In order to glue up panels the old-timers would apply glue to the edge of two boards and then rub them together until they were sticky then set them aside to dry, no clamps. Has anyone tried this with our modern glues? Sure would save on the clamps. What are your opinions and experiences.
ZABO2
Edited 8/31/2009 1:48 pm ET by Zabo2
Replies
Doing the rubbed joint does require very well mated boards. It works particularly well with hide glue which first gels and then shrinks, pulling the joint together.
It may work to a degree with PVA glues, and I doubt it would work at all with polyurethane glues or epoxy. But we know that with PVA glues the glue bond achieved with heavy clamping is stronger than a lightly clamped joint or a rubbed joint. Camping will definately give you a stronger bond with PVA glues.
You will also note that 18th century furniture makers used as few panel glue ups as possible, much preferring wide boards. Mostly the rubbed joints they used were for things like glue blocks.
I tried it with white glue many years ago and it seemed to work okay, but only for comparatively short pieces.
Now, with the decidedly non modern hot hide glue it really is a viable option. I especially like to glue drawer bottoms this way; their thinness makes clamping somewhat difficult because of the need for cauls. I have only used it for drawer bottoms in the 30" and less range. The downside, is the joints have to fit perfectly in both directions. On thicker stock I just plane a nice spring joint and throw on some clamps. A well done spring joint saves on clamps too.
Rob Millard
http://www.americanfederalperiod.
Somebody on another forum posted a test he did recently. Rubbed joint with Titebond, moderate clamp pressure with Titebond, and heavy clamp pressure with Titebond. (I think they were lap joints.) After the three pieces cured, he stressed the joints. The rubbed joint failed at the glue line. The other two held the way they were supposed to. His opinion is that the heavy clamp pressure produced the strongest joint and pooh-poohed the notion of the "glue-starved" joint. I'm not sure how he arrived at that conclusion, that heavy pressure is better than moderate pressure, but the rubbed joint was definitely not very strong. Rubbed joints with hide glue have been used for a long, long time. However, there is the question: In what applications?
Joe,
I have always questioned the concept of a glue starved joint from clamping pressure. While I don't apply heavy clamping pressure, I can't see any reasonable amount of pressure squeezing enough glue out to cause a loss of strength. I avoid heavy clamping pressure because I feel the joints should fit together well without significant pressure; otherwise you are building stress into the piece.
I often break the off cuts on the rubbed joints I have made, and they always have broken near, but not at the glue line, so I believe them to be sufficiently strong.
Rob Millard
I avoid heavy clamping pressure because I feel the joints should fit together well without significant pressure; otherwise you are building stress into the piece.
So true... One of the first tables I built I clamped down hard. When I removed it from the clamps it had a nice bow to it. Looking back I remember it bowing up a little in the clamps. These days I use a little less pressure, and cauls.
As many wise people have said already, good surface preparation is key to the joint.
So true, but open to mis-interpretation. I like rubbed joints and prefer quarter sawn, but here the temperature is moderate and, for me, the trick is to plane the joining faces at one go by hand and then apply just enough glue, hot or new stuff and rub just enough to feel the grab. No delay or the open pores may attract dust. Then lean the panel against a support and let it dry. Go away and pick it up next day!
The nice bit is when the grains match and the joint is hard to find. But like most things, the harder one tries to be perfect, the worse things turn out.
M.
Rob
One of the things that seems to be left out of the rationale... if the rub block falls off you just put some HIDE GLUE back on and rub it back in place for another.. I don't know how many years but its so easy to fix just do it.
I like the idea of the next guy doing a repair on one of my pieces and thinking: this guy was thinking of the next guy down the road.
If you have done repairs you acquire a different view of "long lasting pieces" -- especially chairs.
d
I too like the idea of making it easy for some future restorer (hopefully long in the future).
I once glued a candlestand together and was quite proud of myself, but then several hours later, I realized I had glued the top on facing the wrong way. Some hot water and about a half hour, was all it took to "fix" the mistake.
Rob Millardhttp://www.americanfederalperiod.com
Oh yea. been there. Try that with Gorilla glue.. that will be the day.
About hide. I have been experimenting with different gram weight stuff. There's a supplier down in Charlotte, NC area who really knows his stuff. He spent some 30-40 years going around the world buying and selling hide. After a few messages with him, I bought a pound of each weight and fooled with mixing and glue tests. I'm not prepared to begin any debates from my findings but there is a big learning curve with the glue(much like shellac types and cuts) and it is worth experimenting on your own to find what works best for you in different situations. After 30 years of working with hide glue I have learned some new stuff: my veneer mix and my mix for edge joining can be the same but I prefer the ease of using a heavier weight now for veneer work.
