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BUILDERS HINTS
(From CP21, Page 6, July, 1979)

      Bob Lokey, of Universal City, Texas, recommends the following method of repairing a bad gouge in blue foam. Use a 1 7/8" dia. hole saw with the guide drill bit removed, and turn it by hand centered over the damage until about 1/2" deep. Remove the center ‘plug ‘ with a chisel. Now use a 2" dia. hole saw with guide drill bit removed, and cut a plug from some scrap foam. Paint a little slurry on the bottom of the 2" plug , and "screw’ it into the hole made by the 1 7/8" dia. hole saw, until it firmly bottoms out. Use a hard sanding block to sand it down flush. Bob says it works beautifully. Don’t neglect to use slurry to glue the plug in, though, a plug, just forced in dry is not structurally acceptable. If you need to hot wire through the plugged area, leave out the slurry until after hot wiring is complete, then slurry and nail the piece in place until cured.

     Several builders have purchased the CD1145 worm gear from Boston, and have received a webbed cast gear with lightning holes in the web. This gear can be used if you follow this procedure:
     Remove all grease, and sand blast or sand with 60 grit, the webbed area. Lay the gear down on some Saran wrap on a flat surface. Now mix up some flox and trowel it into the lightening holes making sure to get good squeeze out, and thoroughly fill all voids. Trowel off excess, level with the gear and allow it to harden.
     Now drill and countersink 4 #12 holes for AN509 bolts and bolt to NG steel weldment. This system works great, we have it on N4EZ with no problems. Viggen builders can use the same method in the worm-woregear main gear system as it uses the same Boston gear.
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FEATHERFILL:  Some builders have not read their newsletters and are still experiencing problems with Featherfill.  This newsletter bulletin supercedes all previous instruction including Section V on Finishing.  Before attempting to apply Featherfill - surface must be dry, dull and clean!  A "fog" or "tack" coat (very light coat) of Featherfill should be sprayed or brushed on and allowed to "tack" up for 10 - 20 minutes.  Now mix up a batch of Featherfill (must be thoroughly mixed using a paddle or wire in a drill press) and mix 25% -50% micro balloons by volume into the Featherfill.  Use a 2" brush, and brush it all over the part you are working on. Allow this to cure thoroughly, then dry sand using new 100 grit and a spline.   As soon as you see glass high spots quit!
     Again brush on Featherfill - micro balloons in any remaining low places, allow to cure and then sand with 100 grit and spline. Generally these two applications as described above will be sufficient for all but the worst surface, three applications at the most. You should use 1-1/2 gallons at the most on a VariEze.

     Note that the Styrofoam referred to in the plans as blue foam is not as blue as it once was, in fact some builders have reported receiving almost white foam. This is ok, just be sure it is Styrofoam, which it will be if you purchase it from one of our designated suppliers Wicks or Aircraft Spruce.

     The speckled paint finish as seen inside Fred Keller’s cockpit at Oshkosh last year, is "Zoletone" which is available from most paint supplies, one of which is Paramount Paints, Westminster, Ca

     Joe Deady reports that he has been using a pair of ski goggles when sanding or grinding with excellent results. The soft foam seal is designed to keep out fine particles like snow and conforms to your face, even with a dust mask on, and it stays completely fog free.

     Installing Jiran Fuel Tanks. The fuel tank bottoms are pretty straightforward, but don’t forget to remove the peel ply!!  Then paint a generous coat of pure epoxy all over the inner surface of the tank.  Do this with the tanks at the same temperature as the shop. (Don’t bring them into a cool construction environment, after they have been stored in a hot shed, or visa-versa).  When you get ready to put the Jiran fuel tank tops in place, do not build a small "ledge" along the fuselage as shown for the home built tanks.  Cut a 3" wide strip of BID at 450 and lay it up on the edge of the tank top, lapping onto the tank 1-1/2". Be careful not to wet the 1-1/2" overhanging half of the BID tape.  Allow this to cure for three hours, then install the tank top with flox and tapes, and wet out the BID tape onto the fuselage as shown.   After this cures, trowel dry micro into any gap between the tank and fuselage and apply two BID tapes over this joint lapping equally onto the tank and fuselage.
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When making your main landing gear attachment tabs, in Section I chapter 18, you are told to layup your pads on a ‘piece of paper’.  Do NOT use waxed paper in this application, as it is possible for the epoxy to pick up wax, and then to have in effect a wax barrier between the tabs and the gear leg.