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greendane

Core Sound 17 keel maintenance

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greendane    8

Hi All--I picked up a CS17 almost a year ago. Yesterday I finally got it flipped over for some maintenance on the keel. There is some exposed wood and am not sure the best way to go about this. Looking for input from the fine folks here.

First, I plan to take off the aluminum rail and the two steel (not stainless) trailer "roller guards" (the aluminum covers the front 2/3 of the keel--the back only has the two guards). Next, I plan to remove the paint the length of the keel (and an inch or so on either side of it) and start removing bad wood. If it's not too bad, I'm thinking I'll fill it up back to original form with thickened epoxy (with wood flour). If there are places where it's worse, I'll carve out that section and epoxy some oak in to replace it. Because I didn't build it, I'm not sure how it was constructed but it looks like the keel was glassed. After I fill it all back in, should I reglass it? One layer? And am I better to use something other than aluminum? I've read about brass and all that, but most of this wear comes from the trailer, not use in the water or on beaches. 

 

Second, as you can see in the pictures, the bow takes a little bit of a beating. I primarily boat in the saltwater around Camano and Whidbey Islands north of Seattle. The beaches are pretty rocky most of the time (and I do my best to find the "softest" landings I can). You can also see some of the roller scars from not quite getting it lined up before pulling in onto the trailer. (I'm getting better at it but I sail single-handed a good bit of the time--and sometimes the water conditions are pretty choppy at retrieval) I'm wondering what options I have to keep this part of the boat better protected. Extra layers of epoxy? Some strips of glass? Other? 

 

Thanks in advance. 

 

-Bryan

keel exposed wood.jpg

keel roller guard.jpg

bow underside.jpg

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Chick Ludwig    111

Hi Bryan, yack---what a mess! "Roller guards"? Not sure what you mean. Looks like the "keel" starts quite  way back from where the curve of the bow stops. If so, as long as you're repairing it, bring it as far forward as you can. normally, it's ok to fill with epoxy putty, but on this large an area, and with the stress of the trailer rollers on it, I'd "fish" in a new piece of wood. I know it's a lot of work, but I'd totally remove the keel and glass covering it. Then glass across under where the keel was. Add back a new keel, but don't glass over it. Some folks consider the keel as "sacrificial" and bed it down instead of using epoxy. when it's worn out, just replace it.

 

I don't think it really matters what the metal strip is, but you will get corrosion from stainless screws through the aluminum strip. I use "hollow back" stainless rub rail made for boats, but it's pretty expensive. Like this, but 3/4" wide. https://www.amazon.com/Plshd-Hlw-Back12Rubrail-Snlss/dp/B00144AWV8/ref=sr_1_fkmr2_4?ie=UTF8&qid=1488228163&sr=8-4-fkmr2&keywords=stainless+rub+rail+strips++boat

 

Maybe a couple of layers of glass ahead of the keel and just far enough up the bow curve to get beyond where the beach scrubs it. There is a commercial "Keel Guard" available that you could use here. https://www.amazon.com/Gator-Guards-5-KS-COLSIZ-KeelShield-Protector/dp/B004C0LA62

I used to have it to protect customers boats when I was in the boat repair business. 

 

be sure that the metal brackets that hold your trailer rollers are well covered somehow. Do you have upright trailer guides kinda like these? http://www.overtons.com/modperl/product/details.cgi?pdesc=Tie-Down-48-Boat-Guides-Pair&i=94392

They really help to load when you are a "single hander".

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greendane    8

Thanks Chick. If I were to go with the sacrificial keel, can you tell me more about the difference between "bedding it down" vs epoxy? (The epoxy part I get--not sure about how to install it in a way that makes it easy to take out when it's time. I'm also not sure how I'd get the current one out if it's already epoxied in. "Lot of work" is right!

 

I'll probably go with some extra glass on the front to protect it. Simple enough. 

 

I'll be doing some work on the trailer too and make sure I do something to cover those trailer brackets. Thanks for the advice. 

 

This might amount to another thread--but when I repaint this, I'll do all of it. How much paint should I take off (new will be same color) and what is the best way to do that? I can't tell what kind of paint it is. Looks a bit like latex to me but I don't really know. 

