more work on the... Radial Fuselage.

February 28, 2026
       4130...
                   yeah, 4130.

What a beautiful Colorado day... to spend with BIG ASS BIRD. It was beautiful outside too. I'm not use to 65 degree sunny days on the last day of February.

Today I spent time figuring out the air exit in the firewall. Based on the CAD drawings of the Pitts Model 12 firewall I followed (whether right or wrong) there is an air exit at the center bottom of the firewall. To prevent all that air from rushing into the cockpit I need to come up with a air 'duct' to allow it to follow back and down from the engine compartment.

Near six hours later and I think I have the plan and the third revision of a pattern to use for that plan. And thinking this through, I'd like to fashion this piece out of something that is more fire resistant than aluminum. Right now I'm unsure if I'll use a piece of the stainless steel that I have from making the firewall.

Why? It's not that easy to work with... at all. Originally thinking to make it out of aluminum... not suce a good idea. I'm now thinking of creating this out of maybe thin 4130 and running some stiffeners along the long 19inch surface to keep it from bening under the force of the wind. This will allow me to make a 'box' that can be welded up AND fire proof that area. I like that idea.

I also located the rod that connects the fuel on/off to the actual fuel valve. Loosely bolted that into place with the incorrect hardware (which WILL be changed to AN.)

Random thought... I need to figure out a way to put more hours in a month on the build. At this pace it's going to take me more than forever to complete it. With it being 45 minutes to an hour away I'm not able to walk out to it each night to put and hour or more on it. (insert a little sad face)

Have a great week...

March 8, 2026
       Quality time...
                   and yeah, a lot of thinking too.

Some quality time spent with Fernanda yesterday, out hiking some of Colorado's great outdoors... time for some quality time with BIG ASS BIRD today.

Almost there... but still a long ways off. A lot, A LOT, of little things, and still some BIG things left to do.

Pattern for the air exhaust whatchamacallit made last weekend. This weekend... testing out that pattern.

Had a scrap piece of .0320 laying around for just this occasion. Rough hand cut, then cut to the line. Did the bends on it by using the small hand-held bender I have... but should have used that Black and Decker clamping table I have. It always made nice bends in thinner metals. BUT... I didn't and it didn't change the results which was to see if this is what I was looking for. And it was.

With a few tweaks to the final pieces... this puppy is a go! All I need to do is order the metal for it and then make more accurate measurements before making the final piece.

Spent the rest of my time figuring out how I was going to enclose the areas around the main gear legs coming into the fuselage. Right now... from the gear legs forward, I have an open space. Ya know how you play with something even though you don't know which direction it's going to take you? That was me today. I wanted to figure this out but not quite sure how to go about doing it. It was a lot of play today. And still more playing to do. I'll have to see if I can find a few images of that area online... or better yet, ask the biplane form guys.

March 28, 2026
       Another test piece...
                   Final answer.

Messing around with planes...

Continued work on the exhaust opening for the firewall. Another iteration and another tweak and the final pattern is ready to be reproduced into an actual piece.

It's going to be challenging to make this baby out of stainless steel. Anything else and it's not really going to be 'fireproof'. Asked the question to the builders on the biplane forum their thoughts.

April 19, 25 and 26, 2026
       Cutting...
                   and cutting and cutting and cutting and...

Not sure what happened the other week, but it looks like I didn't update the site even though I did put some time in on it.

Still working hard on the air exhaust tunnel for the engine compartment.

Bought some .0320 4130 to make the piece. (Note: The Pitts 12 guys are using aluminum... a lot lighter than the 4130, but what happens if there is a fire in the engine comparment???). Figured the trade off, just this once for safety over weight, was worth the trade off.

Laid the masking tape. Figured out the set-back and bend allowance for the thickness of the piece and the bend I was going to put on it... drew the pattern on the masking tape and started cutting... and cutting and cutting and cutting... The throat on the band saw wasn't deep enough to cut the extra metal off of the piece (unless I wanted to throw away a 10inch wide by 24inch wide piece of metal by cutting it in to manageable thin scrap pieces (of which I wasn't going to do). and... Too thick for tin snips, and I could only cut so much with a regular hacksaw. Luckily I have a small hacksaw blade handle that you can attach a blade on to and cut as looooooooong a piece as you wanted. It just takes so looooooooong to cut, by hand. I must have put a good two and a half hours of cutting on that piece.

