Plywood is an extremely useful material, for both architectural applications and making furniture. But the finish that the various plywood products provide isn’t necessarily attractive. While it is common to stain and varnish plywood or to paint it, there are applications where something more is needed; an actual covering material.
When we’re talking about covering plywood, we need to be clear about what we’re referring to. We could be talking about either just covering the edges or covering the entire panel. Much will depend on the type of plywood we are using, the application and the finish we are looking for.
When talking about high-quality cabinet-grade hardwood plywood, the only thing we would normally want to cover is the edges. The hardwood veneer on the face of the plywood is normally quite attractive, especially when stained and varnished. It would be a waste of money to use an expensive plywood product like this, designed specifically for furniture and cabinetry, but cover it up with some other material. However, the exposed edges of this plywood may need to be covered, if they are not already covered by other parts of the project, as they don’t have the same beauty as the face.
Covering Plywood Edges
For furniture and cabinetry made out of hardwood plywood, only the edges need to be covered. This is done in one of three ways, depending on the design of the project. Two of those ways involve the use of wood and the third is plastic.
Wood veneer edge treatment provides the most unobtrusive option for covering the edges of hardwood plywood, often leaving the appearance that the piece is made out of solid hardwood, if installed properly. If you are already using wood veneer somewhere in the project, you might choose to use some of the same veneer for the edges. If not, then there is veneer edging made with hot-melt glue already applied to the back side, making it very easy to install.
For an expert level finish to this edging, cut off the core veneers of the plywood, leaving a tongue of the face veneer sticking out, which overhangs the edge the same amount as the thickness of the veneer you’ll be using on the edges. This will allow the face veneer to cover the whole surface, rather than having the edge veneer visible from the face of the board.
The commercially available veneer with hot melt glue is the easiest to work with. It comes available in a variety of widths, although 3/4” is the easiest to find. To attach it, position it on the edge of the plywood and melt the hot-melt adhesive with a clothes iron, as if you were ironing the veneer in place. If the veneer is wider than the board is thick, the extra material can be trimmed off with a sharp knife. Always be careful to work with the grain direction, when cutting.
Using your own veneer is a touch more complicated, as it doesn’t already have the adhesive attached. In this case, you’ll need to apply a thin coating of wood glue to both the back side of the veneer and the surface you are gluing it onto, spreading it out with a small brush. Allow the glue to dry about 45 minutes and then attach the veneer to the plywood, using an iron, in the same way that the pre-glued wood veneer trim is attached.
A slightly more visible way of covering the edges, which can nevertheless look quite attractive, is to use a 1/8” to 1/4” thick strip of hardwood banding to cover the edge. This can be cut out of the same hardwood that is being used elsewhere in the project, or a contrasting hardwood, depending on the style you prefer. The banding is glued with wood glue or glued and nailed to the edge.
There are several ways of attaching this banding to the edge of the plywood, such as cutting a tongue and groove. But the most common way is to simply glue it in place, either using edge clamps to hold it while the glue dries or using a brad nails to hold it while the glue dries. However, if you use brads, the nail holes will have to be filled.
A third option for banding is to attach a square strip of wood, gluing it into a 90 degree, angled notch cut into the edge of the board for it, as shown in the diagram below.
In this case, the edge of the plywood needs to be cut at a 45 degree angle, with either a table saw or a router, to make a place to insert the hardwood edge piece. The trim piece is cut from a hardwood board, and then glued into the notch. Excess material is then cut off on a table saw.
The advantage of this method is that it provides you with a durable hardwood edge, which is more resistant to damage than veneer is, while still making the finished piece look like it is all solid hardwood. It’s a bit harder to do, but the results are worth it.
Finally, there is one other way of edge banding; that’s using wood screen molding, which usually comes in 3/4” width. This can either be plain or beaded, but will be made of the same whitewood that is commonly used for other architectural trim moldings.
Plastic trim is commonly found, factory installed, in furniture made of plywood. It is something like veneer, with rounded edges, except it is made of plastic. This piece fits into a groove, cut into the edge of the plywood, as if it were tongue and groove.
You can buy this material, in a variety of colors and widths. While it doesn’t provide anywhere near as nice an edge as hardwood edge banding or veneer, it is an easy way to finish off an edge, which will go well with casual areas, work areas and children’s playrooms.
Covering Plywood Surfaces
There are a number of materials that can be used for the purpose of covering plywood panels, giving them a nice and attractive look. These provide a very different look, to the point where it may not be obvious that the project is made out of wood, let alone plywood.
Fabric is considered to be the oldest and simplest means of covering plywood projects. The selection of fabric though would have to be made very carefully considering the look that you want to give to the project. Almost all fabrics will stick to all plywood products, if the right adhesive is used.