When I have some time to balance my data sheet and test my blather again, I think I might put some info out for others to try. Its a low cost adventure and it certainly has some worthy findings for builders doing traditional construction. Time to go. Back in the shop today for a 12hr run.
till then
d
Edited 9/5/2009 7:21 am ET by danmart
VERY FUNNY!
I think we all have done the same many times in our lifetime...
Somebody on another forum posted a test he did recently.
I think this thread references the test or a similar:
http://forums.taunton.com/fw-knots/messages?msg=47790.1
His conclusion was even odder, his joints failed on the glueline... but he still concludes you only need a little pressure!
Hi Rob,
I have had instances in using white or yellow glue in a rubbed joint in Queen Anne knee blocks where the joint itself is slightly open when the blocks are worked down. That is, the bead of dried glue over top the joint hides an open glue line. It is as if the glue migrated out of the joint as it dried, leaving what appears as a starved joint. Not always, but often enough :-( I put a little (spring clamp) pressure on them nowadays.
Ray
Ray,
I made my rubbed joint with white glue, over 25 years ago. At the time I had never heard of hide glue, but I saw a rubbed joint in an Audels Carpenter's and Builder's Guide. The scale of the drawing showed what looked like an 18" board. I never got it to work with a board that long (surprise, surprise since I was using the wrong glue). I did get it to work with a board about half that long, although given my lack knowledge at the time, I can't say how strong it was.
Rob Millard
The advantage for me of a rubbed joint on the thin cabinet sides is the surfaces mate up and there are no clamps that can bow the work. So I feel for thin stuff I get a better seam than if I used clamps.
Here are too many photos but the point is , on this small chest of drawers I am making , all the sides came out great and have tight fit up on both sides of each panel. I don't have a great deal of experience making these up and am still able to get very satisfactory results.
The nickel is there for judging size of components but is always centered over a glued joint, except in the one pic when on the edge to show the thickness of these panels. The small side panels are a bit thinner than the longer top and bottom panels.
On the pic called " InsideClose " the seem runs under the nickel and perpendicular to the little dados.
I use magnification to check the fit while I make adjustments with the plane to close up any gaps. I do not go for a sprung joint.
Happy rubbing,
roc
Give me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Edited 9/1/2009 1:22 am by roc
"The advantage for me of a rubbed joint on the thin cabinet sides is the surfaces mate up and the clamps don't bow the work."Seems like a bit of a hack. Wouldn't it be better to use caul sticks over the surface (between the edge clamps) near the edges and clamp those so the boards don't bow or bend at the glueline?Alternately, you could use quartersawn. I'll bet that doesn't bow...Andy
> hack<A person or method of work that takes short cuts and disregards subtlety and quality in favor of speed for the sake of speed. Sounds like an insult. Are you trying to insult me ?>caul sticks<Why use more stuff. I don't need cauls to get excellent results. Or clamps. Clamps have weight and can distort or twist thin panels.>could use quartersawn<First off quarter sawn is boring to look at and is reserved for drawer sides.Second of all quarter sawn is dimensionally more stable over time but will have no advantage until the environment changes and in actuality is weaker in a bow situation than what I have here.Perhaps I am dense and not understanding your point. Do you have a visual example of your suggestion.rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Edited 9/1/2009 12:45 am by roc
"Sounds like an insult. Are you trying to insult me ?"Everyone takes shortcuts in some places. I can't stop you from being insulted if that's your inclination. "Why use more stuff."'cause it works?..."First off quarter sawn is boring to look at"That was a joke for Bob. I went silly last night. Please forgive me and I will try to not call you anything, ask you anything, or suggest you anything. I use clamps to keep panel glueups flat. Wondered if there was a good reason to not is all. Andy
OK, that was me that deleted the message #14 and I aint tellin ye what I said neither.
I'll back off on the q-sawn cuz I was cutting some q-sawn red oak and I swear one of them rays was stickin it's tongue out at me. Making sealed torsion boxes for the sides of a boat and red oak shouldn't be used. Got some white?
