'73 Larson tri hull rebuild/restoration thread

[ondarvr]

Like WOG said, you never know what you'll find in a 43 year old boat.

There was little to no actual engineering done on boats from that era, they just built them, if it broke they made the next one a bit stronger. Plus tri hulls don't need the same support as a flat bottom or V hull, so few or no stringers is common.

You can rebuild it as it was, or modify it, but it survived 43 years as built, so rebuilding the way it was will probably far outlast the time you will own it.

 

[gm280]

I am certainly not surprise to see that everything is rotted and gone. After all it is an old boat. But you have come to the best place on the net for good help, suggestions and ideas. There are really good knowledgeable folks on these forums to assist you along with this rebuild. Just keep posting pictures and the questions. JMHO

 

[97fordrunner]

I am certainly not surprise to see that everything is rotted and gone. After all it is an old boat. But you have come to the best place on the net for good help, suggestions and ideas. There are really good knowledgeable folks on these forums to assist you along with this rebuild. Just keep posting pictures and the questions. JMHO

Well I assumed it would be rotten but there was never any wood it looks like they ran a 1x4 from the rear bulk head forward to use to attach the glass to which made a container to pour in foam, I had always assumed all boats had wood stringers, it will when I'm done anyways I guess.

 

[gm280]

Well I assumed it would be rotten but there was never any wood it looks like they ran a 1x4 from the rear bulk head forward to use to attach the glass to which made a container to pour in foam, I had always assumed all boats had wood stringers, it will when I'm done anyways I guess.

I would say you have a good plan for the repairs. Make sure you take lots of pictures and post them along the way. We love pictures and it also helps you see your progress along the way as well. And if you ever plan to sell the boat, you can show the perspective new owner exactly how the boat was rebuild. That would make a sell go so smoothly. :thumb:

 

[97fordrunner]

I would say you have a good plan for the repairs. Make sure you take lots of pictures and post them along the way. We love pictures and it also helps you see your progress along the way as well. And if you ever plan to sell the boat, you can show the perspective new owner exactly how the boat was rebuild. That would make a sell go so smoothly. :thumb:

For sure, gonna work on getting the cap ready to remove this afternoon

 

[97fordrunner]

Well I got some more foam out , ran out of room in the garbage so moved onto removing the rub rail. Who ever put this on last used a really strong silicon adhesive, pulled] a lot of the paint off

 

[gm280]

Yea, it happens like that sometimes. But you were planning on refinish the hull anyways weren't you? So all that paint would have to come off anyways. If you simply feathered the paint and painted over that, it wouldn't be long before it would come off again. So you will have to sand that loose paint off before refinishing. That is exactly what I am presently doing to my hull, sanding and prepping for hull filler and primer. As for filling up the garbage container with rot and soaked form, I know all about that as well. We, wife and I, remove a lot of very heavy soaked foam from my project boat initially. I wish I would have weighed it because it was a lot of weight. It took more then a few garbage containers to hold all of it. Just think how much lighter and solider your boat will be when finished. That equates to a faster hotshot, less gas usage, and more performance as well. And all that is a good thing too. JMHO

Oh, while I am thinking about it. Try your darnedest to scrap off as much of that silicone adhesives as you can before sanding. That stuff plugs the sandpaper really quickly.

 

[97fordrunner]

Roger that on the silicon removal. The foam isn't as saturated as I was expecting. So here is a crazy question, how do guys replace just part of the transom, since this boat doesn't have stringers I'm trying to see if I could get away without pulling the cap, thinking of running the stringers from transom forward as far as I can get and then tie into what's there now and then replace the bottom half of the transom. What are your guys thoughts on this?

 

[gm280]

Roger that on the silicon removal. The foam isn't as saturated as I was expecting. So here is a crazy question, how do guys replace just part of the transom, since this boat doesn't have stringers I'm trying to see if I could get away without pulling the cap, thinking of running the stringers from transom forward as far as I can get and then tie into what's there now and then replace the bottom half of the transom. What are your guys thoughts on this?

My personal opinion. I would replace the entire transom if I were doing it. WHY? Because trying to replace a portion is more effort then it is worth. And the partial replacement will never ever be as strong as one solid piece. But that is just my opinion.

 

[97fordrunner]

My personal opinion. I would replace the entire transom if I were doing it. WHY? Because trying to replace a portion is more effort then it is worth. And the partial replacement will never ever be as strong as one solid piece. But that is just my opinion.

Yeah, I figure on doing just that. If I tried going partial I know I would get it apart and end up doing the hole thing anyways, might as well go all in