The PHILCO Phorum

Full Version: Rippled underlayment fix
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I've got a mod.18H with a lot of loose veneer and some of the underlayment is upheaved and rippled.  Do you cut that out and replace it or can you slice the ripples and reglue it down?  New at veneering but liking the challenge.  Thanks for any replies.

madsowry
See if you can get some hypodermic needless and syringes, and lots of bar clamps, if you can inject glue into the lifting areas and clamp them down with some flat blocks of wood, be sure to warp the blocks in plastic so they don't get stuck to the piece.
Regards
Arran
I've been reading many of these refinishing and re-veneering threads and so far was successful at restraining my fingers, but now I've got a few minutes to kill and thought I'd throw a few things out there.
First, I should mention that I've been professionally refinishing and restoring furniture for 35 years now.

Until the 1960's the single most commonly used glue for veneering and cabinet construction was hide glue. This matters because one of the things about hide glue is it can be heated to get it to release and rebond. That's why luthiers still use the stuff, they use heated knives and such to take apart instruments for repair work.
The typical mistake I encounter in home reglue/repair jobs is failing to remove and clean up the old glue. New glue will not make old glue stick. Yes, sometimes you can get lucky and have glue kind of stick, but in any good glue joint, the wood will fail before before the joint.
Contact cement is not a good choice for veneer work. In fact, in all the years of working with it, (I used to use it exclusively for everything from veneer to laminate countertops) I've yet to find an ideal application for it other than killing brain cells.
Contact cement never actually dries, and as we know wood expands and contracts, sooner or later this problem results in veneer "creep". Another problem is heat, contact cement will release at around 170 degrees Fahrenheit. Set a contact cement veneered piece in direct sunlight in the summertime and watch the bubbles come to life.
Another issue with contact cement is oil based wood stains with a high solvent content (*cough cough* minwax *cough cough*) will also attack and cause the contact cement to release.
If you're going to use contact cement anyway, make sure you're using cross-banded or paper backed veneer.
I've used many suppliers over the years and had luck with most, but for the last ten or so years joewoodworker.com has been heads above the rest. In fact their website is chock full of valuable information, much more than I will type here today, so go see them for information and I'll get off my soapbox...

....until I've the time to type about stripping.
+1 on the contact cement hate.
Hide glue in the 1950s and 60s? Heck no, that stuff was largely displaced from the furniture industry by 1950. Although maybe some small time outfits were still using it, it was by no means the most common glue, why would a furniture factory use it when they had less expensive and more reliable PVA and phenolic based glues available? The reason I know is that I purposely left a post war radio-phono combo outside over the winter once with the hope of salvaging the veneer from it, some lifted a bit at the edges but that was about it, the lumber in the top curled like crazy though. I've never been able to get veneer to stick back down by heating it, regardless of what glue they used, because there just was not enough left to make it stick down again.
 As for contact cement, I have used to to stick down veneer patches in the past, and I never had any issues with bubbling or offgassing through a finish,nor the patch moving around. I was told that the main issue would be that it might dry out and fall off with time, this is the neoprene solvent based stuff, not the water based latex stuff. I prefer to use yellow PVA glue whenever I can, and it seems to do the job, especially the structural repairs, with veneer you don't really need much adhesion to hold it down. PVA will also let go with heat just like hide glue, there are some people who use it like hide glue for just that reason, but unlike hide glue it doesn't crystallize and fall apart on it's own in cabinet joints.
Regards
Arran
Heat and moisture is what's needed for hide glue. Hide glue also will stick to itself, unlike polyvinyl acetate (that's why you've got to remove pva to clean wood to get a successful glue joint).
Cabinet and furniture makers were reluctant to give up hide glue because of most shipping was still done by railroad, a hide glue joint would give while a yellow glue joint would shatter. Railroad shipping was hard on case goods (until the days of cardboard packaging), it's why they invented crazy things like floating joint construction.
I still occasionally see new manufactured cabinets that use hide glue, believe it or not, it's had a resurgence lately.
Yellow glue, like contact cement never actually dries and will creep, especially under load, which is why if you read the label they will state it is not for structural applications.
Yellow glue also tends to bleed through veneer and screw with the surface finish.