Structural Bluetape - For the Love of Making Things

 

Laser Materials: Working with Wood

Pros:

Wood is attractive, easy to find, strong and scratch resistant.  It’s easy to glue, and easy to paint or stain.  

Cons:

Wood has a tendency to change shape and bow when exposed to changes in temperature or humidity.  When choosing a piece of wood, it’s important to try to find a piece that is as flat as possible.  You should also check it again before cutting because if you left it in your hot car all day, it’s probably not going to be the same shape as when you put it in.  Bowing is a real problem when laser cutting because it causes the laser to go in and out of focus as it it moves across the material.

Also you’ll often find the the size listed on a board is not the actual size.  Always check the actual dimensions before you make your purchase.        

Hardwoods / Hobby Boards

Big box hardware stores such as Home Depot will usually carry ¼” Alder and Poplar boards.  You’ll often see them listed as Hobby Boards.  

These are great for laser cutting, they give a nice clean and consistent edge when cut.  The biggest downside is that you rarely can find them in widths larger than 6” (which are often actually only 5 ½”).  

I prefer the darker Alder wood, as it takes stain better, whereas the lighter Poplar boards often have greenish streaks, and are harder to stain.  However either is fine if you plan on painting the finished project.

Engineered Wood and Composites

Plywood and MDF both contain glue, which absorbs the laser energy and makes it harder to cut.  It’s much easier to find these in large panels and a variety of thicknesses.

Plywood looks good and is durable.  There is a wide variety in quality and types of plywood.  Be sure to check the edges carefully before choosing a piece.  What you’re looking for is the composition of the layers, as they will be visible on your cut edges.  You’ll also want to look out for voids in the plywood.  If you see some in the store, there’s likely going to be more hidden voids that may show up on your cut edges.

MDF is also known as Medium Density Fiberboard.  It is made of up of wood fibers that are combined with wax and resin.  It’s the chicken nugget of wood products.  It’s main advantage is that it’s consistent and stable.  You won’t find voids in MDF like you will in plywood, and it’s much more resistant to bowing than other types of wood.

MDF does not have a grain, so it lacks the natural beauty found in other types of wood.  This can be an advantage or disadvantage depending on your application.  MDF is heavier than other types of wood and is very susceptible to moisture damage.  The glue content is much higher than plywood, so it can take more passes or more power to cut with the laser.