Sig Somethin Extra idea??
 

Hello everyone.

I'm helping my cousin get into the building part of the hobby, and so I'm helping him build a Sig Somethin Extra. He asked me a question that I just absolutely did not know, and that was sheeting and fiberglassing the wings.

He wants to completely sheet the wings with the stock 1/16" and fiberglass. Do you guys think this would work? I've sheeted and glassed airplanes of this size and weight in the past with no problem. Sheeting will probably add a couple ounces and glass about the same, so probably 8 ounces more per wing which is really nothing.

Ideas??

Thanks

Jason

RE: Sig Somethin Extra idea??
 

I have built two of these kits by following the regular recommended procedure. I find the wings to be very strong and of a shape that is very easy to get a nice tight film (Monocoat) covering job, even for someone of limited experience (me, of course). I just wonder what advantage he may gain compared to the extra weight that would be added, and would it all be worth the effort? IMO-no.

RE: Sig Somethin Extra idea??
 

Well he says he likes solid wings(not the open bay) and he likes them strong, and would rather paint than use iron on covering. It would not make the airplane bullet proof, but it sure wouldn't show signs of hangar rash as easy.

Jason

RE: Sig Somethin Extra idea??
 

Jason, what you are saying here is adding a full pound to an airplane that should weigh in the 5 lb range. That's a 20% increase in weight!! That's HUGE. Please leave it as designed, the airplane will fly much better. I just finished us a couple sets of 33% Laser wings and each panel after hinging weighs 19 oz.

RE: Sig Somethin Extra idea??
 

Jason,

Based on what you wrote in the first post...I say go for it[8D]. If he wants a painted finish on a nicely designed airplane, then go for it[X(]. If you guys keep it light where you can, and go with light cloth, the air frame will certainly handle the weight. The plane would ultimately be a one off that looks great. Isn't that one of the most important things about building. Build what you want, how you want it, and better yet nobody else has one just like it;). Good luck...............

RE: Sig Somethin Extra idea??
 

Aw Rick, ever the dare-devil. Personally, I see no reason to do this mod, but whatever floats your boat! What do you do about the open bays in the fuse?

RE: Sig Somethin Extra idea??
 

Please take this as humorous as that is my state of mind right now. Seems to be an ongoing trend here on RCU about building and then trimming issues. I see guys wanting to add this and add that to their airplanes. Stetements like, it's only a couple onces. Then further down the road I sometimes see the same guys posting that their airplane lands too fast , snaps out at the top of loops, wants to tip stall on landing, ect. Well the simple answer is your the one who built a heavy airplane now deal with it's poor flying charictaristics. I do tend to expect more out of my airplanes then most, I do beleive that you will only get out of them what you put into them. For that reason I carefully plan every component or part that goes on the airplane. For me it pays in the long run to do so. So bottlom line is this, if you want a good flying airplane. Build it as light as you can, that great looking airplane that is 20% heavier then it should be gets all the ooooohhhs and ahhhhhhs until the first time it stalls into the ground, then it's just an overweight repaired airplane.

RE: Sig Somethin Extra idea??
 

Years ago I did that with what should have been a great flying airplane, a Falcon 56 Mkll. What a mistake!!!! I did it because I had not yet learned how to use Monokote and was intimidated by the thought of it. I fully sheeted the wing (beautiful job of sheeting), filled the balsa on the complete airplane and painted it with epoxy paint. Man, did that thing turn out heavy. It's gorgeous but it takes a .60 size engine to handle it and you guys all know what happens when you put an overweight engine in the nose of a plane.

RE: Sig Somethin Extra idea??
 

One of the best things about a somethin extra is its low weight and slow flight characteristics, by all means add weight and make it look as good as you like, just dont expect it to fly as well as a standard somethin extra.

RE: Sig Somethin Extra idea??
 

After thinking about this post for awhile. I have come to the conclusion.

