I was recently given an old Stirling Supermarine Spitfire. There is no gear in it, just the constructed wing and fuselage. No engine, tanks, wheels, servos, or any of that. It does have some of the pushrods installed, but most are rusted. Now, I only recently started learning to fly, using a Wingdragon 4. I have an experienced pilot training me, but obviously I won't be ready to fly the spitfire for quite a while. My question is this: how do I go about returning this spitfire to useable condition while I'm learing, so that when I am competent to fly it, it will be ready?

I have also heard that Stirling kits tended to be heavy, and this seems like no exception. It weighs about 5 pounds already, with no gear. Of that, the wing is 2lb 6 oz. The wingspan is 64in. The skin is in good condition, just needs some sanding and repaint, but is it too heavy? The skin looks pretty thick (to my untrained eye), so would reskinning it in a thinner balsa cut enough weight? Should I try disassembling it and copying the parts in a lighter material? My mentor suggested I could build a new, composite wing from wire cut foam with some light ribs and balsa skin.

I'm a college student, so while I have enough money to complete it, I'd prefer to spend time before money at the moment. Likewise I'm still learning about both flying and building models, so I'm in no rush. What are your suggestions?

-Dylan

P.S. The two pictures of a skinned spitfire are of mine, the unfinished one is a picture I found of someone elses, and added it to help show the understructure.

And I do have the flaps, they're just not attached. Also, the bottom half of the nose, what I guess is the motor cowling? is just taped on right now, normally it screws on and there is no big gap like its showing in the forward picture

Hi,
First of all, welcome to the sickness, sorry, hobby.
Second, Spitfires are nice to fly once in the air, they tend to try and tip onto their nose when taxing and taking off. So take it very easy with the throttle while on the round.
If the model is slightly heavy then increase your landing speed a little. You don't want to land a Spit slowly anywhy, they do like to tip stall and drop a wing if you slow them down.
A built up wing should be lighter than a foam wing so I would check the condition of the wing you have and finish the model if it looks ok.

Enjoy.

Balsa weight is not a problem at that size. Is the fuse covered with fiberglass? It may need more sanding. Watch the amount of paint, spitfire colors should cover well. I have a 55" spit which weighs 6 lbs RTF and must be landed faily fast. Good luck.

I attached two more pictures. As you can see, they are covered in wood, i assume it's balsa, it's 1/8th inch thick. is that a normal skin thickness for this size plane? The third picture is of the un painted, unfinished (and undusted) area under what i assume used to be extra flaps. also, the surface of the wing, after i sanded some paint off, is still shiny, not raw wood. is it possible the builder layed epoxy over, then painted? that would make it stronger but much heavier...

also, in response to a build wing should be lighter, this kit is from around 1971, so it might not be lighter.... don't know for sure, but does anyone have a wing roughly this size/shape that they could tell me the weight of for comparison?

OK, just in case you try to look something up on this plane, it's made by Sterling Models not Stirling.

In your first set of pics you said you had the missing flaps. OK, those are ailerons.

In the last set of pics you said you have holes for "extra" flaps. OK, those are the ONLY flaps.

Also in the area where you sanded it appears that fiberglass weave can be seen so at least this portion is fiberglass covered. The "gloss" is from whatever was used to apply the fiberglass.

Sorry, by "missing flaps" I ment I have the rudder, two elevator, and two ailerons sections. I do not have the actual flaps, although it appears that the original kit was set up for them but the person who had it before me covered over the holes in the wing (where the pushrod for the flaps would go) with fiberlgass patches. I cut those holes open again, and that revealed the weave i think you're seeing. I looked over it closely again just now, and that's the only fiberglass I can find. The rest is definately wood, I would assume balsa, possibly with some epoxy over it (but I'm not sure).

And sorry for the poor photography (and spelling ) skills

Hmmm, I may need to eat my words... I don't know how you could tell just looking at that bad photo I took, but upon further sanding and close peering, it looks like there IS a layer of fiberglass over the wood. I think. Anyone have any suggestions on how to procede?

Just continue with the build.
The weight will not be a problem, as I said above, just ensure your keep a bit of speed on during landing.
The wing has possibly been covered in Skinning cloth and finishing resin. This is a very good method and gives the model a certain amount of 'ding' proofness. I don't mean it will bounce, but a screwdriver slipping will be less likely to go through the wing.

If you want flaps then go ahead and fit them but you don't need them.

When you get to the painting stage give the entire airframe a good degreesing, and paint her.
Be very careful about battery positiion as the nose on a spit is very short and they do tend to be tail heavy. I suggest you try and check the ballance as you go along to help position the radio kit.

PS.
I had a few spits, believe me, the camoflage works very well, they are hard to see in the air.
Choose your colours carefully.

