Flexible and Strong Wood Glue

Jay Caughron said:

Welded Aluminum WILL crack guaranteed that is why you see aluminum stock trailers and truck trailers in the repair shop all the time they just wont hold up to shock. Thats also why you dont see welded up alum Aircraft except Eclipse it is fusion stick welded which is really cool to watch

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Yeah, most planes are glued, screwed and pop riveted together.

Titanium would be nice too, but the artists don't want anything but wood, and they want a specific wood, the wood they have been using all their lives, beech wood.

Frank Fusco said:

My first thougth: NOT CA
There are many kinds of epoxy glues. The ones used on fiberglass boats comes to mind. They take a lot of pounding and flexing.
Second thought: Does the chair have to be made of wood? How about a white durable plastic. Delrin, with proper sealant would last and last. Of course, that way you would not get repeat orders. Delrin would flex without weakening or breaking.

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The more I look at this the more I think I'm going to go with Titebond II or III for the wood joints, I might use a flexible epoxy for where the metal pieces attach to the wooden chair, right now I understand it is only screwed in place, and eventually the screws loosen, and cannot be tightened. They are aware that there is a shelf life for all of this stuff, they just want to make it as long a shelf life as can be.

Cheers!

Hey Stu try some unidirectional fiber glass with epoxy under the metal bracket that should help with movement. Something like they do with Fiberglass home built Aircraft

Better not build it to last forever or you'll build yourself out of a job

Charlie Plesums said:

...Why did I buy so much? This is stupid logic, so you can skip my rambling. I figured that I needed more than a 5 pound pail for a large table veneering job. 5 pounds was $25, and since I wasn't sure how much more than 5 pounds, I am in for $50 for two buckets. But for $80 I can get 25 pounds, AKA lifetime supply. You can guess what I did.

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Have you run into any shelf life issues with the powder, Charlie? I know the DAP stuff has a somewhat limited shelf life (a couple of years or so, as I recall). I had some once that seemed to get old on me. It didn't dissolve well when mixed with water, and the glue ended up feeling like syrup with fine sand in it. The bond seemed to be weaker too, but I didn't do any specific tests.

Vaughn McMillan said:

Have you run into any shelf life issues with the powder, Charlie? I know the DAP stuff has a somewhat limited shelf life (a couple of years or so, as I recall). I had some once that seemed to get old on me. It didn't dissolve well when mixed with water, and the glue ended up feeling like syrup with fine sand in it. The bond seemed to be weaker too, but I didn't do any specific tests.

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The original bucket I was given was nominally expired (even though it was a plain bucket with no label), but I did some testing and it met and exceeded every expectation, so I used it routinely without problem. When I got the new supply, it looked and acted the same as the "expired but perfect" stuff the other woodworker had given me. The powder is in a closed plastic bag with the air squeezed out, inside a sealed plastic bucket, so I am pretty confident it isn't materially degrading.

I suspect it is like most glue - specifically PVA (Titebond). The official shelf life is only a couple years, but the chemist who invented it was on a forum quite a few years ago, and said that "if it gets thick, just add water, but if it forms clots, discard it" I don't remember what word he used for clots, but I do remember it made me think of blowing my nose. I have had PVA glue MANY years without getting clots, although there is one container (colored Titebond II) that I need to check...

Charlie Plesums said:

The original bucket I was given was nominally expired (even though it was a plain bucket with no label), but I did some testing and it met and exceeded every expectation, so I used it routinely without problem. When I got the new supply, it looked and acted the same as the "expired but perfect" stuff the other woodworker had given me. The powder is in a closed plastic bag with the air squeezed out, inside a sealed plastic bucket, so I am pretty confident it isn't materially degrading.

I suspect it is like most glue - specifically PVA (Titebond). The official shelf life is only a couple years, but the chemist who invented it was on a forum quite a few years ago, and said that "if it gets thick, just add water, but if it forms clots, discard it" I don't remember what word he used for clots, but I do remember it made me think of blowing my nose. I have had PVA glue MANY years without getting clots, although there is one container (colored Titebond II) that I need to check...

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I'll bet the plastic bag helped maintain the glue freshness quite a bit.

And I agree with you on the PVA glues, I've got some that's been going for years, but I'd also had some that clumped up and became unusable.

I think the best option is a composite material. You can get fibers to embed in epoxy: the combination will stick well and be tougher than anything else. An epoxy matrix with glass fibers is pretty far from brittle. I don't recall what material is used for the microfibers commonly mixed into epoxy for use as glue. If you contact one of the companies that sell a range of types of high quality epoxy, you can get good advice on what will fit your application. System Three and West are among these companies. I have had excellent results in different circumstances with at least 5 different System Three epoxies, and they have lots of good info available on their website.

You might even want to consider encapsulating the wood inside fiberglass/epoxy, as is done with woodstrip canoes. It looks like wood, and is very strong.

Alan Schwabacher said:

I think the best option is a composite material. You can get fibers to embed in epoxy: the combination will stick well and be tougher than anything else. An epoxy matrix with glass fibers is pretty far from brittle. I don't recall what material is used for the microfibers commonly mixed into epoxy for use as glue. If you contact one of the companies that sell a range of types of high quality epoxy, you can get good advice on what will fit your application. System Three and West are among these companies. I have had excellent results in different circumstances with at least 5 different System Three epoxies, and they have lots of good info available on their website.

You might even want to consider encapsulating the wood inside fiberglass/epoxy, as is done with woodstrip canoes. It looks like wood, and is very strong.

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Thanks for the input Alan.

Epoxy here in Japan is a bit of a hard nut to crack, the cheap simple stuff you can get but it all dries rock hard, the higher end stuff exists, but it is used mainly in industry and when I've found someone who will sell it to me, it is usually in large formats that I'd never use. I know that most of the epoxies will not ship overseas either.

At this point I'm fairly sure I'll go with basic Titebond II or III but I might also try some Plastic Resin Glue like Charlie and other have suggested. I've read that it is as strong as the yellow glue with the added benefit of a very long open time, which when you are putting something like a chair together would be nice.


We shall see.


I went down to my wood supplier Nakajima Company to see about the price of Beech.


The owner's son who I usually talk to was busy, so I was talking to one of the workers and he was showing me some European Beech, all about 3M (10') long and from about 20cm to 25cm (8" to 10") wide and from 27mm to 66mm (1-1/4" to 2-1/2") thick.


Even the thickest boards they had would not be thick enough to make the two rear legs and back rest pieces of the chair, I need something closer to 70mm (2-3/4") square to make that leg. OK, I thought, I'll just have to glue up two pieces. Then the owners son comes over and we start chatting, I show him the picture of the chair and the blueprints and we talk about the options, then he sort of goes "Wait a minute, a chair...?" and we go over to a different part of the storehouse and there are stacks and stacks of pieces of wood there from about 1" square and 18" long to a full 3-1/2" square and 30" long.... Perfect, I say, what is the wood, he say European Beech, I ask what the pieces are for, he say "Making chairs" we had a good laugh.


Much cheaper than flat long boards too, and they are completely clear, as they are for chairs, good solid straight grained beech.


When I was about to leave he pointed to some wood and asked if I ever use Oak, I said that I did not use much of it, she showed me some European Oak, that was about 6" wide 5/4 thick and maybe 10' long, some of it he had sliced down the middle so it was now about 2/4 thick, he gave me one piece as it was from the outside of the stack and had some stains on it.







Not much of a piece, but is sure has some nice rays in it, the piece I have was about 10' long, 6" wide and 1/2" thick, but to store it easier I cut it in half, so two 5' long pieces. I'm sure I'll find some use for it.


Just a little update.