----- Original Message -----

From: KSFreeflit@aol.com

To: tandyw@flash.net

Sent: Wednesday, October 24, 2007 9:55 AM

Subject: Re: 32 J-3 New Nose Block for Scale Looking Front End

 

Hi Tandy,

 

I have one comment about one of the details on your J-3 Cub.  The rear outlines of the rearmost side windows have a structural problem:  Those two parts (L & R) cry out for lamination to avoid the wood grain structural weakness.

 

Jim O'Reilly

 

When I got the above note from Jim several days ago, I realized that there was indeed a problem. The picture below shows the "wood grain structural weakness" in the rear window outline that Jim is concerned about. Thank goodness there is still time fix the problem.

 

The picture below shows (1) the rear window outline on the plan, (2) the velum pattern I made from the plan outline, and (3) the 1/8" card board template I made using the pattern.

 

I still had several strips of the 1/32" X 3/32" for the stab that I did not use. I waxed the template edges and pinned it down over a piece of wax paper. I also waxed the edges and ends of the balsa blocks used to hold the four strip spline against the template (I use four strips because the laser kerf reduces the 1/32" dimension slightly such that three strips do not measure a full 3/32"). After soaking the four strips of balsa for about an hour, I spread Titebond aliphatic glue between the strips, removed the excess, and formed the rear window spline around the template as shown below.

 

This will be allowed to dry overnight to form a solid rigid spline. In the morning, I will remove the spline from the template and make sure it came out good. Then I will cut out the existing rear window frame and install the new spline in its place........................Tandy