1972 191 Rebuild

[dbiscayne]

I will need to lay 2-3 layers of which I'm thinking 1708 to fill the transom skin void, then add three more layers across the entire transom with 1708 tabbed from 12', 8', 4' (in that order).
are you talking about adding a total of 5 - 6 layers against the inside transom, then the core, then more glass to the exposed inside core? Seems like too much. I believe I went with the following starting at the existing inside skin; 1 layer 1708, 1 layer 1.5 oz mat, let it tack up, then thickened peanut butter troweled on, new core, 2 layers 1708, then varying widths of strips along the edges overlapped onto the hull.
I used (2) 3/4" plywood for the core with mat+12oz cloth+mat+thickened troweled resin between the plywood, so layup might need to be different if your using a different core. I glued the (2) layers together & let dry before installing.
Be sure to have someone there to help out with this step, lots of glassing going on, clamping the core, etc. before the resin kicks.

[tylertarpon10]

I plan on putting 5 layers, 2 to fill the transom to enclose it then three layers in varying sizes to tab to hull sides. Then attach the core which I will more than likely go with (1) 1/2" or (2) 3/4" Coosa boards for the core. Lastly, 2-3 layers to tab the core and make inner transom skin.

I saw that @Marcel had went that route on his 191 and seemed solid.

[dbiscayne]

gotcha, I agree closing in the transom would want some more strength. The thicker you make the core the strength gets much much stronger, like 4x stronger when you double the thickness or something like that. Did you mean (1) 1" or...

[tylertarpon10]

Here's a little update, finishing up school, sold my truck got a new one, and found a great deal on a leaning post live well.



Have reinforced the bottom of the stringer compartments and bulkhead areas. Put fillets at the base of each and added a layer of CSM and a layer of 1708 tape. I think I will be adding another layer of 1708 since this is structural.



Getting ready to start on the transom, sanded the fiberglass skin and marked where any holes are to be filled. Have decided to go the plywood route and seal it well. Any recommendations on wood? I have been thinking of doing marine plywood 4x8 sheets and sealing them thoroughly with resin. 



will be getting more done once I graduate school in about a week.

[tylertarpon10]

Filled in all the holes in the transom and then took her out to the boat ramp to see if she has any other holes and leaks. I did not seem to find any, so that is a good sign.

Made a template out of wood strips and hot glue.

I am not sure if I want to add a crown to the transom or make it flat across. pros and cons to each? what do you guys prefer? let me know since I would like to get the transom finished this week.

[dbiscayne]

I've always thought a slightly rounded crown looks better. But if you're going to have any hatches built into that area it'll obviously be a lot harder to do.

[Mwar410]

A pro to crowning the transom is, it looks like you’re going to use the original cap and it already is dictating a slight crown.

[RickK]

@tylertarpon10 - how will you be mounting the engine? Changing the config of the standard transom bring problems with it - like you can't tilt your engine up. Do you have a porta-bracket in your future?

[tylertarpon10]

I plan on doing a porta bracket, My other question is do I need to raise the stringers to increase the deck height?

I would like to keep the original height and save a lot of time and money, however I am not sure if it is necessary?

[RickK]

The only reason to raise the stringers is to make it self-baling.

[tylertarpon10]

I have not decided if I wanted to raise them or not yet. I will decide when I get closer to that step.

I have bonded the transom core.


Started by cutting my two 3/4 inch plywood and coating them with thinned resin. I used styrene and polyester resin. Let that soak for about 15 min.



I waited until that got tacky and wetted out a layer of CSM.



Then screwed them together and put weights on them.

[dbiscayne]

give that wood a coat of thinned resin before final glassing, especially the edges, to help it last longer.

[dbiscayne]

DOH!  Just saw where you mentioned the thinned resin already never mind.

[tylertarpon10]

A total of 6 layers of 1708 mocked up and clamped to the melamine board





I put 3 layers in the void to match the thickness of the existing skin however, it still needs another layer or two before clamp the transom core in.



The waxed melamine came off easy, nice, and smooth. My only concern is that screwing the melamine into the existing skin created a slight inward curvature that I did not notice. Can this be corrected or flattened when I clamp the core in?

[Ulysses485]

Starting to come together. Sorry to hear about the inward bow. How bad is it? Have you run a straight edge across the back to see that its consistent across the back or primarily at the edges?