On the FWW home page the opening video today by Gary Ragowski features a glue up method. I don’t usually glue lots of narrow boards up and I think Gary did this as a demo to show his technique and make a few points.
After the long discussion we had here a few months earlier on the need to apply lots of pressure — I was wondering if other knotters who aren’t in a rush tend to glue up maybe 2 or 3 boards then put the two groups of 2/3 together to make 6 as opposed to doing all of them at the same time? It just gets a bit hectic for me doing it that way?? I like to wipe down the squeezed out glue with a wet rag and its difficult with 4 seams and lots of clamps.
Second point: After experimenting with high pressure squeezing(earlier subj), I found it critical to alternate the pipe clamps on the top and bottom of the panel. From pictures of other featured demos here and other sites, I see woodworkers putting lots on the bottom and a couple on top. I don’t think that makes for even pressures?? Any thoughts on that position?
a. It doesn’t matter in my experience
b. I alternate the pipe clamps
Are there any knotters out there that have converted to putting lots of clamps on their projects and applying the maximum torque possible after reading about glue and clamps here on knots?? This isn’t a survey- I was just wondering as I commented on the latest video on glue. Lots of techniques.
thanks
dan
Replies
I haven't found alternating makes enough difference with these Bessey or Cabinetmaker clamps. Then again I'm not doing panels any wider that about 30". I'm sure some will say it matters, but I've been woodworking for decades, and the new clamps we've had the past 10 years or so are pretty darned good in terms of pressure points.
I'm still stuck in the old pony clamps with cheap black pipe. I have so many I just can't part with the $$ for new clamps when they work.
I would love to find a woodworker selling 50 used bar clamps. I'd jump on them like a dog on a bone. I just can't have too many of those things.
keep goin'
dan
Dan: First of all, forget about woodworkers selling their clamps. It just doesn't happen. I' too use old gas pipe with basic pony clamp heads, but that's all you need. Make sure that the point of pressure of the screw is aligned with the center of the edge of the board. This will put the pressure on center across the width, and don't tighten so much that the assembled boards begin to bow. I usually tighten the bottom clamps, then add just enough top clamps to pull it into flat, checking as I go. I use spacer strips to hold the pieces up off the clamp bars, the thickness depends on the thickness of the boards I am gluing.I don't usually glue up more than two or three boards at a time. The accuracy gained, and the time saved in planing everything flat is worth the extra step(s).One caution, Before you glue two sub-assemblies together, make sure that your outside edges are still straight.Bob K
Bob
That's about all I do in the shop and its still working. It ain't rocket science. I read some of the threads on glue and I'm not sure if the clamp pressure has gone under the microscope at the cost of ignoring the grain orientation and a good clean straight edge??
There are sawblades being sold as "glue joint quality edges" to save time. What?
I haven't come to that point where I am in such a hurry that the sawblade is "good enough" to just spread the glue and let her go.
I guess it makes sense to some degree.. I don't clean up plywood cuts before I add edge banding. So maybe there is some truth to the claim. When joining 2 pieces of wood, I like to get the edges just right with the jointer and a swipe with the plane. Just my technique. I guess I like the extra step.
later
dan
I find my 30T Forrest WW2 rip blade will make glue ready edges. Sometimes I'll use a smoother or block to get a glassy smooth edge, but it's not really necessary for an invisible joint.
Sometimes I just use a plane.
I pretty much hate my powered jointer - so I use everyhting else to avoid it (sort of like "running around" a backhand shot in tennis).
Once again, the fun of talking about woodworking is that each one has his or her own preferences and favorite tools. I feel about hand planes the way you feel about your jointer. I can't imagine that I can get as accurate an edge, square to the face all the way, with a hand plane as I can get with the jointer. I have a vintage 8" Delta. A few years ago, I stopped one day and spent the time to really tune it, and I haven't had to touch it since. Don't know what I'd do without it.One tip for any novices who might be reading... When jointing the edges to be glued, alternate which face rides along the fence, top face of one board, bottom face of the adjoining board. This will cancel out the 1/2 degree that your fence might be out of square. It will help keep the glued up top flat.Bob K
Better yet; put two boards together with the "face" side together, and run them through at the same time.
When you unfold them to glue them the edges have to match.
Jiggy, that issee not strictly true, and poor practice. You may get away with it if you are machining short narrow boards, of a light softwood that has already been accurately thicknessed. At any other time any discrepancy (such as a concave or convex edge) will be doubled.One of these days you will have a clumsy moment and drop one of those boards-possibly into the cutters....
