David,

I've used a mix of foam safe medium CA for the 1/16" balsa lining (wells) and 5 (stabs) or 30 (wings) min epoxy for attaching LE, TE and tips (well eventually). For laminating the CF strands and for attaching the sheeting I'm using straight Pacer Z-poxy laminating resin - very nice stuff. First time I use Pacer. I guess the price is not just for the brand ($15 for 12 oz up in this neck of the woods). To build the sheeting from 1/16" stock I used GP aliphatic resin.

The CF tape is actually not tape but what I believe is referred to as CF mat - a series of hair thick strands. First time I use this stuff too (The pack is actually about 20 years old [8D]). When applying you have to be careful not to let the ends loose from masking tape and the backing or else it can wind up in a serious mess fast. So you have to apply tape and then cut at the mid point of the tape so both ends always have tape on them. I believe today there are perhaps better alternatives like straight flat CF sections that can be glued on easily and then wet with resin to solidify. However, the tape takes the worry out of warping until you lay up your core sandwich.

I applied laminating resin to the core with a brush locally, then I took my CF strands taped at each end and removed the root end tape while holding the CF very close to the end. Then press down into the resin at the root. Once the CF is wet, it doesn't bunch up. Then with a finger I laid down the remainder toward the tip removing the tape at the very end once it was all wet. I then smoothed it out as much as possible with a finger dipped into alcohol pulling excess epoxy off the tape into a paper towel.

Although it does add perhaps 1 mm of thickness to the core, I hope the deformation of the airfoil won't be something that will be registered by the sheeting. In retrospect, I could have used far less CF - I think a simple 1/4" wide strand in 3 or 4 places along the span would do the trick. I might have added 1/8 oz too much with the amount of CF I used - it's very light stuff. I suspect the cores will be hard as a rock by tomorrow morning...

In applying the laminating resin to sheet the stabs and wings, I paint the epoxy onto the sheeting only using a brush (no need to apply to the cores too like with contact cement. The cores tend to make epoxy disappear fast!) A roller can be used too for larger sheet surfaces but they can also soak up a great deal of glue. Once the entire sheet has been brushed I take a Bondo scraper (I think there's some Teflon in there) and pass it over the sheets. This spreads out the glue nicely and pools up considerable amounts of glue. I actually end up removing about half of the applied epoxy leaving the sheets with a wet sheen to them. One sheet at a time as you proceed building your sandwich.

For reference, I mixed two batches of 1/2 oz of resin for each wing panel (two sheets). The first sheet takes up about 3/4 of the resin brushed on but returns about 1/4 ounce scraped back into the container. In short, the resin used to laminate a 40" wing is about 1 oz (a tad less actually).

I weighed my CF prepped cores just before sheeting to 42g each (<1.5 oz). The steel retract pushrods and clevises are put in place prior to laying down the top sheets. We'll see how much the no contest skins adds to the cores but I'm feeling confident that I can probably come in with a finished wing at about 8 oz leaving me with another 8 oz or so for the fuse and empennage. My goal is a 16-18 oz airframe unfinished with no gear.

That was a tad long.

David.