Fiberglass Help

[jmiller]

I can read many forums and discussions but still not sure where to start. I took the i/o off my boat and want to plug the hole and put an outboard on it. Where do I start? Is there someone who I can talk to about this or will someone call me please Jason 425-299-1914

[Helmar]

Plugging a Outdrive hole to use a Outboard.

I am sure you can get all kinds of different ways to do this project.
Me, I would make a pattern that will fit Inside the hole to start with.

You can buy small qualities of products I would use.

West marine has West System Epoxy that I would use to laminate up enough pieces of plywood to fill the opening.

You can also get Fiberglass Repair Kits to cover the plywood.

I would first Clean the wood area around the hole. This might require opening it up even a little larger to get to Good Clean wood.
Whatever it takes to get to Clean Dry Wood.
Take a piece of plywood that will Overlap or is larger than the hole that will fit on the Inside of the transom hole.
Use some kind if Wood Sealer. I use MarXite to seal the wood and double seal the edges.
Screw it to the inside of the transom with stainless wood screws.
You can Also mix up some epoxy resin that you apply to the Transom as well as a small coating of it to the plywood hole cover that your going to attach.

Now I would start laminating up pieces of plywood that will fill the hole from the outside of the transom.
Use some sort of straight edge across the hole as you want to build up the hole so you have between 1/6th to 1/8" depression left.
That depression you will fill with fiberglass cloth and some sort of filler. I use Evercoat Lite, which can be purchased in quart cans.

Seal each piece of transom hole plugs or whatever you want to call them with MarXite, double dose the edges.
I would Epoxy each one into the hole, using Screws to hold it tight in place.

After epoxying each one in place, I then would mix up a batch of epoxy and use a filler to make a peanut butter thickness slurry to put in around the voids or edges of the plugs your going to use.
You can also get a quart of Silica Powder as a filler at places like West Marine.

Once you have all your plugs sealed, epoxied into place, your 1/6" to 1/8th void or depression left to fill, I would then use the West System epoxy again to attach the fiberglass cloth.
Use a 1 inch or whatever chip brush and slather the epoxy in the hole or depression. Have the fiberglass cloth cut to size and place it into the depression. Using your gloved hands and or brush, make sure the cloth gets soaked up with the epoxy.
What you want here is the Fiberglass cloth to Fill that void and to be as flush as you can make it.

Then fill any other small voids with Evercoat lite.
Sand and paint with two part epoxy type paint.


I am sure you will hear other ways to do this but, you asked, and this is the way I would have done that job.
If I was to put a jack plate for an outboard to hang, I would want to make darn sure I the strength to hold it.

My 2 cents

[slo-mo]

Take it to Helmar!

[jmiller]

Thats what I was thinking too. Helmar thanks for the help, like you say there are many ways to do it but you gave me the info and thats the way I will do it. Thanks so much for the help now I am on my way to play.

[Marty Loken (Norseboater)]

Converting I/O's to Outboards

Jason -

By coincidence, we're in the middle of doing the same thing to a 20-foot 1958 Skagit express--originally an outboard, and going back to an outboard after years as an inboard-outboard. (The boat belongs to Charlie and Pat Johns of Richland.)

In the case of our project, the entire transom was rotten, so we began by cutting and chiseling away all of the old plywood. After making a simple pattern from the inside, we started the layup with 6mm (1/4-inch) marine-mahogany plywood, since with the curved Skagit transom we couldn't easily bend thicker ply to the shape...especially at its outer edges, where the transom has a fair radius. After doing all of the cleanup steps mentioned by Helmar, we epoxied the first layer in place with silica-thickened West System epoxy. Where we couldn't get at the first layer of plywood with clamps, we held it in place by temporarily screwing in from the outside of the transom (after drilling small pilot holes in the Skagit's outer transom skin). After the epoxy cured, we removed the holding screws and filled the pilot holes with Evercoat Lite, a two-part epoxy filler that's far more sandable than Bondo.

With the first inner layer of new transom in place, you can fill the i/o hole with a filler piece of marine ply that's approximately the same thickness as the boat's fiberglass skin. In the case of the Skagit, 4mm Okoume ply worked perfectly, coming right out to the surface of the glass transom.

That's where we are right now--the hole is plugged and we've got Layer #1 on the inside of the transom. In the case of the Skagit, we'll add two more layers of 1/4-inch ply to the first one, screwing them in place from the inside while the epoxy cures. Then, with strength having been recreated in the transom, we'll switch to half-inch ply, adding three layers of half-inch, bringing the total transom thickness out to almost 2-1/2 inches--enough for Charlie and Pat to hang their 115 Merc.

The photos below show some of the process, step-by-step. The first shot shows the transom after we'd removed all of the old, rotten ply. The second photo shows the first layer of 1/4-inch ply clamped in place, with the epoxy curing. Next is a photo showing tracing paper being used to get the exact shape of the i/o cutout to be filled, along with a large hole that housed the i/o steering arm. The last photos show the transom with the filler piece epoxied in place. Next, we'll overlay most of the outside of the transom with a thin layer of fiberglass cloth (to be faired-in on its edges), just to make sure the new transom looks factory-smooth.

Good luck with your project...

- Marty

[Sammamish1]

Don't take it to Helmar! He is very very busy right now!

[jmiller]

Thanks for the visuals Marty, they help me out a ton. Do you mind if I call sometime if I have a question? Oh and what does faired in on the edges mean?

[Marty Loken (Norseboater)]

Transom Work

Jason -

Sure, call anytime during weekdays at (360) 301-6737.

- Marty