Richard E Posted September 11, 2017 Share Posted September 11, 2017 On 10/09/2017 at 10:59 PM, Corsairfoxfouruncle said: Though the idea of a whif as an allied version of Luft'46 of either a B-29 or B-36 would make for an interesting build? Discounting the conversation about the effect of the weight of the paint finish, a multi-coloured B-29 Formation Assembly Ship could create an interesting WHIF scheme. 1 Link to comment Share on other sites More sharing options...
Corsairfoxfouruncle Posted September 11, 2017 Share Posted September 11, 2017 Giorgio .... In the interest of being Friendly let us agree to Disagree right here right now, I have read different. I have read the paints were very much considerably heavier than that. If you take into account those paints were all based on lead oxides i tend to believe they were much more than 71 pounds. But again its a difference of opinion and i really don't care to get into an argument over it. 1 Link to comment Share on other sites More sharing options...
Troy Smith Posted September 12, 2017 Share Posted September 12, 2017 22 hours ago, Thud4444 said: He wrote they where mostly being used to lure the Luftwaffe out of hiding so the American fighters could destroy them. ( hence the high visibility markings) But in Asia it could actually help bring about an allied victory. He was the main proponent of adopting RAF tactics with the B29. Which made him famous or infamous, depending on who you ask. the high visibilty markings were formation use by the USAAF. the fact that the USAAF had a fighter the could reach Germany was not planned, but the result of a series of events not asked for by the Americans, like the Mustang, and that the British had got Packard to build the Merlin under licence. The US heavy bombers were supposed to be self defending the B-29 did't work as planned over japan in many cases because of the Jet-Stream, which was unknown at the time. https://en.wikipedia.org/wiki/Jet_stream Quote Many sources credit real understanding of the nature of jet streams to regular and repeated flight-path traversals during World War II. Flyers consistently noticed westerly tailwinds in excess of 100 mph (160 km/h) in flights, for example, from the US to the UK.[11]Similarly in 1944 a team of American meteorologists in Guam, including Reid Bryson, had enough observations to forecast very high west winds that would slow bombers going to Japan.[12] 59 minutes ago, Corsairfoxfouruncle said: I have read different. I have read the paints were very much considerably heavier than that. If you take into account those paints were all based on lead oxides i tend to believe they were much more than 71 pounds. read where? in @Dana Bell book page 51, "Return to natural metal" Quote Removing all paint led to only minor weight savings(about 71 pounds on a B-24) but did leave an easily maintained surface Dana is a member here so may add in. Paint was left off to ease manufacture. Link to comment Share on other sites More sharing options...
Corsairfoxfouruncle Posted September 12, 2017 Share Posted September 12, 2017 (edited) Again as i said in my last post. I DO NOT CARE TO GET INTO AN ARGUMENT. I will believe what i believe. I mean absolutely No disrespect to Mr.Bell. I really truly mean that and have refered to Mr.Bell multiple times in my own research. However the few times its come up in my life, and i spent 2 years training to become an aircraft mechanic. In my training with aviation powerplants and airframes one of the things you are taught is liquid weights. A gallon of water weighs in at about 8.0 pounds. A gallon of oil weighs in about 6.6 pounds. Which is why oil floats on water. So i do have some background to base my argument on. The paints were considerably heavier. I've seen quotes pushing as much as 1 ton. However even i don't believe that. I believe the weight came closer to 3-400 lbs for a Four engined heavy. So 71 pounds would denote about 8 gallons of paint and additives to paint a B-17 ? I seriously doubt that. You cant paint a house with 8 gallons of paint. And a B-17 is considerably larger. A B-24 more so than that. So i really do doubt 8 gallons covered those planes. When you incorporate all the repaints, and the multiple layers put on at the Factory. Like my previous post said we can agree to disagree. Edited September 12, 2017 by Corsairfoxfouruncle 2 Link to comment Share on other sites More sharing options...
