# Alternative covering method?

Discussion in 'Wood Construction' started by halfscalemustang, Dec 25, 2010.

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1. Dec 28, 2010

### orion

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The weight penalty of the ply/composite could add up but how much I don't know simply because I don't know what skin thickness you'll need to make a proper structure.

Okume is generally not available from lumber yards but I think there is a US distributor so you shouldn't have too much trouble finding it.

Graphite fabric is easy to find but it is somewhat pricey. But you probably wont need all that much of it so the cost shouldn't be outrageous.

2. Dec 28, 2010

### rheuschele

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I don't know what you paid, but unless it was free, it was too much. There are a whole lot bigger problems there then replacing skin. It looks like your spars are broken, wood is rotten, landing gear is collapsed. It almost looks like the builder used any kind of wood he had lying around the house and didn't seal anything. On the side is an EAA chapter #. Contact them and ask about it. Also ask them if they can look up any paperwork for it's inspections. Get the N number and look it up on the FAA data base and accident data base. You might be better off fixing the mustang next to the plane first. You may also want to contact the manufacturers of the mustang kits and see if this was some kind of prototype.
Ron

3. Dec 28, 2010

### Dan Thomas

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What sort of engine is that in that P-51?

Dan

4. Dec 28, 2010

### halfscalemustang

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There is absolutely no damage to the landing gear, it is in perfect working order. Already checked the N-number, no report of any kind of any accident. Read through all the inspection papers, which was done in 05, and it states very clearly that it is a one off design of the gentlemans own design work and is not based off of any kits. There is some rot, which is why I am pulling all of the skin off in the first place. To see the extent of the damage and rot. Inside the cockpit and tail cone the wood looks very solid. No, it was not free, I paid a little money for it, but to anyone who has scratch built a project they know the thousands of hours required to find everything, buy everything, figure out how everything will fit and assemble it. In my opinion it made a lot of sense to find something that needed some work than drop $20,000 on a AND build it, not to mention how many scale p-51's have you seen for sale latley for anything less than$250,000? The engine is a 1980 honda cb650 motorcycle engine, the prop drive is connected directly to the crankshaft via gear reduction.

5. Dec 28, 2010

### BBerson

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That looks like an abandoned airframe to me. It may have been too heavy to fly safely. If it did fly, I would assume it required great skill. A half scale P-51 that is overweight is very scary.

And replacing the thin aluminum with anything else will only make it heavier.
I don't see any full depth wing spar in the photo... big concern about that, as well.

6. Dec 28, 2010

### halfscalemustang

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It has flown, and I believe quite a bit. It weighs 630lbs dry. The guy who built it had a business in which he restored antique corvettes and worked on experimental aircraft. I have a reciept for all the wood that was used and it was bought from an aircraft supply catalog. The wing spar is another reason I'm taking the skin off, to see how its built.

7. Dec 29, 2010

### rheuschele

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Sorry, didn't mean to upset you but it looks like that plane had one hell of a hard landing. It looks like it came down fast, hard and flat. That would explain the crinkle in the fuselage by the e in experimental. I'd bet the landing gear absorbed the impact along with the tail section just enough not to hit the bottom of the fuse, but enough to break the spars. Either way, your going to have to tear down everything to inspect including an engine tear down. Keep us up to date but i still think your better off starting from scratch. Start making drawings based on this plane, you may have a winner.
Ron

8. Dec 29, 2010

### halfscalemustang

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This is exactly why i started asking about how to recover and what to recover it with. I knew that it would have to be completely taken apart and thourghly inspected and i am unsure of how to recover it. I would like to have some idea of a better way to cover it so that maybe i can incorporate that into the rebuild and maybe deal with the weight issues. Also, when it was built, the builder had two identicle engines majorly overhauled. I have the reciepts to confirm this. I am planning on making some modifications to the spare engine as well as checking it over and using it. The damage is a baffling mystery to me and everyone else that has looked at it. Until now i have ruled it out to a case of mishandling? That crinkle in the side of the fuse is interesting, i have noticed it, but i didnt think it had taken a hard landing. definately going to have to regroup and look it over again, anything else i can look for to confirm the landing theory? Thanks again for your help Ron

9. Dec 29, 2010

### halfscalemustang

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also, forgot to ask, how should i go about de-skinning it? Just rip the aluminum off wrecking ball style? or disect it brad by brad?

10. Dec 29, 2010

### rheuschele

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Just my opinion, but no one but you can answer whether or not the skin is structural until you remove it. If it was, it shouldn't have been 1x2 pieces. Looking at your pictures, it would be my guess that the builder had quite a bit of trouble with the brads holding it together and kept banging them in each time they came out. You need to join the EAA and get into the local chapter there so someone local can help you. We all can keep guessing but until someone lays there hands on it, it is still a guess. If you keep looking for answers for the entire project here, you will never complete a safe plane. Everyone here can tell you what they have done on their builds, and what they have learned about different materials, but you still need a hands on opinion. It really sounds to me, that the guy who built it just decided to build without following rules or safe design practices. He just wanted a P-51. Again, just my opinion. Below I've posted 2 links, one for plywood, the other for aluminum sheets. They also have the weights for each so you can see that plywood is either lighter or close to the same weight as aluminum sheets. I still think you're better off starting from scratch and build around the engine (depending on what engine it is) and the instruments you've already paid for. Good luck to you.
Ron

Wicks Aircraft Supply
Wicks Aircraft Supply

11. Dec 30, 2010

### halfscalemustang

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Even though I'm not in complete agreement with you I do greatly appreciate all of your help and input. Thanks again for the the lead on some supplies!

