SUPER CHEETAH Restoration
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May 31, 2009
, 01:02 AM
Ask me about VTPR
Joined Aug 2002
Now its starting to look like a flying machine...Used 1/16" balsa sheeting by joining two 4" x 36" sheets using white glue. Cut each skin close to wing planform with leaving about a 1/2" all the way around for extra measure. 3M Super 77 aerosol contact cement was used to apply the skins. I have done over a dozen models with this stuff without a hitch. The key is do it in warm weather, keep it light and let set for 3mins before mating the surfaces. Coat BOTH surfaces or you will have delamination problems.
Once set up for awhile (6 hours) with weight applied in the saddles, the excess balsa skin is trimmed and sanded flush all the way around. Prepared the raw leading edge surface very carefully so it becomes flat and not rounded using a hand planer instead of a sanding block to make flat as possible. Mixed up some 30min epoxy and coated both the leading edge and the wing panel surfaces. Taped up and let set for 2 hours.
I use half round x 1/2" pine moulding for tough leading edges. makes for a nice wing cutter in combat, hahaha! De-taped the LE's and began to make some serious chips. Takes about an hour each panel to get a good Phillips Entry contour. The planer is a lifesaver followed up with a 12" long block sander and 220 grit.
Next is glassing the center section. I use a 2-1/2" wide piece of 1.5oz with a 3' wide piece of .5oz S glass on top. Z-Poxy was used as the adhesive because i like the way its flexible and not prone to cracking. Little tough to sand down but if you let it cure overnite it responds well. After BOTH sides are glassed up, the edges of the glass seam to balsa is filled and sanded with light spackle. Yes, monokote will adhere to the spackle as long as you have a 400 finish and the right iron heat.
Finally, the wing tips are capped with 1/4" hard balsa and sanded flush all the way around. Lots of sanding and chipmaking in this business huh? The ailerons are 1-3/4" wide for great roll rate even at low speeds. They will also serve as flaperons to slow this bad boy down into the LZ. Trailing edges are sanded to 1/32" to keep things clean and minimal drag. Ends of surfaces are beveled to eliminate neusence denting on landings.
A general inspection for straight and true lines and detailed with 400 grit all over make the wing ready for monokote!
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Ready for hard pine leading edge. Lookout foamies!
Its cooking up
Half round hard pine molding.
Using a hand planer makes the leading edge in short order.
Roughed out Phillips Entry.
A layer of 1.5 oz glass and a layer of .5 oz S glass is the recipe top and bottom.