More Fuselage Parts Coated With JetFlex

Yesterday, work continued prepping section 29 parts … the previously separated and deburred F-00026-L&R instrument stack angles required all the nutplate rivet holes to be machine countersunk per the plans.

Using a #40-100 degree countersink bit in the countersink cage to countersink the nutplate rivet holes on one of the F-00026 instrument stack angles.

Both F-00026 stack angles after machine countersinking.

 

A few more items were also worked on prior to today’s JetFlex paint session. The F-1201Q-L&R battery angles were separated, deburred and required having the rivet holes for a sole nutplate on each angle to be countersunk per the plans. The F-1202D instrument panel attach strips were also separated and deburred.

Machine countersinking nutplate rivet holes on one of the F-1201Q battery angles.

F-1202D instrument panel attach strips prior to being separated on the band saw and deburred with a Scotch-Brite wheel.

 

Yesterday the work session in the shop was short due to an unexpected trip to a metal shop. I was talking to Mike about the bent W-1237C seat back angles and wondered if Mike’s friend Steffon, who owns a metal fabrication shop, had a metal press outfitted for taking the bow out of angle stock. As luck would have it, Mike was going to Steffon’s metal shop in the afternoon and so I tagged along and brought the bent angles along in the hopes there would be a jig of some sort available to remove the bows in the material.

 

When Mike and I got to Steffon’s shop, I was told that the shop does not have the tool I was hoping to find there … the feeling of hope quickly turned to despair, thinking that I would have to take the time to build a jig to straighten the angles. Then Steffon said, “I usually use a metal bender for that type of thing, you are welcome to give it a try”. Ah hah! The feeling of despair quickly changed to a small glimmer of hope. Steffon lead us to a nifty power metal forming tool capable of forming metal stock into circles or any radius desired. After showing Mike and I where the forming wheels and shims were located, we were left alone …. man vs. machine. Setting up this machine was a little like working on a Chinese puzzle … the sides of the wheels have recesses of different depths so depending on which way the wheels are placed against one other on the same shaft, will create gaps for the angle to ride in. After a little trial and error Mike and I were able to configure all three wheels with the aid of some shims to accept the angle aluminum.

 

It became quickly apparent this tool would take no prisoners and would easily gobble up metal, clothing and fingers alike … and never so much as burp. We started out very conservative and feed the angle through the rollers one side at a time and slowly increased the amount of downward pressure applied by the center wheel until the angle was finally straight. The machine has digital readout so the settings were replicated on the other pieces once we knew where to stop.  Worked great!!! Thanks Steffon!!

 

The downside is the drive wheels have small groves on them and they left very small marks on the metal … fortunately, we worked the metal in small steps so the marks are not at all deep and should smooth out nicely should I decide I even want to bother making them go away.

Straightened W-1237C seat back angles placed back to back … must say they look a whole lot better than the photo posted a couple of days ago. If the photo is zoomed in on, the small marks left by the drive wheels can be seen.

 

Today the morning was spent putting the finishing touches on the next small batch of parts ready for primer. The afternoon was spent spraying JetFlex onto the parts that were primed during the spray session earlier in the week. This time the DOG Aviation paint department had good results with the Jet Flex interior paint … the spray tip was cleaned often with a toothbrush dipped in water and ammonia solution. The tendency to splatter paint occasionally was, for the most part, eliminated by the frequent tip cleanings. The gun was never run dry and the cleaning solution was run into the gun immediately after painting was completed, so cleanup went well.

 

Was hoping to spray primer on the parts worked on earlier in the morning but by the time I was ready for that, it was getting too late to spray ... would have been doing cleanup well into the dark. Hopefully I can get the parts sprayed tomorrow afternoon.

Next small batch of parts ready for primer.

Section 29 Parts Prep Begins

After the seat angle issue mentioned in the last post, decided to move on and deal with the bent angles later. If time permits, I may prime and paint the seat backs later this week since they are a larger structure and it would be good to get them out of the way now. However, for the time being, continued moving forward and began preparing section 29 forward fuselage parts for primer and in some cases interior paint.

