Thread: Any tips for laminating spotted gum?

Acetone is your friend....lol. A quick wipe over surfaces to be glued immediately before applying adhesive.

I've had good success with Titebond II on freshly planed surfaces. It's a cross linking PVA glue so I imagine other cross linking PVAs would work as well.

For stair building with spotty this was used for good reason:
http://www.timbatechsolutions.com/up...lyurethane.pdf

As Mr. B says, fresh surface, quick wipe with a generous serve of acetone, and glue as soon as it's dry.

Originally Posted by springwater

For stair building with spotty this was used for good reason:
http://www.timbatechsolutions.com/up...lyurethane.pdf

They look like a useful supplier. Checked the TimbaTech website, and they have a very wide range of specialty adhesive products

RB

Ditto the foregoing comments and lots of clamping pressure with those glues.

Regards
Paul

Thanks so much everyone! Super helpful 😄 I didn't know acetone was so handy, I have heaps around for when I use CA, so that's awesome! Really appreciate the advice.

I'm not super experienced with australian hardwoods other than I try to avoid them for anything furniture related... What I do know is they move after they have been milled and ready for glue up, and nothing will stop them if they decide to move. And it doesn't matter what glue you use, if they start warping again the joint will pop.

So mill it all and then let it sit for a month and see if it's still flat. If it warps/moves then flatten again and it should be good to go. For gum wood I wouldn't use a cross linked pva glue. They're strong but I suspect over the years they will let go with the gum wood. It would be a cascading effect. But that's based upon my knowledge of gum woods, which is not much because I avoid them. I'd be going with a good quality epoxy with a bit of sawdust for a matrix. No matter what glue you use, give the surfaces a wipe with some new 80 grit. It will score the surface - all glues desire a scored surface.

It was said here that you should crank the clamps down really tight. My recommendation is you don't do that. It will squeeze out the glue and you'll end up with glue starvation. With softwoods and most northern hemisphere woods you can wrestle them into submission but aussie hardwoods - nope. You will flex the wood, which will introduce stress that down the track may pop.

Hard to describe the right pressure in writing but don't white knuckle the clamps as you tighten them down. But also remember, if you don't get a fair bit of squeeze out you may have put too little glue on. Might be in your favour to crack the joint and put some more glue in there and clamp it all back up.

YMMV

Spotted gum can sometimes be a problem particularly if it is a dense and oily piece. It varies significantly. I’ve had the most success using polyurethane glue (froth glue as we call it). It foams up in the presence of moist air.
Don’t over clamp the joint. Rather, the joint should be well fitted and then glued and firm but not over clamped.
Epoxy or PVA glues may fail. Not always but the risk is there.
All the best.
Pete.

polyurethane glue all the way. The others will always creep at the joins.

Originally Posted by The Spin Doctor

It was said here that you should crank the clamps down really tight. My recommendation is you don't do that. It will squeeze out the glue and you'll end up with glue starvation. With softwoods and most northern hemisphere woods you can wrestle them into submission but aussie hardwoods - nope. You will flex the wood, which will introduce stress that down the track may pop.

SPD

On re-reading my post I realise I wasn't clear.

My comment on clamping pressure related to PVA glues such as Titebond, to quote one brand name. The recommended clamping pressure for Spotted Gum is 1000KPa and temperatures above 20°C using PVA style glues. Probably needless to say, but the timber should be well seasoned too. Certainly epoxy glues should not be clamped up hard as they are a gap filling glue and rely on a significant amount of product to achieve a sound bond.

I can't speak for the polyurethane glues as my experience with them is very limited. The only comment I have there is that I was completely unable to store the product as it went hard in the containers very quickly and I vowed never to use it again. Perhaps if you purchase only enough for the immediate job at hand....

Returning to the original post I note that one handle will be exposed to the elements. Epoxy glue has better water resistance than the other two products. It is the one the boat builders use.

Regards
Paul

Reading a few replies here and doing so digging I'd say polyurethane glue would be the go. I've always been a bit suspicious of it in that I didn't know anything about it's lasting quality over decades. I know epoxy well and for the most part pva and uf109 but poly was a mystery. So I looked it up. Stuffs been around since the 1930s and used a lot in Europe, so I'd say that's a pretty good endorsement.