Hours 88
Total Hours 1458
I got off work on the 26th of November. We had a great Thanksgiving with the kids and grand kids. I got a little work in on the plane on Sunday the 30th, after they all left and we got back from church. Then Monday morning, I was in full swing.
I had glued on the windscreen earlier. I spent a lot of time looking at other peoples websites trying to figure out where to end the fairing on the plexi and aluminum. I finally came up with the above configuration. The white tape has yellow tape underneath it to give extra protection to the plexi while sanding later. I ran a double layer of packing tape over the slider canopy and waxed it with mold release wax and then closed and latched it. The top of the fairing over the rollbar was taped off to about 3". I knew I would trim this down later on the aft side.
I then sanded and scuffed up the aluminum and plexi with 80 grit sandpaper.
I cut a few miles of 8 oz fiberglass bid cloth strips ranging from 1/2" to 3". I didn't know how much I was going to need so I just kept cutting. I cut a 3" piece of heavy carbon fiber I had had for years from my model building days for over the roll bar to give it extra strength. This will be where I will get a hand hold getting in and out of the plane so I want it to be strong.
I filled the gap over the sanded sika with epoxy with cotton flox and black pigment mixed in. I mixed black pigment in all of this layup to avoid seeing anything but black from the inside of the cockpit. I bought the large bottle of black pigment from ASC and could have easily got by with the small bottle but oh well, you never know.
I cant tell you exactly how many layers of cloth I ran, but it was probably more than 5 all together. I started with the thin strips and worked my way up to the thick strips trying to form the fairing as close to the final shape I wanted as possible. The last layer layed up just touching the white tape. I layed up 4-5 layers over the top of the roll bar with the second layer being the carbon fiber. I worked slow so the layers would cure a little so they wouldn't slide off the vertical parts.Then I applied the peel ply and waited till the next evening as this was 24hr west systems epoxy. I wished I had taken more pics but I was busy and my hands were sticky!
I then peeled off the peel ply and began sanding. I sanded to acquire the final shape and to bring down the edge next to the white tape. Using the white tape worked very well for sanding down the black epoxy. You could really see when you needed to quit sanding. Lots of people would take the top layer of tape off and sand down to the bottom tape but I decided not to for some reason. After I was satisfied, I countersunk and riveted the fairing to the aluminum at about 4 places with pull rivets.Two being on the corners in the pic above. Most people do not do this but it makes me feel a little more secure knowing there is a mechanical bond to hold the fairing on and not just the epoxy/aluminum bond. Of coarse this will make it more difficult if I ever have to replace the windscreen.
Then I mixed and applied a thick dry layer of epoxy and microballons and filled in all the low spots. I over applied this stuff but it sands easy and I kinda wanted to get the final shape in one try.
Then it was back to sanding. I used this electric sander (would not be without it) and this sanding tool I made with 3" PVC and 80 grit paper glued on with spray adhesive. The micro sanded easy and I had this thing whipped in about 3 hrs! Very smooth in all directions.
I had some holes and plenty of smaller pinholes but it looked very good! I decided to go ahead and get the canopy loose and roll it back. This took some doing and I got a little nervous but I took my time and it finally released. I then trimmed the top over the roll bar to an even width. This allowed the canopy to slide under the fairing about a good 1/2" when closed. It looked great! The lip of the fairing is very strong so I will not worry about bracing myself with it when entering or exiting the cockpit.
I then painted on a layer of thinned epoxy and acetone, as vans describes in the instructions for removing pinholes, and squeegeed it off with a credit card, waited several hrs and did it again, waited several hrs and did it again. I had heard horror stories about these pinholes and I was going to try to beat them early! I then let it cure for 24 hrs. Then I sanded the epoxy with 240 grit paper. I found that the paper loaded up dry sanding but when I wet sanded it worked good so I wet sanded it with 320 grit using a spray bottle of water till it was all level and scuffed. I had bought some smooth prime and decided to use it. I could still see a few low spots in the epoxy and a couple of pinholes but it looked pretty good. I got out the quart of Poly Fiber "Smooth Prime" (58.00 per quart, this stuff better be good!) and started stirring it up. After a full hour of hand and mechanical stirring it was apparent I was not going to get all the particles in the primer to dissolve. I warmed it up and mixed on it for another hour and it still had small hard particles in it so I strained the particles out with a paint strainer. I then brushed on three coats at about 2 hrs apart. This stuff is thick and worked great! I sanded that night with 240 then 320 grit and the finish was great! I could not find 1 pinhole or low spot! I called it good. I will scuff it again and prime it with Stewart Systems Ecko Prime before the final Eckocrylic topcoat. I peeled off all the tape and the above picture was what I got! This was a task that I had studied and planned and worried about for at least a year!
