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Use part of the first cup mixed without any flox added to quickly paint the carbon fiber spar cap in the top skin with a very light coat of the mixture. Don’t be neat about it and don’t worry about the edges. Just get it on most of the cap. Don’t paint beyond the carbon at the ends. And HURRY! Also coat the areas where the BL00 and the BL65 bonding strips will adhere. Do NOT coat where the other ribs are going to adhere.

In each of the 200 gram cups of mixture you will add 1& ½ small mixing cups of flox after the hardener is mixed in. This will thicken up the mixture. It will still flow, but it will be more like ketchup than chocolate syrup. Add one cup and stir it in and then add the ½ cup and stir it in. These are the small paper bathroom water cups we’re talking about. About 3 ounces each. The ones we all use for mixing small amounts of epoxy.

While one person is mixing the cups of material, preferably 2 others will be applying the material to the top of the spar. After you have one end of the spar coated, one person can put down his brush and get the serrated squeegee and work down the spar scrapping the material off into a cup. This will leave behind the nice neat rows of adhesive. It really won’t look like a lot of material, but if you use the BIG TEETH, yes, that will be enough. It has worked out perfectly for us every time. Use the material you scrape off to continue on the other end of the spar, but your partner should have already been applying other material to that end while you were scrapping. The mixing person can start questioning whether to mix any more material after the 4th or 5th cup.

When the spar is almost coated, the mixing person can add extra flox to left over material or to a fresh cup of material to make it like soft butter. To a fresh cup, this takes about 2 and 1/2 small cups of flox to 200 grams of resin.

This mixture is then used to pile up about ¼ of material on top of all the ribs and the bonding strips on the 00 and the BL65 ribs. On the bonding strips, I like to peak the material down the center so it is higher than ¼ so it will have a better chance of sealing completely and taper it to the edges of the strips. The only reason for the bonding strips is to aid the sealing of the tanks. They are not needed for strength.

I like to take one final step in applying the adhesive. I make a Cake Decorators Funnel out of a gallon size Zip Lock Baggy. I place one cup of the regular adhesive and flox mixture into the bag and go from one end of the spar to the other laying a ¼ bead of material right down the center all the way. After placing the mixture in the baggy, close the top securely after getting all the air out. You can then snip just a tiny amount off of one bottom corner of the baggy. Now you can squeeze the bag and the material will flow out in a bead and at a speed that you can control by the amount of pressure you apply. Be careful that the baggy doesn’t pop open at the top while you are squeezing. I gather the bag by the top and squeeze down. That’s why they call me Chef Tom!

Finally, the last big change in getting a well bonded wing is to place everything you can find on top of the upper wing skin after it is in place and you have the shear web cleco’d. Start in the center of the wing and work out toward the ends with the weights. There should not be one inch of the surface of the upper skin directly over the spar that doesn’t have something really heavy on it. We use 5 gallon jugs of water, old car batteries, sacks of cement, bags of lead shot and anything else we can to insure that the skin is going to mash that adhesive into submission, or at least into squeezing out. You should have all this weight stuff located and handy before starting this whole process. Don’t wait until after the thing is closed up and then start trying to find stuff to weight it down

GLASS GOOSE GAZETTE * ISSUE #17, June 15, 2000
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