Vertical cross grain veneer

[Ronn W]

So Iam looking at building a federal style sideboard.  It was common back in the day to veneer that front of the horizontal rails between the drawers with veneer of the same species as the rest of the piece with the grain running vertical.  last summer made a mock up of this piece out of poplar and glued poplar veneer to a length of rail.  I pulled ilt out this week and saw that gaps had developed in the veneer.  Let me explain.......The length of the rails is greater than the width of the boards that I had to cut the venner from.  Widest board was about 8" which gives me 8" long pieces of cross grain veneer.  I had to butt the pieces together to cover the length of the rail.  It appears that he 8" long veneer pieces have shrunk and there are now gaps at the joints between pieces.  I think that I used liquid hide glue.  The final peice will be mahogany.  How do I prevent this from happening on the final piece?  The picutre show the gaps in the 1/16" veneer and the banding that was applied later.

Thanks for your help.

[pkinneb]

Ronn If it were me I would run another test piece using veneer about half that thickness 1/16" ish and Titebond (probably 3 given the mahogany) or a purpose meant veneer glue like Ultra-CAT™ PPR Veneer Glue.

[Ronn W]

Thanks for the reply.  I have started some test pieces.   All with 1/16" mahogany veneer.  I have to be sure of my method because by the time the veneer is appied the project is ready for assembly and so much work has gone into it that gaps in the veneer would be almost unfixable and catastrophic.

1.  Hold the joints in the veneer pieces together with veneer tape.  Use Liquid hide glue and clamp with cauls.

2.  Hold joints together with veneer tape but also glue the joints from the back side and let cure before applying to rail with hide glue, cauls and clamps.  If this works, it will allow me to glue together enough pieces for my longest rail (27") and in install veneer as one piece.

3.  Iron on method applying 2 coats fo PVA to veneer and rail and letting dry (but not cure) before ironing.  I am thinking that this takes the mositure out the equation.

4.  Same as #3 except use liquid hide glue.

5.  I also need to test if the iron will damge a layer of scotch or packing tape the is use to mask the strip along the rail edge where 1/16" thick banding will be applied.

#1 and # 2 and done - going to wait for glue to cure and check for gaps.

#'s 3, 4 & 5 are in progress.

Incidentally, I talke to Keven Southwick at Woodcraft.  He also suggested doing tests but added that #3 above was his preferred method.  He is usually using 1/42" veneer.

More to come in a few days........

[Mark J]

Are you using quarter sawn veneer?   Are you experimenting with poplar or the wood you're going to use (different shrinkage)?

[Ronn W]

Here are some results.........

1.  Hold the joints in the veneer pieces together with veneer tape.  Use Liquid hide glue and clamp with cauls.   Result:  This worked nicely

2.  Hold joints together with veneer tape but also glue the joints from the back side and let cure before applying to rail with hide glue, cauls and clamps.  If this works, it will allow me to glue together enough pieces for my longest rail (27") and in install veneer as one piece.   Result:   Worked

3.  Iron on method applying 2 coats of PVA to veneer and rail and letting dry (but not cure) before ironing.  Glue the veneer pieces with PVA glue and let harden before applying to rail.  I am thinking that this takes the mositure out the equation.  Result:  Got gaps at the veneer joints.  Why?  The ironing process softened the glue the joints as well as the glue under the veneer allowing veneer to move a little.  Using PVA glue to join adjacent pieces of veneer does not help because heat destroys the bond between pieces.  I am not entirely satisfied with this explanation.  This method did not work.

4.   Same as #3 except use liquid hide glue. Result:  Same as #2 except that once heated the pieces slide even more easily than with PVA glue.  This method did not work.

5.  I also needed to test if the iron will damage a layer of scotch or packing tape the is used to mask the strip along the rail edge where 1/16" thick banding will be applied.  I did this in conjunction with #6.  The tape survived but was difficult to remove.

6.  I added this test.  Glue pieces together with PVA glue and then taped the show side across the joints with blue tape.   Use PVA glue and iron method without removing the tape. Result:  I am sure that the PVA glue added nothing to this (see #3) but the blue tape held the veneer pieces together and held up to the heat of the iron.  Blue tape was easy to peel off afterward.  This method worked.   Side note:  Since the blue tape was so easy to remove I may try to use blue tape instead of difficult to remove scotch tape to mask off for the banding.

7.  I should add another test like #6 only using liquid hide glue instead of PVA.  Note:  The process takes a lot longer with hide glue because of the long dry time.

There are more methods that I can think of: Like installing the veneer one piece at a time.  But this is enough for now.