Christopher Charles
04-22-2014, 6:16 PM
Hello all,
I have a toothing blade for my scraping plane and have done a bit of hammer veneering. The experience has gotten me thinking about the practice of roughing surfaces to improve glue adhesion. Especially when empirical glue tests generally demonstrate wood failure before glue failure (at least with modern glues) on joints that were smooth when glued.
After I toothed my bench top, it occurred to me that perhaps toothing is employed in traditional veneering primarily to provide "sticktion" between the veneer and base during hammer veneering (more specifically to increase the lateral force required to move the veneer once lubricated by the hide glue).
And that the general idea that roughing surfaces is a hold over from veneering? I recall it being taught as a general principle in my middle school shop class-i.e., that everything should be roughed up with sand paper prior to gluing. Or perhaps my shop teacher had been into too much glue....
Thoughts?
Chris C.
I have a toothing blade for my scraping plane and have done a bit of hammer veneering. The experience has gotten me thinking about the practice of roughing surfaces to improve glue adhesion. Especially when empirical glue tests generally demonstrate wood failure before glue failure (at least with modern glues) on joints that were smooth when glued.
After I toothed my bench top, it occurred to me that perhaps toothing is employed in traditional veneering primarily to provide "sticktion" between the veneer and base during hammer veneering (more specifically to increase the lateral force required to move the veneer once lubricated by the hide glue).
And that the general idea that roughing surfaces is a hold over from veneering? I recall it being taught as a general principle in my middle school shop class-i.e., that everything should be roughed up with sand paper prior to gluing. Or perhaps my shop teacher had been into too much glue....
Thoughts?
Chris C.