RV-9A, SoCal - Page 19

rightrudder · #**181** 05-09-2015, 09:06 PM

It felt great to bolt up the Catto 70/70 for the first time and fit the spinner. A huge relief that the forward bulkhead fits nice and snug on the spinner, with maybe 1/16" of fiberglass overhanging the rear bulkhead, so no spacer required.

I went the extra mile and built up the cowling where it meets the spinner with dry micro...a ton of work, but there was just too much of a gap for the level of finish I'm aiming for. The rear bulkhead had a minimum of 1/4" clearance (11 o'clock, facing the front of the plane) and a maximum of 1/2" (5 o'clock). Since I wanted a nice, even 1/4" clearance all around, I glued some little chunks of 1/4" bass wood near the 5 o'clock position, which will be encapsulated in the dry micro when finished.

Got some glass (a panel from the coffee table was ideal), mixed up a bunch of "frosting" and smooshed the waxed glass down over it. Darn, not enough micro....do a second application, sand, sand, sand. The third application was for the cowling seam, where I used some waxed aluminum sheet to make a nice crisp parting line. The garage looks like a flour mill and I'll probably die of "microsphere lung," but it turned out good!

Waterobert · #**182** 05-09-2015, 10:09 PM

Looking good Doug, lol

rightrudder · #**183** 05-13-2015, 11:41 PM

Made the filler widget pieces for the spinner. I ended up using 0.040 aluminum for the backing plates because it's easier to bend to the spinner's curvature. It's a light piece, and with two hefty screws it's not going anywhere. All the shaping made the end come up short on the rear bulkhead (just 3/8" or so, but it looks terrible), so I extended it using the bulkhead as a mold. Underneath is a scarf joint with three layers of 9 oz, then a blob o' flox on top.

Next up, the "speed blister" (

) on the lower cowling for mixture arm clearance. I found some cheap plasticine clay at Michael's (Craftsmart brand, $2.99 a pound), sliced the brick in half to make a nice slab, applied it to the taped-up cowling and molded it with my fingers. It's a little larger than it needs to be, but I wanted to make sure there's never any contact on startup/shutdown.

Then a coat of paste wax, which of course is mold release, but it also lets you smooth the clay more easily into the final shape. More eyeballing, tweaking, and application of a second coat of wax. For the initial layup, I used two layers of some extremely light cloth that I dug out of my rc plane stash, in the hopes the exterior will need less final sanding & filling. I plan to reinforce it later from the inside with 9 oz. cloth.

rightrudder · #**184** 05-14-2015, 09:32 PM

Here's the blister after trimming. It came off the clay pretty cleanly. I wiped down the inside with acetone, scuffed it, applied some 9 oz. cloth, then floxed it to the cowling with the aid of some clecos. From the inside of the cowling, I smeared a generous fillet of flox around the perimeter of the mating surface, so it's super solid.

The filler piece for the spinner turned out good...a lot of work to add this small extension.

It's a cold, rainy day in SoCal, so it takes forever for epoxy to set up.

rightrudder · #**185** 05-20-2015, 06:49 PM

More work on the cowling. I sanded and epoxied the inner surface, then applied the thermal aluminum barrier.

The oil door hinge required a flat surface for attachment to the cowling, so I laid up a nice slab of flox and attached it with both rivets and G-Loc epoxy.

The last shot shows the front of the nose gear intersection fairing. At first I had drilled the holes and riveted the nut plates to the cowling, but the screws and Tinnerman washers were a very ill fit when tightened down. So I redid the attachments, drilling the holes at an angle to match the fairing, and securing the nut plates at the same angle...no rivets, I just encased them in blobs of flox.

To finish it off, I filled the underside of the fairing with flox too, so I can crank down on the screws without distorting the fairing. A little heavy, yes, but with my Catto FP prop and dinky alternator, I need the weight up front. This ought to do it, along with my nose wheel machined from depleted uranium.

rockwoodrv9 · #**186** 05-20-2015, 07:21 PM

Nice Doug. There is lots of work in the cowl. I have mine fitted - but not finished. There is a BIG difference. Very clean looking thermal coating work.

bruceh · #**187** 05-20-2015, 08:15 PM

Doug, you might want to run a bit more of the reflective material up the sides of the cowl. Mine is starting to show some discoloration in that area and I'm planning on adding some fiberfrax and reflective shielding up the sides of the lower cowl.

