#1
IP: 199.68.38.6
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Catalina 30 Keel Stub/Smile
I have known since buying the boat that at some point in time I would have to address the "smile" - the issue with the keel stub. I also have the fiberglass scrubbed off the bottom of the keel at the bow end from (I assume) various groundings over the years (I am responsible for three instances).
My plan of attack for keel stub: dig everything out around the keel bolts, sand down well, and rather than using core (or plywood ) use epoxy, fiberglass mat, roving, and cloth and alternating layers of GL 10 fiberglass sheet cut to fit (with holes for the keel bolts). Build this back until one solid fiberglass keel stub around 3/8" or 1/2" less than original level. Then obtain a piece of stainless plate, cut to fit with holes for keel bolts, place in bed of epoxy and filler, and then layer with epoxy and fiberglass cloth. Install new washers and nuts; torque after everything fully cured. Torque again after boat in water. My plan of attack for keel stub/keel junction outside: clean all bottom paint off well; sand well, dig vigorously into crack. Do a wide area around crack. Fill crack with epoxy and filler. Apply multiple layers of cloth extended well on each side of crack. Sand smooth/fair with epoxy compound. Bottom paint. My plan of attack for bottom of keel: clean all bottom paint off well; sand well, do a wide area around bare area. File exposed lead keel to "bright". Apply multiple layers of cloth extended well around bare area. Sand smooth/fair with epoxy compound. Bottom paint. Quite a few Catalina folks here - anyone been down this road? If so, did you lift the engine to get to that area around the back two bolts? Thanks.
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1978 Catalina 30 |
#2
IP: 99.30.185.198
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I have owned my C-30 for about 7 years during which time it has been hauled twice for bottom paint. At the time of the first haul, the "Catalina smile" was fairly noticeable but not drastic. The keel bolts seemed to be solid so the decision was made to just grind out the smile and fill the void with a slightly flexible filler and then cover with bottom paint. At the second haulout, a close inspection showed that there was only a slight sign of flexing in that area. I realize that these 30 some year old C-30s probably have a wide range of smiles that should be addressed appropriately but, at least in my case the "patch" was effective.
Tom P.S. Rumor has it that another C-30 owner is in the design phase of an internal SS brace that should go a long way toward curing this design problem. |
#3
IP: 24.152.132.65
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http://www.moyermarineforum.com/foru...ead.php?t=6226 roughly posts 45 ~ 60
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 10-21-2019 at 08:26 PM. |
#4
IP: 174.96.76.34
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Thanks all. I reviewed the thread Neil referenced. That thread showed the appropriate approach recommended by Catalina, which is also what in have seen in a web search.
The approach Neil is developing is intriguing to me. I assume Neil's boat-building experience allows this insight. Neil, even if the metal bracing you are developing were readily available to order, if that plywood core in the keel stub gets wet and rots then wouldn't there still be a problem due to side-to-side forces acting on the keel and keel bolts? I looked at many boats in the yard yesterday. The seam is readily observed in most boats, many have a crack. The degree of the crack varies.
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1978 Catalina 30 |
#5
IP: 24.152.132.65
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The stainless floors are designed such that they do not contact the bottom of the bilge, visible in the picture of the patterns in place. They bear on the curvature of the hull where it turns to the keel stump. Therefore all loads borne by the stainless floors and lag bolts are independent of the plywood shoe, the reason the shoe does not have to be removed.
The curvature at the keel stump is the strongest area of the hull, designed to withstand side leveraging of a 4300 lb. keel when heeled under sail.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#6
IP: 108.79.1.46
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I dug out all the plywood in the keel stub and glassed it in as per Catalina's recommendation. Yes, I did have to remove the engine to access the aft most keelbolt. I also left a 3/16" keel to hull joint on the outside filled with sikaflex just in case of movement in the future.
I did this in two phases- 1. removed and replaced stub around first 7 bolts (no need to pull engine) 2. pulled engine and finished the job I was originally hoping the first part would be good enough, but there was still a little movement aft so I realized I really needed to do it all the way.
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john '77 catalina 30 #783 the only way to be sure is to make sure |
#7
IP: 174.96.76.34
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John, any issues since?
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1978 Catalina 30 |
#8
IP: 12.219.49.130
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FWIW: The Catalina 27 has the same smile issue. I ground out a 3/16" (or so) groove and filled it with 5200 fast cure. That has kept things water tight for more than a decade.
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Mike |
#9
IP: 161.213.49.150
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Quote:
TRUE GRIT |
#10
IP: 206.125.176.3
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I have also done the 5200 repair on the crack. I was able to get a hack saw blade in my crack and used that as a cleaning device. After 5200, I used high-density West epoxy on the first batch to complete the repair, and then faired with low-density West. This has proven adequate...several years later, the only thing I see about is about a 1" long ripple in the bottom paint, with the initial repair probably 24" long.
I also added six 1/2" diameter lag bolts spaced roughly in between the original studs. I have not ripped the bilge apart yet..I will wait and do that when I have to also do the mast step, which seems another common failure area, or maybe some "Dutton keel floors". Sounds like jbsoukup did it correctly!
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#11
IP: 108.31.90.116
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Finally! A good use for that "Devil Adhesive"!!
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@(^.^)@ Ed 1977 Pearson P-323 "Dolce Vita" with rebuilt Atomic-4 |
#12
IP: 108.79.1.46
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I just did the aft keel bolt this past winter so I won't know if I'm successful until the fall haul-out. Although there was no perceptible movement when lifted off the cradle.