old thumper Posted September 12, 2017 Share Posted September 12, 2017 (edited) I don't really want to get into an argument over paint weight either, but to be 8 gallons it must have been airbrushed on like alclad. Also aren't US gallons smaller than Imperial gallons making the amount of paint used even less? I do a bit of diy and Coxsairfoxfouruncle does have a point, it would take more than 8 tins of emulsion to turn a B-17 brilliant white and possibly more to make it magnolia. Continuing with the diy theme, if these bombers didn't need painting then why would they paint them. I don't creosote my fence for fun, I do it out of need. Yes there is an argument to say the B-17 and B-24s were used to attract the Luftwaffe but they weren't painted bright colours to make clearer targets. They had red and yellow tails etc to help them form into tight defensive boxes. Going back to the RAF Bomber Command v Eighth Air Force thing it is my understanding that by the end of the war Bomber Command was achieving a good level of accuracy by using modern technology and pathfinders, granted though the results were just rubbish to start with and it was a long journey to get there. The large formations used by the 8th A F together with these formations dropping on command of a lead bomb aimer sometimes through cloud with the aid of radar achieved pretty much the same effect as Bomber Command, namely everything blown to smithereens over a large area. Yes we are possibly spoiled today with our Tomahawk missiles, these days people feel hard done by if their house gets blown up when it was the one next door that had the baddies in it. Back in WWII though accuracy was far more approximate, but it probably looked good at the time. It wouldn't have been very sensible to send 12 B-17s over at a time, the Luftwaffe had to be inundated by them but large numbers of bombers spread over a wide area of sky all dropping their bombs at the same time left a big mess across a wide area. No doubt the B-29 was a superior aircraft to any other of it's type, but I think it would have been a different war had it arrived in Europe. There are a lot of things about the effect of the Allied bombing on Germany that people still argue over, maybe a bomber that was more difficult to shoot down could have taken us down the wrong road. Edited September 12, 2017 by old thumper 2 Link to comment Share on other sites More sharing options...
Troy Smith Posted September 12, 2017 Share Posted September 12, 2017 51 minutes ago, Corsairfoxfouruncle said: one of the things you are taught is liquid weights. but we are not talking about the weight of wet paint, but weight of dry paint. paint is basically pigment and a binder resin in a solvent. The solvent evaporates, so the wet weight of paint is going to be considerably more than the dry weight, and the dry weight it what is being quoted. Anyway, this got me curious, so I did some searching. FWIW, here's some weights from Boeing for airliners http://www.boeing.com/commercial/aeromagazine/aero_05/textonly/fo01txt.html Table 1: Decorative Paint Scheme Weights, Lb (Kg) 717-200 MD-80/-90 MD-11 737-700 757-200 767-300 777-200 747-400 Upper and lower half of fuselage and tail painted plus customer markings 119 (54.0) 155 (70.3) 427 (193.7) 179 (81.2) 239 (108.4) 299 (135.6) 475 (215.5) 555 (251.7) Upper half of fuselage and tail painted plus customer markings 94 (42.6) 120 (54.4) 312 (141.5) 130 (59.0) 157 (71.2) 202 (91.6) 330 (149.7) 368 (166.9) Polished skin and customer markings 23 (10.4) 25 (11.3) 45 (20.4) 25 (11.3) 30 (13.6) 40 (91.6) 50 (22.7) 55 (24.9) Less paint reduces takeoff weight and fuel consumption considerably. The weight of paint for a typical decorative paint scheme varies among Boeing airplanes. Note that the paint weights given are representative of a typical paint scheme with a 4-mil* (0.1016-mm) paint thickness. Paint thickness varies between 3.5 to 5.5 mil (0.0889 to 0.1397 mm). *mil=0.001 in and https://www.defensemedianetwork.com/stories/the-u-s-army-air-forces-strips-its-planes-of-paint/ Quote No record exists about how much a gallon of paint used on the aircraft weighed. Contemporary reports stated that with the elimination of the paint, fighters would be “fifteen to twenty pounds lighter” and heavy bombers would “lose seventy to eighty pounds.” One recent study on the subject noted that the paint during this period was undoubtedly lead-based and “probably copper fortified.” A gallon of such paint could weigh as much as 30 pounds, though for aircraft it was more likely to be in the 10-pound range. A B-17 has a surface area of 4,200 square feet and took about 35 gallons of paint to coat. If the paint weighed 10 pounds a gallon wet, after accounting for evaporation the weight would be roughly 300 pounds. though the article is not particularly accurate regarding painting of planes, and without a weight for the paint involved it's a bit vague, and the contemporary reports would more likely have known the paint weight rather than some modern guesstimate? Does B-17 have a surface area of 4,200 sq ft? As for lead paint being heavy, while pure lead is dense, but when in a chemical compound it's density depends on the molecular structure and how much metal is in the paint. but the actual weight from Boeing are of interest, and don't include wings.... 3 Link to comment Share on other sites More sharing options...
Corsairfoxfouruncle Posted September 12, 2017 Share Posted September 12, 2017 First off Thank you troy for the charts. I believe They don't include wings as most commercial airliner wings were originally in nmf that had a clearcoat, and interior corrosion control. You can only see the bottom of wings from the ground so less useful for advertising. Two im not sure how much square footage of surface area a B-17 E,F,G would have let alone a B-24 ? Like i said in my last post. I didnt think 71 pounds was realistic. If you dehydrated the paint completely maybe? To its powdered ingredients. But those paints though dry to the touch were rubbery. Ive actually crawled inside of several warbirds and real aircraft. So i believe they would've been heavier. I think 3-400 pounds seems a more realistic weight. But i again digress and maintain that is my personal belief. Link to comment Share on other sites More sharing options...