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PAR    188

Epoxy will marry the keel to the boat, while a bedding will permit its eventual removal, when the time comes again (it always does, especially if you haven't planned for it). Polyurethane and polysulfide are the usual choices and on this boat either is fine. BoatLife caulk is a commonly available polyurethane.

 

A protective keel rub strip is a wise choice. There are a few options, with metal being generally prefered, though plastics work too and don't corrode. Whichever you choose, use small, short length screws to hold it on. This strip is also sacrificial in nature, so if it bashes into something hard, the dainty screws will shear off or pull out and the strip will drop off. This is better than having larger, longer screws tear half the keel off the boat as they do their best to rip it off in a hard grounding or bottom strike. Bed this rub strip too, like the keel.

 

To remove the existing keel, use a reciprocating saw, set just above the bottom of the boat. You can steer these pretty good and they'll cut through fasteners if you find some. If you do find fasteners, stop and see if you can dig them out (vise grips and some cussing), as you really don't want to leave them in, particularly if cut. Once you got the bulk of it off, do as Chick suggests and repair the hull, make a flat spot for the new keel to land on, then lay some light cloth (6 ounce will do) over the area, so the hull shell is sealed. Hell, some industrial "Velcro" for the keel might be a better way to go, instead of screws, because there's no fastener penetrations. Personally, I'd be inclined to not reinstall the keel, just go "naked". She'll not track quite as good, but there'd be a little less drag. 

 

Instead of covering the roller brackets, just get larger diameter rollers, so the boat can't bash into them, before it hits the rollers. If you can't find bigger rollers, well you have no choice but to grind or saw the "ears" off the brackets, which is a pain in the butt, though often required. Consider tossing the rollers altogether. Well fitting bunks will easily support the boat and you can't damage the bottom on the rollers, if they're not there.

 

Take some denatured alcohol on a rag and rub the paint. If you see some color, it's acrylic (latex), if not, it's a polyurethane or an alkyd (oil). Just sand what you need to sand if the paint is in good shape (well stuck). A good scuff and some new paint is normal. No need to grind it off and start over. You will have to make some repairs, so these area's will need some grinding, fairing compound, primer and paint, but this is also pretty normal.

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greendane    8

PAR--many thanks! All very helpful info. 

 

Do you suspect the existing fasteners for the keel are from the inside of the boat? (Thinking through how to "dig them out" when I find them.) And IF I decided to put a keel on, would I fasten from the inside? Or would the BoatLife caulk be an adequate enough adhesive? And of course, what acts as the "clamp"on the keel while it cures. Gravity? Or do I have to use screws to get it to stay? 

 

I need to do some weighing of how I go about this because my trailer is on the outs and maybe has 1 - 2 seasons left on it. With all the saltwater here, I'll likely be upgrading to a galvanized trailer and the ones I've seen are bunks only (no rollers). My concern there is how easy the boat is to pull in on the bunks. Perhaps these trailers sit lower, but with my existing one, I usually can only get the back roller under water before my truck wheels are in the water. Fortunately the boat is light enough to pull almost half way on by hand  before I need to use the crank. 

 

Thanks again for the tips. Pulling the keel all the way off will also allow me to ensure there wasn't any water creeping to the hull.

 

-Bryan

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PaulSmith    2

Bryan - I'd give different advice.  I'm a fellow Puget Sound sailor who has maintained a fleet of small wooden boats based at Tulare Beach (which faces Camano from the mainland) for the past 30 years & who has sailed a wooden 18' centerboard trailer boat (the picture on my signature) for the same period.  We drag the fleet of dinghies up & down the beach on a daily basis in the summer - though our beach is medium gravel, not cobble, and has few barnacles to really chew on the hull.  The best option we've found is to put a 1/8" to 1/4" thick pad of fiberglass (roving and mat) and epoxy on the wear points and then rebuild it as it wears off.  On the dinghies, which get picked up at the bow and drug, that wear point is the middle keel and the back corners.  The fiberglass pad is the only thing we've found that works.  Lightweight metal on the outside means fasteners through or into the hull - and those always seem to get worked loose and then cause leaks and let water into the wood.  For my 18'  boat, which gets beached but not drug up the beach, I have a 1 1/2" wide half oval brass strip on the bow that runs back to the centerboard.  It has a full glass skin on the wood that is tripled 6 oz glass cloth in the area around the bow and forefoot.  Between the brass (sitting on an oak keel) and the glass I've never gone through to the wood though I have twice repaired the glass & repainted in the past 30 years.  The brass is heavy enough it doesn't flex with impacts much - which would work the fasteners loose.

