repair advice

Mark Spolarich

Mark Spolarich

Well-known member
I started giving the old scull boat I bought a good going over and have discovered the keelson board (I think that is the right term) was waterlogged and rotten. Here is a picture of before I opened it up:


I was pretty sure the hull was hand laid fiberglass and that was confirmed when I removed the board. The board was screwed to the keel and covered in fiberglass. Post removal:




The keel is also soaked in water and it will have to be removed. My plan is to remove the remaining keelson board and the keel, then use new wood to repair. I am not sure on how to ensure the keel is solidly attached to the existing fiberglas. Do I spread epoxy resin inside the formed keel and then install a pre-epoxied board or is there another method I should use? I believe I can loft the keel measurement to get the new board close to the right size (the keel tapers towards the bow, sorry no bottom hull pics yet).

Am I thinking right about this or am I way off base? Not experienced at this in any way, just applying what I have learned by reading on this site and from building my one and only boat.
 
Last edited:
Good morning, Mark~

A fine little puzzle to start the morning.....

I do not yet have a fully-formulated suggestion - but I do have a few questions and thoughts.

Is the 'glass keel fully molded around the wooden keel? Is it intact (largely) and sound ? In essence, does it function as part of the molded hull ? (that photo of the bottom would be great!)

I am thinking of lots of canoe keels as well as skegs and strakes on small craft and that are molded as part of the hull. If so, their "corrugated" shape provides ample stiffness and should not require wooden structural members. The interior spaces created by these molded shapes only need to be filled if there is a danger of wear-through or puncture (as in most duckboat keels).

Once you have both the keelson and the keel wood removed, I would test the lengthwise hull stiffness. I'd support the hull on 2 horses - one at each end - and see how much sag there is in the bottom. I imagine the cockpit/deck structure will provide a lot of longitudinal stiffness - so I would set some heavy weights (paint gallons, etc) along the keel's length to see how much deflection there might be. I am hoping you will see little defection IF the molded keel is integral with the hull bottom.

In any event, I would hesitate to re-fill the void with a wooden keel. It is the most difficult approach, probably the heaviest, and the one most likely to absorb water if future breaches of the 'glass skin occur. If the hull is stiff longitudinally, I would pour some closed-cell foam (8 pound/cubic foot) into the space. (Another option would be PVC lumber). Cut/grind it flush with the hull interior when cured. Then seal it in with 3 ever-wider layers of cloth and epoxy (4", 6", 8").

On the outside of the hull, I would repair any problems (grind, fill, etc) then ultimately cover the entire molded keel with a new layer of cloth + epoxy; the cloth could cover the bottom and sides of the keel and extend a couple of inches onto the hull bottom on either side of the keel. If you expect to ground out frequently, a second layer of cloth over the bottom of the keel would be helpful.

I am not sure you will need a new keelson. I am guessing it may have served a purpose - maintained a certain shape to the hull bottom - during the original construction, but would no longer provide any real benefit. If you did want to add one, I would seal it (maybe use Philippine Mahogany) in epoxy and then "fasten" it with either thickened epoxy or 3M 5200.

One final question: Were/are there floorboards ? I am wondering if they keyed into the keelson to keep them in place.

I hope this helps. I may change my thinking entirely once I see the keel from the outside......

SJS
 
Steve, I was hoping you would chime in! Thanks for the advice and direction(s) for me to head in. I was racking my brain trying to figure some of this out because my experience is limited.

Is the 'glass keel fully molded around the wooden keel? Is it intact (largely) and sound ? In essence, does it function as part of the molded hull ? (that photo of the bottom would be great!)
A: Yes, the glass is fully molded around the wooden keel. Best I can tell the glass keel is intact and sound, will need sanded and a new layer put over it to ensure there is no future issues.
Were/are there floorboards?
A: Yes, they have a "notch" cut out to set over the keelson board but may not need it. The darn thing is made to last (read: heavy) and nothing wrong with it at all.
IMG_0960_zpsmnvbwzzv.jpg

IMG_0959_zpslkmyl7wr.jpg


My plan is to cover the whole boat in a new layer of glass after I work through any issues I find while sanding. I have to re-do the transom because if was repaired using poly instead of epoxy resin. This was a recent repair so no signs of rot there. I did find some on one the interior sideboards where is used to connect to the transom. That repair is in progress now, nothing major.

