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Post  944_Jim on Sun Apr 21, 2019 1:42 am

Back when I wanted.to build a twin, I bought my BHM Mosquito. I really hated the plank wing, profile fuselage kit. In the end, I built it anyway.

While researching other Mosquitoes, I came across this one. I can't remember the website I scored it from, but it was English, as in, across the pond.
More digging to ID it ensued. A fellow on RCGroups identified the plan, and even provided a quality copy from the magazine it came in. The scans are over there.

Dave Cowell of DPC Models did the lasercut for me from the plan I provided. I don't know how it came out to be the "junior" version, but decided to power it with a pair of .020s. I'm on the fence between Pee Wees or Tee Dees. I have a pair of each.

One of the things that drives me nuts is a flat bottomed wing that tapers down in thickness. It makes the wing look upside down when viewed head-on. The plans even indicate tapering the wing spars down from the top in order to make the wing easier to build. Well, I've been looking at the bones for too long. The build began today using aliphatic wood glue...it seems to work well enough for my speed entry.

There are mistakes, but I'm not pointing them out. In the end, the wing should taper up off the table, while the top tapers down. I hope this gives a nice look to the wing:

7/8 Brown-Novotnik Mosquito Img_2106
7/8 Brown-Novotnik Mosquito Img_2105
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Post  944_Jim on Tue Apr 23, 2019 1:00 am

So what happens when you bite off more than you can chew? I dunno, but I'm lost between the projects.

I need a sealer for the speed entry. So I don't feel too much guilt jumping over to glue and sand another kit.
My dope and talc sanding sealer ran out. I expect.to complete this one with tissue/dope...old school!
What is available at Lowe's that dope won't react negatively with? Will Deft sanding sealer work, or is it only for under Rust-Oleum type finishes?
Thanks in advance,7/8 Brown-Novotnik Mosquito Img_2117
7/8 Brown-Novotnik Mosquito Img_2115
7/8 Brown-Novotnik Mosquito Img_2116
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Post  Ken Cook on Tue Apr 23, 2019 1:28 am

Jim, let me just say this first. The model you show is laser cut therefore it deserves a decent finish that's fast drying. Dope is that finish. Let me just clarify this as well. You say tissue, tissue is for rubber power models and color trim on top of silkspan and raw balsa. 1/2A models usually offer a lighter 000 silkspan, the light silkspan is no good PERIOD unless it's going over planked surfaces. I personally gave up using silksplan on 1/2A models, the grass around here is a constant nuisance and tears it. In addition, it only takes the clip to pop off the cylinder head and it goes right through the wing. If your using silkspan you want a medium or OO grade for lighter models. You can apply silkspan using thinned Elmer's glue with water. The problem with doing so on laser cut wood is that you have to be quick, you have to apply equal amounts of the thinned glue to both sides or it will twist like a pretzel. This was a non issue with old kit wood that was die cut, reason being is that die cut worked better with harder wood where laser cut kits don't. You get much lighter wood in a laser cut kit but it's also prone to warping unless certain measures are taken.

       For your speed model, you can use Polycrilic water based urethane as a base and Rustoleum as a finish. I don't prefer either but that's me. I fly a lot when I can and the models I have that were built by others using Rustoleum are all failing. Dope fails as well but not at the rate I have seen the Rustoleum. When you start introducing higher nitro, the enamel finishes fail even quicker.

         The Mosquito looks to me like it deserves a good base such butyrate dope. 3 coats of clear on the framework, attachment coat and 3 more clear coats all coats thinned. You could always cover with Doculam and paint the camo scheme on top of it and save all the rigmarole using dopes. You could do the entire plane in the Doculam.
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Post  944_Jim on Tue Apr 23, 2019 1:52 am

Thanks Ken,

I like dope! While I say tissue, I mean something along the lines of Guillows silkspan.
Dan McEntee (or you) sold me a few sheets of "DocSpan" a couple of years ago. This was the stuff that was chatted-up at StuntHanger a fee years back. I need to find it. Failing that, I have some Esaki tissue from Penn Valley Hobby. I'm always reluctant to call any paper product silkspan since it has no silk in it!

