Swap Meet Balsa Find, Hangar 9 P-47 Thunderbolt

[Joker 53150]

I'm in the final steps of my Balsa Build Along Extra 300S, so while paint dries and the weekend is still young I started on another "quick" (?) project. This P-47 Jug was found at a swap meet in Green Bay a week ago, yet another plane I just couldn't pass up. The seller had it priced a little higher than I was willing to pay. It came with an OS .61 glow engine, but no receiver or battery. At the end of the show he still had it and was willing to deal a bit so we agreed on a price and I walked out with it.

The plane isn't perfect, and it needs some work, but it's solid and this should be a quick project. I'm focusing now on getting as many small projects done on my various planes so they're ready for Spring flying season.

Here's what I'm starting with, a solid and complete airframe.




Strange thing to fix #1, the previous owner left all of the screws for the ailerons full-length instead of using shorter screws or cutting the excess off.




There are a few spots where covering is coming loose, such as this invasion stripe. This is normally a quick & easy fix. There are a number of wrinkles that also need a little touch-up.




These are the new parts going into the plane. The fuel-stopper kit was also purchased at the swap meet. It's my favorite type, made with metal instead of plastic. The battery is a standard 6 volt receiver pack, which will be monitored by the VoltWatch2. A new power switch is also going in as the original was cracked. It was also glued in instead of using the normal screws and backing plate, so old glue will be removed and extra holes around the switch will be covered.




The plane came with retracts which work nicely, however the gear struts are bent backwards slightly so the tire contacts the wheel well housing, keeping it from moving easily. This should be a quick & easy fix as well.




Two cowl mounting blocks are mounted too far in on the firewall, causing big dimples in the cowl when the screws are tightened. A couple spacers and epoxy will take care of that problem. You can also see the cowl has a fair amount of grime on it. This is AFTER I cleaned most of it off!




Turning to the inside of the plane, the fuel tank is going to get some attention from me. It was wrapped in two thin layers of foam and pushed into the nose. While this may work, it's not very secure and the tank could slide around a bit. I'll go through it and decide if I want to re-use this tank or I may try and fit a larger one since there is plenty of space.




Tons of room for the wiring, battery, and receiver needed to get the plane finished up.




Since it won't be started for a while I pulled the glowplug to feed some oil into the cylinder and carb. The engine has plenty of compression and the original glowplug works well, so I'm very optimistic about it firing up for me.




I opened the tank and found the previous owner ran the lines the same way I like to do them - with dual clunks and a dedicated feed/siphon line. The clunks may get re-used, but the rest of the fuel line pieces are getting tossed out, even though they're in decent shape. They're cheap to replace and I don't want to pull the tank again any time soon.




The OS .61 is mounted sideways and included a Pitts-style muffler. I need to adjust the silicone exhaust tubes so they're aiming out the bottom of the cowl evenly, and will add a few zip-ties for extra security so they don't fall off in flight. The muffler will be pulled so I can run it through my antifreeze Jacuzzi which will clean it nicely. The engine could use a little cleaning, but it's not too bad at this time. The big reason for pulling the muffler is so I can check the muffler gasket. A bad gasket will cause a big mess over time and will keep the engine from running properly.

 

[roversgonemad]

That tank install was epic!! Surely it wouldn't go anywhere!!! Cool find, hopefully the price was excellent.

 

[Joker 53150]

The tank came out with a light tug, not secure enough, in my opinion. The new tank is about 2 ounces bigger and a zip tie is used as the strap. Foam is wrapped around for the padding, and other than needing a new fuel dot the system is complete.

The seller was asking $200 and I ended up paying $150, a good deal.

 

[roversgonemad]

Honestly, it's hard to believe it stayed in place during flight. Sloppy foam, and just sort of wedged.... I have had tanks that I thought were pretty dang secure, and they moved in flight. I really like to glue a piece of wood behind tanks to hold them securely. It's usually pretty easy to break a thin piece of balsa out of the way if a tank needs some attention.

