Vacuum veneer question
#6
I've done some hammer veneering but this is the fist time I'm using a vacuum bag. The question I have is how do you keep veneer from shifting on the substrate?

I'm building a walnut sofa table and originally I hadn't intended to veneer the front aprons and drawer. But then I came across a piece of walnut that screamed out to be used to veneer the front. I understand that normally you cut the substrate larger than the veneer and trim later but the problem is that the parts are already cut and the joinery completed so the veneer will need to be cut to the size of the parts. I'd prefer not starting over if possible, although it I guess it could be done. Is there a way to insure the veneer doesn't shift after it goes into the bag? The veneer is shop sawn walnut, probably 3/32" going onto solid walnut substrate.

Thanks for all advice.

Cliff
‘The problem with the world is that intelligent people are full of doubts, while the stupid ones are full of confidence
Charles Bukowski
Reply
#7
When we did bent lamination with the vacuum press and bag at Tom McLaughlin shop we used masking tape we taped the ply down to the form and that kept it from shifting
Formerly known as John's Woodshop
Reply
#8
I have shot some 23ga pins in the substrate leaving them just proud of the surface to grip the veneer. If they are too long snip them off with side cutters.

g
I've only had one...in dog beers.

"You can see the stars and still not see the light"
The Eagles: Already Gone
Reply
#9
The simple answer in this case is to make the veneer slightly larger than the substrate, then use a router with a bottom bearing, flush trim bit to trim it flush afterwards.  I do this all the time.  If you are veneering only one side of your substrate put the veneer on the bottom.  That way the vacuum bag won't break the veneer as it pulls it down over the edge of the substrate, as would happen if it were on top.  If you are veneering both sides, then the way to stop the top veneer from being broken is to surround the substrate with some narrow offcuts the same thickness as what's being put into the press (substrate + veneer).  The bag will bridge across the little gap and not crack the veneer.  Or use a top caul.  Either way works.  

In all cases, put a piece of breather mesh (I use heavy duty window screen) down first, onto your bottom caul.  Put the stack to be veneered on that, and then cover it with another layer of breather mesh.  That way vacuum will be uniformly distributed everywhere.  

As mentioned earlier, you can keep the parts in proper registration with blue painters tape.  

John
Reply
#10
I think the painters tape is the best approach given your situation.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.