My Wido Satan was actually covered using Christmas gift tissue. While the stuff doesn't shrink much, this can be a bonus on a parallelogram-looking wing like this one. The minimal shrink requires careful application in order to produce that "drum-tight" skin.
I guess I'll sacrifice a bottle of clear dope and mix up some talc in it...I was hoping Dreft worked under dope. But you are right. This one deserves an all out effort at my best.

Now the prop-driven rocket sled....well, it may just get sanding primer knocked down to the first fuzz, and a quick shot of poly-U. It is destined to be a one-time launch..My camera will need to be set up, and one of my sons trained to push the launch button. Shoot, I still need to mount the rocket tube, the balloon tank tube/body, and build a dolly. The end of April is coming too fast!
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Post  Ken Cook on Tue Apr 23, 2019 2:15 am

Just one thing to note, the Mosquito in the pic is a flat bottom wing. If your intentions are to stunt this plane, I would consider otherwise. It will be a nice looking roundy rounder but anything other than a loop is pushing the envelope. Penn Valley was my favorite hobby shop which I would visit weekly. I went there for 40+ years. It was very sad when they closed their doors. Bill the owner is still alive but not doing well and Jean his wife sadly passed away prior to them closing. Jap tissue is really not suitable for glow powered models. It can work but tears are very likely not to mention oil migration into it. If you can find the Doc paper, I highly suggest it. It's weight is slightly heavier but it's durability will offset the other issues.
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Post  944_Jim on Tue Apr 23, 2019 3:13 am

Just roundie-roundie. I like the mini-size it turned out to be. Roughly the size of the Sterling DC-3/C-47. I fly off of concrete right now. So thin tissue is good enough. I fly to land, not crash. Besides, that mentality ensures I won't run out of room for planes lol!

Dave Cowell of DPC Models cut this one for me as a favor. It is a prototype, and I owe him the build report. I think I've had it for about two years...the kit pile continues to grow. I still need to finish the Scientific Red Tiger DPC Reproduction featured here. Mr. Steve (he is here somewhere) sold me his Red Tiger, and it went to Dave for reproduction about 18 months ago. My reproduction showed up in only a few weeks.
Clearing the bench of punched your parts will give me the room for the BHM Challenger next.

My boys have no real interest in my childhood hobby. I plan on building and flying all of the kits. The "build and fly a few times" is the thing for me...if my wife passes first, they'll all be wall art in the living room! I like seeing my work, well, work! Once it has worked, I'm set to start another. Sure, I have my favorites. Those will continue to fly until they are splinters. One thing for sure, I plan on no "Estate Sale" for these toys.

The next Mosquito I build will be the Frog 36" kit. While the patterns cost me $$, I bought the rib tracings for the Frog from a guy in England. That one has fairly flat, but symmetrical wings. It'll be a few years, but I'm hoping to put a pair of Medallion .09s (no throttle) or OS LA .15s (throttle if the Roberts 3-line bellcrank fits). If two-line, it better fly better than the BHM Mosquito!
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Post  getback on Tue Apr 23, 2019 3:18 pm

Im i really like the kit you got , the profile just has the look of Action in it . Bee watching the build , if i were to do a twin i think it would bee this one ?! Airplane
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Post  rsv1cox on Tue Apr 23, 2019 4:41 pm

Your have a touch of Mosquito mania Jim. I like that kit, but would prefer a built up fuselage to go along with the wing. Does Dave Cowel intend to do more?

I have preached about this to a silent choir here for awhile but this Minwax sanding sealer has worked very well on my not so wonderful builds. I have no idea how it would work on tissue, but you could be my Guinea pig. Smile

7/8 Brown-Novotnik Mosquito Minwax13
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Post  944_Jim on Tue Apr 23, 2019 6:06 pm

rsv1cox wrote:
I have preached about this to a silent choir here for awhile but this Minwax sanding sealer has worked very well on my not so wonderful builds.  I have no idea how it would work on tissue, but you could be my Guinea pig.  Smile

Hi Bob,

He may go forward and add it to his catalog. I hope so! He does want the build log...so that is a good sign.

Will this stuff work UNDER dope? I need to seal the speed plane, and also prep the Mini Mossie. I'm tempted to take a detour with the Mossie, and convert the fuselage to a Comet. I bet a nice, red plane would be easy to see. All I need to do is cut a new fuselage with a more rearward canopy, and a new rudder. Boom, instant DH Comet!
Thanks much!
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Post  rsv1cox on Tue Apr 23, 2019 7:00 pm

Yes, I used it under my BHM Cyclone then sprayed with Top Flights Lustrekote.

