Painted flaps and trim tab (again)

 We spent a few hours carefully filing and sanding out the paint runs on the flaps and trim tab.  We decided to paint a practice piece so that we could dial in the process before painting real parts again.  When the part was hung vertically, we had difficulty getting a coat thick enough to be smooth, but not too thick that it would cause runs.  Part of this may be due to the fact that the temperature in the garage drops when we open the doors for ventilation, which increases the likelihood of runs (lower temps lead to longer cure times and increased odds of runs).  We then tried painting with the test part in a horizontal orientation, which doubles the time needed to paint the parts since we have to let one side dry overnight before spraying the other side. We also decided to take our chances and try painting the small trim tab at the same time.  This method worked well and the parts came out very nice with no runs and relatively smooth surface. 

We also took even more precautions to reduce dust   We are using an airgun to blow any dust off of our suits before entering the room, and taking extra care to blow and tack the surfaces before painting.

We prepped the flaps for paint again, and sprayed them with "vestal white".  We were happy with the results and had zero runs.  Still had a few small dust particles in the paint, but much better than before.  We also had a little bit of overspray on the bottom side when spraying the top side, which was a side effect of spraying the two sides on different days.  We used a buffer to remove this overspray which took some effort.  We'll try to take some steps to reduce this overspray in the future.  Still learning.   Hours: 10

Flaps painted

Paint Scheme

Quite a few years ago, I (Michael) bought a add-on for X-plane Flight Simulator that included a Just Aircraft SuperSTOL. It is a perfect vehicle to experiment different paint schemes for our project.  Yes, we are building a nose wheel Highlander, but this was the closest option.  So after many iterations Ed and I have settled on our paint scheme.  Without further ado.....  Hours: 5

Painting flap and trim-tab

Next we decided to paint the flaps which are going to be painted with Superflite's "Cessna Vestal White", an off-white color.  We built a few new supports that hung down from the ceiling of the paint room so that the parts could be fixed rigidly and not swing around while spraying, which was an issue we ran into during the priming.  This time around, we took extra steps to try and fix the dust issue.  We ran the paint booth fans for about 20-30 minutes prior to painting to reduce the dust population in the room, used tack rags to wipe any dust, and blew the parts off with air prior to painting (these tips came from internet searches of other painters who deal with this issue).  We also wet the floor prior to painting (another common trick), but had done this last time when we still got a lot of dust in the paint. 

We sprayed a mist coat, and then a full cross-coat of the Vestal white.  At first glance, the parts looked great, and the good news is that we only saw a couple dust specs in the paint.  However, upon further inspection, the bad news is that we ended up with a ton of runs in the paint on both the right and left flap.  We may have thinned the paint a little too much, and I may have sprayed the last coat too slowly.  I've been pretty successful priming and painting without runs up to this point, but not so lucky this time around.  Sigh...this will take some time to fix as we will have to sand and respray.  Another learning experience.  I'd like to be able to do less learning, and more painting.  

Dreaded Run in the flap

The trim tab came out better, but has one small run at the bottom that we need to fix.   Hours: 6

Trim tab painted

WingTip Painting

We moved from priming to painting for now.  The airplane is going to be mostly white, but the lower fuselage will be orange, and there will be other orange highlights.  The wingtips are planned to be orange, so we decided to paint those first to see how they look with some color.  

Michael mixing up some "Ocala Orange" paint

We first did a mist coat, and followed with a full cross coat.  The parts initially came out looking beautiful, but on closer inspection we noticed a huge run, and a lot of orange peel.  The run was due to a mistake where I had the gun fan spray set incorrectly for the direction I was spraying (newbie error).  We sanded the run down, and sanded so much that it needed to be repainting.  We ended up just sanding both parts and repainting. 

Parts with a coat of  shiny paint

The second time around, the parts came out much better with no runs, but we ended up with a lot of dust in the paint, even though we were using a paint booth to try and minimize this.  We decided to just carefully sand and polish the painted parts to get rid of the dust, which worked out fine, but was a lot of effort.  Next time we will take extra steps to further reduce the amount of dust on the parts.

Hours: 8

Wing tip priming (again)

 We filled all the small pinholes and divots in both of the fiberglass wing tips with epoxy filler... and also added a little more filler in other spots to smooth some transitions out.  Then we sanded them down, cleaned them up, and then reshot the primer.   This time it came out much better.  Hours: 6

WingTip primed for 2nd time

Wing Tips, cont

We added 2 pieces of balsa wood to each wingtip to close up the back end. These were carefully cut and sanded to fit precisely in the openings, then we applied 2 coats of epoxy sealer, and glued them in place with Hysol adhesive.   We had used a few small screws in the balsa to aid installation, but went back with lightweight filler to fill in the screw holes as well as smooth out the transitions between fiberglass and balsa.

Balsa pieces glued in place

We cleaned the parts and shot a coat of primer.  Initially it looked ok at a distance, but when we got closer we noticed a ton of pin-holes in the primer, which were apparently caused by small pinholes/divots in the fiberglass surface.  We weren't happy with how this looked, so are now in the process of sanding it down, and will take extra steps to ensure the surface is smooth without divots prior to priming again.  This is one of those frustrating learning experiences, but we'll know better next time.

Hours: 10

Coat of primer on wingtips