Is this terminal (within common sense)

[Brian Blake]

This is a 1970's 17ft Pelin Plywood "Nomad". Not sure how globally popular they were but here in New Zealand they were well known. This is a family boat with a bit of sentimental value more than actual.

I'm part way through replacing some rot in the outer ply and giving it a general once in ten years tidy up, repaint etc. Today I lifted the floor and began to climb around checking the frames etc, and to my horror, they seem to be mostly shot to heck.

Frames 1 & 2 (going forward from the stern not counting the transom) have multiple cracks in them and on the port side, the ribs seem to be separating from the frame to the point where I have a 1/8" gap between the frame and the rib in some places.

Frame 2 has had some plywood attached to it at some point I guess as additional support which is also now cracked.

Attached is a set of photos showing the various offences. I wonder if someone more knowing than me has any thought on how serious these are? where the frames turn to go up the sides appear to be intact as do the sides.

I'm now trying to decide if this is now firewood, albeit that i love this boat and it would feel criminal to scrap it, but I can manage mildly complex issues on the boat (rot etc) but frames and the likes worry me about seaworthiness.

Any and all advice greatly received, this is a gorgeous boat and sits so nicely in the water, but I don't want to get into it over my head or unsafely once the family is aboard.

Thanks
Brian

 

[fallguy]

You are wise to ground the boat if you have any uncertainty.

From the pictures; it looks like something that could be repaired, however, it is extremely difficult to understand the root cause of the problems from these pictures; at least for me.

The good news is modern chemistry, aka epoxy, can really support old wood boat repairs.

But as far as I am concerned; root cause is simply too hard to define for me from these pictures. Another forum member might have seen this before.

If you have rot; all of it must be repaired or replaced with good timber. A frame can be repaired with laminated sections rather than replacing the entire part. It all depends on how extensive the rot is...no rot can be left in a structural component.

Find a wood boat guy locally.

 

[Mr Efficiency]

How do you go about replacing "rot in the outer ply" ?

 

[Brian Blake]

If you look in the back of one of the photos the rot was isolated to one area where the port joined the transom. I've cut it all out plus a safety margin of about 10% and have no issue in repatching the ply and reskinning the transom part with appropriate materials. That is reasonably easy to fix.

I can't find any sign of rot in the frames, just some hard cracking and separation from the frame. I can replace the cracked ply "laminated patch" on the frame shown, those don't worry me so much. I am not so confident however on removing the screws in the rib joints and "re-fixing" them to the ribs as I just know nothing about the physics going on with ribs/frames related the structural integrity. I'm also concerned about what might be causing it, the old symptom v cause issue.

Is the gap forming possibly a symptom of something I can't see? Aside of a couple of dock rashes the rest of the hull is in good condition. I'm really struggling to find any local help on this as everyone in NZ owns a boat and no one wants to look at the older ones. I was happy to pay a boat builder to fix the rot for me, but none were interested, it wasn't even a price issue, they just weren't interested so off to youtube and forums I went.

Thanks
Brian

 

[Brian Blake]

How do you go about replacing "rot in the outer ply" ?

I should have said "fixing".

I'm still suffering the emotional turmoil of potentially losing one of my all-time favourite boats.... i found these issues about 2 hours ago.

 

[fallguy]

If you hang or push on the gunwale near the frames in question, can you see if the gaps are moving or changing?

My hunch is something else weakened and caused the gaps.

Like a problem either at the gunwales or the stem.

Sometimes it takes more than one person. One would push or pull on the hull gunwales or stem or keel from underneath or the sides while the other watches the areas in question.

Most wood boats are repairable. I burned two in my life. One was cold molded mahogany that had rotted through the shell and the other was a repairabl CC kit boat not worth repairing for the final value (no love either).

 

[Brian Blake]

If you hang or push on the gunwale near the frames in question, can you see if the gaps are moving or changing?

I could put a strop around the boat and bring some tension onto the gunwales which presumably would expose any broken joints I cant see in the frames?

I guess I'm looking for movement in the gap between the frame and ribs? And nearest the weak spot would expect that movement to be more pronounced right?

 

[fallguy]

I could put a strop around the boat and bring some tension onto the gunwales which presumably would expose any broken joints I cant see in the frames?

I guess I'm looking for movement in the gap between the frame and ribs? And nearest the weak spot would expect that movement to be more pronounced right?

Yes. You want to understand what is allowing the gap, so you are looking for other areas of trouble, like the keel or some more rot.

The strapping might fool you. Better to watch while a 200 pound fellow hangs on each gunwale.

