Replies

1. 
   tom77 | Mar 05, 2007 02:54am | #1

   I would be concerned about warping with the situation you described.  Water from the glue will be absorbed into the veneer before it tacks, and then after the glue is set, the water will eventually evaporate, causing the glued panel to warp.  The conventional approach in veneered panels is to veneer both sides, thus balancing these forces. 

   I have no experience using a thin core like you described.  Do you have enough material to do a test?

   A glue like Unibond 800 or Gorrila Glue might work better.  I am not sure and would do an experiment if it were my project.

   Good luck, Tom.

2. 
   sasha | Mar 05, 2007 03:41am | #2

   I would be concerned about the thin backing, but it might works as you are mounting it to the refrigerator and that will be flat.  If I were going to proceed, I'd go to the Oakwood Veneer site and ask one of their experts whether the back side of the panel should be veneered.  They've always been helpful to me. 

3. 
   jeanlou | Mar 05, 2007 03:43am | #3

   Bigfork

   What material is the backer board? Is it plastic laminate backer board? You can use waterbased glues on veneer, but it must stay in the press until the glue is cured, and then you must leave the panels vertical to allow them to dry evenly and completely. Urea based glues are safer (veneer wise), but both will work and both will stick to laminate backer board, if that is what you are using.

   As the previous poster suggested, you need to balance the glue up, so you will have twice 1/8" plus 1/16" backer plus about 1/16" glue thickness. Is this going to fit in the frame of the fridge?  JL

1. 
   Bigfork | Mar 07, 2007 06:16am | #4

   Thanks for the response JeanLou. 

    

   I was planning on using something like a door-skin, or other thin plywood that measured 1/16" thick.  That would take the total thickness up to 3/16" which is what the existing board is.

   I wasn't planning on counter-laminating as I don't have space or enough of the 1/8" boards.  Maybe I'll just edge-glue them (long-grain to ling grain) and leave it at that.

    

2. 
   tom77 | Mar 07, 2007 05:21pm | #5

   JL,

   Your additions to this thread were helpful, but I would take issue with one minor part.  When using PVA glues in a vacuum press, the glue up needs to come out of the press after about an hour, allowing the glue to continue setting up in the presence of air.  Otherwise, there is a significant risk of black spotting which is not recoverable.  I usually let the glue continue to set at least overnight before working on the panel.

   Best regards, Tom

1. 
   jeanlou | Mar 07, 2007 05:46pm | #6

   Tom

   Ahhh, the ubiquitous vacuum bag system. Sorry, but I do not know a thing about it. I am a throw back to the cold press / hot press generation of wood workers. You, however, seem to have gone the vacuum route (evolution of the woodworker). I never have so for me, putting something in the press means the mechanical cold or hot press. I should have been a bit more specific.

   Interesting info though, that raises a question in my mind. With only an hour in the press, you would be relying on the tack that developed to keep everything together as the curing process and then the drying continues. Do you ever have failures, bubbling, or even outright delamination?   JL

1. 
   tom77 | Mar 08, 2007 05:50am | #7

   JL,

   I use a cold press PVA from Joe Woodworker primarily, although I have also tried Titebond III.  I have had good results, with one exception:  I did a chess board with wenge and anegre veneers and had buckling problems with the anegre.  The reason was that the wenge was much thicker than the anegre.  (the difference between the two was .009")  I didn't have enough compliance between the clamping caul and the veneer, so the anegre absorbed moisture, expanded and buckled.  It was ugly.

   I remade the chess board using walnut and anegre, and this time achieved a good result.

   Best regards, Tom.

1. 
   jeanlou | Mar 08, 2007 05:55pm | #8

   Tom

   If ever you find yourself in a similar situation try this:

   Put a piece of soft paper (like newsprint without any writing on it) on your lay up and then a piece of flannel  material (single or even double layer) over the paper before you start pressing. The material helps to fill in the gaps a bit and insure even and consistent pressure. I always use this method when I have several layers of veneer tape criss-crossing the work and it has never failed me. Make sure that there are no folds in the material directly over the lay up.

   When I make chess boards I will chose materials that are close in thickness; bang on is better.  JL

2. 
   tom77 | Mar 08, 2007 10:24pm | #9

   JL,

   Thanks for the tip.  Paul Schurch recommends a type of canvas for the same purpose.  Some of my marquetry friends are pressing in a vacuum press with no clamping cauls, letting the bag conform to the surface variations.  That seems to work also.

   I have enjoyed having this interchange with you.

   Best regards, Tom.

3. 
   jeanlou | Mar 09, 2007 05:56am | #10

   Tom

   How do you lay up your chess boards?  JL

4. 
   tom77 | Mar 09, 2007 05:57pm | #11

   JL,

   There is a nice description in Jack Metcalfe and John Apps book on marquetry.  (The Marquetry Course)  I will try to describe it clearly.  First step is to cut five strips of light veneer and four strips of dark veneer to the width of the finished squares.  Then edge join these with veneer tape in the sequence light, dark, light, -----.

   Next, cut this taped up assembly into strips at right angles the the original strips, again at the finished width of the squares.  You should end up with eight strips of nine squares each.  Now assemble these by alternating the alignment to produce the final layout.  Trim off the extra squares.

   I make two gage blocks that are the same width as the board squares.  I use these as an alignment gages for cutting the strips.  The process requires two straight edges.  If you want more detail, just email me.  I could also scan and email a picture of the pages in the book if you want.

   Best regards, Tom.

5. 
   jeanlou | Mar 09, 2007 06:21pm | #12

   Thanks Tom, but I was curious if you did it in strips or, like some people, in squares. I always use the method you describe.

   The very first board I ever made I cut the veneer with a hand held veneer saw to the finished size and joined the strips without any other work on the veneers. The results were actually very good, but likely beginner's luck (the saw was sharp).

   I still cut using the hand held veneer saw, but I then clamp all the strips, which are slightly wider than the finished square size I want, between 2 sized pieces of wood that have their long edges clad in aluminum. I then sand flat, stopping when I hit metal, and everything is perfect for the layup. I repeat the above when I have cut the second set of strips at 90 degrees to the original strips.

   Have a good woodworking day.  JL

6. 
   tom77 | Mar 09, 2007 08:39pm | #13

   JL,

   That sounds like a very good method.  Thanks.  I have used both the veneer saw on fragile veneers and a scalpel on the long grain ones.  I need to improve on always cutting from the glue side, in order to avoid unnecessary gaps.

   Tom.

7. 
   jeanlou | Mar 09, 2007 11:21pm | #14

   Tom

   When doing marquetry, and in-filling, I can see that it helps to undercut the piece being fitted into the space to fill. Ideally, it is always best to have square cuts meeting square cuts, in order to afford the largest possible gluing surface on the perimeter.  JL