Empennage Tips, SB 14-01-31

Hours 75
Total Hours 1591

I made progress during my two weeks off but I can't believe how much time it takes to finish up these last few items. I had other things going on so I was only able to work on the plane but about 7 days. First I needed to complete the SB 14-01-31 on the horizontal stabilizer.

I had done quite a lot of reading while at the rig about performing this operation. First I finished drilling out the rivets holding the aft edge of the top and bottom skin to gain better access to spar.

My relief notches in the spar were not as deep and the instructions called for so I honed them out. I drew a target using the measurements provided.

Then trimmed the flanges and sanded them smooth.

Fitting and back drilling the doublers.

Every thing is back drilled and de burred. I started worrying about a few of the holes on the ends of the angles that I may have got off drilling out the rivets. I had a very sinking feeling as a few of them were a little over sized. Some could have been from the original rivets being over driven but a few were from my drill bit wondering a small amount. I had drilled these out before I did extensive reading on how to remove rivets. I just knew I was going to have to rebuild the stabilizer! As I was  I pulled up the SB instructions from the Vans site and they had added Tech notes at the end describing what could be done if this happened. The instructions said you can use a 5/32 rivet if the holes would clean up with a #20 bit! I cant tell you how relieved I was! I hate to admit it, but I didn't even know they made a 5/32 rivet! I got on ACS and ordered a variety of 5/32 rivets and a #20 angle drill bit. I rushed the order to two day delivery and was back in business before I knew it!

I used a 5/32" rivet anywhere a hole was oversize. The main places were the last two rivets on the end of the angles. I am very pleased. The fix was not printed on the original instructions so I thought I was in for replacing the angles and maybe the spar also! This is something you cant take chances with!

The back side of the doublers installed. Also riveted up the ribs and rib angles. Riveted up the aft skins. I'm glad I did this as I can see, it would be more difficult after painting. Now it was time to attack the empennage tips!

I was foolish for riveting the tips on after I finished building the empennage so the first thing I did was drill them all off. The pulled rivets were a piece of cake though after drilling those solid rivets in the spar earlier! I cut an end piece out of thin aluminum sheet and shaped them to fit. Then I super glued  them in the tips. Then I mixed up a batch of flox and layed up a good fillet on the inside and a smaller on on the outside.

After the flox set up a bit, I mixed some micro and finished filling the recessed end. The micro buildup is about 3/8" deep. You don't want these things coming loose as they could bind your elevator!

I cleaned up the elevator tips and layed up a layer of light FG cloth over the joint.

This is the stab tip after I sanded down the micro. I riveted it back on and layed the light cloth up over the joint.

I frosted the tips with micro to fill in the joints and allow me to shape the end to match up with the stab tip.

Same for the stab tip.

I sanded it all down and clamped the two together and shaped them to match up.

I was sure to allow a 1/8" gap between the tips. Don't want anything getting caught in here later!

I set the vertical stab and rudder up on a 2x6 and plywood stand and re attached and formed them to match.

After glassing the joints and basic shaping was done. I ground down two sides of a 1/4" carriage head bolt so it would fit in the gap and used it to hold the rudder in the neutral position while I sanded and shaped the tips to match. 

I bet I worked on the tips 10 times at least getting them shaped and filled! Every time I thought I was finished, I would find something else that needed to be filled or re shaped. I've been thru a mountain of sandpaper. I used to worry about the cost of new sand paper but I got over it!

Every time I would put on a new layer of micro or filler on the tips, I would work on something else while they cured. Here I am installing the center cabin cover after configuring them to allow my throttle and mixture cable to pass thru. I re installed the empennage on the plane as I want to do more engine test runs.

I had two 2.5" x 5/16" grade 8 bolts holding my throttle and mixture bracket on the bottom of my engine sump. I wanted to safety wire them. I tried to find and order drilled ones but could not find any this long! So, I drilled them myself after much trial and error! The small bit would finally bite and then twist off! I went thru several bits doing this. These bolts are hard! Finally learned, you have to go very slow and have very much patience!

