Is glue squeeze out - REQUIRED

[Tom DiBiasio]

So I have started my journey down the rabbit hole of wood veneering. I acquired a full blown vacuum press setup and my first project is a waterfall bubinga coffee table. Due to the fact that this table will live its life about 5 feet in front of my fireplace insert wood stove, I decided the substrate needed to be stable as possible. So I decided to layup 1/2" Baltic Birch ply between two layers of 1/4" MDF. I decided to use some of my newly acquired veneering tools to make up the substrate, vacuum press and bags for clamping, for the adhesive I decided to use titebond original and used the medium density glue roller I bought for applying veneer glue to spread the titebond. I put some pencil marks on the substrate before applying the glue and am confident that I had complete coverage, however after removing the "sandwich" from the press I noticed that I had VERY LITTLE squeeze out and in some areas none at all. It got me wondering to myself if a squeeze out is really necessary to have confidence in a glue up? Again I am sure that I had glue on all mating surfaces, meaning that glue was rolled on all four planes. After two hours in the press and an overnight cure the panels seem to be very solid so I think I am good but thought to ask the question - should glue squeeze out be the goal for future projects?

[Tony Leonard]

Well, a lot of veneer glues and additives aim to reduce squeezeout for veneering. So, I would say that no, it is not a requirement to achieve a good joint. Myself, I prefer to get 'just a little.' Too much can cause multiple issues. There are better glues than Titebond I for veneering. Not sure how much heat your table will see that close to a wood stove, but keep in mind that Titebond is thermoplastic (hope I'm using the correct term?). Some folks even use it with an iron to make their own iron on glue.

Not sure about your substrate. I've always just used 3/4" MDF for tables and such.

Waterfall bubinga is some beautiful stuff! I've made a lot of projects out of it. After a few coats of finish, it is really gorgeous.

Vac bag veneering is fun stuff. I just finished a small box using crazy figured walnut. I've done things as big as dresser sides too. I learned a lot at Daryl Kleil's site and at Joe Woodworker's site. Still learning!

[John TenEyck]

I rarely use TB for vacuum laminating but I don't think it matters what glue you use. You don't need squeeze out, IMO. What you need is glue between the two pieces being glued. Squeeze out always gives us some confidence that we really did have enough glue but it's not a requirement, not for me anyway. I almost always use Plastic Resin Glue for vacuum laminating. I follow the guidelines to use 1 lb of resin for 40 square feet of substrate. I apply it with a foam roller, and allow 60 gms of resin to fill the 4.5" roller cover. That always turns out to be the right amount, even though it never looks like it will be when you are actually rolling it out. And you apply it only to one layer. The manufacturer says the correct amount is when you see a few tiny bubbles of glue along the seams. Most times I do, sometimes I don't, but I've never had anything separate.

I would either ask Titebond or figure out on your own what the correct coverage rate is and then weigh out that amount of glue for the number of square feet you need to cover. Add to that how much it takes to saturate the roller cover you are using. With veneer you normally only put glue on the substrate, because if you put it on the veneer it will curl, etc. and then you've got a problem.

John

[Richard Wolf]

I've always used unibomd 800 for a glue for vacuum bagging. Care must be used not to use too much glue, because the vacuum will suck it through the veneer pores. But they make a product to stop that, a glue blocker. I always used this company for my equipment and supplies; https://www.vacupress.com/

[Jim Morgan]

Compared to most joinery, you have a tremendous amount of surface area, so it is unlikely that your substrate will delaminate. You could tap around with the handle end of a spoon to see if there are any voids. This is more likely to occur between veneer and substrate. To cure a bubble in the veneer, make a small incision with the grain with a fine blade (e.g., a Swann Morton scalpel), inject a bit of glue, and re-press.

[Kevin Jenness]

Just a comment on your substrate- that seems like unnecessary work. The Baltic Birch I have used is generally not that flat. MDF is widely used,or for moisture exposure Medex. A nice platform stock for veneering (or painting) that is lighter and stronger than MDF is Garnica Pluma-Ply HD, with a calibrated, nearly void-free European poplar veneer core and thin high density fiberboard faces. I get it from Atlantic Plywood.

[Tom DiBiasio]

Hi Guys - thanks for all the informative responses. I think I was not very clear in my original post, at this stage I am only laying up the substrate using titebond - for the actual veneering I will be using Uni800.

@Kevin - THANKS for the heads up about the HD plywood option. I have never been to Atlantic but they have a storefront in Providence which is only about 40 min drive from where I live. Can you share approximate cost? As you are also in New England I guess the cost will be very similar to what it is in Royalton?

[Jim Morgan]

Atlantic Plywood does not do cash sales - they will only sell to you if you are a business that has an account with them. If you don't qualify and don't know someone who will buy for you, you can order through a lumber yard (e.g., L. Sweet) at a mark-up & pick it up at Alantic in East Providence.