If you use contest grade balsa, maybe at the most an extra one ounce per wing panel.
Depending on what you use to cover it will or will not break you. I have used .55 oz. Fiberglass from CST on my pattern planes.
Couple of steps i use.
1 Sand the sheeting smooth vacuum it off.
2 Put one coat of Balsarite for film over all the wing sheeting. It stinks bad but it seals the wood so the epoxy will not soak into the sheeting and add a ton of weight.
3 Use either the .55 oz. fiberglass or the 3/4oz. fiberglass. Put this on with Zap finishing epoxy or i have used Great Planes finishing and Bob Smith Finish cure as well. I add about 10% of acetone to the mixture. If you add to much acetone it will get real gummy and not want to dry for about a month.
4 using a paint brush not a acid brush but a nice soft paint brush. about 3/4 of a inch wide works for me allthough i have used a 1/2 wide one as well. Put a light coat over the fiberglass as light as you can. Be stingy with the resin.
5 While the Resin is wet in other words right after you are done putting it on. put Micro balloons over the surface and work them into the resin by hand. I use a bare hand for this not a glove. This is to fill the weave without anymore resin. as you rub this in. You will feel the Micro balloons being absorbed by the resin until all you feel is the Micro balloons not any resin at all.
6 Repeat with the other panel
7 using a sanding block sand the excess fiberglass overlap off the trailing edge and the leading edge of both wing panels
8 Repeat steps 1 thru 7 for the other halves.
9 Sand everything trying your best not to cut into the fiberglass cloth. If you do cut into the glass use a little bit of CA and rub it in with your finger with a small piece of wax paper. All the while marveling at how easy it is to sand with the Micro balloons in it.
10 Stand back and amaze yourself on how little weight is in it. Maybe another one ounce per wing panel.
11 Whatever primer you decide to use the thinner the coat needed for coverage the better. Paint adds zero strength only adds weight. Steps 1 and 9 are the important steps. Skip on the sanding and your primer coat will be trying to fill all kinds of voids, grooves and other ugly things.
12 I would be shocked if you add 6 ounces over the stock wings with Monokote. You can make some of that up with either Hites HS-225 or Tower Hobbies TS 35 Servos Might save you a 1/2 ounce per servo.

RE: Sig Somethin Extra idea??
 

Can you guys tell me the weight of each wing panel on your SSE?

Just as an experiment (we can buy a new wing kit from Sig) we ended up sheeting and glassing with 3/4oz glass and used the method d bodary used, and so far with servo and aileron, each wing panel comes out to 1 pound,so basically 2 pounds total weight for the wings. Is this alot? I've read 8-9 oz per wing panel if built normally. Its a big weight increase IMO.

Thoughts?

Thanks

Jason

RE: Sig Somethin Extra idea??
 

I just weighed both my wing panels including HS-422 servos, Ultra cote covering,Ailerons, linkages and 6 inch servo extensions. They are 12.0 ounces each. including one that has a 1/4 oz. of lead at the tip for lateral balance. The wing tube is another 2.5 ounces

RE: Sig Somethin Extra idea??
 

I beat the carp out of mine. The somethin extra is too heavy to begin with. I put an OS .55 in mine then had to derate the speed by using a larger pitch prop. It is a great plane to begin with. The idea is lighter not heavier. Indestructable planes fly crappy. Thats why the ARF's are built so light, fly so good.

RE: Sig Somethin Extra idea??
 

I just weighed my wing panels 7.5oz. each. That is a finished wing with paper and cardboard tubes installed-no servos, coveringor ailerons, lightly sanded.

RE: Sig Somethin Extra idea??
 

On my finished kit, one finished panel 10.8 oz.. Thats with 1/4 inch tristock on leading edge of aileron, standard futaba servo, 6 inch extension wire control rod and monocoat covering. J hook installed, ready to assemble onto plane. This is pretty close to the other posters finished weight of 12 oz. so we are seeing 11-12 oz. built per regular process. Maybe the other weights you saw (8-9 oz) were without servos?

RE: Sig Somethin Extra idea??
 

I've built a few SSE's and have 2 here at home. They are too heavy when built as-is. First, toss out the ply used for servos and just use some hardwood to anchor them down. It's a good idea to make a front hatch in the nose for fuel tank access. From what I've seen in the past, Sig ships heavy tanks and you can save a few oz with Sullivans. The Dubro featherlite wheels save a lot of weight and a small electric foam wheel is good for the tailwheel. Use a mini servo for throttle linkage.

The SSE is an excellent model with impeccable flying characteristics. I've used them for first time trainers without buddy boxes. Adding tip plates to the wings increases handling and low speed stall characteristics. My first SSE had enlarged rudder and elevators with counter balances. It was given to me when the builder was tired of repairing it. It has taken a beating in at least 8 crashes and is still a great beater airplane. I made the mod of cutting down the top rounded portions of the formers from firewall to turtledeck to be flat with a flat sheet of balsa. I use a wood screw in the front to keep the hatch tied down. I can get to anything easily this way.

RE: Sig Somethin Extra idea??
 

Jason - my wings with DS821 servos, 12" extensions, J-hooks, Ultracote w/ trim - are: R 11.8 oz.; L 12.2 oz. (1/2 lead added for lateral balance)