TurboOtter

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I guess this would be a good forum for this thread. I will be rolling out my Unionville Otter in the next month or so,and I keep tripping over this box on the floor, so I better build it and hang it up out of harms way.
I have done a couple of searches on the TF P-39 in here and have had no luck in finding out any construction tips for this bird. I imagine it goes together the same as the other Gold Box TF kits. Anything to watch out for here? I have found a set of Rom Air Retracts to fit it. Any good, and where can parts be found for these guys. I plan on an OS 61 FX for power.
Thanks

bgi

My Feedback: (7)

Looking for the same info. I'm thinking of using 3/32" sheeting on the wing to help strengthen it up a bit. Maybe I won't poke so many fingers through it. I don't plan to glass this one since it's my 1st warbird.

The tip i picked up is: Reinforce the front retract mount (if you install retracts) or you'll be re-installing it regularly.

at6fan

My Feedback: (13)

I built the TF Gold Edition P-39 two years ago. I scaled it out with retracts (spring air), flaps, cockpit kit, and belly drop tank. I build carefully and light. I used dope and tissue to finish which if done properly weighs less than a monokote type finish. I will tell you that a 61 FX will fly the plane but just barely. Spend the extra few bucks and drop a 91FX in. It fits the same mount as the 61 and you will appreciate the extra power. My plane flew wonderful. With a little flaps it lands like a trainer. It will really turn heads because not many were built. It was never a popular plane in WW2 with the Americans or British. The Russians loved it because we sold them for next to nothing. They had lots of success using it in as a ground attack plane. I sold mine to make room for other projects. It builds great. I would not recommend 3/32 wing sheeting for the weight factor. If you edge glue the wing skins and sand them prior to sheeting the wing frame they will come out just fine. Be careful handling so you do not poke holes in the sheeting. Happy building and feel free to e-mail me with any questions you might have.

Lynn

bgi

My Feedback: (7)

Suppose I go for 3/32" with fixed gear? I'm not into spending the $$$'s for good retracts just yet. Should still be pretty light.

I'm tempted by that tissue/dope program too. Heard it is a good way to go.

thanks

at6fan

My Feedback: (13)

You will definately save weight with fixed gear. However the plane looks way cool on a low pass with the gear in the wheel!! If you would like advice on the tissue and dope thing feel free to e-mail me direct and I will tell you how I do it. All of my Top Flite warbirds are finished in this manner. It is seamless and totally fuelproof. It takes paint extremely well. Creates quite a smell but worth the effort even though it is an old fashioned way of finishing.

Lynn

bgi

My Feedback: (7)

I built several tissue/dope models back in the late 60's and early 70's, so I'm familiar with the smell! These models didn't have much, if any, sheeting to cover with tissue.

I HAVE heard some (not much) about doing warbirds that way over balsa sheeting. Seems to be easier than glass and epoxy but how strong is it? This will be an outdoors or open garage activity.

Do you have any figures on weight differences between the three methods (Monokote/Ultracote vs Tissue/dope vs Glass/epoxy)? I haven't built the fuse yet, so it will be a few months before the wing gets started.

I'll ping you when I get ready. Thanks!

LQUAN

My Feedback: (17)

Hi Lynn,

I'm really interrested in the dope/tissue method for my TF P-40E. I realy hate the expoxy/glass method because it takes forever for me to squeze all of the bubbles out and it still requires a lot of sanding and filling to get the surface smooth. I really cannot afford a vacumm-bag system to do this right. I don't like the iron-on film on warbird either. It looks unreal and it can't protect the soft balsa under it. Does the finish of dope/tissue come out hard to prevent minor dings?

First of all, with dope/tissue method, does the surface come out smooth and strong like expoxy/glass? How do you do this in the open rib area of the rudder and elevators?

Please let us know what brand of dope and tissue you are using as well as the instructions. Thanks in advance.

at6fan

My Feedback: (13)

If you do dope and tissue right it is as light if not lighter than monokote. Obviously glass is heavier and much stronger. To me the strength is not an issue. The strength of my models comes from the structure not from the covering. Since they are fully sheeted warbirds they are stronger than open bay structures that rely on the covering to help strengthen them. As the airplane contacts the ground at a high rate of speed it dosen't much matter how they are covered anyways!! I cover the flight controls with super coverite or solartex. They both take paint very well and you get the realistic fabric look of the real thing. Look forward to hearing from you.

Lynn

at6fan

My Feedback: (13)

