Help! 1970 GW Invader 10' Restoration

[1960Fleetform]

I just purchased a 10' Invader and am beginning my 2nd ever full restoration. I've looked at a couple other Invader restorations that needed the transom replaced and reinforced and the entire hull reinforced with fiberglass and marine plywood, the same as mine.

I began with removing the rub rail, rivets, and breaking the bond between the top and bottom halfs and removed the top. I started to remove all the old rotted floor and fiberglass and found myself down to the bare hull.

My question is how do I reinforce the hull? Do I lay multiple sheets of glass, then resin soaked marine plywood, follwed by glass on top of that? Or can I just lay the plywood on the bare hull and fiberglass it in?

Any help would be greatly appreciated! Keep in mind that this boat will be equipped with a 65 hp outboard, so whatever will make it the most structurally-sound is the way I want to go. Thanks!

 

[Chinewalker]

Re: Help! 1970 GW Invader 10' Restoration

I redid a GW Invader Banchie (13-footer) and it didn't have any core material for the bottom - just stringers. I thought the smaller ones had a balsa core for the bottom? If so, I would go with that. I've seen some do that with a vacuum bag to get the core to adhere completely, but I've also seen where someone supported the hull well and laid a plastic sheet over the curing epoxy & balsa and then poured sand over the sheet to press it all together.
If your original core was plywood, I'd be careful about just laying a sheet in there as it may not take the contours of the bottom. Might have to score it on the back side. And yes, you would bed it in epoxy to make the plywood one with the skin...

 

[1960Fleetform]

Re: Help! 1970 GW Invader 10' Restoration

Your boat was one of the restorations I saw on share a project. The wood in between the hull and the top layer of fiberglass was 3/4" and was cut into little squares. It was so rotted I can't tell what kind of wood it is. I've never worked with balsa before. What is the procedure and is there anywhere specific to get it?

 

[Chinewalker]

Re: Help! 1970 GW Invader 10' Restoration

That I can't help you with. I know there's a guy on ScreamAndFly.com who recored a Hydrostream with balsa and used the vacuum bag method. I think he detailed where he got his material...