Deburred quite a few little parts today which are not worth mentioning … but also worked on some larger parts that required more than just a good deburring. The F-1201H upper fuselage doubler required quite a bit of attention. There are 46 rivet holes on the part that required machine countersinking using a #40-100 degree countersink bit. This part receives 23 nutplates which are to be installed on the F-1201H with flush solid rivets. Each of the 23 nutplates also requires having the screw hole dimpled for a #8 screw.

Hanging the W-1201H upper fuselage doubler over the edge of the bench to machine countersink the nutplate rivet holes with a #40-100 degree bit per the plans.

Dimpling the 23 screw holes per the plans using #8 dimple dies in the pneumatic squeezer.

 

The F-1201R antenna shelf was deburred and required having the rivet holes for two nutplates dimpled. Two of the rivet holes were just past the reach of the pneumatic squeezer’s yoke so I decided to place the #40-100 degree dimple dies in Pete’s C-frame and use it to dimple the four rivet holes.

Pete’s C-frame outfitted with #40-100 degree dimple dies quickly made the required four dimples in the back of the F-1201R antenna shelf.

The forward fuselage receives stiffeners that attach to the fuselage’s side skins in two areas. The F-1295 and F-1202N-1 stiffeners required being separated into a left and right stiffener. Both stiffeners were too long to fit the band saw, so the pieces were separated with a hand hack saw tool and deburred. Because both stiffeners will attach to the fuselage’s side skin, all four stiffeners were dimpled for the flush rivets being used on the RV-12 project.

Separating the F-1295-L&R stiffeners with a hand hack saw.

Dimpling the F-1295 stiffeners for flush rivets using a #30-120 degree dimple die in the pneumatic squeezer.  The F-1202N-1 L&R stiffeners were also dimpled for flush rivets.

 

Work continued on separating and deburring the F-00026-L&R instrument stack mounting angles. Both angles will require quite a few machine countersinks so decided to save that for tomorrow.

More Preparations For Paint

Continuing on while the weather seems cooperative, more parts were prepared for priming. In addition to a few small miscellaneous parts, the F-1273-L&R baggage area corner skins were deburred and dimpled for the flush rivets being used on the RV-12 project. Note, not all of the holes on the F-1273 corner skins were dimpled … in particular, the rivet holes that reside in the NDZ “no dimple zone” which is that area of the corner skin that will be attached to the F-1270 fuselage skin doubler. As previously mentioned, the wing hides the F-1270 doubler plate, so the decision was made not to dimple for flush rivets in this area. This translated to only dimpling the aft 11 rivet holes along the top edge of the F-1273 skins. The C-frame was also called into action to dimple two holes on each F-1273 corner skin that could not be reached with the pneumatic squeezer.

Dimpling one of the F-1273 skins using the pneumatic squeezer outfitted with #30-120 degree dimple dies.

Jan helping to hold a F-1273 corner skin in position for dimpling with the C-frame.

Both F-1273 skins dimpled for flush rivets … note only the aft 11 holes on the top row of the skin are dimpled. Pointing to the forward 14 rivet holes that reside in the NDZ which were not dimpled. 

The F-1207A baggage bulkhead top piece was also deburred and dimpled for flush rivets. The flanges on this piece are approximately 80 degrees and after dimpling, the flange angle was readjusted to bring it back to 80 degrees.

Dimpling the F-1207A baggage bulkhead top piece for flush rivets using #30-120 degree dimple dies.

Using an angle gage to check that the flange angle is set correctly after the dimpling was completed.

The next section in the plans covers construction of the seats. The F-1237C-L&R seatback angles were located and it became quickly apparent there was a small issue with the angles. They are all bowed which was quite a letdown considering the quality of the parts in the kit thus far. The metal is .125 thick and whacking it with a mallet is having little affect so think the pieces will require the help of a press at a metal shop or fabricating a bending jig to get them straightened. Both solutions will require extra time which I don't feel I have weather wise.

