How do I flatten my veneers I've just bought? -With Pictures

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nick1982

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Hi,

Thanks for you help everyone in advance, this may be a noob question.

I'm making some pick guards, I'll be making a veneer sandwich of three layers.

The veneers have arrived today but they are wavey.

How do I get them flat without breaking them? Do I wet them and press them?

I have made a veneer press, not the prettiest thing but it should do the job.

I'm worried if i flatten them in the press it'll just flatten one bit out on top of the other, they seem to have expanded in parts. Is it possible to get them flat?

Thanks again.

Nick
 

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I may have answered my own question.

I wet it and stuck one in the press, it's as flat as a pancake now.

But how will i get it to dry flat? Is it a case of just leaving it in there for a few days? I have 48 veneers to flatten, is there a quicker way?

Thanks

Nick
 
there was a post on here a while ago which discussed this. let me see if I can find it for you
 
Hi, thanks for you replies

I've had a little play around with flattening. when I damp them and press them they come out super flat. But they don't stay that way for long.

My next question is... is it really necessary for me to flatten them before I glue them?....

I am glueing three veneers together with cascamite to make a kind of veneer plywood. It will be, Burr Poplar, walnut, burr poplar. If the veneers are damp and flat, and I apply glue, then press them together and allow to set, will this be ok?

Basically.. does it matter if the veneers are not completely dry before I glue them together.. and does it matter if they are not flat? as the press seems to take care of that anyway.

Thanks,

Nick
 
That was what I wondered when I asked if they were sacrificial - or replaceable. Presumably you would then use an animal glue of some sort - which entails moisture, obviously, so you could get away with them damp so long as you left them in a press for long enough. Someone with more experience of animal glue will correct me if I'm wrong, I'm sure.
 
They are permanent things, I plan to stain them and have them spray lacquered afterwards to protect them.

They are sacrificial in the sense that you can remove them form the guitar and replace/repair them if they are too damaged. but looked after they really should last the life of the guitar.

Basically, Cascamite is water soluble to begin, so presumably so long as the veneers are not too wet, I can glue them together and press them. And then if i leave them for 24 hours to cure in the press. hopefully i should end up with a strong bonded piece of plywood? made from veneers about 1.5mm thick....

I just wonder if the steps of soaking them in solution - which I notice on recipe has cascamite in - and drying them flat is necessary if I am sticking them together anyway. I could combine the steps?

I'm trying to avoid flat pressing 48 veneers! ha.
 
I'd say glue them damp and they'll flatten.

But ...

When you take them out of the press, watch for them curling. If so, back in the press until fully dry.

As the wood dries it will shrink across the grain (and a little along, though much less).

And there are no guarantees that it won't move with humidity, though ply is much more stable if the centre ply has the grain at 90 degrees. If all the grain runs the same way, it might curl a little.

I'd glue up one as an experiment, and then one day expose it to humidity (a day in the bathroom) and then aridity (a day next to a radiator). If it stays flat, you've won!
 
As a further thought, I'm wondering whether this might be the application for liquid hide glue. That reactivates with damp heat, so if the ply curls you can steam iron it flat (some domestic negotiation required) and then press it until cool, when it should keep its shape.

Might be worth investing a few pounds in a mixed veneer pack via eBay and experimenting on that. You want to get your process right before you start using the good stuff.
 
I was thinking the same thing... There will be a bit of experimentation.

good advice.

One set of veneers are in the press at the moment, I wet them and then put sections of cotton sheet between them.

Is this likely to be a good idea? Or do they need to be kept damp if keeping them for a while.

Thanks again.
 
nick1982":3s8r2x9a said:
I am glueing three veneers together with cascamite to make a kind of veneer plywood. It will be, Burr Poplar, walnut, burr poplar. If the veneers are damp and flat, and I apply glue, then press them together and allow to set, will this be ok?
I suspect not, although I could wrong - your experiments will tell you soon enough I imagine. Most common wood adhesives are designed to work with dry wood. The adhesive manufacturer's definition of dry wood is 20% MC and below (which happens to pretty much correspond with most other wood industry definitions of 'dry' wood). I've seen several adhesive failures where people have attempted to bond together wet or green wood. I can't recall any successes, although admittedly those applications weren't with veneers but in larger constructions. In all those cases I witnessed, the glue either just stayed wet, or in the case of PVA type formulations the glue turned into a sort of chalky appearing almost dust like powder. For damp, or even very wet wood bonding, the adhesive I turn to is polyurethane adhesive which seems to work very well, although I'm not fond of the stuff for the majority of dry wood bonding applications, mainly because I've found quite a few joints bonded with it tend to break relatively easily compared to other adhesives such as urea formaldehyde, PVA, epoxy resin and hide glue for instance.

Basically.. does it matter if the veneers are not completely dry before I glue them together.. and does it matter if they are not flat? as the press seems to take care of that anyway.
From what I've said above I suggest you try to dry your veneers to something below 20% MC. As to the second part of your question, from your admittedly not especially clear photograph, your veneers don't appear to be particularly buckled or wrinkled and probably good enough as is to bond together without additional flattening. Did you go to my article on testing for and flattening veneers that marcros linked you to a couple of days ago? I think there's enough information in that short article for you to assess if flattening is required and how to go about achieving it if it's needed. Slainte.
 

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