Before gluing any fabric to plywood, it is essential that the plywood is sanded. You’re looking to accomplish two seemingly opposite things here. The first is to eliminate sharp or rough edges, corners and splinters, which could cut or poke through the fabric. The other is to rough up the surface of the plywood, in order to ensure that the glue will adhere. Using 120 to 150 grit sandpaper for this should accomplish both purposes.
The best adhesive to use for attaching most fabric to plywood is a spray adhesive; something like 3M type 77, which is essentially a thinned down version of contact cement. For fabric, you probably want to spray it on the fabric and not the plywood, then put the fabric in place, smoothing it down.
When using this adhesive, be aware that it dries quickly and once dry, you can’t move the fabric. So you want to be careful about the placement of the fabric on the wood, avoiding wrinkles. Be careful to center the fabric over the wood, so that you can wrap it around the edges and glue it in place. Be sure to do the folding and gluing around the edges in an organized way, so that you can end up with neatly folded corners.
Some people recommend the use of hot glue with fabric, but this only works with heavier fabrics, like some of the heavy upholstery fabrics. If hot melt glue is used with thinner fabrics, it will soak through the fabric and be visible.
When using hot melt glue, only apply the glue around the edges of the panel you are covering, sticking the fabric to it immediately. One advantage of using this method is that you can insert quilt batting under the fabric, before sticking it down, giving the panel a softer feel.
Covering a plywood panel with vinyl upholstery is much like covering it with fabric, with the exception that contact cement is used, rather than spray adhesive or hot melt glue. While those adhesives can be used, they are not strong enough for long-term. Another alternative is to use a staple gun to attach the vinyl, if your design allows you a means of covering the edge with the staples in it.
There are also vinyl products which are specifically designed to be installed as a covering for plywood. These products are not really an upholstery product, but rather designed to provide a specific texture and style, becoming the surface and totally hiding the plywood underneath. Some appear metallic, while others could take on the appearance of fake alligator skin or other textures. In any case, they are designed to provide a specific “look” to finish off modern styled furniture.
Vinyl floor covering can even be used as a covering for plywood, although it rarely is. But in the case of a play room, with say a play fort in it, vinyl flooring may be used as a covering on parts of the fort, especially walkways. As this floor covering is normally installed over plywood subflooring, installing it to any other plywood project is just like installing it onto the floor.
Fiberglass normally isn’t used as a “finish” for plywood, but plywood is often used as a support for fiberglass. Combining fiberglass with plywood provides a durable mix that is waterproof and strong. Such a combination is common on boats, but can also be used in recreational vehicles and outdoor furniture. It will work anywhere that you need something strong, attractive and waterproof.
I must warn you though, working with fiberglass is messy; so be prepared for that. Always wear rubber gloves when working with fiberglass and cover the workbench or floor with both waterproof and absorbent coverings.
When designing projects to be covered with fiberglass, you want to avoid sharp edges and corners. Fiberglass cloth is very loosely woven and corners will jab through it easily. This leaves you with a corner which is essentially unfinished, even while the rest of the board is. Better to use rounded corners and round all your edges, so that the fiberglass can cover the entire project evenly.
Before applying the fiberglass, the project should be finished and sanded. You’ll want to sand all surfaces with 120 to 150 grit sandpaper, in order to provide a surface which is just rough enough for the fiberglass resin to get a good “bite” on. Be sure to wipe the sawdust off the surface.
A minimum of two layers of fiberglass cloth is needed for any project. More layers can be used. If you are trying to build up a thick coating of fiberglass, it would be best to use “woven roving,” which is a fiberglass cloth product made with a much larger yarn diameter. One layer of woven roving is the equivalent to roughly five layers of normal fiberglass cloth. This is an approximate, as there are more than one type of fiberglass cloth and more than one kind of woven roving.
You can use either fiberglass resin or liquid epoxy for fiberglass work. Different products have different working times, so pay attention to that when you buy it. You’re usually better off with an epoxy that has a 30 to 60 minute working time, when doing fiberglass work. I’ve had way too much epoxy harden on me, right in the middle of applying my fiberglass. Mix enough resin for what you need, but not too much. Excess rosin or epoxy that hardens is of no use to you and these materials are expensive.
Before starting, cut as many layers of fiberglass cloth as you need. These should be larger than the surface you are covering, so that the excess can be wrapped around the edges.
Paint a layer of rosin or epoxy onto the surface, using a disposable paintbrush. Neatness isn’t all that important, but you don’t want to miss any spots.
Lay the fiberglass cloth onto the project, centering it and folding the edges over the sides, sticking them there. Be sure to do that now, as you can’t do it later. You can move and reposition the cloth somewhat, but don’t overdo that, as it tends to start coming apart.
Continue alternating layers of rosin and cloth until you have built up as thick a finish as you want. Always cover the last layer of cloth with a thick coating of fiberglass resin or epoxy.
The finished fiberglass can be sanded and painted or have gel coating applied, once it has had time for the rosin or epoxy to thoroughly cure.