 

 Anyway, you cant see them here, but they secure the bracket that holds the throttle and mixture cable. Thats about it for this session. I'm pretty sure I may be the slowest builder in history but I am moving forward. I want to do some more test runs with the engine before dismantling the plane for paint. At this point, other than paint and final assembly, all that remains is the wing root fairing, and the canopy lock but I'm sure there will be plenty of small things to iron out . I really hope that I can get the paint booth constructed and the plane disassembled during my next session. maybe even PAINT something!

More Fiberglass, New Flow Divider, Start SB 14-01-31, Misc

Hours 58
Total Hours 1516


December 24, 2014. Tis the season as Clark Griswald would say! My two weeks off wasn't very fruitful  for airplane building because of holiday parties and a 3 day period when the weather got bad and we lost electricity at times during an ice storm, but, we had a wonderful time with family and Christmas so it was worth a little sacrifice on the project! You will see some holiday decorations in some of these pics as we had the Batla Family Christmas in the hanger on the 26th. My sweet thing was a Batla before I swept her away in Holy Matrimony 33 some odd years ago! She also has a very large family....... I will say this, I have the most wonderful Barn/Hanger in the world! My propane radiant heater with attic fans kept my Hanger warm and toasty thru a lot of nasty days! There is no way I could have took on a airplane project like this without my hanger!

The last time I ran my engine, when I shut it down, the flow divider spit fuel out of the weep hole in the top! This happened on the first engine start but had not in the next several starts so I thought it might not be a issue. Wrong! I called Precision Airmotive, they handle Bendix fuel injection, and inquired about the problem. They said the divider needed to be rebuilt as fuel was leaking by the diaphragm. So, I ordered a fresh rebuilt flow divider from Aircraft Supply and Repair in Pennsylvania. It was another added expense but I certainly cant take a chance on leaking fuel starting an engine fire in fight! I have tags saying my fuel servo had been overhauled 75 hrs ago in 2006 but says nothing about the divider....It also gave me the opportunity to reroute my fuel line to the divider to a more direct route. Of coarse, I had to order a shorter fuel line from TS Flightlines but at this point, another 60 bucks is a drop in the bucket! I could not rig the other divider like this because I couldnt break the fittings out to re arrange them. Anyway, all installed in the pic above.

I "joggled" the flap skins to match the bottom of the fuselage.

  

I installed the glare shield pad I purchased from Classic Aero and it is very nice! All the fretting I've done worrying about the painted black glare shield was wasted energy! It looks great just painted with flat black paint! Then I installed the fancy LED light strip underneath the glare shield that came with the dimmer control and it looks great!

Couldnt help but take another pic of the panel! I then removed the Dynon screens (just the screws in the panel) and  re installed the roll bar brace. (Not Pictured) Takes about 10 minutes to remove the screws in the screens and pull them aside. Then you can work on anything behind the panel! Defiantly an advantage to having the Dynon or any other glass panel screens on the panel.....You cant see the turn and slip ball here but somehow my ADAHRS got mounted slightly off level causing my ball to be slightly left. I jacked up and leveled the plane then shimmed the ADAHRS up very slightly to correct the problem. I also tested my pitot system for leaks using a shringe. I blocked off the pitot and aoa lines and injected 3 cc's of air into the system. I turned on the Skyview and the ASI said 170 MPH. It held like a rock. Then I calibrated my auto pilot servos and then tested the AP. Tested good! I then calibrated my flaps and trim system.

Then it was back to work on the lower cowl. I had brushed two coats of Smooth Prime on after two skim coats of epoxy to make sure to get rid of all the dreaded pinholes everybody talks about. Next time I will do this different! To much sanding! This bottom half took about 4 hrs to hand sand smooth after the Smooth Prime! it sands easy but it seems you can never get it finished! Finally I was satisfied but found more imperfections that needed attention. But, NO pinholes!

Then I thought for sure the other parts would be smooth enough not to have pinholes. Wrong! After light sanding with 220 grit, I could see all kind of pinholes with sanding dust in them in these gear leg fairings! Then I decided to skim coat them. I thinned the epoxy 1 to 1 with acetone and put on two coats about 4 hrs apart, skimming off the excess epoxy each time shortly after brushing it on. Messy!