BABALU · #**188** 05-20-2015, 08:31 PM

Very nice work Doug, impressive. I've been checking in on your progress every now and then , not that I know much , but it's obvious you are talented.
I'm curious what the RV world would tell somebody interested in building what they should expect their ballpark cost to be to get flying in a nicely equipt RV9 . I've seen estimates of 50- 60 but Now that I'm fully invested in my 9 I feel that those numbers are unrealistic , at least for a solid fresh aircraft.. I wanted something I could fly right now so I bought a project plane and have been transforming it into what I think is a good solid aircraft and I realize that has run my cost up , I'm well over 60 G by the way, more like 70 to be honest but I didn't invest thousands of hours of basically free labor , yes I realize to some people building is what it's all about and I understand that .I'm just Curious to where others are at , ballpark if anybody cares to weigh in . Hey , If you love it , and we do, its worth it regardless just as long as you fly it a lot ,and I do and you will.

rightrudder · #**189** 05-21-2015, 01:59 PM

Thanks for the replies and insight, guys. Yes, the cowling seems never-ending sometimes...I must have mixed up 50 small batches of epoxy and micro for various small jobs. I don't think I'm up to doing all the pinhole filling and external finishing, so I've resigned myself to write a bigger check to the painters to have that done.

Bruce, thanks for the tip. I've got some of the aluminum tape left, so I'll add a couple of strips up the sides. My "thermal coating" material is actually Harbor Freight aluminum tape. I tested a piece applied to some scrap fiberglass with a lighter...cooked a spot with direct flame for a good 30 seconds and the adhesive stayed put. We'll see how it performs in the real world.

Babulu, I think a good slow-build -9, day/night VFR, could certainly be built for $50K-$60K, but that's going the used-engine route and painting it yourself. I'm figuring on about $80K-$85K with the QB fuse & wings, a new Lycoming and professional paint. I look at it as equivalent to buying a nice European luxury sedan. It's crazy how much some folks put into the panel alone....$25K or $35K!

Yes, I certainly could've purchased a very nice flying, well built RV for the same or even less, but I really wanted a project that I could throw myself into. And I got it!!

To fend off cowling burnout syndrome, I had to work on something else. So last night I swung the plane 90 degrees in the garage, bolted on the tail feathers and did an initial fit/trim on the empennage fairing. The fit is actually pretty decent, but the parts overlapping the horiz. stab's LE need to be recontoured, and the left side up against the vert. stab has too large a gap. I've worked it over pretty good with a heat gun, and I'm sure there a few more gains to be made this way, but at least a little fiberglass surgery will be involved. Access to the washer/dryer is a bit compromised!!

BABALU · #**190** 05-21-2015, 04:08 PM

Quote:

Originally Posted by rightrudder

Thanks for the replies and insight, guys. Yes, the cowling seems never-ending sometimes...I must have mixed up 50 small batches of epoxy and micro for various small jobs. I don't think I'm up to doing all the pinhole filling and external finishing, so I've resigned myself to write a bigger check to the painters to have that done.

Bruce, thanks for the tip. I've got some of the aluminum tape left, so I'll add a couple of strips up the sides. My "thermal coating" material is actually Harbor Freight aluminum tape. I tested a piece applied to some scrap fiberglass with a lighter...cooked a spot with direct flame for a good 30 seconds and the adhesive stayed put. We'll see how it performs in the real world.

Babulu, I think a good slow-build -9, day/night VFR, could certainly be built for $50K-$60K, but that's going the used-engine route and painting it yourself. I'm figuring on about $80K-$85K with the QB fuse & wings, a new Lycoming and professional paint. I look at it as equivalent to buying a nice European luxury sedan. It's crazy how much some folks put into the panel alone....$25K or $35K!

Yes, I certainly could've purchased a very nice flying, well built RV for the same or even less, but I really wanted a project that I could throw myself into. And I got it!!

To fend off cowling burnout syndrome, I had to work on something else. So last night I swung the plane 90 degrees in the garage, bolted on the tail feathers and did an initial fit/trim on the empennage fairing. The fit is actually pretty decent, but the parts overlapping the horiz. stab's LE need to be recontoured, and the left side up against the vert. stab has too large a gap. I've worked it over pretty good with a heat gun, and I'm sure there a few more gains to be made this way, but at least a little fiberglass surgery will be involved. Access to the washer/dryer is a bit compromised!!

I agree 80 - 85 is exactly where we are at for the aircraft you describe, and that's what I have, I plane I would fly any where with confidence. Keep up the good work looking forward to your first flight. I actually live by First Flight. KFFA so I get to first flight all the time.haha.