Help: 1969 18' Tournament skier twin Mercury 1350s restoration

Your call.

jim

 

Ok, the core is nearly out and the deck is almost ready to remove. It's time for supplies, which means questions too. I'd like anyone's thoughts on the following:

1. Planning on kerfed, scrimmed end brain balsa core, 1" thick?
2. Marine grade plywood for the transom, two layers of 3/4" with 3 layers of fiberglass should make about 2" which is about all the clamps on my old motors can fit.
3. What plywood should I use for the floor? Thinking 5/8" AB exterior, would 1/2" work, since it's being glassed.
4. What kind cloth to use? Thinking Woven/roven? over the core, maybe the floor too. Or bidirectional?
5. Fir stringers if I can find it.
6. Good places to get the above. I live south of Atlanta.

Btw, I finally got some pictures, I'll post as soon as I can.

Thanks,
Dave

 

I would go with 1/2 inch floor and save some weight.

jim

 

X2 to Jim's response for the floor/deck. 1/2 inch ply is all you need. I used 1/2 inch marine ply to replace the rear decks on the 1975 18 and 1985 20 and they do not deflect once they are glassed in. I recommend useing Marine ply, not AB (assuming the later refers to the grade on each side of the board). Marine ply has (supposidly) no voids between the ply layers and is chemically treated for rot. You will also what to coat the boards and stringers with a 50/50% mix of resin and acetone to provide an initial sealcoat. I used non directional glass on the floor but did note that the transom replacement of the 20 was done with woven roven (I had the transom done at a repair shop). Don't know how many layers or the weight of the cloth.

Kevin-

 

I would leave the deck on to help hold the hull shape. How is the boat supported? The set up must be strong enough to support what ever weight is needed to re-core. The bottom must be kept perfectly straight during the re-coring.

I have witnessed some re-core jobs that ended with a hook in the hull or incomplete core bonding to the hull because they were not properly supported. That will kill the performance.

jim

 

1/2" plywood would be adequate for a floor. The type of plywood you use is dependent on how long you want the floor to last and your checkbook. AB plywood is the least expensive route but whatever you use glass the bottom of the plywood floor before installation. It's all about water intrusion. Keep the water out and any wood will last a long time.

I use 2 kinds of cloth - a 2oz 6" wide for tabbing parts in and the heavy duty 45-45 17oz bi-ax. The reason I use the 45-45 weave instead of the 0-90 weave is that I get glass fibers attaching in 2 directions instead of one. The 17oz may be a bit of an overkill but if I used 8oz I would do 2 layers. If you are hanging 2 motors the boat cannot be too strong.

 

Ok,

Half inch it is, probably marine grade, definitely resined. Will use woven roven on transom and core. Probably something smoother (bias probably) on the floor.

The boat is on a fixture with four bunks and a bow support. Probably going to pop the deck and prep it first (the plywood strips around the edge need replacing among other things.) Then tack it on to do the core & floor. Then remove it again to do transom. Speaking of which: It looked like Mark Bano was replacing a transom after the floor was in. We haven't gotten the back of the floor out yet. Does the plywood in the transom rest on top of the core, or does the core butt against the plywood? What is the preferred order of replacement?

I've decided I want a fin and saw that dynaski has them available. Since my boat never had one, i need to know where to mount it.

Thanks,
Dave

 

The aft edge of my fin is 51 inches forward of the transom.

The four bunks supporting your hull need to be beefy enough to keep the bottom straight with what ever load is placed on them. It could be your weight or any weight used to press the core down on the bottom. I can't stress that enough.

jim

 

The core butts up against the transom so the transom has to go in 1st.

 

After you put the transom in I would leave a small space at the center stern uncored to install a bilge pump. Put some small pieces of wood in to contain the resin from the core. They will be glassed over later. If you plan on having a depth gauge now is the time to think of where you want that thru-the-hull transducer as they will not work through a core. I picked a spot about 4' forward of the transom and when I put the core in I left a 4" square for the transducer and mounted it at the same time I resined the core.