OK here is how I do it. I'm sure there are better ways but this works for me. I use Sig nitrate and butyrate dope. A half pint of each and one pint of thinner is plenty for a 60 size warbird. Sand , sand and sand prior to starting. The smoother the better as with iron on film. I mix the dope 50/50 with the thinner. If it's cold use a little more thinner. The first coat is nitrate dope thinned with baby powder (talcum) added. This helps fill the grain and sands very easily for a smooth base. I buy several sheets of Silkspan (tissue). Wet the tissue and spread it over the surface to be covered. It is very easy to work out bubbles just spray it with more water. Once it is smooth spread on a coat of thinned nitrate dope. Always use the nitrate first as this bonds the tissue to the wood. Coat it one more time before you try to sand as the tissue will tear at this stage. Lightly sand with 600 paper dry. I've tried to wet sand and don't like it. Just be careful and sand lightly. After you have three coats of nitrate you now switch to the butyrate. This is the top coat because it is fuelproof. The idea here it that each successive coat melts into the previous one. As you sand the butyrate the weave of the tissue should dissappear. After two or three coats of butyrate you are now ready to prime. I use Krylon gray primer. This is wet sanded until you have a smooth finish. Don't be afraid to do two or three coats of primer as most of it is sanded off. As you lay up the tissue give your seams extra coats of unthinned dope. This builds up faster than thinned and allows you to sand until the seam disappears. Use the same method aroung wingtips. Wet the paper good and stretch it like you would monokote. As it tears away dope it over and over and continue to sand between coats. I guarantee that the seam will blend away. Just takes a little extra effort. Once you are primed and smooth use the paint of your choice. My favorite is 21st Century military flat colors. After decals I spray with Top Flite flat Lusterkote. This requires extra work but the end result is well worth it. Cover the flight control surfaces with a good fabric such as Solartex. This takes paint well and gives you the authentic look of the real thing. This process does not work over open bays. You will punch a hole in it just by breathing on it. For sheeted surfaces only! The tissue will not prevent you from aquiring minor dings and scratches. Use the above process to repair holes that you may aquire. I have made several repair to my Texan and it is now getting that broken in look. Show me a warbird that didn't have some minor dings and dents after a few combat sorties. Hope this helps. If I missed something important or my babbling dosen't make sense feel free to e-mail me direct at lynn.demaree @mibatt.ang.af.mil

Lynn

LQUAN

My Feedback: (17)

Thank you Lynn. I really appreciate you take the time to type all that instructions.

paladin

My Feedback: (9)

Lynn, Excellent! I use a very similar process with nitrate only. I still have the plane I tryed this on first built in 1983 (just a minute, gotta take my shoes off). Yup, 19 years old now 20 this summer. For open surfaces I use Sig Koveral, The process is the same as you've stated but this stuff heat shrinks. So I'll put three coats of 50/50 on the wood sanding lightly between coats and when the last coat is on I can iron on the Koverall just like monokote/ultracoat. In those areas were it does not want to stick I brush on alittle more 50/50 then hit it with the iron. once all the edges are tacked down I strink the center fabric and go to your process. Makes beutifull, strong conrtol surfaces that look fabric covered for those warbirds that had open control surfaces.

Good luck guy's

at6fan

My Feedback: (13)

Stix It works great with Sig Koverall. This stuff makes it stick to the wood like crazy and never comes loose.

Lynn

bgi

My Feedback: (7)

"Wet the tissue and spread it over the surface to be covered. It is very easy to work out bubbles just spray it with more water. Once it is smooth spread on a coat of thinned nitrate dope."

You let the water dry before you apply nitrate? I do. Just checking.

Good stuff here. Thanks!

at6fan

My Feedback: (13)

I put on the dope while the tissue is still wet. I find if I allow it to dry it has more tendancy to bubble. I also spray out any bubbles while applying the dope. I brought some pictures in to work to get scanned. I'll try and post them today.

Lynn

at6fan

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Hi guys. Here's my plane. Sorry that the picture is not as good as I would have liked. The plane in the background is my other ground attack plane!!

justrfb

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Is that an A-10 Warthog? Do you really fly it? I also am a big fan of the A-6 (at6fan... that is what you mean with your RCU name right?)... Nice P-39 by the way...

Justrfb (checking all my options)

at6fan

My Feedback: (13)

Justrfb,

Yes that is a Warthog in the background. 110th Fighter Wing, Michigan Air National Guard. I am a maintenance superintendant. Makes a nice backdrop for my RC stuff. It also generates alot of interest when I sell stuff online. Yes I am a huge fan of the AT6-Texan. I currently fly a Top Flite AT6 finished in the colors of the South African air demonstration team. I'll post a picture when I get a chance.

Lynn

Oryx

Hi at6fan

I thought you may be interested in this. After WWII there was little detailed information coming out of the Soviet Union (as the cold war also started intensifying) and a lot of material published in the West at the time came from German sources from their experiences against the Soviets, as well as of course informed assumptions on how equipment was used and how it performed. A lot of people at the time assumed that, due to the US and in particular British dislike for the P-39 as a fighter, as well as the presence of the heavy 37mm cannon, the Soviets used it primarily as a ground attack fighter and tank buster. This is actually not completely true and unfortunately found its way through the literature (one author quoting another) until recently when the Soviet archives became much more accessable.

The Soviets indeed used the P-39 as a ground attack fighter when the opportunity arose (the same way as the Brits did with the Spitfire and the Americans with the Mustang), but that was never its primary role. It was used in the VVS as a pure fighter and since much of the air combat on the Eastern Front occured at relatively low altitudes, the high altitude performance of the P-39 was never an issue with them. It is interesting to note that three out of the four top scoring Soviet pilots flew the P-39 for a large portion of their kills:
Alexandr Pokryshkin: 59 (48)
Nikolay Gulaev: 57 (41)
Grigoriy Rechkalov: 56 (50)
(The kill numbers in parenthesis are portion of kills achieved while flying the P-39)
These are only topped by Kozhedub with his 62 kills in the LA-5 and La-7.

Note also that the VVS ended up using most of their relatively large number of lend-lease Spitfires for PVO service to protect cities, they completely rejected the P-47 for service (among a lot of other aircraft well liked by the West), but they seemed to love their P-39s and some of the top scoring pilots chose to keep flying the P-39s even when some of the better Soviet aircraft became available such as the Yak-3/9 and La-5FN/La-7...

Sorry for the off-topic post but I thought someone might find the info interesting.

Regards,
Oryx