[wymbly1971]

Unionville Hobbies gives absolutely no guidance on window installation at all. Even the windsheild installation instruction is lousy. Something to the effect of, "Trim the windsheild, glue the windsheild". The windsheild will be installed once the covering is complete.

I'm fairly new to this game, so I had to ask around.

My buddy Darren came up with a method that I liked.

1. The window openings were already cut, so place the glazing material over ther opening and trace the hole.

2. Next, cut the glazing from the sheet and leave a little extra around the perimeter. I actually found that about 3/32" worked quite nicely.

3. Once cut out and edge sanded smooth, trace the window onto the wood sheeting.

4. VERY carefully, use a blunt ended bit in your rotary tool to slot out to the lines you traced onto the wood and to the depth of the glazing.

5. I then used RC 56 to glue the glazing into the hole.

6. Finally, mask the windows off and use a light inside the fuse to shine through the window. Trim the masking tape (leaving the tape on the window) away. A person could fill the slight gap at this point before covering. I didn't because I intend to use aluminum tape to simulate a frame.

The intent here is to cover the whole side of the fuse (in my case, with Koverall) and later cut through it and peel it off, masking tape and all. The windows should appear nearly flush like on the full sized aircraft.

[canadianf1pilot]

Looking good Trev....

I'll try to give ya a bit more notice befor our next event...lol

I am thinking there still is a pile of work to do to get that thunderchicken in the air....keep up the good work and keep the pic's coming....

Bill

[cf-drg]

Yup looking good.... Better than mine Trevor (truthfully)..That's it I'm not posting anymore of my building threads... Naaaah just kidding, I don't have one ... I did not start anything floaty this year, first time in 6 years... Guess I'm getting old or something (truth is I got get rid of some of them).... Keep em coming Trevor...

[wymbly1971]

Well, the airframe is as done as it ever will be.

Pic 1 - Notice that I use this opportunity to secure the little strings used to pull the servo leads. I simply tie them around a pin and stick them into a rib. Once the fabric goes on, you're stuck with it until finished.

The directions that come with SIG Koverall aren't all that good. Most of my "cloth and dope" knowledge came from reading, reading reading and from guys here on RC Canada. As such, if there are some Koverall gods out there, speak up...! At least for the sake of the next guy.

Dope smells like Ambroid glue if you don't know. Notice I'm doing this outside. Even then, the smell of this dope will make you sick if you get too close. Try using a charcoal respirator if you can.

When I started this job, I had 2 pints of Nitrate dope. It was not enough to do this airplane. I could have used at least another pint of dope and a couple pints of the dark and creamy to go with.

The first step is to sand, sand, sand. You want to basically get the wood silky smooth everywhere you expect the fabric to touch. Also, round off those ribs! Also round off little blocks you added that are very near the fabric surface, such as control horn mount pads, hinge reinforcements etc. Either you want the fabric to touch, or you don't. Make sure there is a clear difference between them. That applies to formers also that are very close.

Pic 2 - Now comes the part that is not so clear and everyone has a different way to do it. Here's what I did. I thinned some Nitrate dope 50/50 with automotive laquer thinner (or gun wash)and applied 2 coats of it to all the wood work where I expected the fabric to touch. These coats soaks right into the wood and you hardly know they went on. There seems to be no compatibility problems using laquer thinner BTW.

The next coat went on full strength. It was sanded smooth when dried.

Then another good heavy coat, full strength. I sanded it slightly to get it smooth.

In hindsight, I should have continued applying Nitrate dope and sanding until the grain of the wood stopped accepting the dope.

I will outline what happens if you don't! Basically, the wood continues to suck all your good paint away even after the fabric is sealed BIG frustration!

The rest of the covering is surprisingly easy. The method is a lot like any other covering. Start at the bottom and at the aft end. That way, all the laps are from the front so that wind and fuel can't get under an edge in flight.

Pic 3 - I started with a main wing. Cut a piece of fabric about 1" larger than the underside of the wing panel. Orient the fabric so the long threads (warp) are spanwise (root to tip) and the wheft is coardwise (LE to TE).

Just like any other covering, start at the middle of the LE.

Using dope as adhesive works like this. You hold the fabric against the wood and apply dope with a brush. The dope soaks through and "melts" and combines with the coats of dope you already put on. Then, when dry, good luck getting them back apart. In July, this process happens faster than I can describe it! Literally, you work non stop and apply the whole piece of fabric in only a few minutes!

Pic 4 - After tacking the LE at the middle, pull the fabric so it is taught and tack the TE at the middle. From there, work your way out to the 4 corners by pulling the fabric and continuously adhering. Don't pull the fabric too tight otherwise you'll have a weird curvy grain but don't let it sag either.

You find that the results are surprisingly nice once you get a system going.

[twnotter]

Looks good!! Can't wait to see the final product.

[canadianf1pilot]

great post Trev....I might just try that on my super cub....

Bill

[jiott]

Hi Trvor:
I like the idea of coating the balsa frame with something; afterall it is a float plane and will eventually take a dunking. The coating will protect the balsa from swelling. I used Solartex fabric (self-adhesive) on my Norseman, but first used a spray can of polyurethane to lightly coat the whole balsa frame, wings and fuse inside and out. The Solartex sticks very well to the polyurethane (it also does on bare balsa). Yes, I have dunked mine twice (blown over in the wind) with absolutely no damage. Your method is a little different than mine, but I think the results will be good.

Jim

[wymbly1971]

The fuselage follows the same logic as the wings. Start at the bottom and aft and work your way up and forward.

I applied a few special pieces before covering the fuse. Thin strips of fabric are fully adhered in the fillets of the aircraft or anywhere else that I feel an adequate overlap may not be possible. This step is purely for reinforcement and I'm not even sure it's 100% neccessary. In any event, it adds almost nothing in weight and couldn't hurt. I have the peace of mind that the fabric will be continuous everwhere.

When I applied fabric to the sheeted surfaces, I only adhere it along the edges just like the wing. I will use the iron to shrink it nice and tight before sealing (and fully adhering). The sheeted area of this Norseman is made up from a ton of smaller pieces. It's wise to keep the laps small and clean. I doesn't have to be perfect though, as you will see furthur into the build.

I learned quickly to apply a little extra dope to the edges and leave a bit unattached. When you cut the fabric with a SHARP razor blade, the extra dope helps prevent the fabric from fraying. After cutting, use a little dope to finish adhering the edge. We've all worked with fibrglass cloth. This stuff is almost as bad and the little threads are a nightmare to get rid of...especially if they happen to get stuck down.

I always get a kick out of this Norseman from the bottom. I always think it's got little stumpy legs. Now that I'm applying fabric, I get weird thought that I'm dressing it, LOL.

[vonJaerschky]

Nice work on the Norseman! Here's a picture of mine taken at Chilliwack BC last May. It's a great flying model. Mine is scratch built from a combination of my own plans and an enlarged free flight plan. Best of luck with yours.

[canadianf1pilot]

well you sold me, I got som koverall but I was wondering where you found nitrate dope?

Bill