KevinK Posted September 12, 2017 Share Posted September 12, 2017 Just as an interesting data point: when I was on the Space Shuttle program, we changed the External Tank finish after the first two flights, from a white Titanium Dioxide paint finish to the bare foam. The removal (well, non-application) of the paint saved 600 lb in total vehicle mass. 5 Link to comment Share on other sites More sharing options...
rayprit Posted September 12, 2017 Share Posted September 12, 2017 THREAD DRIFT WARNING I heard one of the main reasons the United States got rid of paint was because they no longer needed it? Due to air supremacy, no need to camaflage anymore.....no need to paint beneath fuselage, nothing to attack them, anything that did attack was on a suicide mission as generally fighters and bombers flew in greater formations and were able to fend off most attacks......... 1 Link to comment Share on other sites More sharing options...
Giorgio N Posted September 12, 2017 Share Posted September 12, 2017 In the contest of trying to determine the reasons behind the USAAF switch to natural metal surfaces, I don't think that determining the exact weight of the paint is important anyway. The figures of 71 lbs. for a B-24 and 15-20 for other aircrafts may or not be accurate but this is what the relevant authorities mentioned and what they were working with, meaning that they expected weight reduction in that order of magnitude. Any decision on the matter would have been based on figures like these. According to Dana Bell's book mentioned above, the main interest of Ground Proving Command was not much the reduction of weight but rather the increase in speed potentially achievable by eliminating the paint. This proved in the end to be way less than hoped for (hope based on previous tests), something that as I said is not surprising. One aspect that should be considered is that by late 1943 a number of shortcuts had already been introduced in the painting procedures. North American for example had been exempted since 1942 from coating most internal surfaces with a primer, as everyone who has ever tried to determine the colours of P-51s wheel wells already knows. For this reason it's hard to compare modern aircrafts with those built in those years as the requirements are different when it comes to durability. Some risk of corrosion was acceptable on a P-51 built in 1943, it would not be acceptable on a liner operating today. 1 Link to comment Share on other sites More sharing options...
Don McIntyre Posted September 12, 2017 Share Posted September 12, 2017 I think that the reason the B-29 wasn't used in Europe was that the USAAF felt they had enough bombers that could reach Germany that they didn't need it there. I wonder if when the B-29 was finally in service the Allies could "see light at the end if the tunnel?" as far as the defeat of Germany. They did need that reach in the PTO, though... 1 Link to comment Share on other sites More sharing options...
qn30jEkPz7 Posted September 14, 2017 Share Posted September 14, 2017 On 12/09/2017 at 02:01, Corsairfoxfouruncle said: Again as i said in my last post. I DO NOT CARE TO GET INTO AN ARGUMENT. I will believe what i believe. I mean absolutely No disrespect to Mr.Bell. I really truly mean that and have refered to Mr.Bell multiple times in my own research. However the few times its come up in my life, and i spent 2 years training to become an aircraft mechanic. In my training with aviation powerplants and airframes one of the things you are taught is liquid weights. A gallon of water weighs in at about 8.0 pounds. A gallon of oil weighs in about 6.6 pounds. Which is why oil floats on water. So i do have some background to base my argument on. The paints were considerably heavier. I've seen quotes pushing as much as 1 ton. However even i don't believe that. I believe the weight came closer to 3-400 lbs for a Four engined heavy. So 71 pounds would denote about 8 gallons of paint and additives to paint a B-17 ? I seriously doubt that. You cant paint a house with 8 gallons of paint. And a B-17 is considerably larger. A B-24 more so than that. So i really do doubt 8 gallons covered those planes. When you incorporate all the repaints, and the multiple layers put on at the Factory. Like my previous post said we can agree to disagree. A gallon of paint in the can isn't the same as what ends up in the dried and cured film - the solvents (VOCs or volatile organic compounds) make up a large proportion of the can (less now with waterborne and high solids formulations) 100litres of so of dried film spread out at a couple of hundred microns thick can go a long long way Link to comment Share on other sites More sharing options...
qn30jEkPz7 Posted September 14, 2017 Share Posted September 14, 2017 200microns is 0.2mm Assuming 400kg of dried film is 500L volume then at that film thickness it should cover 2500 square metres 200microns is on the thick side - I'd guess 10 for a chromate primer tops and then 60-100 for top coats Link to comment Share on other sites More sharing options...
