Cover or Paint a Thermic 2.5 M

[Robert Bauer]

What are the thoughts on covering with an UltraCoat type covering, or painting. I am thinking covering will add some strength, but at what cost.

[Hawksnest]

Originally posted by Robert Bauer
What are the thoughts on covering with an UltraCoat type covering, or painting. I am thinking covering will add some strength, but at what cost.
I finished my Castor 2.5 (same wing) with three light coats of clear water based polyurethane and left it go at that. If you use a foam paintbrush, you can get very light coats. I have a Condor TD plane, and a homebrew slope plane with Obechi sheeted wings, and both are covered with Ultracote. The Condor with transparent lite, and the slope plane with flourescent solid colors. It all works, but I would think you may want to keep the Thermic as light as possible, with a couple coats of poly, and just stripes with Ultracote. After all, you bought it because it is a very light, nice performing plane. :D BG

[Masterpiece]

Hi,

I painted my JK Thermic wings with clear spray can enamal polyurethane with EXCELLENT results. Firstly I sanded the veneer with 400 grit paper and then did 2 "light" coat first to just cover the surface and seal the wood (I didn't want the enamal from getting into the foam). I then again sanded with the 400 paper to smooth the lacquer and did a finally last coat of the polyurethane to fully seal the wood. On the under wing tips I did a bright red for visibilty.

I found the instruction's sequence of preparing the wings to be out of order (actually a lot was out of order including the v tail preperation). I found that you should firstly make a template of the wings cores so that you have a reference of when you come to cutting out the servo cables line and for cutting the correct holes in the fuselage on the wing seat. In the instructions it says to firstly cut out the hole where the servo cable will exit and then glue and bandage the wings together, BUT this will only enourage glue from gluing the wings together and from the epoxy from the bandage to get into the cable line :rolleyes:, making it harder to clear the hole later. Also I used 1.5mm ply to cover the cores where the outer wing tips meets the inner wing (making it a 3 piece wing) as the gap was too large for a layer of fibreglass to fill. Gluing ply instead of fibreglassing in this area will make a gapless connection with very little effort. I have gone with making the wings with ailerons and flaps and I am very eager to see how it will perform. My only concern is that I will be operating 6 micro servos with a 600maH battery (the only pack that will fit into the slim fuselage). Another alteration I have gone with is to bolt the wing on with 2 bolts, instead of 1 bolt at the T.E with the leading edge being connected to the fuselage with a slide-in bolt. I have had problems with slide in bolts at the leading edge before with other planes (they simply rip out on a rough landing or a slight bump of a wing tip upon landing). Having the 2 bolt option means that it will be more secure, but a bit more fiddly.

It's a great plane. The wings are dead straight and absolutely beautifully finished off. Everything fits perfectly. It's a keeper for sure.

Later,
Glen

[Jack Hyde]

Masterpiece,
I have used 600 mah packs in many 6 servo sailplanes. I find I use about 80 mah per hour at the field flying by myself - launch, fly, retrieve , launch... No chitchat time. About 2 yrs ago I started using 1300 mah nicads that are the same size as the older 600's as far as I can see. The larger pack gives more margin.

[vario]

i have heard that you must paint both top and bottom of the wing at the same time to avoid warps,seems to make sence after all there wood wings?????

,,,,vario

[Masterpiece]

Originally posted by vario
i have heard that you must paint both top and bottom of the wing at the same time to avoid warps,seems to make sence after all there wood wings?????

,,,,vario

I was a bit cautious of this intially too but I had no problems with the wings warping. I first painted the bottom of the wings and then the top. I think my luck was in the fact that I didn't soak out the wings with paint (which will induce warps), but instead just lightly coated them to seal and then did the final coat for that super smooth finish. The v tail was the same no warps. But then the quarter grain balsa of the tail is pretty stiff too.

Later,
Glen

[Robert Bauer]

Glen !! Thanks for the tips on the wing. I sure do agree on the 2 bolt hold down. I am also going to beef up the joint on the tail feathers with some FG at the joint and where the control horns connect. I found 2/3AA 1200 MHA NIMH packs at Servo City for $18.95 if you are interested.

[Masterpiece]

I almost forgot to ask ......... Jack Hyde. With the battery pack I take it that you would get about 6 - 7 hours with a 600maH battery pack. I am just afraid that the 600's will run out of power whilst in mid flight and my plane will kiss the ground. I looked at the 1300's but unfortunately they were a little too big (but not impossible) to fit the servos in as well. So you think I will be fine with the 600 battery pack?

Later,
Glen

[Masterpiece]

Originally posted by Robert Bauer
Glen !! Thanks for the tips on the wing. I sure do agree on the 2 bolt hold down. I am also going to beef up the joint on the tail feathers with some FG at the joint and where the control horns connect. I found 2/3AA 1200 MHA NIMH packs at Servo City for $18.95 if you are interested.

They sound perfect but I already have the 600's. Thanks anyway. The good thing is that I know that I can get some higher capacity batteries in the future if need be.

Happy flying,
Glen

PS: don't forget to post some photos of your plane when finished. I'll be doing the same soon.