1980 GT-150 refurb

[79Glastron]

I put some of my other projects on hold (SSV-177) and decided to work on the GT and try to get it finished so I can use it this summer.

I knew the boat had a weak transom and the floor wasn't right. It ended up the PO screwed down a piece of 3/4 over the existing floor, making the floor even higher than it needs to be. My goal is to have a structurally sound hull, install a Mercury 115, and have a decent interior. My gel coat is ok and I think it will come back with some wet sanding and buffing.

This past weekend I removed the top deck, removed the transom, ski locker, and part of the floor. I did not have a circular saw with me to remove the rest of the floor. Once the top was removed I made a few drawings and took many measurements to aid in reassembly. I am planning on relocating the drain hole to the center, and making the transom full width of the hull, and had some wood to the under floor frame work.

I am not sure what wood I should use for the stringers. Lowes has some 5/4 pressure treated timber and I think they would make a strong frame work. I was planning on using 3/4 for transom and bulkheads/braces, and 1/2 for the floor.

Another stumbling block I have are the seats. I do not have the original seats. I am wondering what seat configuration would work ok and not be too spendy. I would like to have original type seats, but I have nothing to go by. Let the suggestions flow in!

Here are some pics from the work.

 

[Woodonglass]

Re: 1980 GT-150 refurb

Do a search for archbuilder. His boat is very similar to this an you'll find a lot of great ideas from his rebuild. For your stingers, deck and transom, I'd just use the Arauco Plywood from Lowes.

 

[Cadwelder]

Re: 1980 GT-150 refurb

+1 on the Arauco plywood. As many here know I'm a hugh marine grade plywood fan, but just recently tried the Arauco plywood from Lowes. It's really good stuff, it doesn't drink resin like the regular exterior grade and is near void free. Cuts well and it fairly flat, I don't think you can beat it for the price as compared to marine grade.

I still use marine grade for stringers, but will now switch over to the Arauco for everything else...

Yep on the 1/2", it's fine for your deck, as far as the treated lumber, I'm not a fan of it for anything.....

CW

 

[boatnut74]

Re: 1980 GT-150 refurb

I really like those GT 150's. I have a GT 160 I am currently working on. I saw your post on the classic glastron site as well but never got a chance to reply. A 115 should really make that thing fly. I agree with using the Auruco, it's really good stuff. The pressure treated usually isn't a great idea due to the fact that it stays pretty wet and there's a good chance of the glass delamming over time.

 

[79Glastron]

Re: 1980 GT-150 refurb

I continued work today on the GT. I grabbed my circular saw, grinder, and pry bar and got to work. I removed all the old floor and the stringers. I removed the center stringer in one piece to use a pattern. Right now I have a whole bunch of grinding to do, not really looking forward to that part, but it needs to be done.

There is a thick layer of resin that goes over top of where the floor meets the hull. Now that the wood is gone, its kinda like a lip in the hull. I am not really sure how much I need to remove of this. Here is a pic of what I'm talking about. Hopefully some of you GT-150 guys know what I'm talking about.

As for wood, I was planning using 2 layers of 3/4 ply glued together with resin and a piece of CSM, and tab/cover in 1708 for the transom. As far as stringers, I'm ruling out poplar (too soft) and pressure treated (resin delamination). Two pieces of 1/2 glued together might be the ticket. It should be very strong, affordable, and easy to cut to size.

From here I plan on grinding out the hull, repair any spots that might need attention, and install the transom. Stay tuned.

 

[79Glastron]

Re: 1980 GT-150 refurb

I made some progress today on the GT. I did some grinding on the transom and rear part of the hull. The transom needs more work and the whole hull needs a day of work yet.

I made a decision about the stringers. I visited a local lumber yard and found some nice 1X6 fur boards. They come in up to 12' lengths, perfect for the GT. I am going to get one 1X6X12, and one 1X4X10. That should be enough for one center and two out board stringers. I'll probably get another board to make some cross braces. I am also planning on doing a full width transom for added strength.

The game plan is lots of grinding, and getting the transom in, this weekend? Maybe.....

 

[79Glastron]

Re: 1980 GT-150 refurb

Not a very productive weekend. I got up early and the power went off, great start to the day. I had some running around to do, get a hair cut, and get some lumber for the GT. I got back and it was still off. I figured I would mow the grass, once I was done, stil off....grrrrr. By this time it was getting close to noon. I went down to my Dad's barn to remove the 115 Mercury from my other Glastron. I was by myself and used our John Deere tractor with a loader to remove the motor using the threaded lifting eye. I didn't have the camera to take pics of the removal. It was kinda awkward sitting the motor in the back of my trailer. I put an old tire down on the trailer and started leaning the lower unit on that while I let the loader down. Once it was down I repositioned the tire and placed a block of wood under the lower unit. I was fearing after the fact that I could have bent the crankshaft leaning the motor over like that, but figured if it is strong enough to support the engine in tension, it would be ok in shear. Plus not all the weight was on the crank. Hopefully you experts will agree with me.

I got home that evening and the power was back on. I did some grinding until it got dark.

Sunday I didn't get a whole lot done, it was hot and I had band practice in the middle of the afternoon. I put my complete transom on the boat and was figuring a way to clamp it down once I applied the BP. I hope to get some work done this week and get the transom done atleast by next weekend. I fear I'm falling behind, I'm trying to splash it by August 5th.

I also need to build a stand for the 115 so I can run it before I mount it to the GT.
Thanks!