Along the keel where my roller trailer can shred the sides of the keel when loading in bad weather I've got a fillet of glass & epoxy protecting the wood.  1/2" wide at the bottom tapering to nothing at the outer edge of the keel.  And a metal strip full width on top.  That forces the roller away from the outer corner of the keel.

 

I'd suggest you add a pad of glass 4" wide on your bow, then a good stiff metal bow guard all the way to the centerboard.  You should be able to remove the frayed wood along your keel and repair it with glass & epoxy - and add a sacrificial wear guard in the spot for next time. 

Your middle picture looks scary - I don't see any grain in that "wood".  If the builder put something weird in there you might have to take it all off.  The keel strip is just sitting on the plywood hull - the integrity of the hull isn't compromised if you have to take the keel off.  It's just work.

 

For your trailering situation - particularly those exposed ramps on the outside of Camano - you really want to get a roller trailer.  My latest boat requires a bunk trailer & I HATE loading it with any kind of a cross wind.  The roller trailer for my 18' boat is a dream by comparison.

 

My dad & I built & sold a CS15 last year.

 

Paul Smith

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greendane    8

Thanks Paul (and I should say neighbor!). Thanks for the insight--and empathy with the local conditions. I've had my share of challenges at the State Park. Actually had to back my trailer down on the beach on the north side of the north dock to retrieve once because of the thrashing. A couple questions if I may...

 

I haven't worked with fiberglass yet--what do you mean by "roving and mat"? And should I remove all the paint where I put the pad? 

 

And the keel "just sitting on the hull"--your opinion on epoxy vs other adhesive?

 

BTW, the "wood" in the back isn't actually wood. It was a metal plate that the builder put there for the roller to rest on and I guess distribute the weight a little better. It's still smashed down a little though. Wasn't stainless. I took one of them off (there are 2) and two of the fourd screw heads just twisted right off.

 

 

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PaulSmith    2

Bryan - Glad to help!  After watching wooden boats at Tulare for all my life years my vote for the last 20 years is to encapsulate all wood in epoxy & make sure it stays sealed away from water.  That means surfaces, screw holes, everything. Otherwise it swells & shrinks & checks.  Wood is a great bendy structural material that doesn't wear out but letting it get wet is bad.  Traditional wood boat builders would totally disagree with that. 

 

Roving & mat are two different types of fiberglass cloth - roving being very heavy & thick but woven & matt is random strands in a sheet.  You need the wear pad full of glass fully wetted with resin but not floating in it.  Read the Guogen Brothers book or similar.  Never put resin over paint - when the paint fails (and it will) the resin just peels off.  You want to sand down to good fiberglass/resin or clean wood before applying more resin & glass.

 

Re the Keel - I just meant you could cut off the keel & sand it down flush to the hull without affecting the integrity of the hull.  I would epoxy the keel to the hull screwing it down unless you have a way to clamp it without screws (the screws are just there to hold the parts together while the epoxy cures) and then put a full length metal strip covering the entire length of the keel full width of the keel.  Epoxy the keel before putting the metal on & put epoxy in the screw holes to seal the wood before screwing the screw in.

 

If the metal you found wasn't brass, bronze, stainless steel or aluminum replace it.  try to match the fasteners to the metal you use.  Hard to do with Aluminum - easier with stainless or bronze.  Fisheries Supply has silicon bronze and inexpensive good stainless screws.  If the boats spends most of it's time on the trailer and less int eh water this isn't a huge issue.  Look up Galvanic Corroision.

 

Enjoy!

 

If you're not in a rush I am at Tulare about every other weekend and could come by to look at what you have.

 

Paul

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Hirilonde    170
2 hours ago, PaulSmith said:

  Wood is a great bendy structural material that doesn't wear out but letting it get wet is bad.  Traditional wood boat builders would totally disagree with that.

