February, 2014 - Web Scarfs

Plywood strips 1/8" thick -- called "webs" -- are glued to the inside and outside of the spar ladders.   Starting with 4' by 4' plywood sheets, I had to end up with twelve 4" wide strips 17 feet or longer.

Cutting the 4' by 4' strips was easy enough using the table saw.   The radial saw worked fine to cut the end pieces.
   
The plans call for diagonal scarf joints.  I used the band saw to make the 45 degree angle cuts.
   

But then I had to "scarf" each strip end one and a half inch.  I tried a bunch of techniques but nothing worked.  Kevin, another Triplane builder on the Aerodrome Forum told me how he did it (his came out great by the way).  He said buy a used Sears Radial Saw and then buy a sanding drum that screws on to the accessory plug of the saw.  When nothing else had worked for me, I finally took his suggestion.  Here's a picture the Sears Radial Saw I bought off Craig's List.

I made a little table to secure the plywood strips to.   The beauty of the radial saw is that you can adjust the blade, or the accessory plug, in three dimensions.
   
The plywood strip is flat, and the sanding drum is at a slight angle, enough to get the desired one and a half inch scarf.  You will see.
 
I secured the work to the little table with the brass nails.  Worked great.
   
Here is an example of a nice scarf cut straight across the strip.
   
A nice 45 degree scarf.   Each strip end is scarfed but on opposite sides.  They get glued overlaying each other.
   
An example of how the work is secured to the table with the nails, then I draw the spinning sanding drum over the work a couple of times.
   
A better look.
   
A rare action shot of me using the radial saw to scarf.
   
 
   
Each web requires five or six strips scarfed and glued together.   Here are sets of scarfed strips for five webs.  I need a total of 12.  Lots of work.
   
 
   
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