veneer seams

Ejc | Posted in General Discussion on September 15, 2020 08:48am

morning!
soo, im on the learning curve with hot hide glue, and im really liking it.
but i have a problem thats driving me a little nuts. when i do a bookmatch i lay one piece down and hammer it flat, then overlap the second piece and glue it down, using a straightedge i take a xacto knife and make a careful seam cut, take away the cutoffs above anad below. then lay the seam down flat. come back in about ten minutes and the seam liftslike a small tent and wont lay down flat again! it appears the two leaves continue to “swell” pushing the seam up.
so, for those experienced and in the know, whats going on and how do i fix it and more importantly , how do i do it right?
regards
eric

Replies

DRBWWing | Sep 15, 2020 09:45am | #1
Is it actual hide glue or Old Brown Glue? I've had this happen with OBG.

Recently I did a crotch mahogany top and the same thing happened, even though the veneer was softened and the seams were perfectly tight. I initially thought I hadn't squeezed the glue out but I concluded (right or wrong) it was the glue and the fact I didn't have clamping pressure right over the seam.

It can be fixed by applying heat and clamping with cauls.

The veneering I've done so far, its become quite apparent I need to invest in a vaccuum press.
lat_axe | Sep 16, 2020 07:02am | #2
That's very interesting about the Old Brown Glue possibly being the cause of the veneer swelling a bit more. Presumably the OBG is liquid at room temperature because it has extra water in it (compared to hot hide glue) that slowly evaporates once the OBG is taken out of the bottle and applied to some work, so it then sets ........? If so, that extra water might be the source of the veneer swelling.

Patrick Edwards is it who makes Old Brown Glue? He has some really good info here on the FWW website and may even answer a question if he notices it ......

Lataxe
DRBWWing | Sep 16, 2020 10:47am | #3
Just to be clear as I stated, right or wrong, I am wondering if anyone else has an idea it could be the glue.

It is a good product I've had good results with it every where else.

As I mentioned, too, I'm not sure my clamping was adequate along the seam line.
Ejc | Sep 16, 2020 01:05pm | #4
old brown glue is great stuff and i use it for joinery, but for veneer ive been using hot hide glue. i think i may have found the problem, but still not sure.
i made a new batch of glue and tried it this morning, seemed better. i think the problem was the glue was too thin, too much water. the thicker glue did not have the same problem.
[email protected] | Sep 16, 2020 04:30pm | #5
When joining veneer i was always taught to first join the two pieces with a small amount of white glue.You do this by placing the underside together and holding it with blue tape.Flip it to the face side ,bend at the seam,apply white glue and fold it back. use stretchey electrician tape to pull seams tight where necessary.When dry,say 20 minutes,carefully remove blue tape from the back and glue the veneer down .Remove electricians tape first