Nice Pair

Of course I'm referring to those beautiful little Clipped Cub wings waiting for assembly. These are stored in my good friend Claude Rich's hanger, seems the wedding party wanted some airplane shots. He sent me these for motivational purposes!
The cold returned today so just a little progress, I installed the nut plates on the heater air intake. This allows you to remove the cowl by just taking out the 4 external screws instead of messing around with the two heater hoses inside the cowling.

I then repaired the the forward pin location on the nose bowl. The hole was really enlarged, so I made an inside doubler and flush riveted it on the back side. This area is covered by the top cowling so this will not show. Most of it will be covered by the grommet anyway.

I thought about making a whole new front doubler but it just was not worth the work. Structurally this repair is fine.

More doubler work tomorrow.

Nose Bowl

Well , winter returned for Sunday and Monday so no progress on the Cub. I can heat the air in the shop no problem , but my hands are just too old to work with cold tools. Today was beautiful and warmed up into the high 50's. After lunch I went to work on the cowl and finished at 7:30.  I worked on fitting the nose bowl to the lower cowl. I installed everything on the airplane and made the final adjustments before drilling the rivet holes. The nose bowl had multiple holes where it had been installed and removed before. Some lined up and some did not. You can see in this picture it was an ugly situation.

  I've been thinking about this for a couple days and the solution came to me as I was working today. The rivets would have to be installed with washers to add bearing area. This would have been easy with pop rivets, however I would never use those for this application, too much vibration. I ended up using a short length of vinyl tubing to push the washer into place as the rivet was squeezed or driven . The tubing is cut just a little shorter than the rivet before it is driven, like this.

  You then drive the rivet normally and the tubing compresses and pushes the washer down tight. The rivet expands the tubing and the shop head forms normally. Pull the tubing off and it's good to go.

Here are a few shots of the completed job. One of the problems was that the nose bowl did not exactly match the lower cowl. Since they both have wire beads at the edge I could not just trim them to match.
You can see it in these pictures at the joint

I ended up using a small triangular filler piece to continue the cowl line and make this less obvious. I think it will look OK with some paint on it.

Tomorrow I will add the doublers at the carb air intake and the heater air inlet and the cowl will be pretty much finished. Still no word on the exhaust, been 3 weeks today. BC wanted to say HI to his mom!

More cowling

Only made  a little progress today, were having a little spring cold snap here and for some reason I just don't get out to the shop until after lunch? I started by installing everything  to see how it all fit after the repairs. I then marked the nose bowl for trimming around the carburetor air intake. This is normally really close on a Cub and when you install a Bracket air filter it almost always chafes on the edges. To preclude this I cut the opening so I had 1/2 inch clearance all the way around. I tried adding washers behind the engine mounts to change the thrust angle , but the air box is too close to the pivot point and it really made no difference. Here is is before, you can see that the box is really close to the right side.

Because the Bracket filter sticks out about an inch,  I trimmed the top edge to keep it from chafing . This also allowed me to clean up some existing cracks. After trimming I fitted it all up again.

Much better now with even clearance all the way around. Here are a couple shots of the cowl all assembled.

Before I can fit the repair/reinforcement patches to the nose bowl, I need to rivet it to the lower cowl. I  figured now was the best time to complete the final smoothing of the nose bowl. I spent about an hour between the planishing hammer and hammer/dolly. Since I'm not brave enough to try and anneal this, it only came out so smooth. I think with a little filler it will look OK. Here is the end result.

  I picked up this tool the other day at the Harbor Freight. I had to take it apart and adjust the spacing to match the existing corrugations on the cowl edge. Worked perfect to adjust the edge angle.

That's about it for today, tomorrow is supposed to be in the 30's with rain . I will probably spend the day curled up with this treasure I bought off Ebay!

Lower cowl

Been working on the lower aft cowl for the last couple days and completed it today. Tomorrow I will begin fitting the lower nose bowl. I removed the fiberglass nose bowl and repaired a number of areas. Someone had cut a 3 holes to access items without removing the cowl. I decided to patch all these and add screws to the air intake for the heaters making the cowl easy to remove. I started by repairing the cutouts where the exhaust pipe enters the cowl. With the "C" series Continental installed the exhaust has to be lowered to clear the oil screen housing. Someone had hacked open the holes and just left the rough edges so of course it cracked in several places. I cleaned up the existing holes as best I could and installed a doubler plate of 032 on both sides. Initially I used AN 470 rivets but it looked like shit so I went ahead and countersunk them . Here is the left side, I left a 470 rivet at the end of the crack.