Got it rough-cut to size then took it over to the bandsaw to cut to just before the line. THEN over to filing it to the line with a rasp file then finish file then 120, 220, 320 sandpaper. Still had some daylight left so I began to bend that SOB. Ya wouldn't think, but you'd be wrong... hand bending .032 4130 is a bitch. If I was in Mantua I would have had the tools and tables to clamp it, heat it, bend it (easily) and be done with it. But I ain't and I didn't. Left for the day with more bending to do!

Back the next day for more bending... and it didn't get any easier than the day before, no matter how much I prayed the night before.

Finally got that heavy SOB bent and sized it up to its spot on the firewall... sa-weet! Fits like a glove. Good enough? It was Good enough, but... good enough isn't Good Enough. The top flange fell short of the 3/4inch that I was looking for. And since it was, I now had the choice of making it with a thinner piece of metal. Searched for quite a bit and found a nice piece of .025 4130.

Laid the strips of masking tape down on the metal after cleaning it up. Figured out the set-back and bend allowance and got about drawing up the pattern on the metal. Rough-cut (yup! with tin snips) then took it to the bandsaw and cut just before the line... then filed and sanded to size. It's now ready to be bent to shape.

Side note: .032 4130 weighs 1.31 lbs/sq ft. .025 4130 weight 1.022 lbs/sq ft. A saving of .5 pounds. Not a lot... but it is a lot. Once I get it cut we'll see how it fits. If I went with .032 2024 T3 aluminum, which weighs .461/sq ft I would have saved an additional pound compared to the .025 4130.

And just an after thought... by looking at the side view of the tunnel on that last image, I think we can get the weight of the piece down to about 1 pound.

Making the air exhaust tunnel. .032 4130


Looking good... with masking tape still on it. :/


Needs trimming to fit curve of belly.

May 2, 2026
       1/2 Pound
                   accept it...

Ahhhh... back to the airport. Bending this .025 is easy peasy. Apparently, TOO easy peasy. The bends looked beautiful... until I needed to trim them to size. No matter how careful I was with cutting with the tin snips... the edges on those bends were looking like potato chips. And lightly hammering them with the deadblow hammer didn't help smoothing them out. Maybe I could, and now thinking... I could make all the cuts to the line before bending without worrying that I didn't have enough meat on it to bend. The .025 is so bendable that it would have held its shape and I wouldn't have had to trim it to fit.

Maybe, just maybe I'll try that (maybe... if I decide to go and buy another piece of .025). But for now, I have a beautiful looking air exhaust tunnel. All I need to do is weld the corners (and I'm hunkering ro getting back to welding). :)

For now... I'll suck it up and take the little bit of extra weight for the fire protection.

Other than that... I started looking at the fuselage for things I needed to do... found the front stabilizer attachment and bolted that on so that I could slide the stabs onto the fuselage.

Need to go out and buy the wood for the 10' x 4' table to begin making the wings.

As soon as I can weld up that air exhaust tunnel I'll drill the holes for mounting it... And then I can hang that Jake.

Yeah... .025 is easy to bend AND potato chip...




Ready to be drilled and attached


She is looking good!

May 9 and 16, 2026
       1/2 Pound
                   TOO MUCH!!!

Flip flopping on this air exhaust tunnel...
Got back to the airport and picked up that beautiful air exhaust tunnel and... it weighs a lot. It really does. I thought, if I can find a piece of 2024T3 (cause it's one of the best known of the high strength aluminum alloys. nuff said) laying around and it's big enough, I'll re-make the re-make of the re-make. And if there wasn't a piece, fair enough, I'll keep the anchor-heavy tunnel and be happy with it.

Didn't have to search long when I found a brand new (I'm not sure how old it is.) piece of .040 2024T3 aluminum. Nice. NICE!

