After a few evenings and a weekend of sanding I'm finally done (cross fingers) with the high-build primer. My last act for today was putting three coats of finish primer on the port float. (I'd show a picture, but it's not very interesting - once you've seen one white primered float, you've pretty much seen them all). I'll note that I sanded the high-build primer all the way down to 150 grit, which is at the high end for the finish primer prep (they recommend 100-150 for preparing the surface). The top coat prep calls for 320-400 grit, but my floats already feel like a baby's bottom -- IMO :-) -- at 150 grit - it will be interesting to see what the extra smoothness will add (if I can even tell).
The extra coats of primer did indeed help in many bad areas, but not all. I've learned some hard lessons during the fairing of these floats. You can't depend too much on the primer, so therefore it's crucial to take your time and be really detailed when doing the initial fairing. In a few areas while fairing, I fooled myself into thinking "ah that'll be fine -- the primer will fill it in easy". Some of those turned out for the worst and needed fixing, but I'll blame it on inexperience this time. It really boils down to "pay now or pay later", and it's better (easier) to pay in the early stages. The primer sands down beautifully, but it won't look its best unless the underlying surface is fair. Let's hope I remember all these lessons when I get to the main hull.
Yesterday I put finish primer on my two test scraps, and today I sanded them down with the electric sander. (Gotta love power tools -- my arms and shoulders are aching after all that extra manual sanding this week.) The high-build is almost chalky when sanding (hence my mention last post about clogged sandpaper), but at least it was very, very quick to sand. In contrast the finish primer seems to cure hard and tough (much like the S3 primer I used on my dinghy) even after only a day of curing. I'm glad I'm switching over to the electric sander now. The Festool vacuum system works wonderfully, so that should cut down on the dust as well.
The new F22 plan book arrived on Friday. All I can say is -- Wow! As I mentioned to another future F22 builder, the new plan book has lots of minor updates, lots of new pages, and this time they were printed on a color laser printer. The pages are absolutely stomp-down gorgeous. I was actually quite pleased with the quality of the inital plans, and wasn't even dreaming of getting anything nicer. Although not 100% complete yet, there is a ton of never-before-seen details in the new book, including things like the wingnet attachments, rudder gudgeon fabrication, poptop fabrication, etc. While cool to see, it also made me stop and realize just how far away I am from being done with this project.
Tomorrow night I'll put the finish primer on the starboard float. Then I'll be busy for awhile, sanding the floats down to 320-400 grit. (I'm kinda wondering, if 400 grit would even make a difference when doing a roll-and-tip job.)