Thread: So there are other glues...

Originally Posted by Onezero

Newbie here! Since high school I have only ever used either standard Aquadhere or no-more-nails to glue wood together.

Seems as though I might be missing out on something better.

At the moment I am making storage boxes for kids toys from ply and a set of draws for work, also from ply!

Before going to the big green shed, I wanted to ask people who know something, because no one there does!

Could I be using something better? I see on youtube blokes using puss coloured glue. I am assuming 'yellow glue'.

The best glue for wood is 'selleys platimum', it is a polyurethane glue which cures with moisture, it expands and creeps into the pores which makes it very strong, it dries hard but more importantly is still flexibile, it is much better than any of the 'runny' polyurethane glues which are sold as wood glues, PVA and it's variants don't even get a look in.
It isn't very popular because it isn't marketed as a woodworking glue by Selleys and worse it comes in a silicone style cartridge, so it doesn't look like a wood glue in the shop.

I agree the poly glue is better but you need to spray the surfaces with water before glueing to make it go off. I'd use it if I was making a new window frame as its also ok with water. So if its outside I'd use it. But for ordinary stuff PVA is ok, But make sure its a reputable make selleys, norton. Don't buy those 1 dollar ones from the junk shop. Yellow glue isn't much difference, they just put a dye in it to tell you its a quality glue (this came from carbatec MEL before you start yelling at me). So a toy box for a kid just keep using what you got.

I have been through a lot of glues and done destruction test and I now generaly use Selleys External Aquadhere on everything. Cheaper than many and very effective. I have done destruction tests with polyurethanes and they are only good for limited joints and situations.

Thanks everyone for the input. Am using Aquadhere at the moment and have a $1 of PVA on the shelf, think I bought it for the school kids paper mache.

Will pick up some Sellys stuff and give that a whirl.

Once you get to PVA adhesives (Aquadhere, Titebond, Aquadhere Exterior, Titebond II), you've hit the 'generally stronger than the wood it is on' point.

After that, the glues have particular specialities which suit them to particular uses.

The drawback of normal PVA is that if the join is loaded, the glue will creep over time - this makes it a poor choice for bent laminations or other uses where the assembly permanently stresses the glue line.

The polyurethanes (typically a dark yellow colour, and they foam up while setting) add considerable water resistance to the join and have some gap filling ability; but the foamy glue isn't all that hard so while they fill the gap, its not a particularly strong filling method. They tend to have a limited shelf life - about a year or two.

After that, it's epoxies, which as well as being as waterproof as plastic (because epoxy is a plastic when cured) give you the ability to control both the colour and thickness of the adhesive, as well as being an excellent gap filler (Want a strong filler? Add aluminium powder. Not incompressible enough? Add granite powder. Need something that sands well? Wood dust or flour.)

Shelf life is pretty well unlimited (there's a thread somewhere here where someone had some from the 70's that was still ok. I've got some from the late 90's that's still fine.) Oh, and they make ocean going wooden yachts with epoxy (and no fasteners).

Then, there's hide glue, an ancient glue with some delightful properties - it is the only glue on the market that is reversible. Steam or hot water will soften it enough for disassembly.

Another unique feature is that hide glue is the only glue that will stick to itself, so regluing doesn't need laborious removal of all the old glue first.

In pellet form, hide glue will keep for ages; heated and mixed...well, it's good for a day or three; after that, let the dog eat it.

Master Splinter has said it very well, I think. Just a couple of points I'd like to add:

1. ALL glues are potentially 'stronger than the wood', however, there are some caveats. The glue line has to be vanishingly thin, in most cases, i.e. a very close mating of glueing surfaces is called for. Gap-filling glues have their place in the scheme of things, no doubt, but I've never had any use for them. IMO, if the joint is well made & appropriate to the purpose, any respectable (wood) glue will stick it satisfactorily.....

2. Hide glue is wonderful stuff & I use it all the time, but it isn't for everyone, nor is it ideal for every job. I use hide glue for furniture that I hope will last a lifetime or two, which means it may need repair at some stage. It's strong, has a quick grab, and is very reliable if used correctly, but it does have a short open time, and if not used correctly, you can get a very weak bond. It does deteriorate quickly once mixed, as MS says, because it becomes contaminated by fungi & bacteria, which chop up the long proteins needed to form the solid glue. You can allay this to a large extent by covering the glue while it's still hot & letting it stay hot for a few minutes before allowing it to cool (I use a wax pot, which has a close-fitting lid). With scrupulous care, a mix could last indefinitely, but it's not really practical, & best to make very small lots and use it up each day - not hard to do once you get used to it. Its strength (being reversible) is also its weakness, as it does NOT like moisture. Mositure softens the glue, but it still has quite a bit of holding strength until it becomes very soft; the real danger is that it allows micro-organisms to do their thing, & over time, the glue wil deteriorate irreversibly.

Despite the inflated claims of some manufacturers, the perfect glue has not yet been invented, & probably never will be. I think there is a place in every shed for several duifferent types of glues. I use PVA for all utilitarian jobs, because of its sheer convenience, long open time & relatively quick cure time. I use epoxy or melamine glues for joints that are going to be stressed (joining boards for Windsor chair seats, for e.g.) or subject to moisture (like a vanity top). I use 'super' glue on rare occasions, and would probably use it more if I was a dedicated turner - good for mending small cracks & so on. And even more rarely, I have been known to use 'hot melt' glue for temporary tacking jobs, but it would have to be one of the least useful adhesives around my shed......

Cheers,

There is no one 'best' glue - it's horses (or in the case of hide glue, horse sauce) for courses.

Between Master Splinter and IanW, you couldn't have a better tutorial. The only thing I would add is that epoxy can give you a longer working time, but goes off quicker in hotter weather.

They'll be the best glued toy boxes on the planet

Another glue is the urea formaldehyde ones which also have their place. You can vary the flexability with the addition of PVA and put fillers in it! Can all get a bit technical. And I think isn't easily available in small quantities. It gets hidden on the shelves at Bunnings. That's if they even still carry it.

I use Titebond II & Titebond III exclusively in my furniture and boxes. Very good stuff!

I haven't seen Selleys 308 (urea formaldehyde) on the shelves of local hardware stores for years. I've got a half used box of it somewhere, but it would have to be at least a quarter-century old, so I hope it keeps well! At least it has a better chance of keeping than the three year old bottle of Selleys polyurethane, which is probably a solid lump by now.

I'm also using ply to make some storage shelving for the back of the 4wd and will end up covering most surfaces with marine type carpet. I've been debating whether to use an epoxy or if a PVA would do the job. I like the idea of the epoxy but only know of the marine versions such as Bote Cote, not cheap.

Any advice one where to source some decent epoxy (I believe there are glueing epoxies and coating epoxies, both with different properties) without breaking the bank? Also thought this method would be more forgiving as I don't have many clamps. The joints are pretty good so could use screws?

Thanks, Indie.