I’ve got a Kougar that’s been around since 1989.
The wing has been broken and glued 3 times now.
The wing weighs 2.6 pounds.
Had anybody made a Balsa wing for a Kougar?

Geeat flying planes, Ive taken mine to the field every day I’ve went this year.

As for a balsa wing, I haven’t seen that for the Kougar. However, Sig still sells the Kougar wing kit for around $60.

Best of luck with the repairs!

How much does your Kougar wing weigh?

That is indeed a heavy wing. Sig has always been notorious for putting heavy wood in their kits though. Although an all wood built up wing would work just fine, unless somone out there has plans/templates scratch building one is going to be a ton of work. Foam wings can actually be made quite light. In most cases the wood selection for the skins and the adhesive used to attach the skins is what piles on the weight. Weight of course is always a factor with our models, lighter will always fly better. If you decide to go with another foam wing, I would be happy to publish some more information and pictures on building light foam wings.

Anything is possible. I built this airplane from pictures and a small picture of the plans. It featured a foam tapered wing. I did a built up wing and the plane is slightly larger than in the plans. Yes, it is doable.

Yes, I’m interested!

As I had stated, the two main components that can add weight in a hurry to a foam wing in the sheeting itself and the adhesive. Back in the day a very popular adhesive was contact cement. Both the foam core and the sheeting were coated after the sheeting was edge glued. The resultant wing was heavy and had ridges that were almost impossible to sand out.

My method is nothing really new but does result in a light and straight wing. The first thing to consider is the sheeting. I tend to order my sheeting pretty well in advance and end up getting a variety of weights although I tend to ask for contest grade. No worries as I tend to put the slightly heavier sheets on the wing high point and at the trailing edge. This gives good overall strength by putting a more dense sheet where the stress is greatest and makes for a bit of a stiffer aileron.

Sheeting preperation begins with trimming the edges straight and then taping them together with blue painters blue painters masking tape. Cut them to size with only 1/8" oversize to the cores. Do not edge glue the sheets together. Core prep is to simply block sand them to get rid of any imperfections and have a nice smooth surface. This is important as what you are doing is increasing the surface area in which the glue will bond the wood to the foam. This drastically reduces the amount of glue used. Dust the cores clean. Do not skimp as any dust left behind will affect the bond strength.

Now its option time. I personally have been applying pressure via vacuum bagging for over 15 years now and I would not use any other method. That is not to say that I expect everyone to run out and get a bagging system although I highly reccomend one. They can be built for well under 100.00. Using a bagging system allows the use of epoxy laminating resin to bond the skins and will yield the lightest weight. However if not bagging, you can use Gorilla Glue.

Now that the cores and sheeting are prepped, apply adhesive to the sheeting. Use just enough to get a light sheen on the surface. I will tend to apply a little heavy and then remove the excess. This is a little faster and allows some glue penetration into the sheeting. Place the sheeting onto the cores and lightly tape into place with blue painters tape. Place the cores with sheeting into the shucks after placing a sheet of 1 mil plastic on the shucks. This keeps the sheeting from sticking to the shucks should any glue bleed through. Tape the shucks together and then tape pieces of 1/4" pressboard to the shucks. The pressboard should be cut to the exact outline of the shucks.

If vacuum bagging, you have used laminating epoxy and will simply place the assembly into a bag and pull 4" of vacuum. I do this on a marble table. Most shops that specialize in stone countertops will sell scraps at a reasonable price. For most applications you only need 4'x2'.

If going with mechanical pressure, you will have used Gorilla Glue and just place the assembly onto a flat table or slab of marble and stack sandbags or phone books on the assembly. It's best not to use rigid weights such as bricks. After 48 hours cure time you are ready to pull the wings out of the shucks and admire your light, straight wing panel.

Although a stab is shown the same prep applies for a wing. Note that the joiner socket, root rib and servo box has been done prior to sheeting.


Application of epoxy laminating resin.


Use just enough to produce a sheen on the skins. This applies for epoxy and Gorilla Glue.

Skins taped into place on the core and placed into shucks.


Pressboard added top and bottom of shucks.


In a bag and under vacuum. Weights can be used as well.

Pretty darned straight.


Sheeted stab complete with stab tube and incidence adjusters. 176 grams.

Thanks!
iI am considering the wing kit from sig.
$60 seems a bit high though.

I agree, I would see if the cores can be found elsewhere and then get the sheeting locally. No doubt that the wing kit will include sheeting for that price but will be of questionable weight. Many craft stores carry balsa. I get a fair amount of mine from Michaels craft store. My wife gets discount coupons all the time for 20 to 25% off entire purchases. They even send out 40% off single item coupons. Since I showed some construction pictures, how about a picture of the finished airplane?

have you built one before?
would you build the wing or make a kit?
how accurate would it be?

Making Wing Ribs

It all depends on which material you are comfortable with; foam or balsa. I’ve been comfortable with balsa. I’m now experimenting with cutting foam wings and building with foam.

As Appowner stated, a balsa wing is not hard to build. Here is a picture of what he states. My plan is just drawn lines on freezer paper. Shaped wing ribs and rib spacing. Tapered wings are best built in a jig, IMO. Even the jig is not hard to make. You just need to give it a try. The sooner you start the sooner you finish; balsa or foam.

I haven’t seen the Kougar wing plan. Thought I’d post these pictures. Wing has LE-TE sweep which may be what a Kougar has. So wing building is not too difficult. Just vary your technique a bit.

You Tube

Good news-I found a built but never flown Kougar!
got it dirt cheap.
its built very well and looks cool because the builder left off the plastic turtleneck and used a different canopy.
I put a Super Tigre 51 on it.
I can’t wait to fly it!