1973 196 rebuild question

[Duffy1470]

more pics.  transom skin looks like swiss cheese

[Duffy1470]

itchy

[Ulysses485]

Nice work. Personally, removing the casting deck and liner as one piece would save you a lot of work and give you an opportunity to get all the structural work done to stringers as necessary. However, it depends what deck height you plan to go with.

[RickK]

The boat was created in 3 parts - the hull, the stringer/bottom liner piece and the liner/cap. The stringers were created out of the boat and then bonded into the hull. The liner was created out of the boat and then bonded to the stringers and sometimes, hull sides. On my 170, the cap was part of the liner. The liner sides were not bonded to the hull sides. The cap being screwed to the top of the hull sides was the attachment point for the liner sides and cap.

Now might be the time to create a detailed drawing of the hull and the stringer placement, string height and width, top and bottom. Lay a 2x4 or 1x2 across the top of the hull sides and get all your measurements from the bottom of the piece you lay across the hull to the top of everything, like the floor, top of stringers, bottom of stringers, both sides, fuel tank area. Get those measurements starting, for example, at the starboard rear and work toward the port side. Work from the rear toward the front and get measurements every foot or so. This drawing will become very valuable to you as you need to reference back to how things were or the width of the stringers at the top at this particular spot, like where you want to attach a t-top or a leaning post, etc.

You also might consider fastening a 2x or 1x2 across the top of the hull to keep its shape.  I screwed small pieces of 1x2 to the outside of the hull at the top and then screwed the 1x2 I used to keep the hull shape to the top edge of the 1x2 I attached to the hullside.

[Duffy1470]

The measurement advice is good and I will do that. I have some more pics of stringer defoaming. There is a lot of foam in the stringers.  Will post those soon.

I would really like to NOT foam the tank in. Is that stupid or unsafe? How much foam does the uscg require? Getting ahead of myself with these questions.

At any rate, when defoaming is complete will pick up Coosa, start grinding and then glass in Coosa. Im sure i will have lots of questions. Have a great day everyone.

[dbiscayne]

If replacing the fuel tank with a poly tank, then no foam is used per manufacturer requirements to allow for expansion. Only straps to keep it in place.
If your tank is aluminum, not sure what USCG requirements say, I always assumed foam was optional in this case as long as the tank is strapped down good.

[Duffy1470]

Roger that dbiscayne. Thanks. No foam for you tank.

[Duffy1470]

i am not good at posting pics

[Duffy1470]

[Duffy1470]

There are two significant voids in what appears to be the factory outer skin. What do all of you think I should do:
    1. Put a matching size piece of Matt in the hole
    2. Smear the peanut butter mixture in it
    3. Proceed with Coosa as if the voids do not exist (what I want to do)
    4. Something else

Which number

[Duffy1470]

Thanks in advance

[RickK]

Usually when you redo the transom coring, you plan to lay in a couple of layers of 1708 to beef up the transom skin. Laying in the 1708 usually includes grinding the inside transom skin and about a foot of the inside hullsides and inside bottom. You can fill in the voids with layers of 3/4oz CSM (chopped fibers) and then cover with the layers of 1708. Lamming the 1708 to include the hullsides and the bottom creates a complete tie-in and makes the transom really strong. Then you start adding the coring, using fillets of thickened resin at all the corners, to include where the transom meets the hull bottom. You seem to have cut the stringers back enough to allow for this.
If you need more info let me know.  There are a lot of examples of doing this.

[Ulysses485]

Agree with Rickk 100%. But keep grinding even if it requires you to remove adjacent structural glass. You’ll be much better off building it back up with new structural glass and building a solid outer skin to build on. Check out my flatback 222. It’s nothing but Matt glass that’s left on the outer skin and I am going to be building up soon.

[Duffy1470]

Thank you gentlemen. On the hull sides on the heavy biaxial I assume it needs to be ground flat in relation to the significant relief/texture of the material itself.... grind the ridges flat? For that matter, how long does a grind last assuming it gets nothing like grease or dirt on it?  Ya'll, for the record,  are ridiculously helpful and gracious with your time and knowledge.  Thank you.

[dbiscayne]

For the hull sides, if you're next to the transom where the new glass will overlap from transom to sides as Rick described just be sure it's ground clean and free of things sticking up that would cause an air void in the new glass. But you don't need to grind the weave of the heavy woven glass out.
grind the ridges flat - do you mean at the ends of the new glass? If so, and you plan on overlapping with glass later on, then yes you'll want to knock that ridge down to once again keep from getting an air void under the new glass.
Best to layup the new glass wet on wet if you can stand the work hours, that would avoid having to grind between layers.