[lstodd]

If you absolutely need a joint to not fail before the wood, use epoxy, mix in some glass fiber cuttings. It's indestructible to the point I wasted considerable amount of sandpaper sanding off a joint I needed to remove. Nothing else would so much as cut it.

PVA ("standard yellow carpenter's glue", titebond, etc) is much weaker and moisture kills it over time.

[jimnotgym]

Epoxy comes at a serious cost

1) It costs a lot of $ to begin with

2) Everything you apply it with is ruined within minutes

3) It can cause terrible dermatitis (always wear multiple pairs of nitrile, not latex, gloves). You can become sensitised to the point that you cannot share a room with sanding dust from it!

4) It's open time is short and varies according to the batch size due to the heat it produces. This means you have to spread large batches out in a tray to lose heat or it goes suddenly hard, or indeed melts your tray!

5) Clean up is nigh on impossible. Normally you are left chipping and sanding what is left

6) It has poor resistance to UV light

7) It leaves a residue that can stop paint sticking

8) It is unsuitable for thin glue lines like are used in furniture and traditional joints

But yes it is phenomenally strong and water resistant.

A better glue for joinery is polyurethane, especially the titebond stuff.

[lstodd]

Yes, there are drawbacks.

I'd say multiple pairs of gloves is overkill, plain medical latex ones do just fine for me. Just don't mix or apply it with a finger.

Open time of modern ones is acceptable, Many times I found myself waiting for it to get more sticky than otherwise. And heat is of no concern for joints.

For point 8 I'm not sure what are you talking about. It's great for thin-layer joints, that's where it actually excels.

Never had any problems with UV, but maybe because it was always painted over (and what's the problem with painting? sand it a bit, that's taken as granted as even epoxy itself won't stick to unsanded epoxy)

Besides, knowing you won't be able to get it off once it gets on something trains concentration and fine motor control :)

As for $ well, it costs a bit more, and time spent on weighing and mixing is well over any cost difference in raw materials. Still in the end you get a joint that'll be the last thing that fails.

[jimnotgym]

I used to work in a chemical factory and the head buyer wouldn't have latex gloves in the building, because they are so porous, so no use nitrile or neoprene. Maybe this link will change your mind about the risk of epoxy exposure[0]. There are loads more if you google it. I read an article once about a poor chap who had to wear an NBC suit to finish his boat.

Open time is not an issue if you are mixing enough for a chair leg, but if you were mixing enough to glue a large lamination it kind of sucks when it smokes in the pot and then goes instantly hard or melts your glue pot[3]. Equally if you were trying to glue up a set of stairs, for instance, you would need a helper just to mix the glue fast enough.

point 8. It shows a glue line in thin laminations [1]. I struggle to get where you are saying it 'excels' at thin joints, in fact the main selling point with epoxy is that it is the only wood glue that is strong across a gap. That is where it excels, loose joints and fillets.

> and what's the problem with painting?

It is called amine blushing.Sanding won't do, it has to be washed off [2]

> Besides, knowing you won't be able to get it off once it gets on something trains concentration and fine motor control :)

Buying new rollers, brushes, tubs for every single joint gets old really quickly if you are a pro user. Again fine if you are gluing a chair leg, a pita if you are glueing large joints.

> it costs a bit more,

It costs a lot more! Titebond in bulk is £10 a litre. West system large packs are nearly £50 a kilo!

> Still in the end you get a joint that'll be the last thing that fails.

Is that always a good thing? Wood moves around a lot and sometimes it can crack a glue line that can just be reglued. With epoxy your wood will split instead.

Epoxy has some amazing qualities, gap filling and water resistance in particular. In a hobby shop it might be worth the hassle, in a pro-shop almost never.

[0]:http://www.fram.nl/workshop/controlled_vacuum_infusion/aller...

[1]:http://www.woodweb.com/knowledge_base/Glue_Choices_for_Tight...

[2]:https://www.epoxycraft.com/amine-blush-what-you-need-to-know...

[3]:https://www.epoxyworks.com/index.php/big-batch-mixing-method...

[lstodd]

Well, we must have completely different applications in mind then.

My experience with epoxy is building boats. Mostly spruce stock and birch plywood, fibergrass all around for surface protection and stiffening; 12-16 meters length.

Can't call this a pro operation, there's that.

Still in my experience, thin epoxy joins are the strongest.

We've tested spliced plywood to destruction - not once did it fail along the joint; delamination across factory glue was always the case.