Spent the day laying out the pattern and cutting and bending this piece. And it looks NICE and it's light weight and it doesn't form into a potato chip when cutting it.

All of this was done on Saturday the 9th. Back to the airport on Saturday the 16th and trimmed the aluminum tunnel to fit the frame then took my time making a few small brackets. Check! check-check!

Wanted to rivet them on but looking at the placement of the anchor nuts on the frame around the air exhaust opening on the firewall that I will be attaching the tunnel to, if I rivet the brackets onto the air exhaust tunnel the holes I need to drill on the tunnel to attach to the frame on the firewall would destroy one or both rivets. no good

So... I'll bond/glue the brackets to the tunnel. T-33 isn't the glue of choice at all (the only stuff I have in the shop). Wanted to ask Scott, my next door hangar neighbor, or Larry... (2) doors down, but neither of them were at the airport (both are aluminum RV guys). So... I'll need to do a little research.

Had time to do some other things so I started attaching more parts on the airframe to get a better feel of where I am (and I am getting close) :)

Took a few minutes to climb up into the cockpit to give a good look-see.

Close to what? We'll see.

Air Exhaust Tunnel, final answer.


That's a bracket.


Just need to attach the windshield. Clean the glass.
Add a few instruments...

May 23, 2026
       I'M TIRED...
                   of posting the same thing!!!

Before I get started... HAPPY MEMORIAL DAY! Thank you to all those who have served and sacrificed everything to keep our Great country Free.

Thank goodness I persevered...
I think I'm close to match-drilling this air exhaust tunnel to the frame on the firewall.

Today I JB Welded the corners on the aluminum air exhaust tunnel. Asked the guys on biplaneforum.com and got quite a few replies. One of the products cost an arm and a leg. I decided on the JB Weld. They use this shit on race cars (I'm thinking...). Anyways. One of the big deal-e-os for me was that it could withstand 550 degree. The more temps it can take, the better.

The stuff sets up real good in 4-6 hours and is like metal in 24-48 hours. Next... I'll un-clamp it, mix some additional JB Weld to fill in any gaps or on the back to make it look purty, wait another week and then sand and match-drill to the firewall. THEN I'm ready to hang that Jake in place!

I'm at a weird spot/time with the build... standing back and looking at it, I've got a lot done. Big things to do... hang the engine, make the wings, cover and paint. YIKES!

I started this long-term project back in December of 1993. Thirty-three years ago. Half my life I've been involved or thinking about BIG ASS BIRD every day. That's a long time. Ahhhh... nostalgic. It's nice to think back about that every once in awhile.

Finished? Maybe in two more years... three at the most. (yeah right... I'm thinking if I can put more time on it).

Standing back looking at it there's quite a few things on my too-do list and nows as good a time as any time access what needs to be done. And here is the list I came up with:

- Finish welding hinges for rudder and stabs, and outside edges
   of stabs.
- Balance elevators
- Make wings
- Make 4' x 10' table so I can make the wings
- Seat cushions (canvas - old school)
- Finish welding brackets for walking beam
- Buy Sheets of aluminum to make (hopefully) the final skins
   Two plus one extra. 4' x 10' x .032
- Hang engine
   Need sand bags to weight the back
- Make and attach covers for areas around engine mounts
   on firewall
- Above covers... 4130 .040 or .032?
- Start figuring out where the holes need to goin the firewall
- Buy O/A and welding rods
- Work on UWCS
   - Attach lower stiffners
   - Attach leading edge ply
- Figure out all hardware and make Excel Sheet
- Figure out steps up to the cockpit
   Look at Wacos, Stearmans, etc for ideas
- Sliding canopy?
- Buy instruments
- Figure out radio antenna
- Buy starter
- ELT backet
- Electrical
- Plumbing for fuel lines
- Fiberglas cowling?
- Covers for openings in belly

Uh... yeah :/ I still have a list of things to do (and this is the major stuff)

Kinda sorta the area for the built-in step? Waco-style?


Waco step.

And as always. See ya... next week.