badger5964

My Feedback: (6)

I had to thin a small piece of 1/8" balsa sheet. The piece was about 1 x 3 inches. I put it between two Great Planes sanders and started rubbing. Worked great! The piece stayed on one sander while the other moved over it. It took just a few moments and it was easy to keep the pieces flat and consistent. Check out the pics.

GREG DOE

It's an old trick. I learned it from a free-flighter 20 years ago. Coarse sandpaper, and fine sandpaper. Put a sheet of fine sandpaper on a flat work surface, and use a coarser paper on your sanding block, or stick.

sensei

I purchased a 96" X 24" 3/4" thick piece aluminum honeycomb panel around 12 or 15 years ago, I have always used it as a sanding board by mounting 220 grit silicon carbide open coat full sheets of sand paper to one side covering nearly the entire side at times, then I just move the work in 45 degree motions over it. I have never found anything that works so true and easily. I soak my joints with thin and medium CA and never worry about how hard it is to sand the high CA glue down because with this method it removes the high spots like butter. As you can see the tail feathers glued up and sitting on the honeycomb panel ready for sanding, and after sanding. This is a 55% fuselage after sanding and gussets glued on after using the same board and method of sanding as the smaller size stuff. Sanding curved surfaces like wings, turtle decks and so I just use a flexible spline board to level the high spot even with the low spots, believe it or not I mound 80 grit sand paper for this process and again a 45 degree motion is used.



Bob

dbacque

My Feedback: (3)

Another trick from the indoor free-flight fliers:

To sand to a desired thickness, place a piece of music wire of the right diameter on each end and use an aluminum sanding bar with very fresh sandpaper. Don't apply any pressure. Use very light strokes to let the sandpaper do the work. This will give you a consistent thickness. You can even sand tapers this way by using different sizes of music wire.

I glue the music wire down to a piece of scrap balsa and place the work piece in between the wires. It won't slip because the wires act as stops and you can't cut too deep. Plus your sanded surface will be flat.

Mark the wire sizes on the board and toss it into your jig box.

Dave

Leroy Gardner

Bob you always do such beautiful work, I bet you don't have to sand very much and have learned all the tricks of the trade.

Leroy

crossman

On the midwest Stearman I needed to taper a piece of balsa to set the incidence of the tail, I used a similar setup with two drill bits of the needed sizes to guide the sander. I started with a razor plane that I extended to lay on the drill bits. I will probably use this method for a current project that I need to thin down some stock.

sensei

Thanks for the kind words Leroy, but to be honest I just take the easy road, let me explain, I literally soak the joints in thin CA, add any and all hardwood doweling for flying wires, control horns, or whatever as illustrated in the pictures also soaking with thin CA then I pull the part from the tabletop and add medium CA fillets to every joint. Once that is done, I sand on the parts by moving the part over the fixed abrasive table top. Take a 24" horizontal stab, it only take about 5 or 6 minutes of sanding to achieve all sanding to perfection, it is so easy and cuts so true its like cheating. The only trick is to glue everything together slightly oversize from your desired thickness when finished. Lets say I wish to have a .375" thick stab when finished sanding, then I start with .500" material, glue and sand. Taking .063" off each side only takes a few minutes to accomplish and renders a surface on each side the is true and has the complete appearance of being machined on a mill.

The only kickers to this are:

1. You must possess a long flat rigid surface.
2. When mounting the 220 grit sand paper sheets do not allow any area of the sand paper sheets to overlap onto another sheet of sand paper.
3. Sand in +/- 45 degree motions using light to medium pressure. That's it, this is fast and simple rendering perfection as the outcome. I actually learned this trick from my old two cycle motorcycle racing days, we would mount wet/dry sand paper to a thick and flat piece of glass and surface our cylinder heads wet in a figure eight motion prior to a reassembly of our engines. Once any builder tries this, they will never go back.

Bob