Back to Work - Cowling & a Big Move

Back home and time to get back to work.

I spent the better part of the morning digging out all the foam in the lower cowl mold. For some reason, the combination of drywall paste, car wax and mold release had a more tenacious grip, so the foam didn't go peacefully.

The first photo shows the cowl/mold just peeled off the engine.

















Finally, I decided to move my project back to my Tee hangar. It was really great to have use of the SIU Aviation Technology facilities, but it's time to move back home. They were kind enough to lend me a student worker for the afternoon, and we got it done in about three hours.

Once back, I took a couple of days to get the hangar properly organized. I learned a lot about organizing workplaces while I was at Dyno Nobel. Some of the main points I try to keep in mind:

• If you don't need it - get rid of it.
• Use visual clues like applying labels.
  
• Keep things you use often close at hand. Things you use only occasionally can be further away.

On vacation

We took a week off to take our granddaughters to Washington D.C. Take a look at Sandy's blog for the rest of the story.

Glassed the lower cowl

The next step is to make all that foam smooth enough to glass. One of the guys in my EAA chapter told me about using drywall compound. It's cheap, easy to get, and water soluble. I put on two coats, sanding in between.

After it's smooth enough for government work, I apply a coat of auto paste wax as a mold release. I also had access to a bit of water soluble mold release, so I gave a final coat of that, just for good measure.

I added two layers of BID then used sheets of dacron as peel ply.

We're going on vacation for a week, so you'll have to wait to see how it turns out.

Stretching the lower cowling

Now comes a part I have not been looking forward to - lengthening the lower cowl to match the upper.

The first thing I had to do was get all the basic engine components in place, the induction system, injectors, and the oil sump. I kind of pieced things together, but wasn't sure how to proceed. I consulted Jeff Sell and Q-2 cowl maker Earnest Martin and they pointed out the grim fact; I would have to flip the plane so I could get a better perspective on it.

Again, the hardest part is often deciding to get on with it.

Carbon Fiber Oil Sump

One of the main tasks is to build a CF oil sump. I wanted to cut down the amount of sump hanging in free air. (As usual, click on the photos for a large version).

I started a few months ago by getting out the Milwaukee Sawzall and start hacking on a chunk of foam. True to form, I just start hacking, then see what comes out of it.

After I got something like it might work, I tried to figure what to do about a mounting flange. I finally decided to make a sandwich with aluminum rings for bread and the CF for the peanut butter.

I kept whittling away on the thing, then finally coated it with drywall paste, car wax, then finally a mold release agent. This is a neat trick. The DW paste is water soluble. Before I coated it with the DW paste I did a water displacement test and it looks like it will hold five quarts. Perfect!

For epoxy, Mike Bergen helped me get some high temp ProSet. This stuff has a 300 minute pot life, but cures nicely in 24 hours. The only issue is that I have to post cure it to 250F or so.

The next trick was figuring how I was going to hole the flange in place while it cured. I figured I could make a little foam collar to support the flange. I would first wrap the entire thing in CF. At the neck, I would leave extra material which would form the flange.

I set the foam collar onto the sump, then placed the lower ring. I then folded the CF outward and placed the top aluminum of top of it. I guess the carbon reacts with aluminum so I first alodined it then I placed a piece of e-glass in between all places where the CF might touch the flanges.

I had predrilled a couple of tiny holes in the flange rings for alignment. I suck in a couple of cotter pins to hold the alignment.

After two days of cure time I spend an hour chipping out the foam. It was pretty easy and most of it came out without a fight. Since both the drywall paste and the mold release are water soluble, it left a nice clean, smooth inner surface.





A quick check looks like it's going to work!

Next comes the drain bung install and the filler neck and dipstick.

Can I make it to Oshkosh?

I have so-o-o-o-o much to get done - I don't know if I can pull it off.

The work is progressing steadily, but not all that fast. I just received the EC3 controller from RWS and have some SIU avionics students starting to help with the wiring harness, but I haven't really finalized the electrical drawings.

The big hitters on the to-do list are:

• Finish CF oil sump.
• Finish installing the new canopy.
• Finish the stretched cowling.
• Paint the cowling, wing and canopy.
• Complete the pressure fuel system installation.
• Install the new Dynon D180 and to all the ship's wiring.

Ugghhh. It's a big list.