Philip Marcou
I use Rockler's version of pipe clamps (with the higher foot and nice crank) on the bottom, Bessey bar clamps at the end seams (with packing tape covered wood bits for padding and glue resistance) as well as to secure cauls - some have deep enough throats that ehy will first seams from either side of the boards aren't super wide, and K-bodies for the top clamps. This is likely overkill, but I never have to do much flattening at the seams. The biggest thing to look out for is warp (of various sorts) across the panel, but in my experience, some of that is inevitable.
- I agree that with the Rockler clamps and k-bodies, the pressure is reasonably parallel and I don't have to worry excessively about top and bottom matching
- I do not usually glue up more than three boards at a time, preferring to do it in stages if necessary for all the reasons you state.
- I wipe the top glue squeeze out as best I can while applying the clamps, and come back an hour or so later - remove the clamps - flip the panels and scrap the bottom glue lines (now gummy) with a beater modern chisel.
- As for pressure, I crank the clamps a good bit, but by no means to the limits of my strength because I find too much pressure increases the chance of bowed panels and crushed edges. It's just not necessary for insible glue lines and strong joints. I use LV's GF 2002 for its properties and open time.
Samson, FWIW, I cannot imagine anything better than a cabinet scraper to work a glue line. Tell me I'm wrong.
Sure, cabinet scrapers are fine too, and I use them on glued joints. All I was saying is that my common practice is to get rid of the glue squeeze out on the undersides with a wide chisel (a modern Buck Bros. I bought from Home Despot for rough carpentry and like jobs) at the point where the glue is gelled but not hard.
I use a chisel also, but only if the glue has hardened. I also have a "rough" chisel for that. There is no one best way. Like my grandmother used to say, "it's good if you like it"
Note: Edited out "goof" which was meant to be "good" LOL!! That one letter change changes the entire tone of my reply. My bad.
Edited 2/12/2008 10:52 pm ET by coolbreeze
only if the glue has hardened
I've done both the Samson method and the coolbreeze method with mixed results sometimes. Might depend on the wood, i.e. soft vs hard. Sometimes, especially with soft woods, when I let the glue harden it has a tendency to pull out chips when removing the glue. Maybe going in the wrong direction?
If there is still some uncured glue it leaves a splatch (?) of glue on the wood but does mnimize the amount left on the wood. Candidate for scraper use after methinks?
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Amazing how astute(the keen part of that definition) folks on this forum are. This would be best had on the veranda with a few cool ones. As soon as one aspect is agreed upon, someone has a "but".
Bob you are right about soft wood. Shooting from the hip, I didn't think about soft wood. With soft wood, the "right" way is to make sure the glue does not harden. Yesterday, I finished gluing up some soft maple and cleaned the glue line with a cabinet scraper. 98% of the time, I deal with the runout while the glue is not rock hard.
Bob, If you are still reading this thread, I need a recommendation for two sided tape. I am going to make up a bunch of TS inserts and need a tape that will hold the template and the workpiece firm for cutting
For years, I would rip boards and glue them straight from the table saw. But, once I got my vises set up and the veritas jointer plane tuned up, it takes only a minute or two to really sweeten the edges. Now, the clamps just hold the wood until the glue dries - they don't have to apply tremendous force to pull a gappy joint together.Tom Iovino
Tom's Workbench
http://tomsworkbench.com
Ya might have me on that one.
I use two sided tape from the local flooring store, never paid any attention to the name as it works. That's what I've seen most folks use but I've not seen/remembered a brand name..
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
The vast majority of all of this is rather moot if you don't try to glue up individual boards already at or scary close to finished thickness.
Edited 2/13/2008 12:52 pm ET by BossCrunk
I think you're overstating things. No matter how much flattening you're raring to do to a glued up panel, you still have limits on the amount of bow, twist, etc. that you can tolerate. Likewise, you still want invisible glue lines.
And each to their own, but I'd rather do a bit more clamping work to ensure that the joints have little or no steps, rather than plane a 1/16" off both faces of a 20" x 36" panel.
Perhaps twenty years ago I came across this idea in a woodworking magazine and made a several of these flat panel clamps. Basically it is
a standard construction channel or strut which you can buy quite cheaply... the nuts for them come with springs on them to make the location of the nut adjustable in the channel. If you make the wooden
part with a bit of a bow upward, then you can tighten down this clamp on a large panel glue up and it helps to keep the whole thing flat. I still put clamps top and bottom of the panel; however, this makes the work go faster and keeps the panels flatter for me. Moksha
Moksha, do you know the proper name for those nuts? Those are perfect for adding a sacrificial fence to a Unifence. I had some but I haven't been able to find any others. Don't know what to call them.Beat it to fit / Paint it to match
It's called UniStrut (a trade name, but it's become generic). You can find the nuts at McMaster-Carr; search for strut channel nuts.
