Luan or Lauan plywood is made from the wood of the “Lauan” tree (i.e. the several Shorea species that are also known as Philippine mahogany or Meranti) found in the South Pacific Rim. It is a medium-grade, relatively light wood that produces a plywood that is much softer than most of the softwood plywood commonly used, even though it would be considered a hardwood plywood if it wasn’t known as its own category of plywood.
The first Luan plywood panels were manufactured in the Far East, principally in the countries of Taiwan, Japan, and Korea more than forty years ago. Since then exports have reached around the globe. The raw wood logs used for the manufacture of Luan plywood at that time were imported mainly from Indonesia, Malaysia, and the Philippines.
The surface finish of Luan plywood is extremely smooth and is mostly without defects. The few, small knotholes which are found are usually filled and sanded smooth with the surface, providing an excellent surface for underlayment and furniture building. However, these small defects generally relegate Luan plywood to projects where the finished product will be painted or where the finish is easily concealed, such as the back panel of dressers and other cabinet cases.
Luan Plywood History
Luan became a favored material for plywood because the tree was so prevalent throughout the Pacific Rim. The tree grew in such a way as to create logs which tended to be straight, with fine-grained wood was consistent with regards to color and density, and the wood fibers were relatively stable. Compared to other trees, it is extremely easy to peel the wood in thin layers, a necessity for producing plywood, especially thin plywood like Luan.
At the same time the wood of the Lauan tree’s suitability for plywood was discovered, the demand for hardwood plywood grew globally. This resulted in huge plywood-manufacturing industries in certain parts of the Pacific, including Indonesia, where an estimated 10 million cubic meters of plywood was manufactured annually.
However, due to overharvesting and lack of sustainability management, the industry has seen a decline. Today’s Luan plywood is not only made from the wood of the Lauan tree, but it is also made from a range of different tropical wood. Nor does the wood only come from the South Pacific Rim. Today it comes from such diverse areas as South America, Africa, Southeast Asia, and the South Pacific Rim.
In order to make Luan plywood, thin ‘slices’ of wood, called plies, are laid over each other at right angles until the desired thickness is reached and glued together. The plies are cut from a tree trunk on a large lathe, which peels off a long, continuous layer of wood veneer, to the desired thickness. Once glued under compression, the sheets are stacked and allowed to dry. Individual plywood sheets are then gently sanded to ensure a smooth finish, while any imperfections are filled in and sanded down once again.
Luan plywood is typically only manufactured in thicknesses of a 1/4 inch, although you can find it as thin as 1/8 inch at times. Being so thin, its utility for furniture and construction is somewhat limited, although it is often used for carcase and bookshelf backs and can also be found used for side panels in older furniture with inset panel sides. What makes it effective in these applications is the low cost of Luan and the applications don’t require plywood with a lot of strength.
Other places where Luan plywood is in common use include the construction of wooden dollhouses, crafts projects and toys. The thin nature and smooth surface of this type of plywood make it ideal for applications where rigidity is needed in wood panels that are wider than three or four inches. It is much easier and cheaper to use Luan plywood for these applications, than it is to use resawn dimensional hardwood lumber.
Luan is rarely used in remodeling, although there are some applications where it is extremely useful, especially when curved surfaces are needed. While there are plywoods manufactured today which are specially designed for curving, Luan has been around longer than any of them. Carpenters learned how to use it for columns, curved walls, archways and reception desks with curved surfaces, long before those specialty plywood products came into existence.
Cutting Luan Plywood
Cutting Luan can be a bit of a challenge, due to it being so thin and flexible. In addition, both the face and reverse veneer layers are extremely thin, causing them to splinter easily. Care must be taken when cutting Luan, especially when crosscutting it.
Whenever possible, you want to cut Luan plywood on a table saw, with a fine-toothed blade. While it is possible to cut it with a normal rip blade, you will get less splintering and saw marks if you switch your blade out to a crosscut one. it will be necessary to support the plywood, as it is not stiff enough to support itself. Table extensions, especially on the left of the blade and the outfeed are extremely useful. If you have someone to assist you with full sheets, it helps make it easier to control the sheet.
For long cuts with a circular saw, especially ripping the plywood, you are best off supporting the Luan on either side, blocking it up with dimensional lumber. Actually, this means supporting the sheet of Luan in four places, unless you are making a narrow cut. The supports should be on either side of the cut line and on the edges of the sheet.
When cutting with a circular saw, set the saw for a shallow cut, so as to minimize the friction of the blade passing through the sheet. When crosscutting Luan plywood, especially with a jigsaw, there is a great tendency for the splintering of the surface veneers. You can solve this problem by cutting through the surface veneer with a utility knife on the cut line. By keeping your saw blade next to this cut and not overlapping it, you avoid splintering the wood on the side you are keeping.
Taking that idea a step further, it is a good idea of making two cuts through the surface veneer, one at your intended cut line and another 3/16” into the scrap piece. That way, you won’t be splintering the surface veneer on the scrap either, keeping it useful for other projects.
This precutting of the surface veneer is especially important when cutting Luan on a jigsaw for use in dollhouses and craft projects. In these cases, there is typically no edging installed on the plywood, other than the edge of the wood panel. Splintering can ruin the piece one is trying to make. For complex cuts, such as scrolling, precutting the face veneer and ignoring the reverse side veneer is typical, as it is almost impossible to cut both exactly the same. However, in these cases, the reverse side of the plywood is normally hidden from view.
