Time to Start Filling and Sanding

To keep this post short and simple, let's just say I used the advice from George Sychrovsky and Wayne Hicks. Be sure you read those two links if you are going to finish your plane. The Prime Directive is, "ONLY FILL ONCE"!!! If you and filling, sanding, filling and sanding, you are doing it wrong. I used their method this time around and am very glad I did. However, I did not go the black primer route.

I used West System, which is non-structural for aircraft, and glass microballoons. First, I filled low areas using the fast hardener. Then I started mixing and mixing and spreading and spreading. I really lathered it on. I bet some places were at least 3/8" think. But again, the idea is to lay it on only once and sand down to the low spots. It took me about 1-1/2 hours per wing panel, doing one at a time.










After about 5 hours of cure time I can go at it with a Stanley Surform file to knock down the high spots.



I used two-foot sanding boards with 36 grit paper. I use the 3M stuff that already has the sticky back. Per George's recommendation, I made the boards from laminated bookshelf boards I got from Lowes, then attached a piece of angle aluminium on the back. Before got really into it, I took a pencil and really marked up the surface. This helped me gauge how much I had sanded and identified the low spots that I would sand down to.

Sand, sand, sand for a couple of hours. Note the pile of dust. Really though, it's not that hard. I just say to myself, "I am going to work on the plane from 9:00 to noon, and when it's time for lunch I will have a sanded wing panel"! I bet I sanded off over 80% of the micro that I applied.

When it looks good with the 36 grit paper, I switched to 80. Just a few minutes with the 80 and that's it! At this point there are all sorts of awful holes, crevices, and scratches. Previous methods would have had us filling and refilling. Yeaucch.

Next, I do the epoxy wipe. Mix up a full cup of West and squeegee it on. I just apply enough to make it wet, then try and squeegee it all off. I am not building coats, I am filling the imperfections. I repeat this every hour until I have applied 4-6 coats.


Next say put some 120 grit paper on the sanding boards, make a few passes and I'm ready for primer! I love it!