I am currently building a sig 4 star 40, and i'm at the point where it is time to sand the leading edges. I see great planes makes a sander that looks like the contours will work for what i am doing. Anyone care to offer input? sanding this by had isnt much fun so far, and if this is the correct contour, it would make things much easier. thanks for the help!

trey

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXK325&P=ML]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXK325&P=ML[/link]

I have seen that tool but I usually make my own. If you want just a round over sander, take a 6-8 inch length of PVC pipe of the diameter that best fits your application and cut it in half, length wise. Use self adhesive sandpaper in the cavity, and a little bit on the outside to give you a better grip. I make sanding tools out of all kinds of stuff.[sm=teeth_smile.gif]

I have the Multi-sander and yes, it will work on your 4-star. It did on my 4-star 60, at least. It has a handle which makes it a little easier to grip that a piece of PVC pipe, but I've used the pipe also if you don't want to spend the loot.

Cut two pieces of sand paper about 2-3" wide, and tape them together end to end. Use them like a "shoe shine" rag and you will get perfectly contured and uniform leading edge. Use 150 -220 grit.

I've used it on my Top Flite Piper Arrow and it worked great.
chopper man

I have several sizes of the PVC sanding tools. I usualy make mine at least as long as a sheet of sand paper. The longer, the straighter the edge will be. One point, use a larger size PVC than the curve of the leading edge unless you are going to cut the pipe into 1/4's. If you use to small a pipe, the edges will dig into the wing as the leading edge curve is actually a series of curves. Just lay a small pipe, or comercial sanding tool on a finished edge. You want to make sure the the true leading edge hits the bottom of the tool before either the top or bottom edge contacts the wing. How do I know how to do it this way? Well I had to replace the top sheeting on my Ruperts because I cut through it sanding the leading edge.

I don't like the strap method as I always get a scalloped edge. Using the long PVC is like using a long plane on it.

Don

The best way to shape a leading edge is not with sandpaper but with a razor plane. Carving will give a much better result in lots less time than sanding and it's oh so much fun.

I use the Master Airscrew Balsa Plane. Run the full length of the LE on each stroke. It takes the wood off faster and with more accuracy and control. Once you get it close, then use a sanding block. You'll even find that you don't need a shaped sanding block.

What once was a chore is now one of my favorite things in building a plane. Unfortunately it works so quickly that the fun ends much too soon.

Dave

Actually, I forgot to mention that I do plane it to the basic shape with the M/A plane before I shoeshine it. Prevents the scalloped effect mentioned by Don.

I'm like Dave, I plane the LE to the rough shape then take it down some more with my finishing sander then either hand sand or use my GP shaped sander to get it smooth. The hand plane just makes things easy and I just hate sanding and all the dust in the shop.

I forgot to mention another trick. Pick up a couple belts for a belt sander. Your choice of grits. I cut them across the seam and this gives me a long, depending on the length belt you select, and stiff belt. I use some double sided tape and tape the belt to a piece of board. You can easilly get a 24" long x 3" belt that is exactly flat when taped down (use sticky paws from the pet shop)

You can also cut short lengths from the belt and it gives you a stiff, but slightly flexable sanding pad, Great for sanding turtle decks and such. simply squeeze the belt by the edges and bow it slightly.

If you want finer grits, check with a lapidary or Rock Shop store. They have, or can get, belts from around 100 grit down to 600 for ultra fine work. These are usually sillicon carbide belts the are used wet. Not much good for shaping balsa, but great for finishing off the fiberglass wheel pants and cowls.

Don