Glue for veneer

[Juss1]

I'm starting the road on vacuum bag veneering and was wondering what type of glue you guys like to use.   For reference I'd like to try out different types of veneer, specifically paper backed, commercial non paper backed, and shop saw.  I definitely want to try out the crotch / figure variety in the future.

I'm watching and reading instructional videos on the subject and I can't seem to find a consensus on the subject.   Some people use hide glue, some modified pva, and yet some say you need the glue to be super ridgid and neither of the previous glues are suitable and say you have to use something like unibond 800.  Tbh the last one sounds a little scary since you have to use formaldehyde. So just curious to what y'all use and specifically why you chose that glue?  Thanks

[adamcherubini]

I've never worked with a vacuum bag with wood working. Technically, it wouldn't produce enough pressure to really achieve the strength PVA can reach, but I'm sure it would work. I think bags and presses are how big industrial veneers are done, so you probably can't go too wrong.

Crotches and figured materials can be trickier to work with. Wood is fickle when straight grained. I'd worry you'd get disbonds. Hopefully someone else will chime in.

My experience is, every time I do veneer, everything goes wrong. So repairing veneer is a big reason I chose to stick with hot hide glue. PVA isn't really repairable. I think its only a matter of time before veneers begin to pop off.

[jcousins2]

have done vacuum bag veneering for many years - however i used shop sawn veneers - 5/64 - so no experience with commercial products.
glue to use is unibond 800. it's dependable and has pretty long open time. when i am pressing i do wrap the bag in an electric blanket - time is the bag is about 3 hours.
jerry

[jteneyck]

I mostly use 1/16" shop sawn veneer, but have used commercial veneer and paper backed stuff, too.  I used to use Weldwood Plastic Resin Glue but it's no longer manufactured so I now use Unibond 800.  Your fears about formaldehyde are unwarranted.  It's in the catalyst; it's not volatile.  Wear vinyl gloves if you feel the need.  I have used epoxy, too, and it works very well.  Polyurethane glue, yes Gorilla Glue, is another good choice structurally, but a pain to clean up.  Do NOT use Better Bond or any thickened PVA glue with shop sawn veneer.  

You have more choices with commercial and paper backed veneer.  You don't need the highly rigid glues like Unibond 800 or epoxy that are needed to bond thicker shop sawn veneer, though they are always a good choice.  TB I and II work really well, despite the low pressure of the vacuum bag.  Better Bond, etc. are said to work well, too.  I don't use it.  

What I really like about Unibond 800 is that it is specifically formulated for use with a vacuum bag; it doesn't require high pressure to achieve a good bond.  It's a nearly universal solution, too, meaning you can use it with any type of veneer and in both flat work or bent laminations.  I also like the easy soap and water clean-up, unlike epoxy.  If I could choose only one glue for veneer work, it would be Unibond 800.  

I've never had a bubble or other unbonded area with any glue in the vacuum bag.  The only glue failure of any kind was from using Better Bond with shop sawn veneer.  The seams lifted up a few days later. 

John

[Juss1]

I mostly use 1/16" shop sawn veneer, but have used commercial veneer and paper backed stuff, too.  I used to use Weldwood Plastic Resin Glue but it's no longer manufactured so I now use Unibond 800.  Your fears about formaldehyde are unwarranted.  It's in the catalyst; it's not volatile.  Wear vinyl gloves if you feel the need.

Ok I've read the danger is more in the dust.  Both during mixing with liquid and then sanding after.  Do you wear a respirator when mixing?

Thanks

[jteneyck]

Ok I've read the danger is more in the dust.  Both during mixing with liquid and then sanding after.  Do you wear a respirator when mixing?

Thanks

Here's the MSDS for Unibond 800:  Link.  Draw your own conclusions.  

I don't wear a respirator mixing, sanding, etc.  

John

[KC]

... I used to use Weldwood Plastic Resin Glue but it's no longer manufactured ...

What?!!! 


I haven't bought any in over a year, but it still shows up on the DAP website.   Several places say 'out of stock', and one retailer says 'manufacturer discontinued', but my Google 'is DAP weldwood plastic resin glue still being manufactured' returns nothing that says it's not being made any longer.  Odd, that.

[jteneyck]

What?!!! 


I haven't bought any in over a year, but it still shows up on the DAP website.   Several places say 'out of stock', and one retailer says 'manufacturer discontinued', but my Google 'is DAP weldwood plastic resin glue still being manufactured' returns nothing that says it's not being made any longer.  Odd, that.

I said the same thing to the DAP person I talked with and they said it was still on the website so people could access the MSDS info.  You may find an odd container for sale here or there, but it hasn't been made for "several years" so when the inventory is gone, it's gone.  

I liked using PRG because I could get it from Amazon for a good price, delivered to my door.  But the switch (actually back) to Unibond 800 has been seamless for me.  It has less odor, is easier to mix, and clean up with soap and water is easier, too.  Best of all, it cures a lot faster.  The only downside is it costs more.  

John

[fredhargis]

I used to use Weldwood Plastic Resin Glue but it's no longer manufactured so I now use Unibond 800. 

John

There's some sad news to me. That's what I use (or, used to use) when vacuum pressing. I also use it on table tops so i wouldn't have glue creep.

[jteneyck]

There's some sad news to me. That's what I use (or, used to use) when vacuum pressing. I also use it on table tops so i wouldn't have glue creep.

Yeah, I called them after I couldn't find it anywhere and was told it hadn't been manufactured for a couple of years.  The good news is Unibond 800 works just as well, actually better for vacuum pressing, and has a similar shelf life.  I never had any vacuum bag failures with PRG, but Unibond 800 was specifically developed for that low pressure application.  Also, Unibond 800 cures at least 2X faster than PRG, even faster still if you juice the catalyst amount.  In the vacuum bag, 3 or 4 hours with a heating blanket on top and it's good.  

If you use TB I you won't have creep in your table top glue ups.  

John