Elmers Polyurethane Glue Question

[NorthIdahoWWer]

This is the first time I've used poly glue of any kind. I'm gluing 2 fir beams together then laminating them with 3/4" oak to create a vertical post for a stairway/landing. I glued the fir beams together yesterday with one bead of glue, dampening both parts as per instructions. After a few hours, I noticed the lack of the foam that's supposed to appear. I removed the clamps only to have the 2 beams come apart with the glue dried in between. I re-dampened the beams, used the equivalent of about 3 beads, in a squiggly pattern down the length of the wood then clamped and allowed to dry overnight. Still no foam this morning but the wood did seem to hold and a chisel driven at different points didn't seem to make the wood separate. Being still paranoid, I will use good ol' Elmers wood glue to laminate on the oak.

So my question is, did I do something wrong? Why is there no foam? I've searched the group on google and didn't find this exact problem.

Thanks,

Will

[Unquestionably Confused]

on 4/13/2005 1:03 PM NorthIdahoWWer said the following:

In the first instance I'm wondering if the wood was cupped, etc. and not in contact. Sounds really strange that you would have NO glue joint as opposed to a weak one in the situation you describe.

Had the glue been opened prior to this? I haven't had that much experience with the polyurethane glues other than once or twice with Gorilla Glue and it performed as advertised but then it was a new bottle.

I'm told that this stuff has a shelf life of ~ 6 months max once opened unless you do something to evacuate the air in the bottle. Whether it's wet or not it should expand, no?

Finally, I don't know that I'd even bother with poly for the project you describe. Using this as a vertical post is not going to subject the joint to much stress. I think I'd probably just get a good smooth surface with the fir beams, glue and nail them up and then glue the oak facade to the resultant post and be done with it. Titebond/Titebond II should be more than adequate for your needs.

If one end of the post is going to be sitting on a concrete floor (basement, maybe?) I'd seal it well and maybe even melt some wax on it to prevent its wicking up moisture from the concrete or a minor flooding.

[NorthIdahoWWer]

Full contact. The boards were run through the planer.

No, brand new bottle

It will be on the main floor, sitting on T&G Fir planking

[Unquestionably Confused]

on 4/13/2005 1:44 PM NorthIdahoWWer said the following:

Strange.

Sorry, I have no answer for your original question then. My thoughts on the necessity of poly hold true in light of the balance of the message. Done properly, a glueup with Titebond, any Titebond, will be stronger than the wood itself. I didn't believe it until I tried it myself.

[Scott Lurndal]

You stated that you placed a single bead on the face of the fir before clamping the first time. Did you spread the bead so that glue covered the entire surface, or did you expect the clamping pressure to redistribute the glue? What were the dimensions of the face of the board, in particular what was the width?

[Hax Planx]

I just tried Elmer's urethane glue for the first time last night. I'm making work stands for various tools out of 2x2 poplar with loose mortise and tenon joints. It started foaming less than 15 minutes after applying it. I wiped it all off once, but it kept coming back. I didn't use any water in the joints, partly because it was raining and humidity was 100%. I checked them just now, and the joints seemed solid as a rock.

[Steve Knight]

it sounds like it was not spread. you get a little bit of adhesion from the glue migrating but it is not very strong. It needs to be spread so you have a shiny layer over the whole surface. then you can clamp it up. it's like any other glue in that way but you only need to do one side.

[NorthIdahoWWer]

I was assuming that the foaming action would make the glue cover the area. It was a 2.5" wide board. Thing is, the instructions are very sparse on the bottle. It just says to dampen both surfaces, says nothing of spreading. Even Elmers' website gives no details on how to use the glues.

Will

[Unquestionably Confused]

Well, now you know but that still leaves the question of non-foaming, non-expansion. There should have been some and there wasn't if I read your post correctly.

[Australopithecus scobis]

1) Whoops. 2) Do you wet the other side, or the side the glue goes on?

[NorthIdahoWWer]

[Steve Knight]

if your working with oily woods it's best to do both sides.

[Scott Lurndal]

The single bead would have had very little surface area to contact moisture on the wetted surface. Not getting foaming in this case is perfectly understandable.

Use a small (3" x 5") piece of formica to spread the glue in a thin layer over one piece and wet the other with a sponge so that the entire contact area is moist. As Steve pointed out, for oily tropicals wet the surface that you spread the glue on before spreading the glue.

[Unquestionably Confused]

I can't speak to Elmer's as I've never used it. However, I have used Gorilla Glue both with and without moisture (other than ambient) and that stuff was like that foam insulation, it was all over the place.

If Elmer's glue is compounded differently, I withdraw the question.