Plywood vs the real thing

[Jim Matthews]

I use plywood in rooms that have running water.

Our kitchens, bath and mudroom all have plywood pieces
that I have made. A decent circular saw and sharp chisel
will yield quality half rabbet joints.

Is it my favorite material to use?
Hardly.

Can fine furniture be made with plywood?
Judge for yourself...


Jamie Robertson sunrise sunset.jpg

[ian maybury]

I enjoy plywood, have no ideological hang ups about it, and have used quite a bit over the years on jobs needing the properties it delivers. The very large BUT over here (i'm not in the US - although it seem you guys are facing similar trends) is that it's here sold almost entirely for construction use - and house builders are driven mostly by cost.

The quality has progressively worsened (the big importers buy from the East) and is so bad now that even supposedly premium WBP (waterproof), marine and birch ply versions are a right PIA for anything requiring accuracy. Internal gaps and overlaps in the veneer, leading to built in stresses and thickness variations (bends when cut into strips if not already warped as supplied), mush internal veneers leading to poor physical properties/floppiness/not properly stiff any more) and not much better on the surface. Surface finish is anyway often very poor - rough and quite hairy. Misleading labelling is another issue - it's common to see a CE stamp which actually on its own means nothing, and most is unmarked or nearly so. (pseudo brand stamps that are probably designed to eliminate traceability while appearing like they are a brand)

It's almost got so that it's necessary to go for one of the specialist high end brands, and to make sure what you buy is to a defined standard to get something usable - maybe Apple Ply or Finn Ply. Which is expensive, and generally not an option here except in very stock grades unless ordering a bale at a time. You guys seem to do better in the US in areas where there is a decent demand for cabinet grade materials.

All that aside ply is great for many sorts of jobs - especially building jigs and fixtures and the like. MDF isn't much different - the cheap grades are now almost like cardboard and the better grades getting to be quite a lot more expensive.

The biggest practical issue that i run into apart from the above is that the poorer quality stuff doesn't take detail very well (e.g. machining on lock mitres for corner joints can be iffy with the pulpy internal veneers and poor gluing - chunks can drop out, or be so weak as to be of little use if cross grain), and the skin is very prone to chipping/splintering on cross grain cuts.

The glue as the others is very hard on edge tools. It'll almost immediately blunt a carbon steel edge (your typical hand tool), and jointing the laminated edge will leave more or less immediately nick even a high speed steel blade. Carbide as in a router cutter or table saw blade tolerates it pretty well...

[Mike Holbrook]

It sounds like the majority of responders have little fear of edge glueing boards to make surfaces for cabinets, bookcases, table tops, furniture...I needed to hear that even though I do read about posters here doing it regularly. I am a little surprised to find that so many do so much with edge glued boards. I can say that the edge gluing I have done so far has not been the issue I thought it might. I see lots of commercially glued wood that has delaminated. The butcher block counter in my kitchen would be an example. Unfortunately many contractors will cut as many cost saving corners as they can.

I have noticed the decreasing quality of plywoods. As mentioned above, cost cutting housing contractors often seem to drive this decline. I bought 10 sheets of depot sale "hardwood" plywood several years ago. Unfortunately the actual wood veneer is so soft & poor in quality, I am having a hard time finding places to use it.

I believe southern yellow pine and poplar are popular woods that are not to expensive. Some of the home stores even carry clear yellow pine that seems to be relatively nice wood for projects. I just bought some that I plan to use to glue up for part of a work surface. I have a few other woods drying for a wokrbench too.

[Brian Holcombe]

Butcher block (end grain Up) does not have a lot of long grain contact. I've also seen it fail because it was mounted in a way that did not allow for movement.

I glued up a piece of 3/8 as a test a long while back and then attempted to snap it at the glue line before it completely cured. It did not fail on the glue line, because often the glue line (long grain to long grain) is stronger than the surrounding material.

[Curt Putnam]

Edge gluing boards into panels just takes a little learning ... I still have a largeish stash of plywood from when I was making store display fixtures. It's great stuff when used for the right application but if I have my druthers I will use solid wood from henceforth forever. The nice thing about using ply for door panels is that you can glue it in, which makes for a much more rigid structure.

Just a couple points to remember about edge gluing. If you subscribe to the theory (proven facts) that modern glue is stronger than the wood, then anything you do to the edge, other than planing it flat and square, will weaken the joint. I've come to the point where I now glue up flattened, but otherwise rough stock and then either run it through the planer if narrow enough to fit or get out the fore's and jointers. I've not yet had the need to flatten a panel wider than 24", thank goodness. Cauls are your friend when it comes to panel glue-ups; make some and use them.

All before is IMO and be sure that YMWV.

[Jim Matthews]

Just a couple points to remember about edge gluing. If you subscribe to the theory (proven facts) that modern glue is stronger than the wood, then anything you do to the edge, other than planing it flat and square, will weaken the joint.

You mean long grain to long grain joints?
Then I concur.

If you're gluing long grain to other grain faces,
I recommend some kind of mechanical joint.

[Pat Barry]

Can fine furniture be made with plywood?
Judge for yourself...


Jamie Robertson sunrise sunset.jpg

That ain't no plywood I've ever seen

[Judson Green]

Some of the home stores even carry clear yellow pine that seems to be relatively nice wood for projects.

If you can find a lumber yard (I've even had some good luck browsing CL) that sells retail you'd get much more bang for your buck. The Borg's are very pricy on select pine, red oak, maple and popular. However if you look they do have some nice boards in the 1-common 1× isle, and I've built furniture (painted) out of construction lumber.