I build both ways and I disagree, but not for the reason you probably think.  Traditional plank of frame boats depend on getting wet and swelling to be sound and forest product boats (plywood) depend on being impervious to water.  They are entirely different games.  This could become a subject all its own

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PaulSmith    2

I would totally agree with your distinction. 

 

To date every boat I've built has been plywood.  They are also all boats that get pulled out of the water when not in use making the swell to seal method annoying to manage.

 

That doesn't mean the traditional method is bad - just not my preference.

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JPower210    4

That doesn't look like a fun job, but I bet when you actually get into it it won't be as bad as you think-  I'll add another suggestion-  when you add some glass on the bow, consider Xynole-  I used it for the bottom of my 17 and have been impressed with it's ability to stand up to beaching better than regular fiberglass.  And I'd definitely consider a metal strip, half round or hollow back running down the stem to the keel.

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PaulSmith    2

I just looked up Xynole & it sounds good!  I've tried Kevlar fabric (I had a bunch of surplus stuff at one point) but once you wear down to the Kevlar is last really well but it gets fuzzy and it is hell trying to cover the fuzz up to get back to a smooth surface.  Can you effectively sand the Xynole?  The Kevlar just got fuzzier yet when you tried to sand it.

 

Paul

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JPower210    4

Unfortunately, it does not sand as easily...but I found that it is worth the hassle, and just takes a bit of a different work plan.  I used a bit more epoxy to make sure that I did not end up sanding into the cloth, (which is a benefit for this application in my mind), and I used a flame to heat seal the "fuzzies" when needed.  It's also a lot friendlier to work with from a cloth standpoint, draping easier and no itch.  It's a lot like a loose weave tshirt fabric.  I wouldn't use it in a very weight sensitive application due to the extra epoxy required, but a few extra pounds on my 17 were worth the reduced maintenance and extra toughness.  I am incorporating it into some of the other projects I am working on as well- right now on a OB 20 that I have started.

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greendane    8

Xynole! Wow. Sounds good and perfectly suited to what I'm trying to do for the bow section. 

 

As it's currently belly up, I can't right now crawl under to confirm, but I have this old pic of the inside of the bow section. Should I assume there is solid wood in there to screw a metal strip on the outside? It looks like visibility disappears under the base of the mast partner. Would it be ok to epoxy a wood strip to screw into? 

 

Last night I started carving back layers of wood in the skeg keel where the steel "roller guards" were screwed on. The busted screws came out all too easily and were rusty. Clearly not sealed well and wrong hardware. The aluminum strip on the front keel has stainless and they seem to be coming out clean. But that doesn't mean water didn't get in there. Probably looking at replacing the keel over the length then. On the new one, will Xynole fabric be a good option here as well, or should I stick with glass? It was clear on the current situation that the 90* edges rubbed through and the glass peeled off too easily.

 

As an aside, (and because it is in the new photo) my boat came with hollow wooden square masts and thus the block-like partners. The masts were both badly damaged and I was able to repair one enough to take it out over the summer. I intend to retrofit for aluminum soon. But one thing at a time...I picked up the boat with Honda 2HP motor and trailer for $1500. So I'm not going to complain too much. 

Main parter.jpg

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greendane    8

Oh, and yes--any recommendation for sourcing the Xynole? I don't see it at Duckworks (only Dynel)

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JPower210    4

I ordered mine, as well as a lot of epoxy, from Raka.com.  But most of the epoxy/glass suppliers have it.  Dynel is similar, but some tests have shown that Xynole is a bit superior from an abrasion/impact standpoint.

 

For the strip-  you don't need a lot of screw to hold it-  I think I used 3/4 inch screws.  The joint at the two hull panels should have an epoxy fillet, as well as the thickness of the wood joining, to take and hold the screws.  I pre drilled undersize, placed a blob of sealant and hand drove the screw to avoid stripping it out.  No problems as of yet.  

 

For the keel-  I ran my glass over the bottom seam, and then screwed the keel on-  the keel got multiple layers of epoxy to seal, but, eventually it will be replaced as a maintenance item.  I didn't like the idea of trying to make the glass or xynole wrap a 90 degree corner either.  And the recommendations above about keel rollers make sense-  my rollers are big enough that the keel can't hit metal as it comes on.  I also found the addition of guide posts on the trailer helped a lot as I typically sail single handed and the wind always seems to want to blow my boat out of line when I am taking it out of the water.