The F-1237C-L&R seat back frame pieces have quite a noticeable bow in them that will require a press of some sort to straighten.

Not being able to tweak the seat angles into relative straightness without getting draconian put me in a sour mood, so decided to call it quits for the evening. May not get these parts painted until spring but don’t really need seats to continue with the build … so thinking I will move on and sort this out later after the good painting weather is over for the season.

More Fuselage Parts Prepped And Primed

In addition to the turtle deck skins and roll bar, the F-1232A roll bar brace and F-1232B mounts were also prepared for primer. Noticed something interesting about the roll bar brace …. some drawings showed the five holes on the aft end of the F-1232A roll bar brace and some did not. The holes are much larger than a #30 rivet so I suspect the holes were added for clearance for the shop heads of the rivets securing the overlapping area of the turtle deck skins.

Because the RV-12 is being built with flush rivets, the skins in that area are being dimpled so I tapered the holes slightly to accommodate the dimples. The forward most hole was left alone because that hole is common to the rear window.

Red circle denotes hole that was not tapered because it is common with the rear window which receives no dimpling. Note the drawing does not show the holes in the aft portion of the F-1232A brace.

This drawing shows the holes in the aft portion of the F-1232A brace.

Dimpling the F-1232B roll bar mounting brackets where they will contact the turtle deck skins.

 

During the rain delays moved ahead and prepped more parts … the F-1254-L&R roll bar support frame, F-1234-L&R canopy decks, and baggage bulkhead components were deburred and dimpled. The F-1277-L&R turtle deck skins were also dimpled for flush rivets except for the holes common to the rear window.

Dimpling one of the F-1254 roll bar support frames for #30-120 degree flush rivets where it attaches to the fuselage side skin.

 

The F-1207C-L&R baggage bulkheads come folded in half - unfolding breaks off the tabs holding the pieces together leaving the tabs seen in the photo.

 

Using the nibbling tool to remove the tabs from the F-1207C baggage bulkhead.

 Dimpling the nutplate rivet holes in the F-1207D baggage bulkhead channels.

Dimpling the outer flanges on the F-1207C-L&R baggage bulkheads for #30-120 degree flush rivets.

Dimpling one of the F-1277 turtle deck skins using a #30-120 degree dimple die for the flush rivets being used on the RV-12 project. 

 

Also worked on a few miscellaneous parts such as the F1207E-L&R  shoulder strap lug (which required machine countersunk for the flush rivets being used in the project) along with the F-1270D doubler for the side skin stiffening retro fit. Because the F-1270D doubler is relatively thin, it was secured to both F-1270 side skin doublers (placed back to back) which also have the same rivet hole pattern. This worked great and prevented rivet hole elongation from the machine countersink process.

Machine countersinking for #30-120 degree flush rivets the F-1270D doubler. The doubler was secured onto the much thicker F-1270 side skin doublers (which were placed back to back) with Clecos. This prevented hole elongation.

Machine countersinking the F-1207E shoulder strap lugs for #30-120 degree flush rivets. It was easier to countersink the holes prior to separating the two lugs on the band saw.

 

F-1207E-L&R shoulder strap lugs after machine countersinking with a #30-120 degree bit.

 

Finally after a couple of days of weather not conducive for painting, late this afternoon all the components worked on over the last week were finally primed with Akzo primer after receiving a good cleaning with Acetone and scuffing with Scotch-Brite pads.

Amassing More Parts For Primer & Paint

The plan was to prime a few parts today but life has a way of changing the pans of even the most committed aircraft builder sometimes. After getting a late afternoon start in the shop, decided to forge ahead and prepare more parts for primer and paint ... actually better this way anyhow makes cleaning the spray gun more worthwhile.