-Steve
Thanks, we called them aircraft nuts and nobody knew what I was talking about.Beat it to fit / Paint it to match
"Thanks, we called them aircraft nuts and nobody knew what I was talking about."You mean aircraft have those too?Tom Iovino
Tom's Workbench
http://tomsworkbench.com
If I have to take an individual board originally destined for a panel glue-up to damn near finished thickness to remove bow and twist it doesn't go into the project.
From a hand tool only perspective IMO it's much easier to work a full panel to finished thickness and true-ness than it is to four square individual boards and then glue them up which requires fussing with the clamps because you don't have but a millimeter or two to spare or the thing is basically garbage. If I'm dovetailing panels to make a carcase there is no way in Hades I'm going to let that process live or die on clamping up. Lots of people do, but that's not my kind of woodworking. If I have a problem with a panel it's almost always because of stock selection. I heat my shop with corkscrewed wood. I don't build with it. I can trace almost all of my early woodworking failures to trying to build with poorly selected stock.
Hell, I have Plano glue racks and I still don't want a knife at my throat at the glue-up stage. That sets a bad precedent for the rest of the project. I save the knife-throat combination for carving that last bellflower whose grain is running off right where you wished it wouldn't.
Edited 2/13/2008 1:46 pm ET by BossCrunk
I think this is interesting stuff to talk about. Although I've glued up scores and scores I'm confident you have WAY more expereince in that regard.
I'm a big fan of leaving myself margins for errors in all aspects of my woodworking. I would never leave myself prey to a milimeter (but then again, I don't tend to make things where it will make any significant difference if the caracase panels are 1" or 15/16ths). I also make story stick and direct type measuring a major part of my working habits and methods. All my joints are custom matings, so to speak.
That said, I like to four square panel members in order to find out something about them and make them fit for glue up. In the course of getting them near sized, I find out if that cup really will come out and stay out, what the grain looks like nearer to my final thickness, and so on. For me, it's also easier to glue up board that are already flat than mess with those that have cup or twist and try to eyeball the board that will be left when I plane the panel.
I agree that stock selection is key, and troublesome boards pretty much inevitably come back to haunt you.
I skim plane (usually with a jack) and trim the ends of all rough stock when it comes in so that I can take a peek under the hood. If individual boards are not too terribly warped after they've been in the shop for a while I don't worry about them. I can't quantify how much distortion is too much. That takes away the art of the whole process for me.
I do process stock for door stiles and rails in stages. I've been burned which means I've been embarrassed by a callback.
I might take a little bit more off individual boards when I'm getting out stock for a panel - purely for grain and color match and to attempt to orient them to make planing easier later. If a board rocks like hell on my bench I put a big X on it and throw it back in the pile. I'll rip it for parts later. If a board looks to my eye to be right on the cusp of being too cupped I lay a straightedge across it and make a judgement call right then. Too much cup - again it gets ripped down for smaller parts.
I know where Boss is coming from, and I'm mostly a power tool worker but employ similar tactics. I select the boards and surface plane one face flat and one edge square and straight. More precisely, I surface one face so that that face has one flat reference point. It could be no more than a flat rim around every bit of the edge, and the middle is still a bit hollow. Then I run the stuff through the thicknesser to get the other side to a similar state as the first face. The chances are here that most wood is removed from somewhere in the centre of the board leaving the edge a touch lower.
The aim is to create boards that are trued up where it matters but 3 to 4 mm thicker than the final desired thickness. Careful edge joinery means the panel comes out pretty flat with manageable steps at the join-- mostly due to slight variations in board thickness at the joining edges. Then it's back to the surface planer for a skim to flatten one face and back through the thicknesser to get that final desired thickness.
If the panel width is greater than what the surface planer (US jointer) can handle, ie, >450 mm, it's only then that I need to edge glue sub- assemblies of already glued up panels. With the two or three already glued up panels now down to the desired thickness this leave just one, or possibly two edge joints needing special care during the glue up. Done right all that's necessary after the glue is properly cured is a bit of light hand planing, scraping, sanding, etc.
Using these techniques I've found it's very rare that I miss my target, but I can see that it's possible for things to go wrong too often for some. That may be down to technique and experience, eg, failing to select boards that are pretty flat and generously oversize in the first place makes things a lot trickier, or even cause failure.