 

[fallguy]

Another thing to look for is a crack or weakness in the keel or stem. Many of these boats have a scarfing or some such joint in the keel or stem and that area is prone to rot. The reason for the joint is the wood used was too short and they piece it.

Like I said, you cannot allow any rot to remain or it will continue to feast and weaken the boat.

But it appears very fixable to me.

Another strategy is to use an awl and probe around the weak area looking for soft spots, but you usually end up needing to paint after that.

 

[sdowney717]

Another thing to look for is a crack or weakness in the keel or stem. Many of these boats have a scarfing or some such joint in the keel or stem and that area is prone to rot. The reason for the joint is the wood used was too short and they piece it.

Like I said, you cannot allow any rot to remain or it will continue to feast and weaken the boat.

But it appears very fixable to me.

Another strategy is to use an awl and probe around the weak area looking for soft spots, but you usually end up needing to paint after that.

Never use an awl, use a screwdriver/ Awl is too sharp, gives a perhaps false indication and destroys the paint.

 

[Mr Efficiency]

The OP needs some block foam installed in this boat, in case something does let go, with the aged structure of it.

 

[fallguy]

Never use an awl, use a screwdriver/ Awl is too sharp, gives a perhaps false indication and destroys the paint.

Well, that isn't a solution. And I would never use an awl unless I found a suspicious area.

Please advise what you WOULD do to find more rot.

 

[fallguy]

The OP needs some block foam installed in this boat, in case something does let go, with the aged structure of it.

Well, the boat is wood, so the big question is how much buoyancy it would have vs gear.

Foam in old wood boats is generally a horrible idea. It usually results in trapped water. And trapped water results in rot.

About the only place it seems practical and not prone to causing rot would be under seats or decks where ingress is unlikely and humidity would also not be catastrophic to the hull.

I have an old wood hull and considered using foam and opted away as we never use the vessel in very treacherous places or seasons.

 

[sdowney717]

Well, that isn't a solution. And I would never use an awl unless I found a suspicious area.

Please advise what you WOULD do to find more rot.

I have a wooden 37 foot Egg Harbor made in 1970 which I have done extensive wood repairs due to rot.
My comment is directed to generally checking for rot all over a wood boat, not for areas I know are rotten. Simply jabbing an awl into good wood is a bad idea.
There are tell tales to rot you can notice just from the appearance. Even feeling the wood by hand you can tell.
I get rid of rotten wood, I don't fix rot. All you need to do is remove the rot, not half the boat. Some people get too aggressive. Rot spores are in non rotten wood naturally. If wood cant get wet, no more rot. Recently have used rubbing alcohol mixed with roach powder (boric acid dissolves in alcohol) to treat wood after scraping or cutting out rot. A heat gun also kills rot and dries out the wood. If you can remove wood using simple tools, then it is rotten wood. For easy filling I use Loctite PL Premium Polyurethane CA mixed with sanding dust or sawdust. It will swell up so I keep it pressed down with cereal bag plastic or use the putty knife to force it back down. Mixing with wood dust allows it to cure in thick layers fast and it allows for a flexible not glass hard repair like epoxy gives you. And this provides a lot of strength. Of course for needed structural repairs where you need the wood replace with wood.

 

[Brian Blake]

Thank you all. I have a few more questions

AWL? What is that? Identified the initial rot as I was able to see some warping of the white paint job. Some gentle prodding with a flathead screwdriver revealed the rest. The majority of the boat is solid, I can only find one small slightly softer area in the portside deck between the gunwale and the cabin wall. As I say its only a little softer than the rest, nothing like the rotted area I had nearer the stern.

Not surprisingly when a put a strop around the boat in two places and proceeded to "pull and push" the strop I could see the gaps between ribs and frames moves ever so slightly. This is to be expected as it was bending the shape of the boat (for what I know about physics) but it hasn't shed any light on other issues. I've been up and down the "keel" (although at 17ft it doesn't have one does it? or is keel generic for the bottom of the boat in this case? I always thought it was a bloody great chunk of weight under a sailboat.).

I can't find any other "doesnt look right" areas or soft spots and I have knocked the hell out of the hull (as its being repainted anyway) with a screwdriver looking for penetrations and sound differences or warping, but nothing.

Is it possible the previous owner did the damage by dropping it off a bloody great wave? We have a fair bit of that sort of thing in New Zealand as we have Sandbars often.

Also, how would i find out if the existing paint (most of which I've sanded & peeled off) is 2 part of enamel? Can't seem to find an answer online.

Thanks
Brian