, you anticipate occasional episodes of this activity, then you may want to consider something closer to the traditional frame saws ("veneer saws") which sawyers used for this type of work. Illustrations of these are found in Roubo, Diderot, Felibien, etc., and they are two-person saws in which a relatively wide web is fixed down the center of the frame. The web is rigidly held by stirrups at either end, and "strain" is put on the web by a screw mechanism or folding wedges.
According to Holtzapffel, in the mid-nineteenth century, veneer saw webs were available in lengths from 4 to 5 feet, and widths of 4 to 5 inches. Also, the webs were .032" to .042" thick, with 2 to 4 points per inch. Of course, these are for two-person saws, so the values would need to be scaled down a bit for a one-person example. But, for material over 12 inches wide, a two-person saw is probably preferable.
I'm not aware that such blades/webs are currently available, so if you were to decide to pursue this option, you would probably wind-up buying a length of spring steel of the proper width and gage, and creating the teeth for yourself.
As to the shape of the teeth, you will want them to be as aggressive as possible without requiring too much effort per stroke. It may be possible that a frame saw will allow for a more aggressive tooth shape than for a hand saw, but it might be safer to start with a tooth configuration known to be effective for regular rip saws. Charles L. Johnson, in his _Saw Dictionary_, recommends a rake/pitch of 87 degrees (i.e, the face of the tooth leans handle-ward three degrees from vertical) and a bevel angle of two degrees for "Fast Heavy Ripping." I would think this would be a pretty safe starting place.
I know there will be controversy about this, but my preference for heavy ripping is to keep the set fairly minimal. This seems counter-intuitive, but the resulting thinner kerf not only requires less effort to achieve, but wider kerfs (and narrower webs/blades) actually add to the task of guiding/correcting the cuts. People who advocate more set to allow for corrections typically then go on to describe methods of achieving these corrections which have little/nothing to do with the width of the kerf. As Holtzapffel describes elsewhere, most tools have some kind of guiding principle in their operation, and this holds true for saws as well.
Finally, even though this contradicts something I recently wrote in another thread ["A foolish consistency is the hob-goblin of little minds."
], if you anticipate doing much sawing out of veneer in materials wider than 12 inches, you may want to consider a riser block for your bandsaw, or another bandsaw of greater capacity.
I'd be most interested in your experience, though, if you decide to undertake this by hand!
Don McConnell
Eureka Springs, AR
