Bug HLG

Here's my method for applying fiberglass to balsa tail surfaces or fuselages: Place wax paper on a flat surface (I use a Walmart clipboard with the clip removed - about $1). Cut a piece of medium weight fiberglass about 1/2" larger than the surface you want to cover. Place the glass on the waxpaper and mix some 30 minute epoxy on another piece of wax paper. Apply the epoxy over the fiberglass using a single edge razor blade for a squeegee. You want to wet the glass but you also want to remove as much epoxy as you can. Lift up an edge of the fiberglass (I've used both tweezers or the S.E. razor blade)and peel up and towards the opposite edge of the glass. You'll notice that some of the epoxy remains on the wax paper. Place the side of the fiberglass that was against the wax paper onto the tail surface. Use the razor blade (or your finger wrapped in a piece of wax paper) to press the glass onto the surface of the tail surface. Place the tail surface wrapped with wax paper (glass on top) on clipboard. Place about four layers of paper towels on top. Place a large telephone book. Add either more books or weights. Leave several hours minimum if not overnight. Trim. Glass should conform to rounded edges (that's why I use the paper towels and flexible telephone books.). Repeat for other side. The trick to this method is that when you pull the epoxy wetted fiberglass from the wax paper, about a third of the epoxy stays on the wax paper and at the same time the remaining epoxy is pulled to the lower fiberglass surface through the weave. The surface produced is not glass smooth. You can feel the weave of the glass. The epoxy is being used to glue the fiberglass to the balsa and this results in the minimum amount of epoxy being used and therefore less weight. The only problem with this method is that it might take some practice to remove the wetted fiberglass from the wax paper without tearing it. I've even done it with .75 ounce fiberglass but it's tricky. To minimize the weight, I only glass the fin and stab, since the rudder and elevator are supported by them. Make the bottom surface of the fin stick down slightly lower than the bottom surface of the rudder - minimize rudder contact with ground. I CA a 1/32" wide strip of .007" thick carbon fiber to the bottom surface of the fin that will come in contact with the ground-about an inch long. John > I haven't made the (+) tail on any of my bugs, but here's a technique that > I've used to toughen up 1/16 sheet flying surfaces. > > cut 2 pieces of 2-ounce fiberglass cloth, a little bigger than the surface > to be strengthened. Spray lightly one side of each piece of cloth with > 3-M Super 77 spray adhesive. Apply the cloth to the surface making sure

> I have been wanting to build a Bug for a while and have a quick question. I have the designs for the cruciform tail group ready to go and was wondering what might be used to "toughen" up the balsa. It says to use 1/16", but it seems like it needs something to stiffen and harder up the wood for a slightly more robust tail group. I was thinking of thinning out some white glue and painting it on then giving it a light sanding, is this necessary? I haven't made the (+) tail on any of my bugs, but here's a technique that I've used to toughen up 1/16 sheet flying surfaces. cut 2 pieces of 2-ounce fiberglass cloth, a little bigger than the surface to be strengthened. Spray lightly one side of each piece of cloth with 3-M Super 77 spray adhesive. Apply the cloth to the surface making sure that it's nice and smooth and the part is not in tension (warped) at all. Mix some 30-minute finishing epoxy (I use Z-poxy, but Wes systems, etc. is fine.) Squeegee some epoxy onto the cloth, then squeegee as much as you can out of the cloth. Place a sheet of wax paper onto a flat surface, then the piece of glassed balsa, then another piece of wax paper, then a piece of 1/4" plywood. The good aircraft kind with no grain to the surface. Then weight down with a good weight, like several cinder blocks - you want 20 lbs. or so. Let cure a couple hours. When you're done you'll need to trim the excess cloth from the part and sand the edges round/square/tapered as necessary. Always do both sides of any part at once or you'll end up with a potato chip. Also be sure to let the part fully cure - I go 4 times the cure time rated on the epoxy, overnight if possible. If you want a lighter surface with less added strength, you can use .75 oz. cloth, but at that point you're not much stronger than a good application of monokote. Al =============================================================================== Allan Wright Jr. | Without love life's just a long fight - Southside University of New Hampshire +-------------------------------------------------- Research Computing Center | WWI Modeling mailing list: wwi@... Internet: aew@... | WWI Modeling WWW Page: http://www.wwi-models.org ===============================================================================

I have been wanting to build a Bug for a while and have a quick question. I have the designs for the cruciform tail group ready to go and was wondering what might be used to "toughen" up the balsa. It says to use 1/16", but it seems like it needs something to stiffen and harder up the wood for a slightly more robust tail group. I was thinking of thinning out some white glue and painting it on then giving it a light sanding, is this necessary? Thanks, Mike