I'm making slow progress on the windscreen. I've spent a lot of time gradually trimming the lower edge along the sides to get it to be just clear of the skin. I figure that it the skin may put stress on the edge of the plexiglas if they are touching. I think it is better to have the loads from the skin to the plexiglas go via the fibreglas fairing, as they will be distributed over a larger area, rather than being concentrated on the edge in the places where it is touching the skin. This has been a painfully slow goal to achieve though, as every time I trim a bit more off the sides that allows the plexiglas to move inwards a bit more, and the skin is higher the further inwards you go. I finally got the final trimming and edge smoothing done this morning.

I have been planning to install a defrost fan, as other builders report that it is needed in cold weather ground operations to keep the windscreen from frosting up on the inside. I purchased a 90 mm computer "muffin fan" to mount under the top skin just behind the front edge of the windscreen. I had planned to install it later, but I realized that the presence of that large hole might change the contour of the front skin a bit, which could affect the fit of the windscreen fairing. So, yesterday I cut the hole for the fan.

Before cutting the defrost fan hole, I decided to do some quick and dirty electro-magnetic interference testing, just to be sure that it would be compatible with the rest of my avionics. I installed the GPS, COM, intercom and EFIS, as they were the most likely victims. I confirmed that the running fan had no effect on any of those items, except that it perturbed the EFIS's internal magnetic heading flux valve. But I will be using a remote flux valve, so this is of no import.

I had partially trimmed the aft edge of F821 forward skin where it meets the canopy skirt, but I still had some interference. I finally realized that I was going to have to extend the windscreen fairing downwards to extend over the front edge of the canopy skirt, so there was no reason to try to keep the aft edge of that skin. Today I trimmed the aft edge so it no longer hit the canopy skirt.

I started covering the windscreen, forward fuselage skin and front of the canopy with 3M 471 vinyl tape. This stuff is a bit expensive, but it is great for this job. It comes in many widths up to 4" wide, but the 2" width I've got seems to be about right. It sticks well, but doesn't leave any residue when it comes off. I stole an idea from someone else and will use electrical tape to mark the planned edges of the fairing. This will allow me to see how much area I need to cover with the fibreglas. And I put several layers of the electrical tape on top of each other to make some thickness. This will make a visible trim line on the bottom of the fairing that I can use to trim it after I pop it off.

Tomorrow I'll finish covering the windscreen, etc and lay up the windscreen fairing.