I removed the spinner and it didn't have that many pinholes. I washed it thoroughly with Stewart Systems heavy duty cleaner. Then cleaned with Lacquer Thinner. (As per Stewarts Instructions) Then washed again in my handy sink. Then dried and sanded the gloss off with 220 grit. I blowed it off very carefully with compressed air to clean out all the pinholes. I dont mean a quick once over, I mean blowing every square inch! Washed again. Dried. Blowed out again. I then brushed on two coats of Stewart Systems Eko Prime Smoke Grey. (Should have sprayed it on) There were several stubborn pinholes I had to come back and work on filling with the primer but I finally got them filled brushing it in. After that dried, I sanded smooth first with 220 then 320. I think this is ready to be sprayed with primer again and paint.

Intersection Fairings had brushed on epoxy, then Smooth Prime, then filled minor imperfections with Super Fill. (the blue stuff).

Filling and shaping wheel pants. Tried Super Fill and Epoxy and Micro, not much difference. The Super Fill may cure a little faster but not that much. I am using the West System resin with the slow hardener with micro. I wished I had purchased a container of the fast hardener so I wouldn't have to wait till the next day to sand but on the other hand, I've have not ran out of things to work on while waiting on epoxy to cure.

Had to build these corners up with glass cloth and flox on my empennage fairing. This piece I cut and shaped a couple of years ago. It fit fairly well. Most people have trouble making it fit but I heated it with my heat gun and re shaped it and got it fitting pretty well. Maybe I'm not as anal about perfection as most builders? Anyway, I smoothed the edges all around. Washed, sanded lightly with 220. Yep, plenty of pinholes!

Here I am shape sanding a wheel pant with a 100 grit paper glued around a 3/4" PVC pipe. Good for gettin in those tight spots.

I conjured up this sanding block. A screwdriver, just the right size, driven into a heated 3/4" PVC pipe and 100 grit glued on. Worked really good and was a brief relief for my aching hands, wrists, and elbows! I would fill these wheel pants, then sand them down the next morning, then fill again, then sand again! It seemed I could always find another spot that needed filling!

  

 While working on these FG parts, I decided to install the UniFax heat barrier that I purchased from ACS. This is to protect the cowl paint from excessive heat from the exhaust system. I forgot to take a pic when finished but I drew a pattern with paper and cut out the Unifax to be anywhere there would be excess heat from the exhaust system. I glued it on with epoxy with a little micro mixed in. Then I covered it all with the aluminum heat shielding that Vans sells. I overlapped the Unifax and stuck down the adhesive backed shielding down to the cleaned cowl bottom. By the way, inside cowl is painted with White engine paint. Darn, I wished I had taken a pic when I was finished! 

The flange where the two cowl halves meet near the spinner needed filling to match up better. I wrapped cellophane on the half that I didnt want the filler to stick to.

Then I filled with Super Fill. I sanded and shaped them the next day and they turned out good. Sorry, I forgot to take that finished pic too!

All this filling and sanding really takes a lot of time not to mention all the Advil I took to relieve my aches and pains.

 This is a picture of my sink. It really paid off putting this sink in the hanger because I washed these parts about a hundred times it seems.

Here is a pic after I got the two skim coats of epoxy on the pants. The power was out and I had to finish using a small generator for light.

Okay, here is what I have learned from all this experimenting with finishing the fiberglass parts....Get the part shaped the way you want it with glass cloth and or epoxy and cotton fibers (flox) for structural items....Use epoxy mixed with micro balloons (micro) to fill and shape where you do not need stength, it is much easier to sand. Mix the micro really thick if you dont want it to run or sag. You can and I have added a little Cabosil to thicken it. I'm not buying anymore fancy fillers, West System  Epoxy and cheap microballoon from ACS is the way to go.

From here on out, I will finish the parts as smooth as I can get them with Micro. Then I will brush on two coats of epoxy thinned with acetone, 2 parts epoxy/ 1 part acetone for pinholes. I will scrape each coat off with a credit card about 30 min after brushing them on. The credit card allows more of the epoxy to stay in the pinhole where a squeegee seems to pull some out. Then I will lightly sand the part with 320 grit to get smooth again and take the gloss off of the Epoxy. Then on to painting. Shoot Eko prime and look for more defects or pinholes. I may use more micro if the defect needs it and I will use glazing putty for pinholes. Sand smooth and re prime. Paint! Polish. That's the plan now! 