I will get a photo of the hull bottom tonight, should be a lot lighter to flip now that the very heavy keelson has been removed and once I pull the keel out.
 
Last edited:
Exposed the keel and started removing some of it. Even though it is waterlogged, oak is hard to break apart!! I was surprised to find the interior of the keel is real smooth.



Steve, you asked for bottom pictures so I managed to roll the scull on its side to get a few for you. From what I can see its solid all the way with just a slight bow slightly forward of midship. Not sure if that will correct itself after the keel is out. If not, its not bad enough for me to worry about.




 
Last edited:
Looks like tom s was on the fairing comittee when it was built. :D


I agree with Steve, some nice dense foam would be great in that keel!
 
Can you tell if the boat was glassed with poly resin???

The inside of the keel is smooth from the way it was layed up I'd guess. Do you intend to use epoxy & cloth VS. CSM & resin.

All the old boats I've worked on seem to indicate cloth will onion peel off and split at the edges. On a keel like that, I would use CSM and resin if you can and glass the inside first. Then I'd attack the outside of the keel for fissures and abscesses before repairing them and fairing.

I would personally avoid putting wood back into a keel like that and stiffen it up with laminate layers cause it's bound to rot again unless you can really keep it dry. On an old boat there will likely be water intrusion again into those areas in my opinion.
 
Last edited:
Can you tell if the boat was glassed with poly resin???

The inside of the keel is smooth from the way it was layed up I'd guess. Do you intend to use epoxy & cloth VS. CSM & resin.

All the old boats I've worked on seem to indicate cloth will onion peel off and split at the edges. On a keel like that, I would use CSM and resin if you can and glass the inside first. Then I'd attach the outside of the keel for fissures and abscesses before repairing them and fairing.

I would personally avoid putting wood back into a keel like that and stiffen it up with laminate layers cause it's bound to rot again unless you can really keep it dry. On an old boat there will likely be water intrusion again into those areas in my opinion.
Click to expand...

I am not sure how to tell the difference between the two. All I can say is the cured glass has an orangish/tan color to it and is pretty hard.

I like Steve's suggestion of using expanding foam inside the keel and closing it up with layers of cloth tape. I don't know how I would do any lamination inside the keel, still a rookie at glassing.

I am going to work on the hull before finishing off the inside of cockpit, including the soon-to-be empty keel area. It needs a good sanding before I can lay any new glass...
 
I'd make that call based on the smell when you sand/grind it.

My point is that epoxy is expensive and if the boat was made with poly resin that will bond just fine for your repairs. CSM is easy to wet out and is unlikely to peel away as badly as cloth seems to do.

Foam in the keel is likely to soak up water and is less rigid that new wood. I would not suggest that, rather 1708. It wouldn't hurt to modify those hard edges either and make em quarter round at least.
 
I'd make that call based on the smell when you sand/grind it.

My point is that epoxy is expensive and if the boat was made with poly resin that will bond just fine for your repairs. CSM is easy to wet out and is unlikely to peel away as badly as cloth seems to do.

Foam in the keel is likely to soak up water and is less rigid that new wood. I would not suggest that, rather 1708. It wouldn't hurt to modify those hard edges either and make em quarter round at least.
Click to expand...

My experience is limited but from what I have read poly won't adhere well to epoxy but epoxy will adhere to poly. Is that correct?

Also, doesn't cloth provide more strength? Is so, could I use CSM for coverage but cloth in places where I need additional strength?
 
True. Old boats were not likely made with epoxy. If the stuff you sand or grind smells its probably polyester resin.

