Restoring/Repurposing a 1979 Cobalt 18' Tri Hull

Hi guys,

I've been perusing this forum for a few weeks now, reading through other's projects, all the advice, etc. I've found it interesting, but I haven't found someone on here who is trying to do exactly what I am, so I thought I'd start a thread.

I bought a very junked out 1979 Cobalt 18TH and so far have gutted it and removed the top cap, never to be replaced. The boat had a sterndrive in it, but I am very much leaning toward converting it to an outboard. The ultimate goal is to repurpose the boat as a center console fishing boat. There is still some glassed in wood in places, even though the stringers were originally foam filled box beams. I am slowly getting toward removing all that glassed in wood, including the transom.

First question, is there a hand tool anyone has used to cut the glass holding the wood in, time is on my side and this is a long-term project. I used a grinder to cut up a lot of the upper deck, but hated how much glass dust it created. Eventually, I just started using a hand saw and that helped, but it is not going to work for the wood that is glassed into the hull.

Goals:

Get all the wood out.
Use only composite materials.
Create an airtight/watertight deck sorta like a Whaler but built inside out. I'm thinking of actually using something like a 4 lb foam from US Composites with forms to create the interior of the boat, including the entire bilge area and then use scuppers so no water ever enters the area below the sole again. This would also be glassed over. I would then have to switch to topside tanks, maybe hidden in a seat compartment.
For the transom, I was thinking Seacast, but it is not compatible with foam or epoxy from what I'm reading, both of which will be used extensively. I could also us Airex or Coosa as that sounds like the direction I'll have to go.
When this thing is done, I basically want it to look like a smaller version of a Carolina Skiff Ultra Elite.

Next question. When they orginally built this thing, it looks like they built the box beams for the stringers, then drilled holes in them and filled them with foam, never patching the holes they drilled. I'm very worried the stringers have water in them and have considered cutting them out. If I then build the forms and fill everything with foam and glass over, would that be sufficient if properly laid up to replace any sort of stringer system?

Final question before I stop babbling. I'd really like to use an Armstrong type bracket to maximize the interior space of the boat. Everything I read is about porpoising concerns on an 18' boat. I'm hoping someone has experience with tri-hulls and can tell me if this concern is mitigated at all by the flatter outer portions of the hull?

I realize it's probably very hard to get a visual of what I'm trying to accomplish from my text, so please let me know if you have questions or if I can clarify any of this...

Thanks,
Brad

 

By the way, I have this thing on a cradle we built. I'm concerned whether I'll be able to walk around and work in the boat if I remove the stringers. I made a youtube video for someone showing what it looks like. You can find it here.