Thread: Toothing Planes

I don't know enough about physics and materials sciences to adequately address your point, Paul. But I'll give it a try.........remembering this is just me trying to make sense of my world based on my education, experience and observations.

I remember the ruler and paper trick, where a sheet of paper is placed over one half of a ruler on a table and the other half juts out from the table. Striking the unsupported end of the ruler breaks the ruler as the air pressure on the paper holds the ruler down. Without striking the ruler it is free to move, sideways, back and forth and likewise a gentle breath will blow away the paper. It is only when striking the ruler suddenly lifts the paper creating a vacuum that the force of the air above comes into play. Before that there is just as much air pressure under the paper as there is pressing down on it.

If the veneer acts the same as the paper, it is only when a vacuum is created under the veneer that it is pressed onto the substrate. Perhaps keying the substrate creates a void that is then temporarily filled with a bit of air and glue. A wet, limp sheet of veneer is placed on the substrate. Hammering expels some of the air and glue and replaces the void with a bit of flexed veneer. As the hammer moves past the flexed veneer it wants to spring back but it is held fast by the air pressure above it.

What do you think?

Of course, vacuum in these examples are really areas of less pressure. And yes, there is much less wiggle if the substrate is keyed.

Originally Posted by homesy135

I don't know enough about physics and materials sciences to adequately address your point, Paul. But I'll give it a try.........remembering this is just me trying to make sense of my world based on my education, experience and observations.

I remember the ruler and paper trick, where a sheet of paper is placed over one half of a ruler on a table and the other half juts out from the table. Striking the unsupported end of the ruler breaks the ruler as the air pressure on the paper holds the ruler down. Without striking the ruler it is free to move, sideways, back and forth and likewise a gentle breath will blow away the paper. It is only when striking the ruler suddenly lifts the paper creating a vacuum that the force of the air above comes into play. Before that there is just as much air pressure under the paper as there is pressing down on it.

If the veneer acts the same as the paper, it is only when a vacuum is created under the veneer that it is pressed onto the substrate. Perhaps keying the substrate creates a void that is then temporarily filled with a bit of air and glue. A wet, limp sheet of veneer is placed on the substrate. Hammering expels some of the air and glue and replaces the void with a bit of flexed veneer. As the hammer moves past the flexed veneer it wants to spring back but it is held fast by the air pressure above it.

What do you think?

Of course, vacuum in these examples are really areas of less pressure. And yes, there is much less wiggle if the substrate is keyed.

That's exactly what happens... but only if the pores in the veneer are clogged with sufficiently thick glue to prevent air being sucked in through the pores, thus allowing the veneer to spring up.

Amateurs often experience difficulty hammering veneer until they grasp the required glue consistency and the amount of free water used during the process. If the glue is too thin (or becomes overly thinned), then the veneer will likely be starved of glue, not take, and possibly spring up. Conversely, if the glue is too thick, then it will not be easily expelled by the hammer, resulting in areas that will shrink long after the surface has been scraped, sanded and finished.

The way hammer veneering works is much the same as the way a wet shower curtain sticks to a wall. The voids are filled with fluid which has a lower vapour pressure than air, so you have virtually no pressure within the interface and 1atm pressure forcing down.

I can't comment on veneering techniques but by coincidence I watched this yesterday

Video: Apply Decorative Wood Veneers On Furniture & Cabinets

That is a great video Chris! Thank you very much.

I'm hot for that guy's workshop

and ... dammit ... I wasn't "needing" to have a veneer saw before I saw that

Don't you just love it when someone's done something so often it's just "oh .. cut here and .. about here and .. oh look - fits perfectly"


Damn you experience!

Cheers,
Paul

I've bookmarked Chris's video for later viewing.

This is the video I found inspiring:

Inlaying and veneering - YouTube


The poster has uploaded a couple more "no nonsense" videos on hammer veneering and making drawers that I found interesting. Worth a look (but not a toothing plane in sight).

Okay, just watched Chris's video. Very nice and a nice saw, too. I'm left handed and use (struggle with) one of those more common veneer saws with the swan neck handle and squarish blade. Paul, let me me know when you're ready to buy a French Veneer Saw and we'll share postage.

I was also chuffed to hear Patrick Edwards explain about the veneer being held by a vacuum. As Derek and Clive say, "Now I've had it confirmed!"

I do like using an iron to make the veneer limp and warm. My veneer is rarely flat.


Today is going to be a good day.....................

WWing advice from Derek and Clive ... Blimey!

Here's an excerpt re Christopher Gabriel - London planemaker - from
Eighteenth-Century Woodworking Tools: Papers Presented at a Tool Symposium May 1994

Eighteenth-Century Woodworking Tools: Papers Presented at a Tool Symposium ... - Google Books

Toothing irons were in healthy demand ...

Gabriel UK.jpg