Too bad that thing is so darn shiny!! Pretty sure the real war planes were painted with a brush, out in the dirt, and they never looked that good. I have seen some photos of actual invasion stripes, and they were a sloppy mess, applied the day before the invasion, according to the photo caption. I have always been a P-47 fan, I built several plastic models of the P-47 when I was a kid. I am partial to the razor back but the bubble canopy is cool as well.

Looks like a decent find for not a lot of cash. Should be a fun plane when it's all rehabilitated.

 

[Joker 53150]

Doing a little test-fitting of the new fuel tank, it should be much more secure than the old one. I'm using a foam pad that is somewhat grippy so the tank won't slide. Even if it does, it can move about 1/4" forward or back total, and couldn't come out. Instead of gluing structure in to hold it in place I found a couple zip ties will do nicely. Now that I know it'll work I can go back and wrap it up so it looks a little neater.




The fuel fill/siphon port has been moved and replaced. Previously it was up in the upper black portion of the nose, and it looks like the previous owner also tried installing it farther forward before realizing the cowl covered that area. :black_eyed: The port doesn't work well as it doesn't securely hold the fuel line, so I replaced it with a new version that twists to lock. ....and I screwed up by not noticing there is a plywood former in that spot. So it was moved back an inch and I'll cover over my mistake when the silver covering I ordered arrives. The old power switch location has a few extra holes that need to be covered as well.




For a receiver I'm going with an 8 channel X-series from FrSky. The plane needs 6 for servos (5 if I want to run the ailerons off a "Y" splitter, plus one channel for the battery monitor and one channel that I'll use for power.

I've ticked a lot of items off the To-Do list, so this plane is almost ready to be put off to the side until the covering and receiver are delivered.

 

[Joker 53150]

A few days away for work and I come home to a box waiting for me - it's the silver covering I ordered to patch the original material. It only took a couple minutes to do, and the results blend very nicely as I went with the same brand/color covering the plane came with when new. The new power switch was also installed, and when done I realized I ordered the version without the LED power light. Oh well, a minor issue that can be changed in the future. Now I'll need to get a small scrap of black covering to patch the two holes on top of the fuselage. To do 'em right I'll need to remove the remaining fuel power ring that is glued in place and then fill the hole with balsa.

 

[Joker 53150]

I forgot to mention this, but here's a tip for patching covering. The ideal shape for a patch uses round corners. Squared corners should be avoided as the most likely spot to start lifting loose is a pointed corner. Rounding the corners of a patch significantly increase the chances of that patch sticking down, so an ideal patch would be round (which isn't always an option). One patch I used on the P-47 was round, where I covered my mistake on cutting a new fuel filler hole, and the other patch was rectangular with rounded corners.

 

[Joker 53150]

With a few remaining details now buttoned up the Jug is done and ready to fire up. I’ll wait till warmer weather as doing this in 30 degree weather isn’t high on my list. Now to finish a few other birds so the fleet is ready!

 

[nhk750]

Looks great, I love a big jug!

 

[Joker 53150]

The Jug lives! Weather was decent to test the engine today, so I put in some glow fuel and gave it a shot. It took a while to get the engine primed, but it fired up and ran great without touching the needles. I think it'll make a little more power with some adjustments, but for now I'm happy just seeing it run.

I'll have to do some work to get it to pull fuel more easily as well, but if I were doing this testing at the field it would have been sent up into the sky!

 

[nhk750]

And I say again, nice collection!

 

[Joker 53150]

The Jug got it's maiden flight with me today after adding about 6 ounces of lead to the nose. I have no idea how the previous owner flew it (if he did??) without the extra weight as it was super tail-heavy.

The first flight was uneventful and the first few minutes were just trimming and getting used to it. Even with all the weight added it wanted to climb so I dialed in some down elevator and a little bit of left aileron. From that time on it was smooth cruising and high-speed low passes, a real joy to fly. Landing wasn't as smooth as I had hoped, but it came down ready for another flight.