The edges of both W-1277 turtle deck skins were filed and smoothed with a Scotch-Brite wheel. Before priming, all the rivet holes with the exception of those common with the rear window will be dimpled for the flush rivets being used on the RV-12 project.

Next up was the W-1254 support frame brace. The W-1254 braces require a little trimming … unfortunately, the amount to be removed was not symmetrical between the two edges that required trimming, so the part could not be run through the band saw. Decided the nibbling tool would be a good option for trimming the material. Jered, a collage student with an interest in aviation, has been keeping tabs on the progress at DOG Aviation. Whenever he visits the next door neighbors, Jered often stops by to see what is being worked on. It is enjoyable to let visitors use the tools to finish off a task … so today I thought Jered may enjoy using the nibbling tool to remove the excess material from the W-1254 support frame braces.

                                As one can see in the photos, a different amount of material is to be taken off one
                                side of the W-1254 brace than the other - which will negate the use of the band saw.

Jered making practice cuts in aluminum with the nibbling tool.

Jered doing a fine job of using the nibbling tool to remove the excess material from one of the W-1254 braces. 

 

The W-1232A roll bar brace was located and deburred and the W-1232B mounting brackets for the brace were located, separated into left and right pieces, then deburred on the Scotch-Brite wheel. A few other miscellaneous parts were also deburred today as well. All of the parts worked on today will ultimately receive primer and interior JetFlex paint because they will be visible in the cockpit area.

 

                                     Deburring the edge of the W-1232A roll bar brace … note all of the parts on

                                     the bench have been deburred and are ready for cleaning and prep for paint.

 

Prior to priming, a few of the parts such as the turtle decks and any brace that rivets onto the fuselage's side skins will require dimpling for the flush rivets being used on the project. That should go fast because with the exception of the outer edges of the turtle deck skins, there are not that many holes to dimple in this batch of parts.

Airport Distraction & Excitement!!!

Even though today was a nice day for painting, I decided to head out to the airport to help Mike with his cowlings and a little project he had planed for his airplane.  Also finished up the hangar wiring yesterday and wanted to test the new outlets and see how well the new light worked.

The new high output florescent fixture works fantastic … I’m so pleased with it that I think I’ll only need to add one more as opposed to two. The new light truly puts out a heap of light. I took a photo in the hangar with just the two incandescent ceiling lights on and another photo with the new light on as well. The area with the new light looks brighter to be sure but that is only half the story … when the incandescent lights were the only lights on in the hangar, the camera compensated for the low lighting by keeping the shutter open for close to two seconds to obtain the proper exposure. When the new high output florescent light was turned on, the camera probably only had the shutter open for 1/8 of a second or so. The light level difference is HUGE but of course, the camera tries to compensate, so the photos don’t look anywhere near as dramatic as it truly is.

Photo taken with just the two incandescent lights on.

Photo taken with the new high output florescent light on ... you can tell the light is bright.

 

The aim of this Blog has been to document the building of the RV-12 and DOG Aviation’s infrastructure … thus far I’ve kept the content true to that. However, today will be an exception because of the cool factor of an encounter Mike and I had this afternoon at the airport.

 

Working on the RV-12 project at the airport will be a mixed blessing. Yes, there will be plenty of room but there are also distractions … lots of great people to meet, cool airplanes to check out and the occasional need for both lending and receiving a helping hand. Today was one of those days to GLADLY lend a helping hand.

Prior to getting started on Mike’s little project, we got in his golf cart (aircraft tug) and headed to the local FBO to get info on some parts Mike was looking for. On the way back to the hangar, Mike noticed a hangar door open and what looked like a radial engine. We just had to turn around and head back to check it out. Much to our amazement, we stumbled upon a gentleman (also named Mike) who was prepping his 1949 NORTH AMERICAN AT-6G with a 600 horsepower Pratt & Whitney R-1340-AN-1 radial engine for an engine start. Apparently, the airplane had not been started in two years because the owner has been out of state.

