Replies

1. 
   kcg99999 | Apr 10, 2002 06:51am | #1

   Hi Matthew,

   PVA dries (grabs) by evaporation of its water base. The hotter it is the faster the glue grabs. Veneer is thin enough so that the heat of an iron can be transmitted through it. The flat of the iron acts to press the veneer flat and squeeze out the glue. Personally, I don’t bother to let the glue dry – I don’t think it’s necessary. I just spread a thick glue line onto the substrate and then iron the veneer down. You can actually feel the glue grab and see the squeeze out bubble. The trick is to use an iron that is hot enough to heat the glue without burning the veneer. I set mine about ¾ of the way up and keep it moving doing a 12" section at a time then repeating.  I use this technique primarily for edgebanding and not for large flat surfaces. It works well for flat and convex surfaces – not well for concave ones. Cauls work better for flat surfaces.

   Hope this helps.

   Kim Carleton Graves
   Carleton Woodworking

   
   

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   Edited 4/9/2002 11:52:20 PM ET by Kim Carleton Graves-Carleton Woodworking

1. 
   matthewlanebryan | Apr 11, 2002 04:33am | #2

   Thank you for the information.  I am really new to veneering.  What are cauls?  Why can't you use the process described in my origonal email for large surfaces?

1. 
   kcg99999 | Apr 12, 2002 04:39pm | #3

   Hi Matthew,

   Sorry for the delay in getting back to you.

   Caul is a generic term for a piece of wood or sheet goods that is used to distribute clamp pressure. The reason clamps and cauls are better than the iron on technique is that you can get both more and more even pressure than you can with the flat of an iron. The reason that ironing doesn’t work very well for large surfaces (though people do it) is that it’s hard to get good pressure over the whole area. You’re often left with bubbles that you have to go back and fix. The result is also not very flat.  So when you sand, it’s easy to sand through. A vacuum bag or a veneer press will give you much better results.

   In my book, Dining Tables, I show the iron-on technique on the curved edge of a boat shaped table. While clamps and cauls would have yielded better results, it is time consuming to make the negative caul needed for a curved surface. The three inch wide surface that I ironed on was about the limit for this technique. I use clamps and cauls on the same table for the ends, which are flat.

   Hope this helps.

   Kim Carleton GravesCarleton Woodworking

   Edited 4/12/2002 11:35:24 AM ET by Kim Carleton Graves-Carleton Woodworking