 

Hope that helps!

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PAR    188

I like to support boats on their centerlines and rollers are common. The bunks simply prevent the boat from flopping over when you turn a corner on the road. In fact, I've used stands instead of bunks, which simply meet the deadrise, a bit forward of the transom. On these I use a "floppy" roller bracket, but replace the rollers with a padded piece of plywood.Sanders-22.thumb.jpg.6c7a0b710d00c32fe9e99d9fab05074b.jpg

Sanders-23.thumb.jpg.f48ddfbe468256d49e9804518c9edcdf.jpg

This is a bigger trailer than most here use, but shows the stands, which are home made. This particular powerboat had its transom hanging past the trailer by about 4', so the stands are about 6' forward of the transom on this 26' boat. The "V" shape thing forward helps guide the forefoot to the trailers centerline and not shown are aft mounted "guides" that help center the boats butt on the trailer centerline. The fore and aft guides are often critical on most trailer boats, because the trailer at launch and recovery is below the boat. The boat is floating and not likely to settle where you want it, as you start to pull her out. Note there's only a single keel roller, but this boat had a big skeg and straight shaft setup, so no place to really support the boat's centerline. What supports this boat are the two bunks, placed in line, directly under the engine bed stringers. This isures no hull distortions when stored on the trailer.

   I can't tell you how many poorly fitted trailers I see. With 'glass boats the worst that happens is a hook or other bunk related distortion is pushed into the hull shell. Wooden boats will pop fasteners, open up seams, etc. if the trailer doesn't fit properly. I bought a boat once, because the owner admitted it had a leak, but he couldn't figure out where or why. I instantly saw the raw water intake fitting pushing up into the hull, because the bunk wasn't properly located. I bought the boat, moved the bunks outboard a few inches and replaced the bedding on the bronze through hull.

   As to keel protection, I prefer to have an easily removable and replaceable metal strip. It's going to get beat up, so I plan on it. Using a layer of 'glass works, but is more of a bother, particularly come time to fix it. Xynole is about 6 times better at abrasion resistance, compaired to regular 'glass cloth. Dynel is about 3 times better than the same weight 'glass cloth. Neither of these fabrics should be used as a structural element, like over a seam. Kevlar is a pain to work with and I see no place for it except on racers, where every ounce is counted.

   The skeg (okay most of them) also is sacrificial in nature, but much less so than a rub strip. If well made, it can take decades of abuse, under a rub strip. If it's attached from the outside, it should have bonded fastener holes. I prefer to bed skegs, again knowing it'll need to be replaced some day. On a CS series type of deal, bonding it on isn't a bad choice. Yeah, it'll make you curse 10 years from now, when you've decided it's too beat up to continue with, but not so bad if you can guide a sawsall pretty good. I think glassing them is a waste of time and eventually causes more harm than offers good. Encapsulation, sure, but sheathing, not so much. A good argument can be made to leave the skeg with just paint, no encapsulation. It will dry and get wet naturally, which is better than having a plastic coating, that can trap moisture if it's breached.

 

 

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JPower210    4
8 hours ago, PAR said:

 

   The skeg (okay most of them) also is sacrificial in nature, but much less so than a rub strip. If well made, it can take decades of abuse, under a rub strip. If it's attached from the outside, it should have bonded fastener holes. I prefer to bed skegs, again knowing it'll need to be replaced some day. On a CS series type of deal, bonding it on isn't a bad choice. Yeah, it'll make you curse 10 years from now, when you've decided it's too beat up to continue with, but not so bad if you can guide a sawsall pretty good. I think glassing them is a waste of time and eventually causes more harm than offers good. Encapsulation, sure, but sheathing, not so much. A good argument can be made to leave the skeg with just paint, no encapsulation. It will dry and get wet naturally, which is better than having a plastic coating, that can trap moisture if it's breached.

 

 

 

I agree wholeheartedly here-  if I were building my 17 right now, I think I would use the most rot resistant wood I could and just paint it.  And bed it on the keel, with the idea that it would need to be removed at some point.  I wonder if a piece of pressure treated might be good, but I would want to get some other opinions before I went that route.

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