5lbs in wood is fine for a 64" wingspan warbird, you might want to sand it down to the glass and lighten some of that filler, and repaint it.
looks as though its ready for retracts, if you want to install the flaps use 1/16 ply to make the split flaps,if you can't find the sterling instructs , Top Flight has down loadable sets, so you will have a idea of how to do them.
there not the exact same but close enough to give you a good idea of the method to use for split flaps on the spit.
another thing is engine size your going to need at least a 61-75 2stroke or a 91-120 4st engine to fly that plane with retractable gear ,engine,radio,and all the misc stuff to go along with it your looking at a 8-10lb plane,its going to be fast.
here's what I am talking about my 11lb Top flight Spitfire powered by a OS 91 4st,retracts,and all the goodies,its glassed with water based poly and 1/2 oz cloth.
and my #1 assistant for scale

OK, I give up. Is skinning cloth the same as fiberglass? Just a new term to me.

Paint. Paint has weight obviously. Plan your paint carefully to keep the weight down. Believe it or not dark colors weigh more than light colors because they carry more pigments. One reason full scale planes are usually painted white base colors. Use a minimum of thin coats to do the job. Surface prep goes a long way toward reducing the need for thick coats.

skinning cloth?petrol? it's all british to me also those brits sure did make a nice looking plane though LOL

Skinning cloth is the very light weight fiberglass covering, it looks and feels a bit like silk.

For your information, petrol is for cars, gas is for cookers, and yes, we did make a nice looking plane.

So it is normal to put skinning cloth over balsa on a built up wing? As a way of hardening the surface to prevent denting etc? Just trying to get my story straight, I'm new to this.

It is one method, I prefer to use this over tissue/dope.
It also gives you a nice surface for painting.
It only works on sheeted surfaces, you can't use it over open structure parts.
You can cover the model in solortex or simular and then paint, but these iron on coverings take practise to apply on curved sections like wing tips. They add NO strength to the model and are not ding proof.
Than said I use this method on some of my small deltas and sport planes because it is quick, (once you get the hang of it), cheep, and comes in a variety of colours.
On my scale and aerobatic models, I use skinning cloth and resin.

so a 1/8th inch balsa skin is typical for a wing this size? it just seems aweful thick, but then, 1/16th seems like it would be too thin...

typical wing sheeting is 1/16 to 3/32 .
you can call it skinning cloth if you like but its "fiberglass" cloth, typical weight used in modeling is between .5 to.75 oz, that is the weight for a sq.ft. of material,it is woven glass fibers in varring weights depending on application,modeling,surfboards,boats.
if it was done a while ago it was probably done with west systems epoxy for the resin or a similar type of material used as the bonding agent.
a popular method now is using water based polyurathane as the resin,but your plane is old enough that its likely done with epoxy.
petrol=gasoline; used for automobiles, and model planes,gas is what you get when you eat a burrito with beans

Well, I will probably need to take off at least part of the skin in order to rebuild the servo connections, reinstall the ailerons and rudder, and add flaps and retracts, right? Can I just cut small holes to install what I need, then patch?

OR, should I go ahead and reskin the plane in a lighter balsa (3/32 or 1/16) then recover with skinning cloth.

I'm tempted to reskin it, since that will also give me a chance to reglue all the joins and such (the plane is almost 15 years older than I am), as well as make it a lot easier to do work on it. I'd also like to make it a little bit lighter, but it sounds like that's not too big a deal. On the other hand, reskinning sounds like it would be pretty difficult, even with the two experts i know advising me.

What're your thoughts?

Someone suggested that rather than mess with reskinning, I just pull the bellcranks out and mount the servos in a hole in the wing, directly in line with the ailerons, elevator and rudder. Then I can just put small, 1/16th balsa plates over the servos so that just the horns stick out, so I can access them for repair and adjustment, but still have the skin look nice.

Does that sound like a better idea? And if I go that route, what sort of equipment should I be looking at, as far as engine and servos? The nose is cut for an exhaust on the left side of the nose, and it sounds like it will need a 60 (which means a size 60 motor, but what exactly does that mean?)

last question first a 60 size plane is one that requires a 60 size 2st as the minimum for flight.
your going to want a larger engine than that for the spit if it ends up being 8lbs or more.
the sizes I listed in the previuos posts will be about right something in the 75 2st range would fly the plane for you even better would be a 4st as they swing larger props as well as have a nice sound for a warbird.

for servo placement the spitfire is a tail heavy plane so mount the rudder,elevator,and throttle servos, as close to the center of gravity as poss, not in the tail or your going to be adding alot of weight in the nose for ballance my spit has 19oz of lead in the nose for ballance and the servos are located in the center of the fuse.
the wing on the other hand is another story yes it is a good idea to make servo hatches for the ailerons,its a much more reliable system for control and will reduce the slop that can occure with the control horn setup for ailerons.
with flaps the control horn system with one servo is fine because they don't get as much use as the ailerons.
cut a slot for the control horn in the hatch and mount the servo to the hatch using small hardwood blocks epoxying them to the ply.
your going to have to make some mounting rails so the hatch is secure to the wing.
typical hatch size is aprox 2.5"X3" for my 60 size planes I use a standard futaba 3004 servo.
when you open up the wing to make the hatch hole, start small and carfully enlarge it to fit your ply square/rectangle .
here is a couple of photos from my Top Flight P-47 wing construction for a typical example of servo hatches in the wing, the P-47 has individual servos for ailerons as well as flaps thats why there's 4 hatches,take notice of the shot of the wing in the Bones the hardwood rails are for the hatches to screw too.
your going to have to do some fitting but it's not that hard.