Second flight started out darn near perfectly with a run straight into the wind. After buzzing around a while the glow engine suddenly quit while down fairly low so I glided through a turn trying to line up the runway again. Unfortunately for me I ran out of airspeed a few degrees from lining it up again and she hit the ground fairly hard and cartwheeled.

Upon inspection here is the damage report: I lost one screw that holds the cowl on, the paint on the cowl is scuffed pretty badly on the bottom, and the prop is broken. Just like the full-scale Jug, this model is STRONG! Oh, and one of the retracts is slightly bent, but can easily be re-bent back into shape.

I'm not 100% sure what caused the glow engine to die but figure it's either the tuning, low fuel level that allowed an air bubble into the line which killed the engine, or possibly a weak glow plug. The prop will be replaced, a new glow plug will be used, and the fuel lines will be checked for possible leaks. Fairly quick & easy work, thankfully it wasn't much more extensive!

 

[PsyBorg]

I would check the o ring on the carb. That would go hand in hand with the hard priming and the stall. Also if the carb has a removable veturi check that for leakage as well.

Glad it came back with scrapes and bruises and not broken limbs. At least this gives you a bit more time to situat CG better now you know how it handled.

 

[Joker 53150]

I'll certainly check it, thanks for the tip. It seems to have fired up much easier now than the first time I started it. Part of that is due to me finally starting to understand how these things work, knowing how to get them to prime without putting a finger over the carb, etc.

 

[nhk750]

Oh man, I hate crashing nice models. At least it wasn't hurt to bad.

 

[wilmracer]

Glad the damage wasn't too bad and that she'll be back in the air soon. What AUW did this come in at? I'm honestly surprised a balsa model this size came through a cartwheel with so little damage

 

[Joker 53150]

I'm not sure on the final weight since my kitchen scale died a while back and hasn't been replaced. Heck, most of my current planes could probably be weighed on a regular bathroom scale now...! It was a single cartwheel and made a lot of noise when it hit, so I'm also super surprised it didn't do any damage. Checking the wing and fuselage over I really couldn't find anything which makes me think it hit first on the bottom of the cowl which absorbed most of the force. Checking through my stash of parts I found a couple wood props in the correct size, so over the next couple days I'll bend the landing gear wire back, pull the cowl to inspect the engine for dirt, and then put the new prop on and check the system for air leaks. My guess is that the tank was getting low enough that it picked up an air bubble.

 

[wilmracer]

I'm not sure on the final weight since my kitchen scale died a while back and hasn't been replaced. Heck, most of my current planes could probably be weighed on a regular bathroom scale now...! It was a single cartwheel and made a lot of noise when it hit, so I'm also super surprised it didn't do any damage. Checking the wing and fuselage over I really couldn't find anything which makes me think it hit first on the bottom of the cowl which absorbed most of the force. Checking through my stash of parts I found a couple wood props in the correct size, so over the next couple days I'll bend the landing gear wire back, pull the cowl to inspect the engine for dirt, and then put the new prop on and check the system for air leaks. My guess is that the tank was getting low enough that it picked up an air bubble.

Nice! Good luck!

I'm watching with extra interest because I just wrapped up a Hangar 9 P-47 and I'm eager to get her airborne. Soon

 

[Joker 53150]

The 1.75 flights I had with it were very nice. Many have stated that the P-47 is a well-mannered warbird and so far I agree with that. Winds weren't the best when I was flying it, but it still handled better than similar planes I've flown in that size. You should have no concerns as long as it's balanced and has enough power.

 

[Joker 53150]

Jug update - the battle scars from the last flight have been repaired, a new prop is on, the landing gear wire is re-bent, and it's been fired up and runs nice and strong. I'm guessing the plane died in flight due to an air bubble getting into the line as it runs nice and strong with no apparent issues once again. That last flight left the ground with maybe 1/2 tank of fuel as I was sharing my glow fuel with a buddy who forgot his and we were trying to use every last drop! She's all ready to go back into battle!