74 tournament skier wood rot

I have a 1974 Hydrodyne 18' Tournament Skier and have recently discovered some rot in the first layer of plywood in the transom just on the port side. I have done some research and found a product to repair this problem without removing the hole transom. I have also found some rot in the floor stringers. They don't apear to be hard to replace but I don't know what kind of wood they are made of? does anyone know??
This project is turning into a major one, it started out by just removing the engine for a bad ring gear. I found the rot in the transom when I was drilling through it for a bilge pump discharge and I always knew there was some soft spots in the floor. At least the hull is solid

 

When I put a new floor in my 79I/O it looked like the big stringer in the middle was heart pine and the small ones were fir. Don't know for sure. Mine were good, but it don't look like it would be a very tough job to replace them.

 

All three stringers should be treated pine.

If the stringers are rotted, then a fair amount of water has found its way into the floor. In such case, the flotation foam is now full of water and you are carrying around a lot of water weight. If this is the case, a total replacement of the floor and flotation foam is necessary to make things right. You can now get closed cell foam, which won't hold water like a sponge.

You can see an entire floor replacement which was done on my '73 in the restoration section.

The odds are that you can also wait a while if the floor is still mostly solid. As long as the balsa core is not breached, you can use your boat with soggy flotation foam and a soft floor - not the end of the world. The boat will just be heavy in the water.

As for the transom, the solution depends to some degree on what you will be satisfied with and what kind of power you are running. If you are going to twin rig, or if you are putting a heavy V6 on the back, you need to address the transom up front with a replacement. Not a small job because it can only be done properly by removing at least the back portion of the deck (although I would do the entire deck so as to not cut the deck, myself). If you are using a smaller, lighter engine, and wish to get a few more years out of the transom that is already there, then you can try one of the Rot Doctor type products. The problem with those products is they do little or nothing for the integrity of the structure itself. Also, because you can't really get between the outside hull and the inside fiberglass under the splashwell, you can't really get to the places that need the treatment. Thus, people often end up just hardening some of the rot in the areas they can get to - such as around the mounting holes. This will do little more than make you feel better.

These are difficult decisions. Tom Miller would probably cut the rear third of the deck and replace the transom for somewhere in the area of $1,500. Not cheap, but it is extremely labor intensive work.

Another option, to buy a bit of time, would be the use of stainless or heavy aluminum transom support plates on both sides of the transom. Many clubs did this over the years to buy time on deteriorating transoms. Again, this does not cure the problem, but it helps hold everything together and spread out the load a bit. Also, if you think the transom is not what it once was, be very sure to use a transom saver when you trailer the boat.
That is about the best overall advice I can give. Good luck!

MarkBano

 

With his being an I/O working on the transom won't be as difficult as an outboard. There is a good bit of access with the engine out. I replaced my floor earlier this year and it wasn't that bad of a job. I did take out all the foam and put new in. When you go to do it use a shovel to take the foam out it makes the job alot easier. I modified the floor and motor cover on my boat also. I will take some pics and post them of the mods.

 

Hey Dyne74:

For stringer material, do not use pressure-treated products. They will not adhere to glass or resin because of the moisture content that they maintain after treatment (plywood flooring included). If you can find it, get a hold of some pecky cypress, this wood is very dense, relatively light and very rot resistant.

If you have an i/o, there is basically no weight on the transom; the weight is carried on the motor mounts for the engine and outdrive. You might get a few years with a bandaid like rot doctor but the glass and gel may get stress (spider) cracks if put under stress.

 

Thanks for all the help.
I have already removed all the floor and floatation from the boat to find out how bad the rot is. I figured I might aswell fix all the rot in the boat at one time that way I should have a solid boat for at least a couple of years. I am not to worried about the transom as this boat is not an outboard (351w with a volvo outdrive) so my transom rot solution should be ok. Thanks again for all the info.
Any diffinative answer about the floor striger material?

 

Hey 74 Dyne:

For stringers, google "cypress" and you should come up with something for suppliers. I miss spoke about "pecky cypress" and ment clean ( grade #1) cypress. It is from the conifer (pine) family bit is very resistant to rot and has good dtructural properties that your project will require. I used it for a couple bulkheads when I replaced my floor (no stringers as they were still in great shape). Good luck!

Kevin-

 

Thanks for all the info, I'll see what I can find.

Nice boat kevinb, when did they stop making this hull design? I've seen them as early as 1968 and yours is the newest I've seen. My boat looks identical but I have a red white and blue stipe. My dad took the windshield off and filled the holes when he bought it in 1979. He gave the boat to me so I'm trying to bring her back to life after sitting for many years. Should turn out nice, it's deffinatly a unique boat. I've never seen another one in person.

Thanks again for the info.

 

Thanks for the complement 74dyne. I actually re-did the bow decals in 1999 in blue to be diffrent. There are a couple boats that were released with all black bow stripes and the curt gowdy signature model was in metal flake silver or red (not my favorite but very 70's . I've got an article from Lee Wangstad that indicates that the 18-foot tournament skier production went to 1978. Thats not to say that there may be a renagade 1979 out there. Hitting the water with something tomorrow.

Cheers,

Kevin-