I did not have the tooling to do the rolled edge, so this is what I ended up with. Some great videos on YouTube on bead rolling if your interested. I think this will be OK for the beater Cub!
The right side needed a little more work because of a previous repair at the forward pin location. I'm not sure why they lowered this pin but I don't need this change to fit my upper cowl. I just extended the inside patch to encompass this location. Looks sorta like an Aircam in this shot!

Here it is all riveted up, there were two cracks in this side.

With a nice thick coat of paint it should look OK for the beater Cub! I then started on the 3 extra holes in the bottom. With my luck , none of them lined up with the gascolator, so I had to do some patching. There were 3 holes, one I assume for the gascolator, another for the oil quick drain, another I'm not sure, and two worn areas where something chafed through. The two holes at the aft edge I repaired with one patch , then cut a new hole to fit my gascolator installation. I cut the existing holes round , then fitted plug patches with an internal doubler. I then cut a new hole to line up with my gascolator. Here are some shots, since this area is curved I used a lot of clecos.

Here it is after riveting, I managed to squeeze all but two of these . I think it came out pretty good.

Then using the same plug patch method , I repaired the oil quick drain hole. In my world if your changing the oil, it's time to inspect the rest of the engine. The cowl needs to come off anyway.

At this location I had to drive all the rivets, while not as nice and uniform as the squeezer , it still came out OK.

At the two chafed areas ,I decided to try a different approach and use a internal patch and a little JBWeld to fill the damaged spots. This will be a test to see how well it holds up. It looked like a piece of SCAT hose rubbed inside the cowl, one spot was worn through and the other was paper thin. I made two round patches due to the curvature of the skin. Here is the worn through spot you can see the other spot just below the patch.

I used thin plastic from a sandwich bag as a release agent and held it in place with masking tape. I applied a thin coat of JBWeld epoxy and then riveted the patch in place. Here are some pictures to illustrate. The tape minimizes the squeeze through and resulting mess and cuts down on sanding.

Since the other worn spot did not go all the way through , I just used the epoxy to fill the void under the internal patch. I will sand this smooth after it dries a couple days.

That  completes the repairs to this section, now I just have to fit up that lower nose bowl.!

Cowling repairs

I've been working my way slowly toward the front of the Cub and completion of this project. This week I have been working on the final cowl fitting. Here is a shot of the cowl pieces as received with the project.

It came with a Wag Aero cowl with a fiberglass nose bowl. The top was really not too bad but the bottom was really hacked up. My friend Scott came through with an original top cowl left over from his project. It needed some minor repairs but was all metal and a properly repaired metal cowl beats a perfect fiberglass cowl any day. When I went to the Gordon Fischer auction last year I bought a metal nose bowl for $5 . Now I had a complete cowl, I just needed to fit it all together. Here is the nose bowl.

I did not really have the right dies for the planishing hammer but managed to to smooth this out a little.

  It will take a few patches but like I said before, repaired metal beats fiberglass. This week I've been working on the top and bottom sections. The first thing I had to do was strip the new top section before any repairs could be completed. I had finally run out of this crappy stripper I had bought at the Lowes, it was more like a gel and dried really fast. So this time I splurged and spent $30 for a gallon of this stuff.

This is the real stuff ! You can feel it starting to burn through two pairs of gloves ! If your looking to go green , do not buy this. If you want to remove paint , this is the shit! Here is the new top cowl after one coat.

There were 4 areas that needed repair on the top, 2 worn pin locations, a small hole and a small crack. The right front side pin hole was worn, I made a internal patch from 032 and riveted it inside. The grommet will cover most of the old ugly hole.

The front pin on the right side had a previous repair, for some reason they used really big round head rivets. I made a new patch piece and installed it with some flush rivets. Once again the grommet and a little JB weld will cover this completely.

On the left side there was a triangular hole worn through near the rear pin location. I cut this out round and fitted a flush patch. It came out pretty good but will show through the paint.

  Finally , there was a small crack starting on the top aft edge where it wears against the boot cowl. I made a reinforcement plate and flush riveted it on the inside.

I had planned to install an F&M oil filter kit and this would had required a large hole in this side to clear the filter. Here is the location marked before I stripped the top. I just don't like the big hole so for now I will just go with the original Continental screen.

You can see the hole I patched at the rear pin location. I did not bother with the the little missing piece forward of the exhaust pipe because the pipe covers this area. Getting late , bottom repairs tomorrow.