Darryl Keil Last Activity 2024-10-10 3:42 PM
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Jim Clement

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Joined: 2007-03-06
Location: Seattle

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Subject : Marquetry two ply?
Posted : 2011-02-17 1:40 PM
Post #36282
I am planning on helping a friend press up a game table top. He has spent months making a marquetry picture for the top and I absolutely can't mess up the pressing process. I seem to recall from a previous post (can't find it) that you can stablize a marquetry picture by first making it into a two ply. Thoughts? Any opinion about grain orientation given the random grain orientation of the marquetry pieces? Any opinion about the wood used for the second ply, given the various species of marquetry wood?

Related question - for the smaller marquetry pictures I have pressed I used canvas as the top caul with good success. This piece - 30" by 50" - is bigger than I've previously attempted. Any new ideas or alternatives (besides rubber) to canvas that might be more appropriate for a larger piece?

Thanks-



 
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Don Stephan

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Location: Cincinnati, Ohio

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Subject : RE: Marquetry two ply?
Posted : 2011-02-17 6:54 PM
Post #36283 - In reply to #36282
Perhaps I've simply been extremely lucky, but I've not bothered to two ply marquetry in the past. Having said that, my pieces have all been pretty small. I've pressed some largish tabletops with multiple pieces of veneer, but not marquetry per se.
Haven't seen any mention of other materials for multiple pieces of veneer other than the ones you mentioned - canvas and rubber.


 
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mike mcnerney

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Joined: 2003-07-17
Location: ottawa ontario

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Subject : RE: Marquetry two ply?
Posted : 2011-02-18 5:38 AM
Post #36284 - In reply to #36282
I worked on a 4 tables recently 30 x 48 & they were simply glued to mdf, not 2 ply, by a guy who has been doing marquetry for a living for decades. Having said that I have done 2 jobs lately that involved some tight bends & have pre glued my veneer to a material called 'polybak' by Richwood. It comes in 3 thicknesses. So you are basically creating your own poly backed veneer. I'm not sure if this helps for a flat panel but for curves, I was able to presand before pressing. I scuffed the surface with 60 or 80 grit.



 
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Darryl Keil

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Subject : RE: Marquetry two ply?
Posted : 2011-02-18 9:43 AM
Post #36285 - In reply to #36282
Jim,

If you want to do a two ply marquetry I would use a nice straight grain mahogany for the backer sheet. Obviously there is no way you can make the backer veneer be 90 degrees to all the veneers in the marquetry which is OK. Because the veneers will be going in many different directions the two ply will want to warp on you so keep it weighted once you take it out of the press. In fact, I would press it onto the substrate as soon as you can. Same day if practical, but definitely by the next day.

Tell me you are not gluing up this panel with yellow glue as that would not be a good idea in this case.

I'm a real fan of natural gum rubber for pressing veneers with different thicknesses. I think you will like it. Natural gum rubber is better than neoprene rubber and always comes in a light tan color.

Darryl Keil


 
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Jim Clement

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Subject : RE: Marquetry two ply?
Posted : 2011-04-12 9:45 AM
Post #36335 - In reply to #36285
I'm still gearing up for this project (new bag, getting familiar with Unibond 800, practice pieces). I have two additional questions about single layer of marquetry/veneer vs. 2-ply. The table top substrate is specified as baltic birch plywood with a 1 1/2" mitered solid wenge border. My friend wants to create a shallow chamfer (maybe 10 degrees) on the table top edge, so a wide wood border is needed.

I understand it is a good idea to use 2 ply to conceal the plywood/solid wood joint. However I have access to a wide belt thickness sander and can get the plywood/wenge surface absolutely flat. Under these circumstances is 2-ply still needed? Also - should the backer be 2-ply or will a single layer suffice?

Thanks -


 
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Darryl Keil

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Subject : RE: Marquetry two ply?
Posted : 2011-04-12 10:33 AM
Post #36337 - In reply to #36335
Jim,

Its not about the flatness of the surface between the plywood and solid but the movement that happens over time at this joint which can telegraph and show through the veneer. For this reason I would two ply it. If you really don't want the second ply to show when you put a bevel on the top, at least make sure you glue the solid edging on with a rigid glue like Unibond 800. Yellow glue's have enough creep to exacerbate the joint problem.

If the piece is fairly large I would two ply the back side veneer as well. If its a small top then single veneer would be acceptable.


 
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Don Stephan

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Subject : RE: Marquetry two ply?
Posted : 2011-04-14 7:31 PM
Post #36341 - In reply to #36337
Recently I had a conversation with a highly regarded marquetry craftsman about marquetry on door panels. The suggestion was always 2 ply slab door panels with hardwood edging to keep the joint from telegraphing, and to three ply marquetry so there is underlying backer perpendicular to grain of the various marquetry pieces, regardless of their grain orientation. Not sure tho how one presses up a three ply. Could swear I did a two ply at least once, but can't remember what it might have been.


 
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Jim Clement

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Subject : RE: Marquetry two ply?
Posted : 2011-04-21 9:19 AM
Post #36345 - In reply to #36282
Thanks all for the replies. I'm probably overthinking this project but I'm influenced by the 80+ hours my friend spent making the marquetry picture, and want to do my part right.

The difficulty is that he wants a 1.5 inch solid wood border around the plywood substrate, with the picture pressd up to the edge of the edge. That means a 2-ply - no problem. I'll balance it with 2 ply backer. His wood border is quite a bit thicker than the plywood, which creates difficulty applying the backer - there will be a depressed veneering surface on the back relative to the wood edge. Ideally I'd like to veneer the backer on, then edge the panel, then veneer the marquetry 2-ply over the framed substrate. This will all take at least several days given my schedule.

The question - do I risk having the 30" by 50" 3/4" baltic birch substrate warp by applying the 2 ply backer without immediately veneering the picture to the top? The other option is to apply the edging then try to press the backer on, realizing that the wood edge is proud of the substrate surface. I'd probably pre-cut the backer then hope that glue squeeze out wouldn't interfere with the fit and that I could get the bag to fit well into the corners.

Thanks. Great forum.


 
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Darryl Keil

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Location: Maine

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Subject : RE: Marquetry two ply?
Posted : 2011-04-21 9:26 PM
Post #36347 - In reply to #36345
Jim,

Here's how I would do it. First, I would not press the backer two ply and then being doing the face side a couple days later, that's asking for warpage.

I would glue the edging on, (and by the way, not with yellow glue) first and then lay down the two ply on both sides. Because you would make the two ply's in advance they will be fairly stable and you can cut the back side one to fit inside the edging fairly accurately. When it comes time to press them up, have a piece of 3/4" plywood that fits inside the edging. This can then serve as a caul so you get good pressure right up to the edges of the two ply inside the frame. The bottom of the panel should face up towards the bag for this idea to work well.

Hope this helps.
Darryl Keil
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