7/8 Brown-Novotnik Mosquito Cycloe13
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Post  Ken Cook on Tue Apr 23, 2019 8:21 pm

Minwax products aside from the water base is oil based which uses paint thinner to thin the product. Dope is lacquer and the solvents will more than likely attack it. It would work with a enamel top coat. Enamel over lacquer not lacquer over enamel.
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Post  rsv1cox on Tue Apr 23, 2019 8:31 pm

Ken Cook wrote:          Minwax products aside from the water base is oil based which uses paint thinner to thin the product. Dope is lacquer and the solvents will more than likely attack it. It would work with a enamel top coat. Enamel over lacquer not lacquer over enamel.


This is water based, water clean-up. The down side is you have to apply to both sides of a wing or it will warp. I apply then wipe off the excess.

Bob
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Post  Ken Cook on Wed Apr 24, 2019 9:31 am

Dope requires a mechanical bond. By this, first coat wicks into the wood, second does the same but melts into the first coat and so forth. Without toothing into the substrate, dope will adhere to itself. This isn't going to take place with a water borne coating. Dope tends to shed if it has nothing to bite onto to. This is why butyrate dope doesn't adhere well to synthetics like nylon, ripstop and ceconite.  If there's any vinyl like compounds within the water base product, it's going to react with the solvents of dope. I personally have used water borne finishes over lacquer, just not the other way around. Minwax does make a lacquer based sealer. The problem with this is that without testing I couldn't offer it's compatibility. Generally speaking, furniture based lacquers are nitrocellulose aka nitrate. Just because the products smell alike, some of them have higher concentrations of tolulene or MEK within them which can have bad results in terms of compatibility.
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Post  944_Jim on Thu Apr 25, 2019 10:54 pm

Wheels...wheels!

Thanks Roddie, I owe you! When is your birthday?
7/8 Brown-Novotnik Mosquito Img_2118


I have wheels for the rest of my life! I think a pair will Lok really good under the Mini Mossie.

Now to go knock together a dolly for the speed plane.
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Post  944_Jim on Sat Apr 27, 2019 3:39 am

Roddie's wheel will fit this kit just right:7/8 Brown-Novotnik Mosquito Img_2119

And now for a quick mock-up converting this to the DH Comet. Looks like a.quick fuselage and rudder cut. I'll use the original Mossie wing and elevator/stabilizer just to minimize material waste. I'm still on the fence with this one, and may actually cut the fuselage just to check.completely mocked up:
7/8 Brown-Novotnik Mosquito Img_2121
7/8 Brown-Novotnik Mosquito Img_2120
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Post  944_Jim on Sat Apr 27, 2019 3:49 am

So those shots really got me going! I had to cut out the fuselage and mock up the paper:
7/8 Brown-Novotnik Mosquito Img_2122
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Post  F4D Phantom II on Sat Apr 27, 2019 11:33 pm

Hello Jim
                My vote is for the mossie, I think it will look great. The wing is coming along nicely.
                                                                                                                Juan
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Post  944_Jim on Mon Apr 29, 2019 3:12 am

OK. Some decisions made. .012" leadouts (they fir the WD-40 tubes), with a little schooling with some extra balsa at the inboard tip. Then a hand made 1.25" bellcrank from the bottom of a retired storm door. I know most will PooPoo the wrapped line through the unbushed bellcrank, but I enjoy building almost more than I do flying. This plane will probably fly a handful of times, then get retired to the living room wall.
I thought the bellcrank is too cute to NOT show. Note the single edge razor blade for scale.
7/8 Brown-Novotnik Mosquito Img_2123
7/8 Brown-Novotnik Mosquito Img_2124
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Post  rsv1cox on Mon Apr 29, 2019 11:28 am

It wasn't the contrasting razor blade that caught my eye Jim but the soldered on control rod. Why no Z bend? I don't like the things but I live with them, but they can easily be removed. I might try the soldered on approach someday.
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Post  944_Jim on Mon Apr 29, 2019 11:42 am

Bob,
I couldn't make the z-bend small enough. The bell crank rides so closely to the mount that it bound up a bit in action.
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