Another useful way of preventing the face veneer from splintering is to cut the Luan with the reverse side up. Splintering comes from the blade coming back up through the sheet of plywood, so this ensures that said up stroke is on the side which will remain hidden.
Finally, taping the surface of the Luan with masking tape helps hold the surface together, helping to prevent splintering. This is especially useful in cases where you are making curved cuts, such as scrolling, where it may not be possible to cut through the surface veneer very accurately or where it might be difficult to follow that cut accurately.
Bending Luan Plywood
There are a number of ways in which Luan plywood can be bent to go around curved surfaces. This is common in the sort of architectural applications mentioned earlier. Commercial offices, especially entryways and reception rooms may be designed with curved surfaces on reception desks and walls, as part of the aesthetics of the room. While other materials can be used to skin over these surfaces, Luan plywood has probably been used more than any other.
This method takes advantage of the saw kerf made when cutting into the plywood; in this case, with a table saw. Making a series of parallel cuts, most of the way through the plywood, from the back and across the direction of the bend, allows the plywood to be bent, creating a curve.
Since we are limited as to the saw kerf, with most circular and table saw blades being 1/8” thick, we are limited to how much curvature we can get out of one cut. That’s why a number of parallel cuts are made. Those cuts need to be evenly spaced apart, so as to keep the curvature smooth. The radius of the curve can be adjusted by how close the kerf cuts are to each other. Because of the difficulty in determining just how such a curve will turn out, it’s always a good idea to make a test piece, before cutting the final one.
Once the plywood is kerf cut, it can either be bent around the supporting structure and fastened in place or it can be glued and clamped around a mold, leaving it overnight to allow the glue time to set. It is a good idea in this case to either wax the mold or put waxed paper between the workpiece and the mold, to keep the glue from sticking to it.
This process requires the use of a steam box and a mold. The plywood is placed over the steam box, which provides both heat and moisture. When sufficiently pliable, the piece is placed around the mold and clamped into place, allowing it to sit for a couple of hours to cool and dry.
Steaming is a process often used for wood instrument bodies, such as guitar bodies. It is more difficult than kerf bending, in that there is a lot of finesse, which only comes from experience, involved in the process.
When steam bending, it is important to realize that there will be some spring back of the material, from the shape of the mold. While it is possible to make a mold which is overly curved, accounting for the spring back, it is difficult. However, once the plywood has been bent to a particular curvature, it will readily bend back to it, accounting for the spring-back, when attached to the underlying structure.
This method has you soak the plywood in water for approximately two hours. Once sufficiently pliable, the plywood is placed on the mold and clamped into place until dry. It is essentially the same as steam bending, without the need for a steam box. People who do not do a lot of bending often use soaking, in place of steam bending, because it is easier.
Before using either steaming or soaking, it is important to verify that the glue used in the manufacture of the plywood will not be affected by the moisture. If it were WBP plywood, this would not be an issue, but to the best of my knowledge, nobody is manufacturing a WBP Luan plywood. Instead, you will need to run your own tests on some scraps of the material you are going to use.
Luan can be used in cabinetmaking, specifically for cabinet sides and backs, where little structural strength is required, and where a smooth surface is desired. Attaching Luan plywood in such cases is best accomplished with staples and glue. Due to the material being thin and the soft nature of the wood, brads or finishing nails tend to pull out. If you choose to fasten Luan with screws, use caution as screw heads can go right through the Luan.
When used for sides of furniture, such as dressers, the Luan is often set into a slot, without fastening, allowing for freedom of expansion due to moisture. This slot also hides the edges of the wood, along with any possible splintering of the surface veneer.
While Luan is not normally used in new construction, there are some excellent applications for it in remodeling. Often, when replacing a floor or countertop, the underlayment is found to be rough; with voids, cracks, glue residue and even unevenness caused by warping. This can be a serious problem for installing hardwood floors, linoleum (whether roll or tile) and laminate countertops. Installing a layer of Luan plywood over the existing underlayment provides a smooth surface for the installation of these finish materials. However, installing Luan plywood under ceramic tile is not recommended as it doesn’t provide a stiff enough surface to prevent cracking of the grout.
As far as flooring is concerned, Luan plywood makes a great underlayment when installed between the subfloor and completed flooring. It provides extra support and ensures a smooth, level finish on which to apply the top layer, whether it is carpet, hardwood floors, or even vinyl tiles.
Red or White Luan
Luan plywood is also often used in the construction of hollow core doors. As red Luan, when stained, resembles mahogany wood, while white Luan, when stained, may resemble Cherrywood, the end result makes a great feature to any home. Of course, hollow core doors are suitable for indoor use only.
This product, however, is not only suitable for home use. It is imminently suitable for different craft projects. Birdhouses, for example, are often constructed of Luan plywood that is 1/8 inch thick. What makes this plywood so popular is that it does not easily split or splinter during cutting, and it is easy to paint over. It is also used as picture frame backing, supplying the support needed to ensure your pictures do not sag after a while.
Luan plywood is perfect for different projects of various sizes. Whether you use it for remodeling purposes in your home, or for miniature woodworking projects, its smoothness ensures an end product that needs little extra care when finishing off the details.