Scientific Mr. Mulligan CL for 1/2A … Plans

Oh, now This was DUMB !!! I tried to paint some enamel we had , on bare Balsa …. Turns out that’s a dumb idea … it would have been Much better if I sealed the wood with some poly first , then added the decorations on top .…. AARGH !!! In such ways are we humbled …. how much we’ve forgotten .

We’re not even going to show pictures of this till we can clean things up a bit first ….

OK, we’re back , and so today we plan to brush on some Polyurethane varnish over all the balsa parts , maybe a couple coats with some sanding in between … Then we’ll paint on the decorations … ( the right way … )

...been a while … Got the parts all sanded , decorated and coated with three coats of polyurethane varnish ( sanded w/600 between coats ) Much nicer and a lot less smelly than Dope … ( aircraft lacquer)

Greenes for you !! He looks Great like the looks of the poly natural and the decals stand out Niely !

Apologies , they were hand painted ( not perfect ) … I’ll make some decals the next time …
Now it’s off to find a bellcrank , or make one … I have an ancient thrust button that I can glue in the wing for the bellcrank mount … nice scrap of thin ply for the leadout guide …plywood control horn ... Then stick it all together … still have to fab triangle stock wing mount braces . Can’t just butt glue it to the fuselage … Coming along, slowly … Lots of good ideas for the next “Scientific” build …

PS. I sure hope that poly is indeed fuel proof …

GPW wrote:PS.  I sure hope that poly is indeed fuel proof …

I was under the impression that "Polyurethane" is fuel (Methanol) proof.. but I don't know about the nitro-methane ingredient found in the 1/2A fuel. You'll probably want to run at least 25% nitro in that Cox Tee Dee .051.. I recently bought "quarts" of fuel from Sig Manufacturing Co. They stock 1/2A fuel under the "Champion" name. It's quality fuel, that anyone here on the forum would recommend. You won't have to pay the "Haz-Mat" shipping-fee.. if you buy quarts. That's the beauty of running small-displacement IC engines in this economy.

Very nice looking plane. I too really like the look of it 'naked' as in bare wood with trim. As for your polyurethane..... I cannot speak for all, but, the Minwax Polyurethane (oil based) in a can that is brushable IS fuelproof as I have not yet had a problem with it on my 1/2a flightbox and my airboat. My 1/2a flightbox houses my 1/2a fuel at 20%, and 25%, and it has not touched the finish. I would say to err on the side of caution and let it sit a few days before using it just to be safe. If it is Minwax waterbased poly, I have still not yet done much for testing with fuel as I only used it for basecoats to seal as you did before painting. Also, the Minwax Polyurethane in a rattle can I had both used and recommended in the past was good and did not yellow as the brush on version, is now apparently no longer fuelproof according to a member of my club that has had bad experiences lately. The old can I had is and was fuelproof so was shocked to hear this. I myself just bought a new can and sprayed my Ringmaster with is so I will be seeing if what he said is true in a week or so.....

222, Good Luck with the Ringmaster , we await your report …

Rod, mine was Varathane Ultimate (?) Indoor oil based polyurethane varnish ( fingers crossed eh ? ) What I “had “ ..

I think any oil based poly will be fine.

Thanks guys , it really is much nicer to work with than the old Dope ... And it seems to be “neutral” in that it will cover different paints and Inks without interacting … I drew my panel lines with a pilot G-2 ball point pen , and painted the windows with Rustoleum enamel … Both covered with no blurring …

We’re back … Burdened by “home projects” we got diverted from the important stuff … Found a piece of thin 1mm aluminum , perfect for making my bellcrank , and we found our old spool of Spiderwire ( fishing box) 30lb. test 8lb. diameter ( thin ) by 300 yards …. You guys think that will work for 35-40 ft lines …??? Also we selected a nice piece of Triangular stock to facilitate mounting the wing to the fuselage ( best Idea I could come up with) … coming together … Having Fun …