At times, while waiting for the fiberglass work to cure, I worked on finishing mounting my wingtips. I used Mike Bullocks method I had mentioned in an earlier post to mount them with hinges. This worked well but took a while getting all the holes drilled, deburred, countersunk, and hing riveted on the tip and the wing.
It turned out great though and looks really clean. I can have the tips off in 5 minutes if needed. The length was a little long on the tips but was easily sanded down to match the ailerons.
I installed a #8 nut plate in the small aluminum rib in the end of the wing tip. The pins are inserted all the way in and stopped on the last eyelet where a #4 screw is installed. Then I cut a 1/2" thick piece of delrin block and drilled holes in it to except the pins. A #8 screw holds this block to the rib and secures the pins.
This took a fairly long screw to get thru the delrin block and the plate nut. Above is a picture of the gap between the aileron and the wing tip. This worried me! If the screw ever started backing out, it could bind the aileron and jam it! I had to think of something else!
This is what I came up with. A piece of scrap .0125 aluminum keeps the pins from backing out. It also requires a short screw so if it backs out, the screw can fall out before jamming the ailerons. The nut plates are oval so the screws fit tight and are unlikely to back out but this makes me feel a lot better. This will surely be a preflight inspection point.I will add a star washer and lock tight to this assembly before the first flight.
Next I started working on the cowl. One more sanding before the epoxy/pinhole treatment begins.
I also layed up multi layers of epoxy and then shaped and ground out a trough for my upper cowl pin keeper. The picture says it all. I had been trying to figure a way to do this for months and this came to me at the last minute. I filled the any low spots in the cowl with super fill and sanded. I then coated the entire inside of the cowl with a coat of epoxy. Let it cure. Then scuffed, prepped, and painted the inside with hi-heat white engine paint.
I then blew out the cowl very carefully, making sure I opened up any pinholes that were filled with dust. I washed the cowl with soap and water, wiped it down with acetone, then blew it out again. Then mixed 1 part epoxy and 1 part acetone and painted the 2 cowl halves with a brush. This mixture is really thin. I waited about an hour then squeegeed off the excess epoxy with a credit card. I let that cure (24 hr west system 209 hardener) about 6 hours. It would have been nice to have some 207 hardener to speed up the process but I didn't have that luxury. At 6 hours the epoxy was still tacky. I painted on another coat of thinned epoxy and did the same steps as I did before then waited. I had planned to put a third coat on but life got in the way and the timing wasn't right so I skipped it. I waited about 36 hours because the acetone in the epoxy seemed to slow down the curing process.
I then commenced to sanding. I wet sanded the cowl halves just as I did
with the windscreen fairing until it was all level and there were no
shiney spots left. I could not find any pinholes at that point but they
are hard to see on a scuffed surface.The tools above were used in the sanding process. The green and pink tubes are cut off of a swimming pool floatys and worked very well on the contours.
I then applied three coats of Smooth Prime on the cowl halves with a brush at about 3 hours apart. Each coat was brushed on alternating directions from coat to coat. It is very important to stir the Smooth Prime often because it is loaded with fillers and stuff that will settle to the bottom of the container you are using. I found one pinhole open up with the primer near the right air duct and I daubbed it real well several times with the brush while priming. I let the cowl cure till the next day.
Then I commenced sanding again. I dry sanded for 4 hours on the top cowl very carefully with 240 grit then 320 grit. I smoothed the surface carefully trying not to take off any more primer than needed to get a finished surface. I thought I had it perfect several times but using a light at different angles, I kept finding spots that needed more sanding. Finally, I was satisfied. I found one low spot that will need a little fill but other than that, it is ready for the Ekoprime. The process I described above takes a lot of time, but the pinholes seem to be a none issue right now.
In between all this fiberglass work, I did manage to start My engine several times and do a run up to 2200 RPM. I am looking for leaks and any other issues I can solve now before taking the wings back off for painting.
now I'm out of time and have to get ready to go back to work tomorrow. I will be on the rig for two weeks, then get off on Christmas Eve. I will spend several days with the family for Christmas then hopefully dive back in to working on the plane again. I am getting close to painting so I'm getting excited!
