My '83 9.2C is on the hard waiting on me to paint the bottom. I noticed some delamination on one side of the rudder. Seems like it may have been caused by a misaligned prop (rudder wants to pull to one side while motoring).
Causation aside, I want to fix it and am looking for any info on rudder construction before I start drilling holes in it. Any help is appreciated. Thanks in advance!
I had a similar issue with the rudder of my 8.5. Water intrusion into the rudder is the most likley culprit. Check the seam between the rudder stock and the fiberglass on the top of the rudder. That's where mine had a small hole.
The rudder is a fiberglass skin over hard foam that encases the rudder frame. I did not disturb the foam to get to the frame, soI can't say what shape that might be in.
To repair:
1. First make three or four templates to get the shape of the foil. I simply scribed the cross section shape onto pieces of luan plywood. Then cut the shape. The hardest part is getting the the shape of the leading and trailing edge of the rudder transferred to the template. Be sure to know the location where you made each template. such as 1 or 2 inches from the top, 1 or 2 inches from the bottom; and about one third down and two thirds down from the top.
2. Knock acros the surface of the rudder at one or two inch intervals. Listen whether hollow or solid sounding. Hollow sound means the skin is delaminated; solid - it's still adhered. You can trace out the delaminated parts so you know how much delamination is there.
3. If just one or two small spots, you might not want to tackle the entire rudder. Dry it out and inject epoxy into the hollow areas to fill the void and relaminate.
If extensive, read on.
4. I did one side at a time. Sand the fiberglass skin off. Water or moisture might be present between the skin and foam. Delaminated skin will be easy to lift off. Skin still laminated will require some sanding.
Let it dry thoroughly. (I did it as a winter project) A little heat under the rudder might help to drive off moisture. A couple 100 watt light bulbs in clamp on reflectors on the floor under the rudder lying on sawhorses
5. Apply several layers fiberglass mat on that entire side of the rudder. Coarser mat against the foam. Finer mat on the surface. With luck, you will get close to the original shape. Use the templates to duplicate the foil shape and sand to blend the areas between the templates. Fil low spots; snad high spots until you have a smooth fair surface fromone template line to the next. Barrier coat; final sand; then bottom paint.
Good luck.