I would use CSM and sandwich 1708 between layers of 1.5oz.

Unless you know its epoxy I wouldn't spend the extra money to use that myself. Its at least twice as expensive in my area. I would be surprised if an old scull boat was made using epoxy...
 
True. Old boats were not likely made with epoxy. If the stuff you sand or grind smells its probably polyester resin.

I would use CSM and sandwich 1708 between layers of 1.5oz.

Unless you know its epoxy I wouldn't spend the extra money to use that myself. Its at least twice as expensive in my area. I would be surprised if an old scull boat was made using epoxy...
Click to expand...

Just so I know I am on the right path with this boat. Last night I determined I need to tear off the old wood/fiberglass on the front deck and replace because of water intrusion at some point in its life.

After installing the new wood I should do an initial layer of 1-1/2oz. CSM/435 poly resin, then a layer of DBM 1708/435 resin, followed by a final layer of 1-1/2oz. CSM/435 resin. Is there anything I need to do to ensure the poly resin adheres to the new wood?

I am still undecided on how I am going to proceed with filling the keel void, leaning towards 2-part expandable marine foam. I will know more after I sand the paint off the hull. I am identifying supplies while still giving the boat a good going over. So far so good, no real surprises on structural integrity.


Bad part (at least for my wife) is I am really liking this and already thinking about finding another old boat........
 
Last edited:
In regard to the deck, I'd avoid using a lot of material and save on weight by just encapsulating the new wood with a layer of 1.5oz CSM. this will be easy to form and wet out around the new wood. Unless you're gonna sit or stand on the deck a lot there shouldn't be a need for a lot of extra beefiness there.

On the keel, since it already has it's shape I'd leave it open like a trough. Once dry and prepped I'd wet out a 6-8" wide layer of 1.5oz CSM and a 6" strip of 1708 that runs the length of the keel. Once that's been bubble rolled and cured I'd sand down the rough spots and scuff it up and cover over with another 8" wide layer of 1.5oz.

If it was me, I wouldn't wanna close in the keel cause if it gets exposed to water again from a crack on the outside or pinhole you'll be back where you started with a waterlogged keel.

Just build the keel with laminate material the whole way and leave it open under your slat floor. Easier to deal with if you have future repairs.

If you did that first you could go after the outside of the keel and remove the hard edges from the old square keel and make a layer of new glass on the outside easier to roll out while looking for fissures in between the new glass and the old stuff. A dremel is great for that and some milled fibers will make good filler putty with a little dixie cup of catalyzed resin.

My .02 cents.

Shoot me an address and I'll send ya some milled fibers and a pile of scrap 1.5oz CSM. You'll probably find ways to use it in corners and detail areas.
 
I originally planned to leave the deck as is. I had found one soft spot up front but covered that with 6oz. cloth to help stiffen it. Once I found this new spot I decided it would be better to just replace the deck. This way I can look inside to see if any support structure needs repaired/replaced.

So, you are saying to not put anything in the keel void (wood is coming out) and just encapsulate it in fiberglass? I am okay with that, just want to make sure it still provides support.

The outside of the keel isn't too sharp, just needs some tlc and sanding all the paint off to ensure its not cracked.

I do appreciate the advice, I am new to this (only built one boat previously) and want to do this right so the boat lasts a long time. PM on the way, thanks for the offer to send the CSM!!
 
just dawned on me....you are talking about rounding the edge of the keel trough and using the CSM and 1708 on that edge....both sides
 
Yes, but by starting on the inside first you might find that it is stiff enough that you can avoid having to do much of anything on the outside other than filling holes or fissures and fairing. I would begin by drying and prepping the inside for new glass in the keel trough and move forward from there. You could always lay in a new floor piece over the whole inside with 3/4oz or 1.5oz CSM too.
 
I plan on adding a layer of 1.5 CSM on the floor when I am done with everything on the inside. I want to add in a drain plug but haven't worked that out yet, more research is needed.
 
You must log in or register to reply here.
Back
Top