 So I'm doing pretty good dispite the weather and the parties. Then disaster struck! I fitted my cowl slightly low anticipating about 5/16" of engine sag. This caused my spinner to be a little high lining up with the cowl. This bothered me. I want my finished plane to look good. I have been doing a lot of reading about shimming the engine mount. Guys do it to raise the engine back up after it sags, why cant I do it before the engine sags, and them take the out when it does? So, I loosened my two top engine mount bolts and stuck a piece of .063 aluminum in the gap. I put the cowl on and the spinner was perfect! A .063 thickness aluminum shim or washer between the motor mount and the firewall brought the spinner down 5/16". I fabricated the aluminum washers and cut a slot in them so I could slide them on and installed them and was feeling real good about myself.....Then....I put the bottom cowl back on and on a whim I decided to check the clearances between engine stuff and cowl and I got a shock! My snorkel was almost touching the bottom of the cowl! I did some research and this is what I came up with...... The cowl Vans sells for a horizontal induction apparently is slightly wider and probably deeper to accommodate the snorkel! I also read that the minimum clearance I could get by with is 3/8" between cowl and snorkel. This left me with two choices.. I could buy a new cowl and spend months fitting and finishing it or I could try to make this one work.

Almost everyone installing a snorkel has to do some kind of surgery on it to make it fit, now, I will not be the exception. I did not want to put an huge ugly blister in the front of my cowl so I carefully trimmed the snorkel until I could easily fit a 3/8" feeler gauge made out of wood all around between the snorkel and cowl. This took about a dozen tries. Off and on with the bottom cowl. I swear, this plane is gonna be worn out before I can fly it just from fitting parts and climbing in and out of the cockpit!

Then using electrical tape for a mold, I began laying up fiberglass sections on the inside of the snorkel. I smoothed the corners using flox and layed up 4 layers of 6 oz cloth. Then worked my way towards the filter laying up in sections.

After completing the lay up, I removed the tape the next morning and this is what I got.

 This is a view from the inside. Now this was a very tedious operation and I had to keep reminding myself to have patience. It took me all day to trim the snorkel and do this layup, about 12 hours! The layup was very stiff but I was concerned that it needed to be as strong as the original part to avoid the snorkel collapsing if the filter became clogged and the alternate air was not opened. I temporarily installed the snorkel and the bottom cowl and felt with my feeler and I still had a little wiggle room with the 3/8" because all this was layed up on the inside. I removed the snorkel and sanded the new bottom with 100 grit and blew it out and cleaned it. 

 Then I layed up a graduated 5 layers of 8 oz cloth starting with smaller than the area to the last two layers covering the entire area and an inch onto the old original fiberglass. I figured the bottom of the cowl has a slight curvature and I could afford a few extra layers in the middle increasing the stiffness and strength of the part. I had a hard time making that last inch to stay down as the 8 oz cloth was pretty stiff. Finally I came up with the idea to use a larger piece of peel ply on those areas and it worked like a charm. Above is the finished product. It is very stiff and strong. Now, my only concern is, I have lost about 10-15% of the flow area inside the snorkel. The concern would be in the area where the snorkel narrows down the most. If this effects the air intake enough to be detrimental, I can do more surgery on the rear section to open it up in the other direction to make up for the difference. I'm not doing that until I can test the engine and see if it needs it. WOW! I may have dodged that bullet but it cost me at least 15 hours. I will also look for rubs when I test the engine with the cowl in a couple of weeks. And I will always want to keep my engine shimmed without sagging or I'll lose my 3/8" clearance. On the bright side, my spinner is level with the top of the cowl now.

 Finally, I removed the tail feathers from the plane.

 I began performing the Service Bulletin  14-01-31 that Vans aircraft put out earlier this year. It is a preventative measure but I would like to do it before painting. It will involve installing spar doublers to beef up areas where inspections on some planes have revealed small cracks in the forward spars.

 I got almost all the rivets drilled out before I ran out of time and had to clean up and get ready to go back to work the next day. Hopefully on the next building session, I can finish the SB, finish the empennage tips, test the engine really good and possibly disassemble for painting.

Windshield, wingtips, and cowl.

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!