Thread: Wrong wood? Wrong glue? or bit of both.

Its not the wood, its the glue. PVA glue will creep under a constant high load especially at elevated temperatures.

Interesting repair method; I've seen whole soles replaced and inserts put in to close up a mouth but never the joins of a laminated plane!

The plane is too good to throw away and chalk up as a learning curve so I hope the repair is fully effective.

Originally Posted by Bohdan

Its not the wood, its the glue. PVA glue will creep under a constant high load especially at elevated temperatures.

PVA isn't a particularly good choice for laminating planes in our climate, alright, John. Some creep more than others, I've found, but the safest course is to use a non-creep glue like epoxy for any joints subjected to constant stress. I suppose you are beating yourself up for leaving it under tension, but it's an easy thing to do. The number of times I've noticed my bandsaw still tensioned several days after I last used it is embarrassing!

By the way, the link to the plane-build in your initial post wouldn't work for me. I think this is this what you pointed to?

Cheers,

I should have known better than use PVA but having watched so many clips on plane making where they use it sort of swayed me. I've a few times cautioned others against PVA as I know it can creep under stress. I guess I just had a lesson on how much stress it takes.
I learned a lot building the plane and it's still teaching me things. Another hot humid summer will tell if the wood itself is ok so fingers crossed.
Ian,
Yes that's the one thanks.

Regards
John

I never use PVA in planes, but I guess the only part of a plane that I glue is the handle. That prevents having to deal with delamination, but it certainly doesn't eliminate plane movement if the wood used isn't sawn perfectly.

I have heard of people using epoxy in infills (obviously, PVA glue wouldn't work there). There is a good case for hide glue in your next laminated plane. It's hard and can be easily taken apart or repaired.

I have a feeling you will be doing some adjusting again. Is there a chance that you could find an attractive contrasting wood (or even brass) and run pins through the plane so that the sides and center cannot move at drastically different rates?

(Re: your comment about others freely gluing planes and all kinds of things with PVA glue, I've noticed the same thing. I've seen a lot of videos on youtube of people doing that with tools or in some cases, pieces of woodwork that are intended to be heirloom. Various versions of hide glue have such a long history of use and a long history of service between repairs that there's no great reason to use PVA glues on anything that's expected to last more than a couple of decades without strain. )

Hmmm... I suppose this is a dumb question - but what PVA glue did you use? Elmer's white glue, Titebond I, something else?

The white glue flavor of PVA is known that its a WHOLE lot more temperature and humidity sensitive than yellow woodworkers glue... It also cold creeps a whole lot more..

Yellow wood workers PVA is used for all sorts of things that live under considerable stress and it holds up well.... Its commonly used on string instruments that routinely see 100-300 lbs of string tension... The glue joint failures we do see on instruments are generally due to poor prep, a poorly fitted joint, wet wood, not enough glue, or too much open time while finding/jockeying the clamps - not glue...

The main reason I use epoxy is because it doesn't cause the wood to warp from a lot of water going into one side of it....

Have heard leatherwood referred to as "propeller wood" by some in the industry in down here. Ie. if a green board isn't well weighted down when you rack it that's what it will turn into. It is possible that the leatherwood could have moved over summer. Your problem may be a combination of both glue and wood movement.
Tony

Originally Posted by truckjohn

.....The white glue flavor of PVA is known that its a WHOLE lot more temperature and humidity sensitive than yellow woodworkers glue... It also cold creeps a whole lot more....

John, as I said, some are worse than others, but all of them are thermoplastic. You can use yellow glues to make 'iron on' veneer, just to prove the point. I guess you don't get weeks on end of high 30s/low40s (i.e. 100 plus on your scale), where you live? Like orraloon, I've had a few unhappy experiences using PVA glues, both before & after I knew I really shouldn't have used it in that application.

Originally Posted by truckjohn

..... Yellow wood workers PVA is used for all sorts of things that live under considerable stress and it holds up well.... Its commonly used on string instruments that routinely see 100-300 lbs of string tension... The glue joint failures we do see on instruments are generally due to poor prep, a poorly fitted joint, wet wood, not enough glue, or too much open time while finding/jockeying the clamps - not glue...

But how much glue area is the force distributed over, and at what typical ambient temperatures? Glue can be 'soft' but still hold, if not subjected to enough force to get them moving. I remember reading about the Mosquito bombers, which relied on a lot of glue joints sticking together, to stay in the air. Someone decided they better check if the protein-based glue they were using was holding up in the ones they were using in the humid tropics. It was, but only just! They decided it might be a good idea to use something that was a bit more water resistant, in future..

Using hide glue is a pita in many ways, but it is creep-resistant at all but extreme environmental temperatures, & has that virtue of being relatively easy to get apart when necessary. Like D.W. I wouldn't use anything else on a piece of furniture I expect (hope!) will last a generation or three. I'm always surprised to see people using pva or other 'permanent' glues on musical instruments. I would have thought such pieces were also intended to last a few generations, and would inevitably need repairs or attention somewhere down the track? Where would we be if Stradivari had used PVA?

Cheers,

Perhaps this thread should have gone in the Glue section. I used Selleys aquadhere exterior thinking it was a step above the common PVA. I guess convenience also played a part as all you do is squeeze it out of a bottle. No mixing required(note to self about short cuts). To be fair however a low angle plane like this is stretching the limits of wood bodied. That and the rotten summer we had with weeks on end of 90% plus humidity. Well lets just say it's been well tested. I am still a bit suss on the wood and something in my head is saying there are reasons why so many planes are made of beech. Anyhow come next summer I will be keeping a very close watch on how it behaves.
Regards
John

A certain English woodworker was employed in Canberra in the 80s to teach the colonials how it's done.
He had brought Casein glue with him.
His next debacle involved Huon Pine.
Later a Nylon strung lounge lifted one leg an inch. (Imperial rules! was on the studio wall)
It was fun.
H.