Thread: Poyurethane glues

Have a read of this -
http://woodgears.ca/joint_strength/glue.html
http://woodgears.ca/joint_strength/failures.html

I did a few tests some years back with poly but wasn't over impressed. My fav was Triton PVA, in the destruction tests I did it caused the most destruction but then tey went bust. I have now gone to Titebond Original for my normal work and AV XL Plus (now a bostic product) for my water resistant jobs.

Here's some more articles. The one I was looking for I couldn't find. It compared epoxy, pva and poly weathering and I seem to recall that it wasn't a glowing report on poly (I think). Funnily enough I had exactly the same experience as you yesterday. I edge jointed and glued two pieces of greenish timber together with Titebond poly for a seat blank and noted the difference between the Selleys product and Titebond too. For my application, glueing wetish wood long grain to long grain it seemed ideal. Removed clamps and worked on it (planed flat and hollowed seat) after just 2 hours. The glue line is absolutely invisible. Subjectively, it seems like a superior product to the selleys.


Popular Woodworking - The Truth About Polyurethane Glue

Best Wood Glue - Wood Glue Showdown [audiojunkies]

Cheers
Michael

Thanks to all who replied here. The quoted references seem to be unanimous that the poly glues will be outperformed by many of the other types. I think I will keep it for any low load, gap filling jobs I come up with!!!

Yes mspil, that looks to be the main use for it. All the links were very interesting and confirmed my own thoughts, nice to hear it all from someone else and not be wondering if you were doing something wrong or is it just me??

I think I will keep it for any low load, gap filling jobs I come up with

Take a look at epoxy with wood flour or (preferably) glass beads for gap filling, the west systems or botecoat product sheets.

Hi mspil
I went down the poly path and now I only use titebond 3.
cheers
conwwod

Originally Posted by mspil

Thanks to all who replied here. The quoted references seem to be unanimous that the poly glues will be outperformed by many of the other types. I think I will keep it for any low load, gap filling jobs I come up with!!!

Poly glue is also dreadful stuff if you get it on your hands. It is however
useful for other non timber applications. I have had success with a variety of materials and it seemed to hold better than epoxy when gluing some plastics.

Originally Posted by mic-d

For my application, glueing wetish wood long grain to long grain it seemed ideal. Removed clamps and worked on it (planed flat and hollowed seat) after just 2 hours. The glue line is absolutely invisible. Subjectively, it seems like a superior product to the selleys.

Just an update on how the project involving polyurethane glue finished up. This is a photo of the finished stool.
Attachment 137287
And in this photo you can just where the boards are joined running from approximately 1.30o'clock to 7.30 o'clock. I would call that an invisible glue line.
Attachment 137288
After a number of days glued (max strength is supposedly reached in 4 hours) I decided to strength test the joint by levering on the legs. I hardly squeezed them at all and pop, this is the result. A very very thin layer of glue mostly attached to one edge, a small amount on the other, and absolutely NO grain tearout whatsoever.
Attachment 137289Attachment 137290
The edge was freshly jointed and gap free, I gave both surfaces a wipe with a damp rag immediately prior to glueup as per instructions. I can't see that I did anything wrong and yet it failed. I will clean up and reglue with PVA. I have 2 big bottles of titebond2 to get through so that is what I will use. But for an application like this where it might end up outdoors titebond 3 would be the best choice.

cheers
Michael

My experience with PolyU seem to indicate that it is fantastic. FAR outperforms PVA - but then, maybe I am doing something wrong with the PVA.

Anyway, I would rate it very highly.

I also use the West System Epoxy for big glue ups - but use the Selleys PolyU for quick glue ups.

Cheers

Cam

Originally Posted by mic-d

Just an update on how the project involving polyurethane glue finished up. This is a photo of the finished stool.
Attachment 137287
And in this photo you can just where the boards are joined running from approximately 1.30o'clock to 7.30 o'clock. I would call that an invisible glue line.
Attachment 137288
After a number of days glued (max strength is supposedly reached in 4 hours) I decided to strength test the joint by levering on the legs. I hardly squeezed them at all and pop, this is the result. A very very thin layer of glue mostly attached to one edge, a small amount on the other, and absolutely NO grain tearout whatsoever.
Attachment 137289Attachment 137290
The edge was freshly jointed and gap free, I gave both surfaces a wipe with a damp rag immediately prior to glueup as per instructions. I can't see that I did anything wrong and yet it failed. I will clean up and reglue with PVA. I have 2 big bottles of titebond2 to get through so that is what I will use. But for an application like this where it might end up outdoors titebond 3 would be the best choice.

cheers
Michael

ermm forget first unedited post I just removed
Did you use enough glue? From the pic looks like there wasnt enough glue in the joint?

Hi Dean, I put plenty of glue on both sides and had plenty of squeeze out all round. I only nipped the clamps up.

Cheers
Michael

Originally Posted by mic-d

Hi Dean, I put plenty of glue on both sides and had plenty of squeeze out all round. I only nipped the clamps up.

Cheers
Michael

Hmm ok just looks like glue only really penetrated one of the mating faces and not the other?

Originally Posted by Dean

Hmm ok just looks like glue only really penetrated one of the mating faces and not the other?

Certainly didn't penetrate one side very well.
Cheers
Michael