DLinevitch Posted August 11, 2021 Share Posted August 11, 2021 (edited) (UPDATED) In my main field of activity, I am mostly engaged in the technical reconstruction of aircrafts and rarely pay attention to the issues of paintwork. However, a recent discussion on Facebook led to a very unexpected discovery that I would like to share with you. Quote According to the tech descriptions, the all variants of I-185 has an all-metal wing center section, with a duralumin fairing riveted to the plywood fuselage. Everything seems to be drawn correctly on the various public drawings. However, why in the photos does the center section look like a plywood one-piece with the fuselage? And the trick is this, on all I-185 Factory №51 used just huge amount of putty, about 100kg per plane! I found a funny document prescribing to spend less putty in order to save weight. There was also information about why this is all, a very poor production culture affected, with the help of putty, defects in aerodynamic surfaces were corrected. And in a very high resolution photo, can see that the edges are metal, not plywood. It is certain that if I-185s began to be made en masse, then the beautiful non-welded transition from the center section to the fuselage could be forgotten, and the fairing would be visible in all details in the photos of production vehicles. By the way, in all prototypes on the entire wing, neither screws and rivets, nor seams between the panels were actually visible, everything was covered with a thick layer of putty and polished. Keep this in mind. PS. The ITP was also putty from top to bottom, so seams and rivets are not visible even in a high-resolution photo. The wing in nature, that's why it took such a huge amount of putty Who would believe that this is the same an all-metal wing? However, this is so, thanks to the thick layer of putty, no seams or rivets are visible. Just an overkill for the modellers, he he 🤣 Edited August 14, 2021 by DLinevitch 12 Link to comment Share on other sites More sharing options...
John Thompson Posted August 11, 2021 Share Posted August 11, 2021 Shades of the perennial chatter about P-51 wing panel joints. But thank you - this is interesting information! John Link to comment Share on other sites More sharing options...
Herb Posted August 11, 2021 Share Posted August 11, 2021 “Quantity has a quality all its own.” ― Joseph Stalin ....including quantity of putty, I guess... 1 1 Link to comment Share on other sites More sharing options...
Graham Boak Posted August 11, 2021 Share Posted August 11, 2021 If you ae trying to prove that your design is faster than the alternatives, a good smooth finish is more important than the weight. 1 Link to comment Share on other sites More sharing options...
Space Ranger Posted August 11, 2021 Share Posted August 11, 2021 Another instance of real world imitating modeling. This reminds me of a tour of the McDonnell Douglas production line during an IPMS-USA national convention during the mid-70s. The assembly lines were full of F-18s for the US Navy, as well as F-15s for Saudi Arabia, in various stages of assembly. I happened to notice some oddly familiar blue patches on F-18 tailplanes in random locations. I asked a worker what it was, and he confirmed my suspicions; those blue patches were slight imperfections that had been filled with 3M Acryl Blue Spot Putty! He showed me a partially used tube of the stuff, the same filler putty I was then using on my models, along with a lot of other modelers. 7 2 Link to comment Share on other sites More sharing options...
Kari Lumppio Posted August 11, 2021 Share Posted August 11, 2021 Hi! Going by memory here so slight caveat. FIAT G.50 from the same era also had puttied wings (and fuselage?) but I think the cover sheeting was not dural but some softer aluminium. Also I do remember that thin fabric was added, too. This may have been case for the I-185, too? BTW Hysol 33564 (NSN Part Number EA960F) is the approved aerodynamic filler for F18 A-F ("contour restoration"). Reference NAVAIR 01-1A-21. It should be red in colour so there has been material change since seventies or manufacturer and US Navy use different materials. Cheers, Kari 1 1 Link to comment Share on other sites More sharing options...
Jackson Duvalier Posted August 12, 2021 Share Posted August 12, 2021 7 hours ago, Kari Lumppio said: BTW Hysol 33564 (NSN Part Number EA960F) is the approved aerodynamic filler for F18 A-F ("contour restoration"). Reference NAVAIR 01-1A-21. It should be red in colour so there has been material change since seventies or manufacturer and US Navy use different materials. If the OEM filler is blue and the repair filler is red one could tell exactly which layers one was sanding, which might be useful. I've used layered primers of different colours to find high/low spots for example. 2 Link to comment Share on other sites More sharing options...
Learstang Posted August 12, 2021 Share Posted August 12, 2021 (edited) Ah yes, the I-185, the TSR.2 of Soviet GPW fighters (oh what might have been...). Interesting information about the metal wing and the puttying. Regards, Jason Edited August 12, 2021 by Learstang Small change. Link to comment Share on other sites More sharing options...
SleeperService Posted August 12, 2021 Share Posted August 12, 2021 23 hours ago, DLinevitch said: In my main field of activity, I am mostly engaged in the technical reconstruction of aircrafts and rarely pay attention to the issues of paintwork. However, a recent discussion on Facebook led to a very unexpected discovery that I would like to share with you. Just an overkill for the modellers, he he 🤣 If a 100kg weight penalty made the plane faster then the surface finish must have been appalling. How would they have been able to mass-produce this if it was accepted for production. Would they have bothered at all or just done certain areas. Thank You for posting this as I have the 1/48 Ark kit which lacks much surface detail bar some very wide panel lines. 1 Link to comment Share on other sites More sharing options...
DLinevitch Posted August 12, 2021 Author Share Posted August 12, 2021 I began to check for an increased love for putty. It turned out that Belyaev DBLK, as well as the I-185, was all densely putty, no seams or rivets were visible on it. Tomashevich "110" is also very hard putty, there are no rivets or seams. 2 Link to comment Share on other sites More sharing options...
Massimo Tessitori Posted August 12, 2021 Share Posted August 12, 2021 Really interesting, and it has an impact on the look of the plane. Anyway I suppose that putty was sanded off, so unsing 100 kg putty wouldn't turn into an increase of weight of 100 kg. 1 Link to comment Share on other sites More sharing options...
DLinevitch Posted August 12, 2021 Author Share Posted August 12, 2021 (edited) 3 hours ago, Massimo Tessitori said: Really interesting, and it has an impact on the look of the plane. Anyway I suppose that putty was sanded off, so unsing 100 kg putty wouldn't turn into an increase of weight of 100 kg. The report on the I-185 "etalon" says that there is still a reserve for reducing the mass of paint and putty by 77 kg! For example, the mass of paint + putty for ITP before and after rework was 14/21 kg. I have already found why there is so much putty, they corrected the irregularities of the curvature of aerodynamic surfaces. Edited August 12, 2021 by DLinevitch 2 Link to comment Share on other sites More sharing options...
John Thompson Posted August 12, 2021 Share Posted August 12, 2021 Plant manager to test pilot: : "That plane you're testing today? We had to use about 100 kilos of putty to get the airfoil shape correct, but don't worry - we sanded off most of it. And the rest probably won't just peel off in mid-flight. Oh, by the way - didn't I lend you 20 rubles last week? I'd like it back, preferably right now..." And to think we complain when we can't get a nice, smoothly-feathered edge with whatever putty we're using - at least our lives don't depend on it. John 1 3 Link to comment Share on other sites More sharing options...
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