Mustang wings...

[LSP_Mike]

Can we have a Mustang wing Group build? I'm in with an F6 wing from the lizard!

[Ironwing]

YEEEEEHAW....aint this just a hoot? It's all part uh the fun fellers.

[Texas]

HI Can someone tell or explain to me what type of filler was used on the P-51 wings. I know for instance they were still using lead to fill repairs on autos and I know that would never work. I also that whatever was used had to stay on a aircraft that was flying somewhere around 400 MPH. I don't thank that bondo or any of the epoxies we take for granted today were even around back then. So this inquiring modeler would like to know.

 

Texas

[Juggernut]

FYI everyone

 

 

Here is a link to an article on ARC regarding this very issue: Mustang Wing Seams

 

He acknowledges that the possibility exists for ground crews to have stripped away the filler during operations, painting, stripping and polishing but does not take a stand one way or the other.

[Texas]

HI I have been looking through some books today trying to find out what they used for filler but no luck. All they said was the wings were filled top and bottom, primed and painted. Just thought I would pass it along in case anyone is interested.

 

Texas

[CPNGROATS]

An interesting question....the "filler" used would have to hold up with some dynamic conditions, weather, flight stress, vibration when the guns were fired, exposure to solvents (ground crews used raw gasoline to clean and strip paint), and the extreme cold temperatures at altitude....

 

Perhaps some period tech manual could shed some light on what was used, or some personal recollection from someone that was there and worked on Mustang maintenance....

 

The paint used to prime and paint the wings could/would add to the durability of the filled areas (IMO)....

 

Cheers,

ggc

[Radub]

Maybe that explains why the manual refers to the "maintenance and repair" of the wing surface? To me it sounds like the filler+smoother was prone to damage (for whatever reason such as vibration, load, flex, temperature fluctuations, hits, scuffs) and it needed regular repair in the field. Otherwise why would they bother to include it in the manual?

Radu

[SeanH]

Hi Guys

Personally I think the lines and the rivets add a touch of realism to our models. Although they may not have always been visible on the full scale aircraft, their presence seems to add realism to a representation of the full scale plane that we build. In my eyes, I find a weathered and oil washed plastic model with rivets and lines more representative of the actual plane than one of the imported carved mahogany models with perfectly smooth surfaces. How we emphasize those lines on a plastic model is a personal choice and some of us do it better than others.

[Dollar65]

Maybe that explains why the manual refers to the "maintenance and repair" of the wing surface? To me it sounds like the filler+smoother was prone to damage (for whatever reason such as vibration, load, flex, temperature fluctuations, hits, scuffs) and it needed regular repair in the field. Otherwise why would they bother to include it in the manual?

Radu

 

In fact, this step is included as the final step of any skin repairs done on the leading edge of the wing, such as panel replacement or bullet holes. It does not states that the filler could break, deteriorate or wear out. From what I have read in restoration reports, it seems to be a pretty tough filler.

 

Laurent

[ssculptor]

In fact, this step is included as the final step of any skin repairs done on the leading edge of the wing, such as panel replacement or bullet holes. It does not states that the filler could break, deteriorate or wear out. From what I have read in restoration reports, it seems to be a pretty tough filler.

HTH,

Laurent

So they did fill the wing surfaces.

Or were supposed to, at least.

Interesting.

 

What I find more interesting is the illustration of the bare hand applying the stripper.

It has been found that many, if not most of the old time paint removers had a deleterious effect on the human heart. So a crewman getting his hands soaked in the paint remover time and time again may live a shorter life because his heart fails prematurely.

Back in "good old days" before OSHA we were allowed to wash our hands in many chemicals. No big deal. I know I did.

Then OSHA, (the United States Occupational Safety & Health Administration section of the U.S. Department of Labor) came along and said NO NO don't do that. :angry:

I have a better understanding of why the life expectancy of people in the USA is getting higher and higher. We no longer take baths in dangerious chemicals, smoking is no longer a "cool" thing to do and we are getting away form the consumption of red meat and trans fats.

Also we have good medical techniques like quadruple bypass operations to keep us, or those of us who can afford medical care, alive for a longer period of time.

Or maybe it just seems longer.

[Slartibartfast]

ACME Airfoil Smoother. I love it! If only the Coyote had used this on his flying contraptions. He may have had enough speed to finally catch that rascally Road Runner.

 

I remember washing car parts in gasoline barehanded. When your skin started to burn, it was time to quit. Lucky for me, this was after lead removal, so I aint dain-bramaged.

[KOTR]

Straight wings do not flex under load. If they do, they break. Swept wings flex, as they are designed to do, otherwise they break. Straight wing spars are fixed structures. They bounce, under certain circumstances they might even twist a little, but they do not flex from tip to tip.

 

J

 

 

Well, my university days are some days in the past, but I can well remember being told fore more than one time in material technology and construction that any structure which does not flex will break...

