Sling TSiLittle Betty

Wing session

Prime/Paint Prep

Paying attention to the zillions of details related to getting ready for priming. The more work you do preparing for paint, the better the final product will be.

Closing Gaps

I really wanted to work on getting gaps as tight as possible. It's nearly impossible for fiberglass parts to come out of the mold and fit perfectly without modification. The Sling manual has you use straps and other mechanical devices to bring the tips into place and close the gaps between parts. There's nothing wrong with these techniques, but they won't get you to a really tight-fit finish. I ended up using JB Weld to pinch and close the gaps at the trailing edge of the part, then filled the gaps between the parts with epoxy and micro-balloons to finish the job. Sanding and fairing complete the job.

Scuff n scratch

Close Wingtip Fit

The manual has you do a bunch of contortions with straps, tap, and other shenanigans to get the wingtip to fit properly. Sling does a great job getting parts manufactured to tight tolerances, but in my experience, fiberglass parts always have gaps that you can't work away by just fitting parts together. Here I'm masking off the aluminum and laying down a mixture of micro-balloons (composite guys are familiar with this stuff) and epoxy to a toothpaste-like consistency. I'll use a spreader to force the mixture into the gap and to fair the interface between the aluminum and the fiberglass. The result is an inability to see where the aluminum structure ends and the fiberglass wingtip starts. The stuff is easy to sand but strong. I'll start with 80 grit and work down to 320 for priming.

You missed one ...

Filling the wing rivets is a tedious, long, repeated job. The idea is to make the pull rivets look like solid rivets. There are thousands of rivets that need to be filled on this airplane. There is no reason to do this other than cosmetics. I'll trade doing this, however, than having to deal with bucked rivets... hands down, every dang day! :)

Wing session

More work on filling rivet holes. Wash rinse and repeat!

Experimenting

There are several options that I've fooled around with to fill the pull rivets. The manual calls for auto body filler. It's readily available and easy to work with, but as I'm doing this in the middle of summer, the material lights up too fast. Pot life can be as short as 5-10 minutes. This forces you to throw away a bunch of material and constantly mix new material. I've found that with a small smear tool and a dremel disk sander, the job becomes a little more efficient.

Wing session

Wing session

Wing session

A short rivet filling session. Small doses seem to be the ticket here. It’s tedious work.

The Pressures On!

A bunch was done in this session. In particular, I'm pressure testing the fuel tank. Anyone who's done the fuel tanks knows it's a messy, stinky, gooey, time-sensitive job. When it's done, you have test the results. I did this with a few clever parts that I stole from another builder. Here's the parts list: 1. Low-pressure air gauge. You only need 1-1.5 psi to test. You don't want to blow your tank up! 2. A shreader valve. 3. The appropriate AN fittings to adapt the pressure guage and shreader gauge to the fuel inlet and fuel pickup ports. 4. A compression fitting (like you'd use on a refrigerator) to seal off the tank vent. 5. A spray bottle with soapy water bottle in it. You don't need this if you're a hopeless optimist and convinced you have no leaks. 6. *Something to pressurize the tank. *Everybody says not to use a compressor, but I did, and it worked just fine. Turn the outlet pressure way down and keep an eye on the pressure gauge. Go slow. I had no problems doing it this way and I didn't blow my tanks up.

Wing session

Wing session

For the first session today, there were a lot of little tiny projects. I'm preparing the left tank for pressure testing. I'm also going around and doing the little jobs like riveting in ribs and other things that are required to wrap up the wing build

Wing session

Finished riveting up the left wing fuel tank.

Wing session

I worked on preparing the left fuel tank for final riveting and sealing.

Wing session

I've finished riveting on the right wing

Wing session

Tonight was a night of tiny projects. I was able to get all of the AN fittings installed into the left fuel tank. I was also able to get the landing and taxi light wired up and mounted into the right wing. Little project projects big progress!

Wing session

I completed a aligning and final riveting of the right flap and the right on. I was amazed at how well they lined up with little to no effort!

More Tanks Sealing Fun!

I pulled the left tank off the wing and ran another bead of proseal around all the edges making sure to hit the corners heavily. That seems to be a problem area. I’ll let that all set up and install the internal plumbing… the fuel pickup, vent, and return lines. After that, I’ll rivet the back channel in. I’m hoping to have the tanks done by the time I leave for OSH. It’s unlikely though I’ll get to pressure testing the left tank as I want that to dry for a week or more. Fingers crossed I know what I’m doing now and there’s no leaks in tank two! #fueltank #wing

Wing session

Finished riveting up the left side wing tank

Wing session

I finished getting the internal skeleton of the left wing tank finished.

