ng wood so I do not use the planning process when building a glider. I just sand longer and make more dust.
Tools For Sanding
One must think of sandpaper as a replacement part for the tool that is called a sanding block. You typically should do very little sanding without a sanding block. Why? Well I believe you lose control if you sand with just sanding paper. Sanding without a hard flat backing surface is the easiest way to make waves in the part that you are trying to shape.
So the first tool you need is a sanding block, actually many sanding blocks. See Photo 2 for my collection of sanding blocks. Now you can go to the typically hardware store and purchase a sanding block, but I don’t and here why. First the store’s sanding blocks are heavy and I need/want control. I don’t need some heavy sanding block, pushing on the wood, making me fight the forces of gravity while I am sanding. Also, the sizes and shapes in the hardware store never seem to be right for me. So I build my own sanding blocks out of balsa wood. Now you don’t need to use your lightest wood, just some junk balsa blocks with do just fine. You can cut the block to any size and shape you want and make it fit you hand, because to have control you need to be comfortable. Later I will discuss how to make a flat portion on your sanding block. Other things to note about a sanding block. The sandpaper must be attached to the entire surface of the block. I use double sided tape to accomplish this. If the sandpaper is allowed to float off the flat surface, your sanding precision will decrease. Also make sanding block as large as possible. The larger the sanding block the harder it is to rock the block. On the other hand you do need some small sanding blocks to sand in tight places.
Collection of many different size and grit Balsa Sanding Blocks
The next tool you need is a hard, flat surface to sand on. I use glass plate. If you watch the garbage others throw out, you can typically find pieces of glass at the curb. The best is when someone replaces their windows, just pick up the window frame with the glass inside. It is pretty easy to remove the frame and then you will have your nice building surface. Marble is also good to work off of but more expensive and harder to find. See Photo Below.
Building/Sanding Surface. Note the duct tape at the one edge which is a sanding fixture/jig used to set the height (.025") of the trailing edge of a wing.
Another item I use a lot is masking/duct tape. It is amazing to me but sandpaper does not cut or sand duct tape or masking tape very well. So I use these tapes as tools and fixtures to control my sanding. I will discuss this a little more in detail later.
So to summarize, the tools you need are:
- Sanding Blocks: Lots of them!
- Sandpaper: Lots of different grits.
- A Flat Surface
- Double Sided Tape
- Masking\Duct Tape
I purchase all my sandpaper from the local hardware store. I found the cheaper sandpapers don’t do as good of job as the expensive ones. I use a 3M product called SandBlaster. See photo below.
SandBlaster sandpaper in a variety of grits.
Basically sandpaper is made from three components. One is the paper or backing surface the "stones" are glued on to. The cheaper sandpaper uses poor quality backing paper, which can be inconsistent in thickness and not very durable. Next is the glue which is used to glue the "stones" to the paper. Again the cheaper the sandpaper the poorer the quality of glue is used. Finally there are the "stones". There are two important features of the stones. One is what material they are made from. Stones made from hard material make sanding process easier and more precise. The second is the size of the "stones". The size of the stone is characterized by the grit of the sandpaper. Sandpaper comes in a variety of grits usually ranging for 60 to 1500. 60 grit is very rough and 1500 grit is very smooth. . A table below shows the sandpaper grit number and the corresponding "stone" size.
|Grit||Average Particle Size (in)|
Precision And Grit Number
If one spends some time to think about things 