Bedders Posted September 14, 2017 Share Posted September 14, 2017 (edited) On 12/09/2017 at 6:51 AM, KevinK said: when I was on the Space Shuttle program, Kevin, I just love this as an opener: for us people who like aviation & stuff you don't get much better credentials than this! Interesting discussion on the B-29s, paint etc too. I'm into Mustangs at the moment, and can just imagine a gaggle of brightly decorated Superfortresses accompanied by similarly gaudy P-51Hs going off to do battle... Edited September 14, 2017 by Bedders 1 Link to comment Share on other sites More sharing options...
Tentacles Posted September 14, 2017 Share Posted September 14, 2017 (edited) Re the decision to go NMF - paint is not only for camouflage, but also to help protect against the elements. I read somewhere that the grim mathematics of war meant that most aircraft would be written off in combat or accidents long before they suffered from corrosion. So it was decided not to bother. Can't remember where I read it though, so I could be wrong. Probably it was s combination of factors. Let's also not forget that as well as saving time and weight, going NMF would also save money. Edited September 14, 2017 by Tentacles 1 Link to comment Share on other sites More sharing options...
48-Alone-Is-Great Posted September 15, 2017 Share Posted September 15, 2017 I remember reading that the B-29 wasn't used over Germany, because allied fighters wouldn't be able to escort it at its preferred high altitude, but German fighters were expected to be able to reach it there. Link to comment Share on other sites More sharing options...
KevinK Posted September 16, 2017 Share Posted September 16, 2017 On 9/14/2017 at 12:35 PM, Bedders said: Kevin, I just love this as an opener: for us people who like aviation & stuff you don't get much better credentials than this! Thank you, Bedders. However, now I read it again, I'm sounding like Uncle Albert Trotter: "... during the War..." 4 2 Link to comment Share on other sites More sharing options...
Michael51 Posted September 17, 2017 Share Posted September 17, 2017 On 11/09/2017 at 10:39 PM, old thumper said: I think it was simply a case of putting the B-29 where it was needed the most. American factories were still producing the older bombers right up until the end of the war, but if Japan had quit fighting earlier then production would probably have ended sooner and the B-29 would have been sent to Great Britain. Good point about the B-17 formations being used as fighter bait to destroy the Luftwaffe. If the German fighters had been useless against the B-29, then presumably they would have been used elsewhere, or the resources diverted to other weapons, or possibly used more against the east. My own view is that the B-29 would have done the same job as the B-24 and B-17 only quicker and more thoroughly. I have always felt that is was myth that the Eighth Air Force precision bombed in Europe as they bombed over such wide areas. For me precision bombing in WW2 was the sort of thing we saw carried out by 617 Squadron and by RAF Mosquitoes. The most accurate bombing by the Americans was probably that done by the Ninth Air Force using the B-26 and other twin engined types. Could not agree more. The notion of the USAAF somehow being 'precision' and the RAF área' is a narrative worth questioning. By 1944, the 8th was well and truly using a lead bombardier for the target and those following employed the navigators as 'toggleiers'. Hardly precision bombing. Michael 2 Link to comment Share on other sites More sharing options...
Albeback52 Posted September 17, 2017 Share Posted September 17, 2017 On 10/09/2017 at 10:59 PM, Corsairfoxfouruncle said: True Saberjet ... and the RAF had the B-29 Washington bomber. Though the idea of a whif as an allied version of Luft'46 of either a B-29 or B-36 would make for an interesting build? And I do rather like the idea of a B-29 in standard Bomber Command colours!! Allan 3 Link to comment Share on other sites More sharing options...
Don McIntyre Posted September 19, 2017 Share Posted September 19, 2017 On 9/17/2017 at 2:31 AM, Albeback52 said: And I do rather like the idea of a B-29 in standard Bomber Command colours!! Allan I'd love to do my Monogram B-29 as a "Washington." 1 Link to comment Share on other sites More sharing options...
Work In Progress Posted September 19, 2017 Share Posted September 19, 2017 Here you go http://www.tigerhobbies.co.uk/Decals-1:48-for-B29-Washingtons-in-RAF-Service-ACD48002?search=ACD 2 Link to comment Share on other sites More sharing options...
Don McIntyre Posted September 20, 2017 Share Posted September 20, 2017 17 hours ago, Work In Progress said: Here you go http://www.tigerhobbies.co.uk/Decals-1:48-for-B29-Washingtons-in-RAF-Service-ACD48002?search=ACD Oh boy, do those look nice! I've never seen a photo of the one with those high visibility red markings. Link to comment Share on other sites More sharing options...
HP42 Posted September 20, 2017 Author Share Posted September 20, 2017 Enjoyed the thread guys, many thanks for the responses. It does make you wonder how potentially different the air campaign might have unfolded if they'd been used. Cheers all. Link to comment Share on other sites More sharing options...
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