Before priming session 2 can start, I had to do some more preperation and scuffing of parts.
I took the F-749L and R forward side baggage covers out and scuffed them. While doing this, I noticed I didn't drill and clean and dimple the bottom nutplate attachments yet.
Used the nutplate template tools and the squeezer took care of the dimpling process. Pay attention, the nutplates go on the bottom of this side cover so dimple like in the picture below.
After scuffing, I also noticed some notch marks on the top side and wondered for a while what those were for.
Well, the manual doesn't explicitely state this and I also don't see hashed trim area's on the plans but if you look on step 4 of DWG29, you can clearly see that the top has a tapered shape and your raw part looks like a rectangle.
Suddenly it becomes clear what those notches were meant for. Yes... just like with the stiffeners, you draw a line between the notches and cut of the part.
Used a ruler and cleco clamps and drawn a line.
Actually made the line on both sides, so it is a bit easier to deburr and phile later.
Used the right handed snips to make the rough cut off.
Then using the vixen phile, 3M wheels en sand paper, cleaned everything up so now they look like this and are ready for priming.
The center section and side skins overlap with the tail cone. That means the overlapping parts need to be primed. I mask taped the outsdie of the tailcone and scuffed it's surface with scotchbrite pads.
On the front side of the side skins, you will use pro-seal to keep the carbon monoxide out of the cockpit in case of problems in the firewall forward. Pro-seal will not adhere well on primer so keep an area of bare aluminum on the front of the side skins.
The sides of the bottom skin are overlapped by the side skin, same story here, mask tape it where it overlaps.
Finally, had to scuff the longerons. I don't like those angles when scuffing and definitly the insides of the angle.
While doing that, I noticed that the forming blocks I purchased and used to bend the longerons actually leave quite a bit of markings and scars on the longerons so I buffed those out with some rotodisc pads on the die grinder.
If I would have to do it again, I would probably not use those forming blocks anymore.
Here's a good look of how nasty it can be.
This is the result after scuffing it up. It looks good now but it does take away some material so I'm not all that happy with it.
The picture below is kind of unsharp but you'll get the idea.
