TOPIC: Restoring my 70's Phantom Tri Hull

Hello all. I am beginning to restore my 1970's Phantom Tri Hull boat this weekend. I am unsure of the exact year as i have no paperwork on it yet. It was my grandfathers, then my fathers, then my other grandfathers, then my uncles, now mine! Needless to say its been sitting for a while

ive stripped out all the carpet and will be pressure washing and buffing this weekend.

My main deal to contend with is the floorboard. Its got some cracks overall is in bad shape. anyone got any good references with helpful tips for beginning fiberglass patching? Any experiences or warning or anything of that nature would be great. Or, even just some success stories and or photos to motivate me to do it right!

i would start by doing the rotten transom test . tilt the motor all the way up and lift up on the skeg as though you were trying to lift the boat up by the motor all the while keeping an eye on the transom for any flexing . most boats that age will have a bad transom unless they were repaired recently . or you can climb under the splashwell with a awl or a sharp screw driver and jab at the transom looking for wet rotten black wood . then the same for the floors and the stringers under the floor . judging by the picture of the floor in your boat , your best bet would be to remove the old floor and replace it with a new one . there is a book you might want to buy its called "Runabout Renovation" , it step by step walks you through a complete boat renovation . just my .02. good luck and keep us posted . Gil

i will give this rotten transform test a shot. Thanks for the pointers. I was at work when i posted my first post and didnt want to get too in detail for the first.

Here is a little more on what i am planning to do. i openly welcome any feedback, even if it is negative or if you want to call me an idiot.

I want to patch the floor (if the transform tests ok) then put either some 1/2 inch or 3/4 inch ply down between the existing, patched fiberglass floorboard and the areas that have fiberglass coming down to the floorboard (in picture-where the shadows are). Once it is in, i would like to build out a center console rather than the previous walkthrough windshield setup, then paint the interior with a light brown or gray Rhino Lining. Feedback??

Well, last weekend i got out the 'ole pressure washer and brush, bucket and oxyclean. I think i did pretty good- threw my back out in the process, but it the boat looks nicer now. The transform is good to go.

Im havin another beer before i go out to the garage to polish out my aluminum side rails. I think i will end up ripping out the old fiberglass floorboard and mounting the 3/4 inch ply to the existing framing. So, tomorrow i will embark on the measuring and procurement of materials to do so, and quite possibly go ahead and do my cuts. here are a few pics of last weekends progress.

I just want some feedback here- Should i go with 1/2 inch ply or 3/4? i know i will be limited in my choices if i buy the treated marine grade ply. I feel like 1/2 inch might be a little thin for all intents and purposes.

Picture is a before picture

Well I did a 68 tri hull.
Floor and transom.

I used seacast for the transom.
Floor was easier. Use the same thickness ply that was in there.
Ditto on that book. I read it.
My stringers and frames were completely rotted.
I did not replace them due to the construction of them. There was a serious grid of woven roving still there. I doubled that up instead, then glued and screwed the new floor down.
I painted poly resin on the bottom side of the floor, and glassed in the top.