I'll use the red oak for the acquarium shelf instead.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 9/1/2009 9:49 pm ET by KiddervilleAcres
An approach that seems to work for me is, after jointing boards on the machine, so trap one on edge in a clamp, and stack the boards up edge to edge. A straightedge then shows how the boards want to align, whether the edges are truly perpendicular to the surfaces. Then I'll shoot the edges with a #8, which always needs 2-4 passes to take a continuous shaving. Whether to form spring joint is personal preference, I generally do so. Finally, I re-stack the boards on edge to confirm the edges are still perpendicular to the surfaces.
At this point, a rub joint with hot hide glue seems to always produce perfectly flat surfaces across the glue-up, and draws the joint tighter as the glue cures, without having to drag out lots of clamps and cauls. My experience is that hot hide glue joints are tighter, the process is as fast or faster, and there's no risk of inherent tension from a mis-aligned edge. Others may have had different experiences, and I am not suggesting one method is better than another.
When clamps are used (need to glue several boards together at once) I haven't found cauls needed to keep the assembly from bowing under clamping pressure - alternating clamps above and below is sufficient. But if you are more comfortable working with cauls, by all means continue doing so.
I also alternate clamps top and bottom. However, until I get more practise with panel glueups, I find that clamps at each end of the joint to keep the panel flat helps me, especially with multiple joints.I have not tried hide glue yet. If it offers the same strength and pulls the joint together (which TbIII does not), I should try it. I suspect it dries faster and would be harder to clamp anyway, no? Btw, a shooting board is on my todo list, or do you just clamp upright and use a plane with fence? I have the planes, but have been more of a machine person to this point. I can see the benefit -- just need the time for the jig and the practise. :)Andy
I've only used a shooting board to leaves of veneer. Took a long time for me to develop the nerve to try shooting the edges of boards free hand, but now that is my approach. Dragging a thin piece of wood (like a 3 inch long piece of paint stir stick) across both ends of the blade suggest how parallel the blade is to the bottom of the plane (tip from a David Charlesworth video). My left thumb is on top of the toe of the plane, pushing down, and my fingers curl under, against the board, trying to keep the middle of the blade centered on the edge of the board. A series of pencil marks across the edge every 1/2" or so help me read my progress, and I watch the shaving to try to keep it centered on the edge. Even with all that, I still sometimes turn a square edge into an angled one, and occasionally the best fix is a visit back to the Powermatic jointer and starting anew with the plane. When I think the plane work is finished, I'll check the edge with a square, and then stack the edges and confirm the boards all lie flat. Takes a few minutes, but then I can re-sequence the boards if I want, turn one or more to the other side, et cetera and be reasonably certain the boards will still lie flat when clamped.
Clamping two boards together and planing their common edge simultaneously is one trick to get a flat joint, but if the boards are re-sequenced in any way the joint may not lie flat, so I struggle with trying to get perfectly square edges. Just my thoughts on the issue.
Thanks. I like the suggestion to plane two together. Not sure if I trust myself freehand though. I'm going to make more use of the plane fence I got from LV until I make a jig for the job. Andy
"The nickel is there for judging size of components . . . "I'm glad you clarified that. I've heard of bridle joints, but never bribed joints. ;-)
The advantage for me of a rubbed joint on the thin cabinet sides is the surfaces mate up and there are no clamps that can bow the work. So I feel for thin stuff I get a better seam than if I used clamps.
Hey Roc--I agree.
Once I get real thin, though, the flexibility of the workpiece and shear thinness makes keeping the faces even.
For thicker (1/8" and less) shop-sawn veneers, I use wedges on a flat surface, wax paper underneath.
View Image
That thin, clamps are a hinderance (or an impossibility for me) anyway. Once I get to 1/4" stuff and thicker, I do use hot hide glue for rub joints. Usually I use liqued HG for the convenience during builds. Veneering outside the vacuum bag I use hot HG.
Before my use of hide glue for rubbed joints, I used white glue intended for gluing miters on moldings prior to nailing. Elmer's ProBond is one, but there is another brand that slips my mind right now that is even a quicker grab. Both work excellent for rubbed joints.
Take care, Mike
Hi Mike,>Wedges etc. for thin<Yah looks like that is a good way to go. Veneer glued together is still fascinating to me when I see it. Such a miniscule amount of surface area at the joint but strong as the rest of the sheet.Thanks for photo. Maybe that was what Andy was trying to tell me and I was just too dense.Keep up the good work !rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Most of my glued joints are Rubed. As in Goldberg.
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