I had to cut a relief in the cowl to clear one of the plug wires. I've seen several guys cover the cut out with a tear drop shaped flairing called a devils cheek. Anyone have any hints on how to make one. I've never done fiberglass work from a plug before. Anything out there on the market to just glue in place? Any hints would be appreciated

Thanks.........Mark

Sometimes you can find a plastic spoon for picnics or kitchen work
and trim them to fit just like they were made for that exact spot,a little glue and your in business.

Just a thought.
BUTCHMAN

You can find small plastic canopies in varying sizes from Sig, I think. You could probably use them directly or use them as a mold for a fiberglass insert. They are only a couple of bucks.

In the past , when I have ordered large cowls , I have also ordered ,on a sheet already formed , Blisters that are perfect for what you want to do. They come in many sizes, mine happen to be about 3" long 1" wide tapered to the tip . You know a teardrop .

Any fiberglass cowl ad in the books would probably be able to get the size you need.

Stay cool,

Tony

Thanks Tony, Do you recall any fiberglass cowl companies that have these items? I'm close to needing them and still deciding whather to go with them or just let the plug cap stick out.

Just checked my cabonet and the sheet I have are 1" high , 1" wide and 3 -3/4" long . I got these from A&A Industries which make large aircraft kits of the old Bud Nosen Kits.

Mr Mulligan was mine which has a 9' wingspan. The cowel they gave you in the kit needed the blisters installed on it.

I ordered a cowl that had blisters already attached but they gave you them to install.

Check the net for their site . If they can't help , I'll send you a couple of the ones I have.

Tony

You can also use a 40 size glass wheel pant-just cut in half,epoxy to the cowl & make a fillet with putty or epoxy/filler.

Mark, if you become really desperate, you can go to a hobby shop (not necessarily RC), and look at plastic airplane model kits. Some of the warbirds have a variety of bombs and external fuel tanks that are supplied in halves and can easily be cut down to a blister.

Seems like a waste of an airplane model, but the price of these kits are cheap enough that it's not that painful.

- George

It is very easy to make your own, tailored to suit the size you need. First cut out the hole in the cowl to give adequate clearance needed. Then draw a teardrop shape where the cheek will attach to the cowl. Use this as a pattern drawn on 1/8th or 3/16th balsa. Then stack (glue) these to the thickness (height) needed, such as 3/4th of an inch. Then sand the glued stack to the shape you want. The lamination of the stack will give you a sort of contour lines to make sure it shape is proportional. Once the mold is shaped to your liking, glue it on a 1/2 or 3/4 dowel or similar stick to use as a handle about 4 to 6 inches long. Then attach the handle to a block or hold it in a vise. Get a couple of latex (disposable) gloves. Cut out a reasonable flat part of the latex and pull it over the mold and wrap it with masking tape over the mold, making sure it has no wrinkles on the surface. With slow dry epoxy, put 2 layers of medium fiberglass cloth over the mold, and one fine layer. Saturate the cloth, and then get a bag of party balloons. Blow up the balloon and press it down over the mold slowly letting the air out of the balloon as press it down over the mold, over the edges of the mold . The balloon will then force the cloth against the mold. After the epoxy cures, trim the edges to mate with the hole in the cowl, with about 1/8th of an inch overlap. Then use small strips of cloth to epoxy the cheek from the inside of the cowl. It is much easier than it sounds. It is relatively inexpensive and the results are well worth it. Much more difficult to describe in writing than to actually do!

Mark ,
mailed out today, should have them in a couple days.

Thanks Tony!!..........I really appreciate your help!

Let me know how much I owe you.

Thanks............Mark

I have had reasonable success on smaller planes cutting out the teardrop and applying the glass directly over the cutout. Here's how:

Cut the hole you need. Get a light weight of cloth and cut an oversize patch. Get some 3M 77 spray and dust the inside of the cowl, just to get a little tack.

Put the patch over the hole and push it through a bit to get the blister shape. Use your fingers to form it out into a good shape and then press the edges down onto the cowl. The 3M will help it stay in place. Work the cloth patiently and it will take the shape you want. Hold the cowl with the opening down so that gravity helps hold the shape. Carefully fix the glass to the cowl using CA just on the edges being carfull not to overdo it. Thin CA will wick down the fibers if you aren't carefull.

Lightly brush resin into the glass using the brush to help maintain the shape of the glass. I only brush it into the glass near the edge, as the epoxy will naturally flow down to the bottom of the blister. With the weight of the epoxy, gravity should be holding the teardrop in a nice parabolic shape.

Let that cure and then add another layer. Add layers as necessary to get the strength you want. Adding another layer outside will make a continuous surface to paint, once it is feathered into the cowl at the edges.