Many people cut scroll saw projects for selling at craft fairs and shows. Some more intricate fretwork patterns and portraits can take a great many hours of cutting to complete. In order to make more effective use of your time and make your hobby profitable, you can use stack cutting to cut multiples of a pattern at once.
There are several ways you can go about stack cutting I am going to discuss the technique I use most often which entails using double-sided carpet tape. I use this method as much as possible because it’s easy to set up and doesn’t allow the layers to move at all if done properly.
First I have to talk about selection of tape. There are many different kinds of carpet tape available to choose from and some will work much better than others. You want to avoid any tape that has a foam core because when you try to separate your layers of wood after cutting, the foam will split and you will have great difficulty removing all the adhesive and foam from the wood. I have had great success with fabric core tape in the past however I have had difficulty finding any of late.
I am currently using Scotch Brand Outdoor Carpet tape CT3010 which works great. This is definitely the strongest sticking tape I have used so you only need tiny pieces to hold your wood together. It does however still require a little work to get the adhesive off.
Some points to remember:
– Be sure not to stack together more layers than your saw/blade combination can handle. I generally don’t recommend stacking too much more than 1/2″ thick with really hard woods because any thicker than that will require you to reduce your feed rate significantly.
– You’ll want to use very small pieces in the work area to hold your layers together if you use the recommended tape (~ 1/2″ square pieces unless you are working on something really big).
– Keep the tape pieces away from any delicate areas in the pattern to reduce the chances of damaging your work when you separate the layers.
– You can be more generous with the tape in waste areas on the wood however you should have at least two pieces in the work area to prevent your layers from moving when the waste is cut away.
– To separate your layers, carefully slide a small knife in between the layers near where the tape is and gently pry apart by twisting the knife until the tape un-sticks. Repeat this for each piece of tape.
– The remaining tape should come off more or less in one piece leaving a small amount of adhesive residue on your wood. I recommend gently shaving the majority of it off with your knife and, if any still remains on the wood, you can use alcohol or mineral spirits to clean it up.
I believe most if not all scroll sawyers out there will eventually have a use for stack cutting. Sometimes a pattern requires multiples of the same piece, other times you may want to do multiples of a project. Stack cutting will make your life easier and a roll of good carpet tape should find its home in your tool box.