Woodworker's Journal 1994-18-2, страница 18

Woodworking Basics

Shopping for Sheet Stock

Choosing between plywood, particleboard and fiberboard by Roger Holmes

Assemble a random selection of woodworkers and you're likely lo find among them a w ide range of opinion on just ahoul every aspec! of the craft. Many of these opinions are not Lightly held. I've known hand tool aficionados. for instance, who refused to have any thing to do w ith the "gear-head" machine woodworkers among us, and vice versa.

Despite our considerable differences, i think there is one fairly safe generalization to be made about woodworkers: The vast majority prefer to work solid wood It looks good lo the eye. feels good to the touch, and there's that specjal thrill in putting a tool lo it. regardless of whether the tool is powered by hand or machine.

The farther our chosen material gets from the iree. however, the less satisfying our relationship with it. Split it from the log or saw it into hoards and most everyone is happy. Peel it off in thin sheets, and we begin to lose some folks. Grind it up and press it into boards, and tile crowd of believers resembles church on Super Bowl Sunday.

Ply wood and Particleboard— One Woodworker's View

I started out as a committed solid-wood woodworker. I shunned veneer unless it could be glued to a solid-wood substrate. Plywood was for workshop shelving, at best. Particleboard was completely beyond the pale, an invention of Philistines (or worse! obviously bent on destroying the traditions of the craft.

It didn't lake long to realize the limitations of such rigid views. Making a complete kitchen of solid cherry reminded me of something my father knew well— "sheet stock." such as plywood, is hard to beat for assembling large numbers of cabinets whose exteriors are almost never seen. A stint w ith a master cabinetmaker in England showed me that even lowly particleboard could be used to advantage in furniture of the highest

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quality. In a very complicated desk, it allowed us to use a construction that would have sell-destructed if subjected to the expansion and contraction of solid wood. And the lovely wood in which we veneered the project couldn't have been obtained in sufficient size to permit solid construction anyway.

I have used a fair amount of sheet material since, for built-ins, shelving and a few "nice" projects. For the most part. I've stuck with the veneer-core hardwood plywood and cabinet-grade particleboard that are available in most tow ns. The ply w ood usually comprises two paper-thin face veneers laid on a stack of thicker veneers of cheaper hardwood or softwood, depending on the quality and the mill. (Fig. 1). Particleboard suitable tor cabinetwork and furniture is distinguished from its construction-grade relations by having finer particles overall tFig. 2). And. like plywood. the sheets are layered -a core of coarser material is sandwiched between two smoothly sanded faces of very fine particles.

I'm not terribly imaginative in my use of sheet slock. Sometimes I piint it: sometimes I veneer over its faces w ith my own matched veneers to get just the look I want. (Unless special ordered, hardwood ply wood seldom offers veneers of sufficient interest or. more importantly. the right matches in the right places to allow you to construct a coherently patterned piece of furniture.)

Dcspiie their utility, i often find myself irritated w ith these materials. Sure, iis great lo be able to design w ithout having to allow for expansion or contraction in any direction. And it is a relief not to hav e to prepare rough stock-—pinning faces lo achieve the desired thickness: edge-gluing lo produce the required widths. With plywood or particleboard. you just set the rip fence and in a few minutes you've got a stack of parts ready for joinery.

But you've also got a stack of raw particleboard or plywood edges. One of the former looks a bit like a Cross-section through a tuna-fish sandwich — the coarse filler a bit ragged between the two finer faces. Becausc ihe inner piys of ihc latter arc prone lo voids, plywood edges can have a gap-tocrthjd look. Boih types of edge require attention to be presentable

Oilier problems crop up depending on the nature of the project. The paper-thin face veneers of hardwood plywood allow defects, patches, or even irregular grain in the cross-bandings (the layer immediately beneath each face) to telegraph through and mar a painted finish or the surface of a thin veneer you might add. Similarly, the coarser chips in the core of particleboard can sometimes telegraph through a sheet's finer, sanded faces. And, while hardwood plywood will support the weight of books, for example. as w ell or better than most solid woods of the same thickness, particleboard of the same thickness will sag under the same load.

Both particleboard and hardwood plywood restrict tha range of joinery available for a given project. Particleboard, for instance, tends to crumble if you get too fancy with corner joints—thin tongues or long grooves. Ply wood has more structural integrity, but cutting certain joints can be a splintery undertaking. Both materials can have problems holding fastenings - particleboard on edge or face; plyw inxl less so, but if your screw digs into an end-grain ply it might cause problems

Better Boards

7 here are. fortunately, alternative sheet materials that offer improvements upon all of the draw backs mentioned. Unfortunately they can be difficult or expensive (or both) to obtain: and they have draw backs of their own. For certain projects. however. the\ may be worth the

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