Here is a way to make your own sanding / linisher belts. This could be a good option if you live in a location where belts are not readily available in the sizes you require. I built a 6" X 48" belt sander and needed to make my own sanding belts due to the lack of suppliers and cost. I first made belts following a popular method of sanding one edge and overlapping the joint, the fixing with epoxy, but it did not provide a flat enough sanding surface for my needs, so I experimented with various ways to find the result I wanted. The solution I ended up with uses a backing cloth fixed with contact adhesive which is elastic and strong and I further strengthened the edges using epoxy. These belts can be mounted in any direction unlike belts that use an overlapped joint. This further removes confusion or mistakes in mounting belts if the direction arrows have become obscure with use, which can be the case.
Step 1: What You Will Need
Sandpaper of your chosen grit (wide sheet or roll)
Tape measure or rule
Pencil or marker
Scissors or utility knife
Close weave cotton cloth
2 part epoxy
Something to mix epoxy on
Wallpaper seam roller (optional)
Scrap pieces of wood for clamping
Plastic sheet to protect the work surface
Step 2: Measure and Cut Sandpaper
I was able to buy 1 meter wide sandpaper sheet as per meter length I require. I bought a sheet 2 meters long. Now I know this method of making belts works well for me, a 3 meter length would have been a better option.
I measured and cut the sheet into 15cm wide strips. This provided me with the material to make 6 belts.
My belts need to be 140cm long to the joint line.
My first experiment was to cut the joint line at an angle similar to that on my old belts. I also experimented using a butt joint for ease and it is just as strong and also an easier way to make the belts.
After cutting to the joint line length I applied a small amount of super glue to hold the edges together while I worked, but this step is not essential.
Step 3: Apply the Backing Cloth
Cut the backing cloth (close weave cotton or denim) 12cm wide. I made sure it was long enough to overhang the width of the belt, so as to trim it later.
Spread an even coat of contact adhesive to the cloth. Use a piece of plastic underneath it to protect the surface you are working on. The instructions for the contact adhesive recommends waiting until the surface is dry to the touch. It does not take long to dry.
Mark a line either side of the joint line on the back of the sandpaper to match the width of the backing cloth. These lines are used as a guide for where to apply the contact adhesive.
Apply the contact adhesive within the guide lines on the back of the sandpaper and wait until it's dry to the touch.
Once it feels dry carefully place the backing cloth between the guidelines on the sandpaper with the 'adhesive applied' surfaces facing each other. It should adhere really well, so you may only get one chance to align it.
Trim any excess overhanging the width of the belt and apply pressure using a wallpaper seam roller. A cloth rubbed over some plastic will also work.
Step 4: Clamp Until the Adhesive Dries
Place a piece of baking paper over the backing cloth.
Sandwich the joined part of belt between some scraps of wood large enough to cover the joint and clamp or weigh down with a heavy object.
Leave for as long as possible. 24 hours or more.
Step 5: Strengthen the Edges of the Joint
Once the contact adhesive has been left to dry mix some 2 part epoxy to apply along the joint line and the edges of the backing cloth. My method is to dab it along the lines leaving it slightly proud, then go back and smooth it out as flat as possible by drawing a small spatula across it.
. I used 5 minute epoxy and I had enough time to finish the process before it set up completely.
Let the epoxy fully cure before using the belt.
Step 6: Further Experiments
I since only use a straight edge butt joint to make my belts. I use the same steps as with the angled joint. I find a straight joint saves time, is easier and faster to repeat the same result. I have not had a belt fail at the joint yet with either method.