Naturally, not every panel needs to be spot on. Table tops for instance have more wriggle room in them than solid wood panels for a cabinet carcase. Slainte.
Richard Jones Furniture
Edited 2/13/2008 3:00 pm by SgianDubh
For the record, I'm not a woodworker who tries to plane all my boards to final thickness and then glue the panel together so perfectly that I never need to touch it again. Rather, I tend to prep my stock as best I can so as to learn its attributes and then glue the most stable and flat ones together into panels with as much precision as possible with cauls etc. for the simple reason that it leaves me less work when the panel comes out of the clamps. I do indeed hand plane my panels always, and extensively when necessary. I always leave myself room for corrections. Here's a pic of some recent panel shavings:
Samson,
Cool picture. I saved a copy - it might look nice on my desktop!Chris @ flairwoodworks
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
I usually do two at a time. It's just not worth the adrenaline to try to do more.
-Steve
Dan, I prefer to do it in stages, especially if the boards are wide and long, or if the total width is comparatively great.
You will always get better results if you use decent sash clamps such as Record Tee bar type which will not flex under normal use. Pipe clamps are too flimsy and just bend , resulting in the need to apply lots of them in alternating pairs- way too much bother.
Good quality sash clamps are expensive but well worth it .
I have not seen the video but it sounds like nonsense.
I didn't watch the video or read the article, so I can't comment on what is in them.
I rarely glue a panel with more than two boards, but on those few occasions when I do, I break the assembly down into section so I don't have as many joints to deal with. I do alternate the clamps ( I use the cheapest pipe clamps I can find, with many of them coming from Big Lots). I don't use very many clamps, in fact on some small table tops with a spring joint I only use one at the center. I also have a kind of rule, that if a small child couldn't apply the clamping pressure required to close the joint then I did something wrong.
Rob Millard
http://www.americanfederalperiod.com
if a small child couldn't apply the clamping pressure required to close the joint then I did something wrong.
I like that. I have always felt uneasy pulling unwilling boards into position. I'd rather get them a little more aligned on the jointer or a swipe or two with the plane before glue time.
dan
I do tend to alternate when I'm using Besseys but if I have any doubts, I ad "bowed" cauls.
I also use black pipes instead of galvanized and to avoid staining, they are all coated in Tung Oil. If it's good enough to line chemical tank cars on trains, it should keep my wood clear. Also,on some pipes I use free sliding PVC couplers on each end as a stand off. Seems to work.
My pressure has always been to the plus side but not as radical as the article. Fresh glue, even glue, moderate temperature and time with adequate pressure does me well.
John
I can't comment on the article. I often glue up numerous boards in a panel. I think the trick is in applying the glue. You want just the right amount, too much causes hydraulic pressure and things can get slippery. I prep all the boards on the jointer, try a dry fit, stand them on edge, apply the glue, smooth it with a brush, apply cauls and a couple of clamps. With cauls and a good fit to begin with, you don't need clamps top and bottom. I don't get lots of squeeze out to clean up. I use a paint type scraper to remove the extra once it is semi-hard.
Beat it to fit / Paint it to match
hammer
good stuff. like the photos.
dan
Dan,
Sometimes I alternate clamps, sometimes I don't. I often, if not always, have more clamps below than above. With parallel jaw clamps such as K-Bodies, I see absolutely no need to alternate. I always check that all the boards are straight (not in an arc) before walking away.
Regarding multiple or single glue-ups, I've done both. Gluing two boards together is definately less hectic than trying to glue 5 before the glue begins to set on the first. If possible, I will do all my gluing at once - less downtime.
I have always believed in a zero-thickness glue line. I always give my clamps the death grip. That said, I haven't quite been sold on the "ideal clamping pressure". As long as the joint closes and is strong, I am happy. By the way, I apply a thin layer of glue to both sides of the joint.
To clean up the glue line, I wait until the glue had hardened before scraping it off with a card scraper. I usually only have 1/8" diameter beads of glue along the joint which jump off when faced with the scraper (this is one hand tool operation where I wear safety glasses!).
Chris @ flairwoodworks
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
If you are working with 3/4 stock use a 3/4" half round inbetween the pipe clamp and the boards. This not only protects the boards edge but more importantly it puts the pressure in the center of the board. You will find it is much harder to buckle the joint this way.I used to attach a piece to the flat end with double sided tape.
I now use a homemade version of a Plano Press, haven't used the 1/2 round trick in years but it does work.
mike
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