 

Mike, the owner of the AT-6, had called a friend for help with pulling the aircraft out of the hangar but the friend was not available. So Mike and I gladly offered our services ... we helped prep the area around the aircraft so it could be safely pulled out of the hangar. Mike’s golf cart is outfitted with a ball hitch on the front … because in addition to being transport for getting around the airport, Mike also uses his golf cart as an aircraft tug to move his airplane in and out of his hangar.  Much to our amazement, the golf cart was able to roll the over 4,000 pound AT-6 out of the hangar.

 

The AT-6 after Mike used his golf cart/aircraft tug to pull the war bird out of the hangar.

 

Mike (the AT-6 owner) began running the prop through to insure the engine did not develop a hydraulic lockup … Mike said with a radial engine, it is suggested to run the prop through for as many revolutions as there are cylinders prior to starting the engine.

 

Looking on and giving moral support as Mike ran the prop through on his AT-6 prior to attempting an engine start.

That, my friends, is a 600 horsepower beast of an aircraft engine.

The name says it all!

 

As is often the case with long term storage of motor homes, boats and aircraft, the batteries go flat. Once that happens … the battery is NEVER the same as Mike quickly discovered. When it was time for Mike to shout “clear prop” … much to all our disappointment, instead of hearing the whine of the starter as it strains to turn the prop, all we heard were a few clicking sounds. After talking to Mike, he said the battery went flat prior to today and he just put a trickle charger on it. Apparently the battery was to far gone to take a deep charge.

Checking the AT-6’s battery voltage with a volt meter.

Since the AT-6 was out of the hangar and there was help, Mike decided he would try to hand prop the AT-6. Of course, there would be a need for somebody in the cockpit while Mike tried hand propping the aircraft … any volunteers? You bet there is!!!

                                   Mike pointing out where the magneto switch is located on his AT-6 along 
                                  with throttle and fuel mixture controls … and most importantly, the brakes.

Mike giving me instructions on how to use the AT-6's hand “wobble pump” to build up fuel pressure with the left hand while at the same time pumping the fuel primer with the right hand. All new to me.

                                      Crash training course over and on my own in the AT-6 cockpit ready for the
                                      big moment ... seems a little snugger than the RV-12 cockpit will be.

                                   Mike tentatively hand propping the 600 horsepower Pratt & Whitney radial engine
                                   while I’m at the controls praying for a good (and uneventful) engine start.


After a few pops, the prop kicking backwards a few times and the engine running backwards for a couple of seconds at one point, much to my disappointment, we never did get the AT-6 to start. Mike was very tentative about hand propping the aircraft and for just cause … people have been seriously injured or worse turning a prop by hand. In the interest of safety, rather than continuing on, we decided since a battery would be needed anyway, it would be better if we just rolled the AT-6 back into the hangar before anybody got seriously hurt. We gave it a good effort, but today was not the day. And of course, my delusions of grandeur of being at the controls of a AT-6 war bird with a running 600 horsepower radial engine evaporated about as fast as the moderately sized puddle of aviation fuel between my feet left by the leakage from manually pumping the engine primer. But hey! What a day!!!

Sadly, there are no photos of Mike’s golf cart/aircraft tug moving the AT-6 because we did not have the camera with us when Mike moved the AT-6 out of the hangar. And when moving the AT-6 back into the hangar, it was all hands on deck because it was necessary to guide the tight fitting AT-6 back into the hangar by pushing near the outer edges of the wing to obtain enough leverage to control the direction of the AT-6 as it was gingerly rolled back into the hangar. But I can tell you it was quite a sight seeing Mike’s golf cart moving that airplane.

By this time, the sun was getting low in the sky and we never did get to work on Mike’s project or put the cowlings back on his airplane. But neither of us cared, we both enjoyed the unexpected distraction and excitement at the airport … not to mention the meeting of a new friend and a potential future helping hand when we need one. Oh, there is also the possibly of cashing in on the offered ride in the AT-6 at some point in the future! Oh, baby!