12. Dec 30, 2010

### Topaz

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The 800# gorilla in the room for me is the overall workmanship in this project. Paint looks like it was slopped on unsealed wood. Joints and connections don't line up very well. As noted by the OP, you can see a crater from the hammer around every single brad down the side of the fuselage. >>>SCARY<<< If he was willing to bash the structure like that to attach the outer, visible, skin, what did he do with the interior structure? The amount of interior damage and broken-up wood in those photos scares the dickens out of me. It looks like at least one wing was broken off. The spars look like they were broken, at the very least. I'm with rheushele - something broke all that wood. Finding out what that was would be my first priority. Just because it wasn't reported to the FAA or NTSB doesn't mean the aircraft wasn't involved in an accident.

HalfScaleMustang, please be very careful with this one. I know it's "your baby" now, and you've got dreams of flying around the sky with this aircraft, but pull back and get some real perspective. The first question ought to be "should I try and fix this", not "how should I fix this".

13. Dec 30, 2010

### Dan Thomas

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Yeah. Be careful. I once bought a low-time wooden homebuilt single-seater that needed "a bit of repair" and it looked a LOT better than this P-51. After three years of working on it I gave up and scrapped it. I got tired of finding low-strength glue joints (guy had used Aerolite in a cold basement; Aerolite is temperature-fussy) and finally a crack in an aft wing spar. Could have built most of a new airplane in that time.

Dan

14. Dec 30, 2010

### halfscalemustang

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Thank you guys for the input and concern. I am a realist, when I get the skin off and if the rest of the airframe is questionable whether it be rot or just flat out built wrong, I will scrap the original air frame and build another using all salvageable pieces as suggested. Also, never mentioned, it does have an unused ballistic chute in it. Which I think is awsome! I have studied the pictures, drawings and all other info carefully, I wish you guys could see it too to get better insight of the construction of the plane. Thanks again

15. Dec 30, 2010

### Topaz

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Check the repack date on that. They have a definite life before they need a refurb and repack.

16. Dec 30, 2010

### PTAirco

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I have to agree that building a new airplane and salvaging whatever is useful is probably easier, quicker and safer than trying to repair what you have there. I don't know how often I have read in books and magazines that one advantage wooden structures have is ease of repair - this is sheer nonsense. Unless making a new part and bolting on the metal fittings counts as "repair". Even minor impact damage spreads three or feet from the point of impact for example and it is hard to find just how far cracks have extended etc. Trying to scarf new pieces into existing structure can be done but it is a huge pain.

And the workmanship of this project looks a little dubious in places too; lots of bolts with far too many threads showing, for example; some so long they appear to be non-aircraft bolts.

Jack up the engine, slide a new airplane underneath and you will fly with a lot more peace of mind.

17. Dec 31, 2010

### MicRuler

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Its your decision but if it were me I'd build a new fuselage. I dont have any experience building or repairing airplanes but I have done a get deal work rebuilding basket-case motorcycles. In my opinion its a hell of lot more safer, easier and efficient to slap in a perfectly fine engine from a wrecked bike into a good egineless frame than it is to fix the old distorted frame. Fixing the old frame may look quick and easy but if you underestimate the task, before you know you end up spending more time, money and effort than it would take building or buying a new one. Plus the finished project is never as good as the original because you had to bulk up the damaged areas which adds weight and in the case of a motorcycle frame you can never get the warped frame as perfect as factory.
W.A.R. or War Aircraft Replicas is selling plans for a number of half scale WWII warbirds for around $275 warbuddies add a little less than$700 in wood and other materials and you have a new plane. You have already paid for 70% of the new airplane (firewall forward, controls, landing gear, canopy, electrical, etc) they only need to be retrofited to the plans or the plans to the parts. I bet that other 30% (wood,glue,nails,plans, tools and labor) would cost about the same or a little over what it would cost to repair and recover the old airframe plus you have new airplane especially since you know little of how your mini 51 was built and why or how it damaged
I have to admit in the first time I saw you mini p51 I thought it was a W.A.R. 51 P51
As PTAirco said

Last edited: Dec 31, 2010
18. Dec 31, 2010

### rheuschele

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Well put Mic, you guys are much better than I at expressing yourselves without sounding mean.
Ron

19. May 10, 2016

### Derswede

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One note....the CB650 engine is notorious for eating charging systems. I owned two of those bikes and went thru several stators. There is a guy in Alabama that rewound them. Never had any mechanical problems with that engine, just the electrical problem. Wish you well on the project!

Old thread, I know.....

20. May 11, 2016

### Tiger Tim

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I wonder what ever happened to this project? Part of me hopes he fixed it up real nice and now it's hanging in a bar somewhere.