Wing session

Wing session

I got the left wing tank riveted up and fitted into the wing. The next step is clear drill all the holes take the wing tank back off of the wing and then seal it. Hopefully the ceiling will go better now that I know what the heck I'm doing.

Wing session

Third round of chasing a tank leak! Also worked on dimpling the left tank skin. #fueltank

Wing session

Wing session

Wing session

Continue to chase down the leak on the right wing tank. Also did some riveting on the top skin of the left wing. I decided to switch out the stock fuel senders for a set of CiES senders. https://ciescorp.net/ The are way easier to install and the company claims fuel accuracy to 1/10 of a gallon. They seem way more robust than the kit supplied units. #fueltank

Wing session

Wing session

Today was a pretty substantial day. I got the Pio system all wired up and all the electrical wiring laid into the left wing. I was also able to build standoffs so the wires don't interfere with Peter tubes and vice versa. I should be ready to start closing up the left wing and installing the top wing skin this weekend. I'll also be able to retest the right fuel tank to see if I sealed up all the leaks. #wingskin

Wing session

I got the end rib set in and clear drilled. And I fitted up the wing tip and got those holes drilled as well. Tomorrow I'll rivet the whole thing together.

Wing session

I did some skin preparation and internal skeleton preparation for the left fuel tank

Wing session

Wing session

Wing session

All the rivets on the bottom skin have been set up and just need to be pulled. That's the end of the session!

Wing session

Worked in cleckoimg in and preparing the bottom skin for riveting.

Wing session

Wing session

Wing session

Wing session

Wing session

Wing session

Wing session

So with the right fuel tank completely sealed and drying, I need to wait about a week before I can test it. Now it's on the left flap. After that the only thing remaining for the wings is gonna be the left wing.

Wing session

I pretty much wrapped up the tank today. It was a continued gooey awful stinky nasty mess but it's done! The only thing I have to do with the tank is to attach some of the brackets on the rear side which involves a little bit more prose but not a lot. It's almost there! #fueltank

Wing session

Starting on the left aileron while the tank pro seal dries.

I cycled between sealing the tank and building the left aileron. Getting the tank together and sealed properly has been time consuming, tedious and messy but it needs to be done right. I have no desire to revisit a leaky tank!!

Wing session

I started working on sealing the tank yesterday. It’s a messy job! I’m breaking from that waiting to get a clear uninterrupted block to finish. Today I’m going to work on the ailerons.

Continue work filling in rivet holes. There’s A LOT of them!!

Working on filling in the rivets while I wait on a pro seal kit. That should be here tomorrow.

Wing session

Wing session

Getting all the parts dry fit and ready for the tank sealing process.

Wing session

Wing session

Wing session

Wing session

I was able to get the nose. Skin riveted onto the outer tip of the right wing. Next step is the fuel tank!

Wing session

Wing session

Wing session

Wing session

Wing session

Wing session

Wing session

Wing session

Wing session

I finished reventing the bottom skin to the right wing

Wing session

I got to a good spot to stop the riveting. About half of the bottom wing skin rivets are set and in place.

Wing session

Wing session

I finished dumping all of the bottom wing skins. Whoa! #riveting #wingskins

Wing session

Wing session

I riveted the rear spa in place as well as all the ribs and fit it up the skin support bracket, and test fit the root rib trailing edges.

Wing session

Wing session

I installed half of the ribs mostly the ones from rib one to rib six to test fit. The next step is to begin riveting ribs one through six onto the main spa. #wing

Wing session

I completed assembling all of the ribs for the right hand wing. I also prepared the other ribs that didn’t need assembly for attachment to the spa.

Wing session

Wing session

Wing session

Wing session

ID bird the majority of the real rear spa parts. The only thing left to do is to clean them and get the sticky label go off. And then we can Cleco the structure together.

Wing session

Rudder session

Rudder session

Rudder session

Rudder session

Other session

Vertical Stabilizer session

Test routes the strobe wiring through the vertical stabilizer. Need to call Mid-west about the coax cable that also needs to run through to support the VOR antenna. #wiring #midwestpanel

And today it begins the plane showed up at least the wings and the elevator and we are stoked to get going!