Kerf and marquetry witha scrollsaw

[ClintO]

I am not sure if this is considered to be sacrilige by the marquetry community.
In this thread http://www.woodworkforums.com/f11/past-age-153676/ there are some old videos of Irish tradesmen building a mahogany dining suite.
The decorations for the backs of the chairs are made from a sandwhich of veneers cut out with a scroll saw

The sandwhich is glued with hide glue and has a waste piece on the bottom

When the craftsman seperates the sandwhich he soaks it in water for 24 hours.

As a novice there are a couple of questions I have:
I thought one of the reasons for using hide glue was the ability to use heat to separate and reposition things

When fitted to the chair there is no kerf gap between the 2 halves, how is that achieved? Did I miss something?
Clint

[mic-d]

I have some guesses. The veneers are soaked in water for 24hrs to really weaken the glue because the parts are so fragile. Reactivating hide glue by heat or moist heat is ok for robust parts, but as soon as it begins to cool it become tenacious again. Ok, that wasn't so much of a guess, the next one is...:)
You'd typically make kerfless marquetry patterns by tilting the bed of the scroll saw (about 7º from memory or was it 12º?) or cutting at an angle freehand, but it looks like the blade is at right angles in the video (and that would be a very thick stack to angle cut without one side being noticeably smaller than the other.) My guess is that there is a kerf, just that it's so fine it is not noticeable and vanishes at the polishing stage.

[ClintO]

I must admit I hadn't thought of either of those.
Tilting the table would work for single, thicker pieces, the tilt would be related to the thickness of the workpiece

[mic-d]

I must admit I hadn't thought of either of those.
Tilting the table would work for single, thicker pieces, the tilt would be related to the thickness of the workpiece

The angled method needs at least pairs of veneers and they can be thin. When cut in pairs, the piece that will become the "inlayed" veneer is as big as the hole it fits courtesy of the tilt which accounts for the kerf. They would have had to do them in smaller stacks to do it this way, otherwise - although each pair would fit together nicely - each chair would have motifs gradually diminishing in size.

I probably just said what I said the first time, just in a different way:U