Hi, all.
I’ve now been hit a second time by a very frustrating problem, and I’m wondering if someone has the answer.
The problem is that after joining boards into a panel and sanding way down, after drying for a while the boards seem to shrink in thickness a bit while the glue (Titebond III) does not and ends up producing a slightly proud dry glue line.
The hard glue is only a hair or two high, but it is enough to see and feel.
The first time it happened, I noticed it before finishing. However, sanding just seemed to reduce both the line and the wood (leaving a line anyway (I guess because the glue is harder than the wood (maple)).
The second time, just now, it happened on some paela (Chakte Viga) after finishing. I sanded the table top down to 1500, and it was like glass. Then I finished it with a mix of alkyd resin varnish and tung oil (guess where I got that recipe…). Finally, I hit it with a couple of coats of Reniasance Wax. It looked great for a few days. Now there are slight proud hairline glue lines at the joints.
It’ll pass, I hope, but it sure would be great to know what I’m doing wrong.
Thanks in advance!
Replies
Are you sure that it's just the glue that is sticking up above the surface of the wood? More often, what you see is a step, where the wood on one side of the joint is higher than on the other. You can get a step even when the wood on both sides of the joint is the same species; if the angle of the grain lines is different on the two sides, the amount of movement will be different.
-Steve
Yes, I'm 99% sure it's glue. It was perfectly smooth (in both cases) at first.
You will find a discussion on the form of glue creep you have described at the bottom of this page at my website. Slainte.richardjonesfurniture.com
Richard, dunno why, but your link doesn't work.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
Try this then Mike: http://www.richardjonesfurniture.com/Articles/panel-glue-ups/panel-glue-ups.html
Slainte.richardjonesfurniture.com
Thanks -- I had found it (your page is bookmarked), but I was afraid the OP may not be able to get there.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.
Nice read and reminded me to go sticker some panels that just came off the clamps a few hours ago.. I got in a hurry for dinner.. blew the shop out and forgot to sticker. :>)
BTW.. I just noticed the new icon so.. congratulations as well deserved.
Sarge..
Thanks. Interesting PVA info.
Richard (My Sons name) I love your Web Pages...
But arfaid I could not afford your skills! Or Mine either!
Sorry - after re-reading, I don't think it's a grain issue. Most joints are VERY closely matched, but all are exhibiting the problem.
Always glue boards up over-thickness at the beginning of the project and let them sit. Finish thickness and plane them right before putting them into the project. Use hide glue; it creeps less.
These boards sat for months before final surfacing and finishing.
Hide glue, eh? For some reason I had the impression it was old technology and new was better. I guess that's why they still sell it...
Thanks!
Epoxy, DAP Plastic Resin, hide glue - all are more rigid in the glue line than a polyvinyl glue.
I've been fortunate never to have run into this problem, but here's what I understand is happening. You start with dry wood. You glue. The moisture in the glue expands the wood around the joint a bit. You sand. When the glue moisture dries, the wood shrinks again, except the glue doesn't, leaving the joint proud.
The only solution I know of is to let the wood re-dry prior to sanding. But as I said, I have no personal experience with this problem so I know no details regarding how long to wait, etc.
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
I believe if anybody could figure out how to prevent glue creep in a fool proof fashion the industry would give them a nobel prize.
Wow. I feel better now (sort of...).
Wayne:
when I started making tables I ran into this problem. I read all the info I could find about glue creep (this is what it is) and never really found a solution which satisfied me.
so I did 2 things: switched to polyurethane glue for glue ups. It sets harder than yellow glue. and I use my domino with 5mm tenons to align the boards. May be overkill, but no more glue creep. pmm
I like overkill. Thanks!
How do you like the Domino, BTW? I keep thinking about it...
Wayne: I love my domino. Agonized over the purchase for at least a year, but now have had it for maybe a year or more. Worth every penny. I am not a traditionalist. I like to build the best furniture possible in the most efficient way possible. Have literally not cut a tenon or mortise since the purchase.
Uses: all joinery: table: align boards as mentioned. the fit is so tight, unlike bisuits, that the boards cannot move up or down during or after glue up. Apron to legs: couple of 8 mm at each joint- done. Chair building: same thing.
not cheap but worth it. pmm
A scraper works wonders!
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