[Mike Holbrook]

I believe cauls can be just about any scrap of wood used when clamping. In relation to edge gluing, I think other posters are using cauls to hold the tops of glued boards in line, along the opposite plain the clamps would normally work? I imagine cauls could be made that would help with just about any clamping application though?

I think I made a post asking about Bowclamps, which are just precisely manufactured cauls that have a groove made to accept an F style clamp. One side of the Bowclamps is manufactured with CNC machines to achieve the "perfect" arch for evenly spreading applied pressure to an entire surface. I suppose the question is whether or not the manufactured Bowclamps derive any significant advantage out of the quality wood and precise dimensions?

Bowclamps come in three sizes 24", 36" and 48". I suspect making ones own cauls allows one to come up with greater variety using less expensive scrap or purchased wood? I would be very interested to hear/see details concerning how various posters make and use their variety of cauls?

[Mike Holbrook]

Judson,

I use to have a couple saw mills relatively close but the expanding Atlanta suburbs have driven them away. I have been driving to a lumber yard, Peach State Lumber to buy wood. They will run wood, bought from them, through their planer for a very reasonable price. Lately it seems like their prices have been creeping up as they appear to be specializing in providing professional cabinet makers etc. with raw wood. I was quoted $2.75 board ft. for clear yellow pine and $3.50-$4.50 for rustic white oak a day or two ago. I asked about culls, #2 wood. I was told that they did not have any at the moment and I would have to drive out there on any given day to see what might be available.

I suspect they only give better pricing to higher volume buyers who do business with them regularly. I probably need to look around for a closer provider who is not quite so volume oriented.

[Brian Holcombe]

If I'm working through a project of a size where I do not want to dimension things myself I will joint them and bring for processing. Planing without jointing can be ok on a project where the boards can be manipulated to become flat, but it's better preceded by jointing.

It's best if you can work with a place that does not mind jointing before planing to thickness.

[Mike Holbrook]

Brian,
The kitchen counter I was talking about is not "true" butcher block. The grain runs side to side not up & down on the boards. Apparently the manufacturer just did not take the time to do the glue job well, a seam came unglued at installation and a couple more have come loose since. I only mentioned it because it added a little to my misgivings about edge glueing.

The lumber I have been buying from Peach State usually has one good (jointed) edge, sometimes it even has a planed surface or two. In the past if any lumber I wanted did not have at least one jointed edge and both surfaces planed, I have had it done before I loaded it. Now that I have a Steel City planer I may try doing it myself.

I have made the mistake of planing before jointing, which can be wasted time or even detrimental which I believe is your point. Lately I try to joint first, unless there is some obvious major surface issue. My more recent work has been rough cabinets and a mobile cart for the planer. I have just been hitting the construction grade lumber with a hand plane on any edges or surfaces that might throw my work significantly out of square. My next projects will call for more precision and nicer materials.

[Mike Henderson]

I believe cauls can be just about any scrap of wood used when clamping. In relation to edge gluing, I think other posters are using cauls to hold the tops of glued boards in line, along the opposite plain the clamps would normally work? I imagine cauls could be made that would help with just about any clamping application though?

I think I made a post asking about Bowclamps, which are just precisely manufactured cauls that have a groove made to accept an F style clamp. One side of the Bowclamps is manufactured with CNC machines to achieve the "perfect" arch for evenly spreading applied pressure to an entire surface. I suppose the question is whether or not the manufactured Bowclamps derive any significant advantage out of the quality wood and precise dimensions?

Bowclamps come in three sizes 24", 36" and 48". I suspect making ones own cauls allows one to come up with greater variety using less expensive scrap or purchased wood? I would be very interested to hear/see details concerning how various posters make and use their variety of cauls?

A problem with any caul is that the curve on the caul needs to take into account the bending characteristics of the wood. And each piece of wood is going to be different. This problem is only real if you want to get the absolute same amount of pressure across the area being clamped with the caul. In the real world, if the curve is not perfect for the wood, you're still going to get a good clamp.

I have a tutorial on my web site on making cauls. One of the things I do in the tutorial is test the cauls after you make them by putting pieces of paper between them and see if you can pull the paper out. This will show that there is pressure all along the caul, but will not indicate that it is the same pressure at all points.

Others have posted techniques for making cauls where you bend the caul wood, then joint it flat while it's bent. This will give you a caul with essentially even pressure all along the caul. I don't remember the technique, but I know some ideas were posted in a thread on SawMill Creek.

If a Bowclamp is cut using a CNC machine, it will likely not produce even pressure along the caul because each piece of wood is different. But it will be close enough to do the job.

Cauls are pretty easy to make and can be made from kiln dried 2 by 4's that you can buy for a couple of dollars each.

And to stick with the main subject of this thread. I use good Baltic birch as a substrate for veneer work occasionally - when MDF will not work as the substrate for one reason or another.

Mike

[Mike Holbrook]

Thanks for the link Mike. I will add making a few cauls to my projects list. I was thinking about doing something similar with hardwood sized more like the Bowclamps. I may have a few pieces left over after I saw up the wood I bought to make a bench. Maybe a few from 2x4s as well, if I can find some decent ones. I have had a hard time finding anything decent in recent months.

I am working on a plan for a top to go on my Noden Adjust A Bench (AAB) base that will use plywood, MDF and glued up clear yellow pine. I want a vise and a replaceable/flippable top on the AAB. Then I will have something to build my Roubo/20th Century bench on.