<October 30, 2005>

Deburred Rear Spar Parts, Drill & Prime

A full day in the shop today. It felt good to get a lot done, but I am tired, and my back hurts from bending over the workbench all day. Ok, I will stop my whining now. I started the day by deburring the rear spars, I then moved onto to match drilling the reinforcing plates to the spar, finishing the day by cleaning and priming all the parts. Like I said, a full day in the shop.

During construction of the tail, I typically stuck to the deburring wheel and Scrotchbrite pads, shying away from the files for deburring. I just didn't trust myself with the files thinking they were to aggressive for deburring. However, after reading Dan's Checkoway's articles about metal work in Kitplanes magazine, I broke out the files today, and I am glad I did. Thanks to Dan, I now have a better faster way to deburr.



I started by deburring the rear spars. My process was simple... clamp the spar to the table, then start with a medium file (not the vixen, it is too aggressive), then the 2" scotchbrite wheel in the die grinder held at 15 to 30-degrees angle to the spar flange, then my medium sanding block, and finishing with the scotchbrite pad (all pictured here). This seems like a lot of work, but it wasn't, with each length of flange only taking 10-15 minutes. The file takes off the real rough stuff, the scotchbrite wheel takes off any marks left by the file, the sanding block helps smooth out small imperfections, and the scotchbrite pads takes it to a very smooth finish.

I found that one of my W-707F's was a little misbent. No big deal, after verifying I wouldn't run into edge-distance issues when I drilled, I marked and trimmed so that the edge fit flush with the spar.

Using the dimensions given on the plans, I clamped both W-707E's in place for drilling.

After match-drilling the 707E's, I drilled a few pilot holes then used my large unibit to drill the holes for the aileron pushrods out to a rough shape. I drilled into some scrap 2x4 clamped between the bench and the spar.

Here are both W-707E's after match-drilling with the spar.

I then got out my Dremel tool with a sanding drum to smooth out the rough cuts for the aileron pushrods. First I did the 707Es individually to get the big (real rough) stuff off, but then I clecoed them back to the spar and sanded them together so that the shapes of the 707E holes matched the spar holes perfectly. This worked great!

I'm sorry Sonoma, did my sanding wake you up?

OK, onto my least favorite part, cleaning and priming. First I scrubbed all the parts down with a soapy scotchbrite pad, then I hung them up to dry while I got all the equipment ready for priming... I hate priming!

Since these parts are somewhat exposed to the elemements, I chose to prime these with the PPG DP48LF 2-Part Pain In the Ass Epoxy Primer. They are now drying overnight, and I will pick up here tomorrow.