Fitting the Cowl

The cowl is a beautiful 2 piece pre-molded fibeglass cowl. It is the best molded piece of fiberglass I have ever seen. Fitting it on, per the instruction is not as bad as you may have heard about. As with any fiberglass part, do not remove any more material than you want to replace later. Sand and fit, sand and fit... a dozen times or so and your in. These little tabs keep the cowl off the spinner plate the correct distance. 

Here is the oil door. Trace from plans, cut, fit the hinge, and presto you have a door.

Here is a shot of the center section at the spinner. I was told by a couple builders that the hinge that is called for here at the junction of the cowl half's gave way w/i 20 hours of flight. So I took their advice and put in .060 t-4 plate with nut plates. This will do the trick.


When it comes time to finishing the cowl, you will find some serious misery.  I have no doubt now, after working on getting the cowling and spinner ready to paint, that I made the right choice in building an aluminum plane.

There are a bazillion pin holes that are a bare to fill. I tried several different methods. None of which work well. I tried epoxy/glass fill, layers of sandable primer, bondo.... All only worked partially well. It would seem the best method works as follows:

1. Use  well thinned epoxy/glass fill , thinned to a consistency of room temperature syrup. A squeegy method really does not get it down in the holes. You have to rub it in by fingers and a glove. Several coats and sanding will be required.

2. Several coats of sandable primer, sanding down each coat to the fiberglass.

3. A final coat of primer.

UPDATE 10/29/01

The bottom right corner of the cowl did not fit well. I am told this is normal and to just build it up w/ fiberglass and microfill which I did. Several layers of 2 inch glass.


last updated 11/05/2002