This is what 1- 6" soft spot looked like on my 18 from underneath.
http://www.classicseacraft.com/commu...1&d=1614255920

Interesting, my largest soft spot was about 18" wide and 30" fore to aft. It was located just to the left of that delta shaped potter putty mark on the above picture. From underneath you can hardly tell it was there. Two years ago I drilled about 40 holes in the area and injected it with gorilla glue just to get me by, knowing that the rebuild was in my future. I figured when I tore this up there would be gorilla glue every where under the sole, but nothing came thru the bottom skin.

Whatever day they made this boat back in 75, they really did a good job of sealing everything up. There is still the original dust from where they flattened some of the pour foam on the outsides and tops of the stringers.
All the foam is as dry as can be. That was a relief.

Got the hull cleaned up a little. Tank platform was ply with glass only on the top so it was rotten. Also got the forward in floor box removed in one piece, plan on reusing it. And got the remainder of the rear battery shelves removed. Next step is to build the tank platform and get the floor templated.

Attachment 23091

consider removing and reinstalling the center keel stringer if you have not done so already.

strick

Why is that?

The 10" that I cut off in the back to allow for the transom rebuild looked dry and solid. And all the glass on both sides looks intact. What should I be looking for?


Thanks.

Yours may be dry. The wood core when wet can expand and contract due to freezing and thawing....weakening the glass..take your boat out in rough water then split the keel. This is one of the spots where we have seen these boats fail. Ask me how I know. Better to take it out and replace with composit for peace of mind.

Strick

Thanks for the explanation.

Keeping in mind I live in boat materials waste land, anything would need shipped in unless it is a construction material, what composite would be used for this?
The existing core appears to be a 1 1/2" by 2+" solid wood piece almost looks like cypress. With about 1/4" of glass laid up and tabbed in.

Edit to add... what would you think about just reinforcing the keel stringer layup that is there now. I could add 2 layers of 1700 on top of 2 layers of 1708 12" tape, and could offset the tape by 3". That would get me new 1708 tabbing out 8" or so on each side and a couple layers of 1700 wrapped on to the keel 3-4" each side.

I would replace with coosa or core cell or similar. You have went this far.

strick

Man, I hear what your are saying but that's going to be a tough pill to swallow. Need to sleep on that for sure. I'll get out there tomorrow, lay down on the keel and talk to it a bit. HaHa.

You could also do a half round piece of PVC. There are lost of examples around, and that's what I did too.

like

I used a 1/2 PVC pipe. While you're in there, I'd take a hard look at the tabbing around that keel and the stringers. If you see black glass, it's likely moisture wicked up under the tabbing. I had to grind out a lot of it.

My tank bed was installed like yours was. and it laying hard on the stringers at the hull joint. I'd look at that joint too and look for any splitting in the stringer tabbing. I ended up entirely rehabbing the stringers and ground them out. I also added a fillet to help take a little stress off the stringer to hull joint.

Yours might be fine, but I'd take a really hard look at all of it and like Strick said, get that old fir keel out while you've got it all apart.

Good luck! It's all looking good.

Only 1/2" PVC pipe?

Half pipe. Looks like 1-1/2 or 2".

So just to go down this rabbit hole.

What would the layup schedule be if you were going to glass in a half of a 3" pipe? The pipe is just for form right, not expecting any structural input from it.
I would assume that the glass would need to be uni-directional(running the long way) for a large majority of the laminate, is that correct?

Also, would I need to support the hull differently, right now it sits on the trailer and it has two keel rollers? It is a bunk trailer.

I have been comfortable with everything else I have done, but Strick's hull splitting story, has me feeling like I need to consult a navel architect on this one!

I can't imagine, at this point, making a keel stringer that is stronger than what they made in '75. The one in there now seems solid. However, I guess I will never know about its integrity until I cut it out. I have drilled 8 holes along it, just thru the glass, and have not found any discolored wood, but that is less than .1% of the area, so really proves nothing.

All that said, other than the no wood argument, why cant I just use whats there as the mold. Get it down to good clean glass and add a few layers?

There is no obvious "black" tabbing, even in the one place that there was an overlap that was not completely rolled down, but its on the top of the keel stringer, so less likely to sit in water.

I didn't replace mine. When I cut the aft 6" +/- for the transom core, the wood inside was as hard a teak. It was not easy to cut out and very solid so I let it be. Also, did not see any messed up looking glass/delamination. I recently purchased a '73 20sf and will be looking at it hard.

No, Sorry. To be clear, it's a SIX inch pipe, cut in 1/2.

[QUOTE=take a potter;270943]So just to go down this rabbit hole.

What would the layup schedule be if you were going to glass in a half of a 3" pipe?

FIRST - This is my FIRST project like this. Lots of guidance from folks here and elsewhere, but there ya go.

I cut a SIX inch drainage pipe in half. First, I ran 3 layers of 1708 down the keel after grinding out all of the old tabbing and cleaning up the glass there. I ran it wide enough to make sure the pipe and the fillet would fall inside of it and that the glass over there pipe when I glassed it in would make contact with it.

I scuffed the pipe, shaped it a little up front to get it to lay down nice and laid it on a bed of cab thickened epoxy along its edges. I then filleted the running edges with thickened cab.

I ran three layers of 1708 over the top of the pipe.

As to other keel support/transverse support etc, I'm sure others on here have more experience than I do.

I added bulkheads between the stringers and ran low transverse supports under my fuel tank beds that were filleted and tabbed in with 1700.

[QUOTE=captsuperfly;270957]Nice work that looks great. Thanks for the information.

I ground alotta crap outta this 23 keel, so went pretty heavy with new glass. A 20”, 16” and a 12” 1700 and a 10” 4008 triax, which is like a 1208 with 28oz? Uni on top. It will get a half round pipe with another 4008 on top. I like being able to bottle jack a keel should the need arise lol

man this is good stuff. does anyone have like a VLOG or some video walkthrough with their restoration. would love to see all of this in action and the thought process behind it.

I can only speak for myself, but doing any more than taking a few pictures, if you are trying to do this on your own would be hard and time consuming. If you had a crew then maybe you could take pictures as people came and left or changed tasks. For me I'm either suited up for sanding and grinding. Or I have epoxy covered gloves on. Or I am looking for the Advil bottle once I straighten up.

The thought process is a little easier, even though it is different for everyone, based on their personality, or goals.

For me I want to use a safe boat, that will last the rest of my life. No intention of "making" money, its a project not a destination. Get it done.

It has been enjoyable though!

Some more progress. Temps were in the 70's this week so got some glassing done outside.

After carefully inspecting the center stringer as well as the tabbing that was visible on the box stringers, I can not find any problems. Therefore against advise, I decided not to replace the center stringer. I ground the glass down on the stringer and about 7" each side. Laid in a nice cabosil filet and skim coated everything with putty to fill any irregularities, then I laid 3x 1700 stepping back an inch each time. I also laid up 2x 1708 to add tabbing to the box stringers.

Attachment 23186

I got the fuel tank shelf laid up with 2x 1700 each side. Then made supports out of PVC and 5200'ed them down. Placed the shelf and bonded it to the supports with 5200 and 2x tabbed it on both sides.

Attachment 23187

Attachment 23188

Attachment 23189

Also got the bottom of the scuppers glassed over after removing the brow, with its associated air gaps between lamination.