How to fix Blistered Veneer

[exapp]

Hello,

Have some veneered marine ply that the top veneer layer has blistered a small bit. Can this be fixed?

I was thinking of placing come thin cardboard over the blisters and ironing. Would anyone have opinions on whether this may be successful.

Should i puncture blister first?

Regards,

Exapp

 

[sailorman]

Inject a little pva with a hypodermic then iron with a barrier between the iron & veneer (thick paper etc)

 

[Refueler]

Second sailorman solution. Do not use epoxy or other resin based - it will not soak in and will make the blister permanent !

 

[srp]

If you slit the veneer along the grain with a scalpel you'll be able to use a slip of card to spread the pva and ensure you've got a good covering. The slit will be invisible after glueing, provided it follows the grain. The excess will squeeze out easily through the slit (if nothing sqeezes out you haven't used enough!). I'd use water resistant pva, as damp is probably the cause of the problem in the first place. The biggest problem is usually clamping, so make sure you've had a 'dry' run, and use a pressure pad covered in parcel tape.

 

[VicS]

Absolutely as srp says. I've have done just that except that the veneer had already split along the grain. Some good heavy weights to hold the veneer down until the glue sets.

 

[sailorman]

wot if its a Bulkhead /forums/images/graemlins/blush.gif

 

[Refueler]

[ QUOTE ]
wot if its a Bulkhead /forums/images/graemlins/blush.gif

[/ QUOTE ]

Strategically placed wood battens and clamps .... DOH !

 

[VicS]

[ QUOTE ]
wot if its a Bulkhead

[/ QUOTE ] He said, "Have some veneered marine ply that the top veneer layer has blistered a small bit" If its a bulkhead he should have said what he meant!

 

[exapp]

Well it's a semi diagonal surface actually under my companionway steps....so not vertical, and not horizontal.

Will be next to impossible to clamp.

That's why i wondered about ironing through some thin cardboard (cornflake box cardboard and the like)

Can you iron PVA?

Exapp...

 

[sailorman]

pva will cure with heat.
we used to run an "Edge banding machine", it uses this principle. an iron will be less temperamental /forums/images/graemlins/wink.gif

On reflection Cacamite ( or what ever its now called ) might be better. it will still "heat cure" & will not leave a glue line.
good luck

 

[Scotty_Tradewind]

Agreed, a thin mix of Cascamite inside a fine cut in line with the grain of a blister may be one solution.
Getting the glue to every part req'd is not easy.
The iron treatment may reactivate the original glue so i would test that method dry first using brown paper between iron and veneer.
Remember the bubble will have stretched the veneer so to heat it with brown paper under the iron may help to soften and push it back to the original shape. Perhaps if that doesn't work a damp cloth under the iron onto the veneer may help but of course damp may have caused the problem in the first place so don't overdo it. To 'clamp' is a problem. Boatbuilders and shipwrights are well familiar with making up battens and wedges. A post accross the boat with other posts at right angles against a pad on the face of the veneer may be one choice. One 'glue up' I had to do last winter req'd huge posts accross the boat to attach a thin strip to one side of a wet locker. No clamps would fit so I ended jamming wedges between the post and the job and by gently tapping them home the wedges brought things together. A dry clamp is vital to try before putting glue to anything in many cases. best of luck, Scotty

 

[sailorman]

the hot iron will set the cascamite.
i used to hot bond formica onto plywood in a heated press with cascamite. it sets in minutes