improvised fuelproofer/ cessna 170 gas power FF experiment

[mr.charlse]

Hi! im building a guillows cessna 170, which will be powered by a cox .020 for free flight. there is however to my knowledge, no fuelproof dope over here in the northpole (Sweden), so i wonder what i can use as a light substitute for fuelproof dope?
//charles

[squirlye]

I can't help you with a substitue for fuel proof dope. But I do want to see a video of your flight.

[mr.charlse]

i am currentluy only in the planning stages, but i will be suer to put up a flight video when im finished i will perhaps even make this a build thread!

[mr.charlse]

Hi again! I couldn't be bothered to take pictures during the build, so i snapped these just right now!

This is the build in it's current stage, all of the actual building has been done, the parts have been sanded, then sanded again, and then polished. I also decided to scallop (i don't know if that's the correct word) out part of the fuselage formers, since i have understood that this makes covering less of a headache, as well as reinforcing the top part of the fuselage (i will do the bottom part after i have glued the nuts for engine mounting behind the front formers.) with 1/16" balsa. The only things left to do now are
Covering
gluing on the bolts behind the front former
mounting the engine
mounting the cowl, with holes for the piston and needle, of course
fixing up some birch dowels for more structual integrities (at the wing mount)
adding excess cellulose to control surfaces for trimtabs.
I do however wonder, do you people think that i should go with colored red tissue for the details, or use the decals in the kit? i've had som unpleasant experience with those guillows decals, or decals at all in fact.
I did also find a great dope, which i reccomend to everyone who needs some fuelproofer, which i ordered from a site called shop4glue.com. the product is called "starspan butyrate dope" and it seems really good!

[Bill Gaylord]

First, great to see folks still using the vintage glow engines on these planes for FF. Hats off to you.
Waterslide decals are tricky, but worth developing the patience to use properly. The best way to develop that, is to apply decals that are 50 years old which crack into pieces and must carefully be pieced together on the model. After that, the "normal" ones become much less frustrating and more of a treat.
I know that Coverite Microlite iron-on is not a tissue, (although they do have synthetic tissue) but if I were to use a fuel powered engine I would not care to use tissue, especially on a model this size. The added doping would offset the weight benefits of tissue, as Microlite would then be comparable in weight. With a bit of experimenting, it's quite easy to work with and should be fuel proof. They do have a synthetic tissue, which I understand now has it's own adhesive, versus the prior version where the heat activated adhesive had to be applied first to the model. I would imagine that their synthetic tissues may be more fuel resistant than standard tissues.
I'm sure some of these guys can recommend clear coating sprays or other similar poly products that would work well for your fuel app, when using tissue.

[mr.charlse]

im gonna see how this works with stick and tissue. great little benchmark to set, i haven't seen anyone do this before, and i've looked quite a bit. im building it completely as instructed, since i always have wondered about if it would work.

[Wildpig]

Mr. Charlse, you model looks well built. Scallop is the correct word for what you did with the formers.

If you want to use butyrate dope on the tissue for fuelproofing, my guess is that it's worth a try. That is the "old time" way of building these models. The waterslide decals have always been a problem for me on tissue models because the surface is rough. If you apply dope, sand, apply dope, sand, etc. you may get a decent surface for the waterslide decal to stick. The fuel residue from the engine will likely eat away the decal.

I like the idea of building a balsa model exactly like it was done 40 or 50 years ago, even if there are better modern methods.

Mr. Gaylord has built some very nice models, maybe I"ll try that Coverite stuff on a later build.

[mr.charlse]

perhaps i will to. However, the store which only minutes ago had quite a few pee wee engine listings on ebay, has now taken them all off, completely. So i'm out of an engine! I was thinking about trying that coxengines.eu place, but that seems a bit dodgy. Does anyone know where one can get a cox pee wee .020, in good condition?

[mr.charlse]

Hello there again chaps! i have made quite a great deal of proggress since my last post

After covering every part of the plane, using 50/50 white glue/water (cascol brand hobby glue) i shrunk it using an atomizer filled with water until every part was taut and stretched. I am currently waiting for my dope to arrive from England, so that i will be able to get my little pee wee on there.. i added some dihedral to the wings, they are a bit unbalanced in the way that they tilt, but i found it to be within the "acceptable" range, considering that this is the first stick and tissue model that i have built in years. I alos decided to use 1.5mm dowels to reinforce the wing, sticking them through the fuselage top, to such an extent that they penetrate the second former. The wings are very rigid now, and will probably be able to withstand the little wheelroll on landing that happens every once in a while..
Speaking of landings, i decided screwed up while bending the wires that a landing gear would probably rip off anyway with so much noseweight, so i decided to leave it off. I also (as i mentioned in a previous post) decided to use all excess cellulose for trimtabs, because i usually like to add a tiny bit of aileron into the trim, making it bank more, which just looks plane baller (pun VERY much intended)
The windscreen came on in a snap, started with attaching the side windows, and then bending the actual windshield down to the little bow part in the middle, and applying lite pressure. There's some glue on it, but i think it looks fine.
on a sidenote, i got me a little pee wee, got a pretty good deal on it, but the best part was that a babe bee was included! both of them were advertised as functional, so i figured that i would make something useful out of the little .049 as well!
I Therefore decided that the next build i make will be a classic veron "cardinal" which is an old kit by Veron, but now reproduced by "The Vintage Model Company". i'll order it as soon as i get my next allowance, hehehe...
As a sidenote, can i perhaps post a build thread of the cardinal as well?