I laminated poplar and oak using titebond II. Several weeks after finishing I noticed that I could feel (but not see) ridges at the glue lines. I sanded smooth and refinished. A week later I am beginning to feel the ridges agian. Is the glue coming out at the joints? What did I do wrong? This is my first attempt at this.
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Glue question
- Thread starter gran
- Start date
Me too
I've had the same thing happen when I glued woods of different densities. It seems that, when sanded, the softer wood will be "lower" to the touch but not to the eye.
Very uniform surfaces help.
I've also been told that the glue will "sand away" much faster than the wood. This leads to the same problem.
Cure? Maybe more clamps and more tightening. I've begun using cauls when clamping.
I've had the same thing happen when I glued woods of different densities. It seems that, when sanded, the softer wood will be "lower" to the touch but not to the eye.
Very uniform surfaces help.
I've also been told that the glue will "sand away" much faster than the wood. This leads to the same problem.
Cure? Maybe more clamps and more tightening. I've begun using cauls when clamping.
Humidity changes?
When I got through sanding it was smooth but changed over time. I was assuming that it was glue but could it have been the different woods swelling or shrinking at different rates depending on humidity?
When I got through sanding it was smooth but changed over time. I was assuming that it was glue but could it have been the different woods swelling or shrinking at different rates depending on humidity?
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glue creep
from another site:
Michael Dresdner: "Glue creep is the term reserved for a guy who borrows your glue bottle and then doesn't give it back. No, wait... that's just a regular, run of the mill creep. Glue creep has come to mean two different things these days. The original meaning refers to the amount of movement a glued up joint will exhibit. Naturally, rigid glues do not allow creep, but more rubbery or flexible adhesives do. I've also seen the term used to define the ridge that forms when a previously flush joint, such as the glue line between two boards joined along the grain, starts to protrude over time."
Simon Watts: "Some glues--especially the poly-vinyl emulsions such as Titebond®, will creep when the glue line is subjected to sheer stress, which happens when one piece tries to slide on the one below. This means that such glues should not be used for heavy, bent laminations: the wood will try to recover and the glue may "creep." For regular surface-to-surface gluing, they are fine, but be aware of their limitations. For bent laminations use epoxy or a plastic resin glue such as Weldwood."
Rob Johnstone: "A glue creep is regularly found at woodworking shows, and he usually catches your ear by saying something like, "psst, hey buddy, ever need to stick something together?" But seriously folks! Glue creep is a term I have heard used for a couple of differing situations. One is the movement of stock while it is being clamped together but the glue is still curing. Another is describing the comparable elasticity of adhesives. Various glues have differing degrees of elasticity. This of course is a comparison of degree … we are talking about glue, and glue bonds materials together. But just for the record, here is how I think of it: white glue allows a bit more movement than yellow glues, epoxy and polyurethanes are rock-hard. Hide glue (a favorite glue of mine) is actually very brittle once it cures. This means that it does not allow bonded material to creep to any significant degree, but it will "fracture" or break apart if stressed beyond a certain point. Furniture and musical instrument makers use this characteristic to their advantage when selecting hide glue for certain tasks."
Moral is to use a rigid glue.
Let epsilon be smaller than zero.
from another site:
Michael Dresdner: "Glue creep is the term reserved for a guy who borrows your glue bottle and then doesn't give it back. No, wait... that's just a regular, run of the mill creep. Glue creep has come to mean two different things these days. The original meaning refers to the amount of movement a glued up joint will exhibit. Naturally, rigid glues do not allow creep, but more rubbery or flexible adhesives do. I've also seen the term used to define the ridge that forms when a previously flush joint, such as the glue line between two boards joined along the grain, starts to protrude over time."
Simon Watts: "Some glues--especially the poly-vinyl emulsions such as Titebond®, will creep when the glue line is subjected to sheer stress, which happens when one piece tries to slide on the one below. This means that such glues should not be used for heavy, bent laminations: the wood will try to recover and the glue may "creep." For regular surface-to-surface gluing, they are fine, but be aware of their limitations. For bent laminations use epoxy or a plastic resin glue such as Weldwood."
Rob Johnstone: "A glue creep is regularly found at woodworking shows, and he usually catches your ear by saying something like, "psst, hey buddy, ever need to stick something together?" But seriously folks! Glue creep is a term I have heard used for a couple of differing situations. One is the movement of stock while it is being clamped together but the glue is still curing. Another is describing the comparable elasticity of adhesives. Various glues have differing degrees of elasticity. This of course is a comparison of degree … we are talking about glue, and glue bonds materials together. But just for the record, here is how I think of it: white glue allows a bit more movement than yellow glues, epoxy and polyurethanes are rock-hard. Hide glue (a favorite glue of mine) is actually very brittle once it cures. This means that it does not allow bonded material to creep to any significant degree, but it will "fracture" or break apart if stressed beyond a certain point. Furniture and musical instrument makers use this characteristic to their advantage when selecting hide glue for certain tasks."
Moral is to use a rigid glue.
Let epsilon be smaller than zero.
It would seem that two dissimilar woods are absorbing moisture, or losing it, at different rates and the glue is flexible enough to allow you to feel the change.
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You just need to let the glue cure for a few days (a week should be good enough but longer is better) before turning.
A sharp cabinet scraper is good for removing the glue ridge after the fact, easier than sanding the whole thing.
A sharp cabinet scraper is good for removing the glue ridge after the fact, easier than sanding the whole thing.
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The problem will eventually stop after several months, but the way that I have taken care of the the glue ridge is to use a razor blade like a cabinet scraper and gently remove it. If done carefully, it won't scratch the adjoining finish. The worst glue about creeping seems to be premixed hide glue.
Bill
Bill
Thanks everyone for the info