 

The parts will, even not pushed to the limits, do the craziest motions, twists and bends, one can imagine, they are just to small to realize it with the bare eye, but can well be measured. As long as everything stays within the limits of the material, everything is fine...

[Radub]

Straight wings do not flex under load. If they do, they break. Swept wings flex, as they are designed to do, otherwise they break. Straight wing spars are fixed structures. They bounce, under certain circumstances they might even twist a little, but they do not flex from tip to tip.

 

J

 

I do not want to push this discussion the wrong way... but the Ta152 had straight wings and they flexed. Eric "Winkle" Brown says so! Also, I can tell from personal experience (I took a number of flying lessons) that straight wings flex. All wings flex. They do not flap around and bend, but they flex a few centimetres - all wings have a safe range.

Anyway, all that is irrelevant to this issue. I only expressed an opinion about why the putty on the wings would need repair and in reply, Thierry explained what the story is. This discussion is already mentioned on HS and the opinion there is that "everyone knows what the score is"... well, as we can all see, it is not as simple as that. This is not being "anal" as someone said there, it it about finding out the truth and getting rid of pseudo-knowledge passed on via forums. The fact is that our prying of this issue has brought out some very interesting facts that do not really agree with "what everyone thinks the score is". As long as we keep this civil, we may actually establish WHAT is right instead of WHO is right. So far, my understanding is that the wings were smooth, but some panel lines remained visible. The rivets are still visible faintly on the real thing, but I doubt they would show on any scale model. However, some of those visible panels were screwed in place with Philips screws which are fairly visible (see the fuel cell panels for example)

HTH

Radu

[alaninaustria]

Straight wings do not flex under load. If they do, they break. Swept wings flex, as they are designed to do, otherwise they break. Straight wing spars are fixed structures. They bounce, under certain circumstances they might even twist a little, but they do not flex from tip to tip.

 

Hej guys! I normally stay clear of such topics.... but after reading the above quote I thought it prudent to set the record straight. Nothing personal, just factual!

After 10000 flight hours, on over 12 different types of commercial aircraft on floats/wheels/skis... I can lead credibility to the fact that all wings, swept back, straight and forward swept wings are all designed to flex from the root to the wing tip. If they didn't, then the aircraft would never have received certification. I am not going to get into the physics of wing structures, but rest assured that wings do flex. When I refuel my bird with a full load of close to 12000 lbs of fuel the wing tips sink a few centimeters... when I rotate the aircraft after the Vr speed call on takeoff there is a lag experienced by all aircraft when the entire all up weight of the aircraft transitions to the wings... and similar to the 'conning' effect seen on helicopter rotors... main wings will flex up increasing the dihedral of the wing. Aircraft that have their engines mounted on the wing experience less of this effect from the engine pylon inboard as a wing that is completely clean such as a Fokker 70/100 or MD 80. The weight of the engine acts as a counter balance to the upward flexing of the main wings. Another aircraft to look at is the BAe 146 with the statically anhedral wings, at rotation the wing is experiencing only a fraction of flex induced dihedral that other commercial aircraft have.

Another aspect of this movement is the loss of paint on the wings of aircraft that are in daily use: military or commercial: if you ever have the chance to inspect the upper and lower surfaces of the wing you will see rivet heads exposed, arc weld lines exposed etc. Some of this is due to the twisting and flexing of the wing, and also from the vibration of the powerplants.

Another thing to remember is that WWII era powerplants were not 'blueprinted' to the same standards as we have in the modern age. The engines built in Germany and on the Allied side were designed for a around a 12 hour life (fighter aircraft), before having to be changed out. The engines sent to hostile environments such as the North African desert were expected to last only 4 hours before change out (this information comes from former luftwaffe maintenace personel that I met at the DTM (located in Berlin) last year). Anyhow, I digress.... the reason I am pointing this out is that the vibrations that were transfered to the airframe from such engines were also a large cause of loosened rivets and bolted structures.

It would be expected that a puttied wing structure of a piston engined fighter aircraft such as a Mustang, (after considerable wear and tear) would lead to a wing surface that would be missing filler along riveted lines, and that there would be areas showing the effects of the stresses experienced during aerial maneuvering.

Interesting topic I would say... and also open to much personal interpretation....

Cheers

Alan

[MikeMaben]

.... the reason I am pointing this out is that the vibrations that were transfered to the airframe from such engines were also a large cause of loosened rivets and bolted structures.

It would be expected that a puttied wing structure of a piston engined fighter aircraft such as a Mustang, (after considerable wear and tear) would lead to a wing surface that would be missing filler along riveted lines, and that there would be areas showing the effects of the stresses experienced during aerial maneuvering.

Interesting topic I would say... and also open to much personal interpretation....

Cheers

Alan

 

...not to mention some rather harsh landings and taxiing around unpaved fields (sometimes).

M

M

...So, they were smooth to start with but not 'all' remained so. Fair ?