After the first phase, when she was hanging on the straps, I could see just the tiniest little bit of movement (opening of the joint all the way at the back) convincing me to pull the engine and finish the job. Of course I had to wait the whole season to do it. What Catalina doesn't tell you is that you should open the keel/hull joint on the outside (IMHO) because when the internal repair is done, and the nuts get torqued there will be some movement of the keel. I know this because I had originally repaired my smile by using a diamond blade on an angle grinder to hog out the crack and filled it with sikaflex. When I tightend up the keel bolts after the repair the hardened sikaflex squeezed out significantly. So if I had to do it all over again, I would 1. pull the engine (not really a big deal on a C-30) 2. open the exterior keel/hull joint (use a 1" wood chisel and hammer, so easy!) 3. use a 4" angle grinder with a diamond blade to cut the perimeter of the bilge (angle it inward, parallel or nearly with the curvature of the hull. Don't worry you won't penetrate the hull.) 4. use a long handled, sharp wood chisel to hack, hack, hack away at that nasty rotten keel stub. 5. glass it in as per Catalina's schedule. (they make 24oz. roving with mat attached for faster build-up in the stub area) I originally used 5200 on my exterior keel/hull joint but I felt it was a little too hard/inflexible. So I cut it out, did the last keel bolt, torqued all the nuts, and then filled it with sikaflex. Hopefully my old '77 is now as good as the newer C-30s that didn't use plywood in the stub. I can't recall ever seeing one of those with a smile.
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john '77 catalina 30 #783 the only way to be sure is to make sure |
#13
IP: 174.96.76.34
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John, how thick was the wood core in the keel stub?
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1978 Catalina 30 |
#14
IP: 108.79.1.46
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mine had a thin layer of 'glass then two layers of 3/4" plywood, then some hard stuff that looked like sand mixed with resin which I did not go beyond, so about 1 1/2"
When I did the aft bolt, I discovered some plywood beneath that sandy layer which I did remove, making the build-up more like 2 1/4" http://www.moyermarine.com/forums/at...1&d=1463531825
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john '77 catalina 30 #783 the only way to be sure is to make sure |
#15
IP: 174.96.76.34
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Thanks, John.
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1978 Catalina 30 |
#16
IP: 71.178.85.60
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John...stainless studs? I can't confirm with your pics, but it looks like they are not..My #511 does NOT have stainless studs and they are heavily corroded due to P.O. leaving the bilge wet. I hear that once you knock the old nuts off the threads underneath are usually in pretty good shape, even on mild steel. I have a die, and some SS nuts to go on the studs if I ever do all the work you've done.
I do not know at what hull number they went to stainless. That info is probably available on the C-30 website.
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) Last edited by sastanley; 05-18-2016 at 08:56 PM. |
#17
IP: 108.79.1.46
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The keel bolts are not stainless steel.
The old nuts were pretty badly corroded on the outside but with chasing the threads before removal and a little heat from a torch, they spun off with no problem. The threads under the nuts were in what I would call 90-95% condition so, obviously, they're made of a good grade of steel. Core 10? She's been in fresh water her whole life and I'm sure that has helped. So, new stainless nuts and washers and hopefully She's good to go for another 30+ years. When I get a chance, I'll post some pictures of my bilge in "as is" condition (referring to another thread)
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john '77 catalina 30 #783 the only way to be sure is to make sure |
#18
IP: 199.68.38.6
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Question as regards materials to use for this repair. I used some Flame-Retardant Garolite (G-10/FR4) from McMaster-Carr for another repair. Very impressive material, quite expensive, difficult to use hand tools on (need diamond tipped blades).
I assume I would tear into this and remove the plywood from both the keel stub as well as the plywood mast compression post block in the bilge. I was thinking I could use Structural Fiberglass (FRP) from McMaster-Carr rather than the G-10. It is not as strong, but is less expensive and much easier to use hand tools on. Opinions?
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1978 Catalina 30 |
#19
IP: 72.69.36.126
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Diamonds are nice but G10 cuts pretty well with carbide-tipped blades. I've used it for lots of stuff - backing/mounting plates, replacement deck after core repair, centerboard handles on a Dyer Dhow - and find it entirely worth the price.
You can buy miscellaneous pieces from Norva Plastics on eBay. Pro tip: you can also call them directly at (757) 622-9281 (Norfolk, VA). |
#20
IP: 24.152.132.65
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I think it's important to replace the plywood shoe with another backing plate in the laminate to spread the load of the keel bolts. Fiberglass by itself does not fare well with localized stress points (see winch, cleat and stanchion installations for examples). The Garolite material mentioned is fiberglass cloth based and because of that I think it might not be the best choice for this application.
Worst case, assuming the original adhesive between the hull and keel is no longer a factor after 40 years, you're counting on the eight bolts for everything. The loads are leveraging loads when the boat is heeled under sail and the force upon them is significant. You're looking at 4300 lbs. on a moment arm of at least 2 feet. In making the repair you're considering I suggest a steel plate, maybe even stainless, of say ˝" thickness cut to the dimensions of the bilge bottom. In other words, I'd replace the plywood shoe with a steel one. My 2˘
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 05-24-2016 at 12:40 AM. |
#21
IP: 107.0.6.242
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2 cents more
Whenever I replace a keel bolt on my wooden boat I always fashion a steel plate to spread the load.
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#22
IP: 12.172.250.194
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I'm pretty confident that replacing wood with G10 of similar dimension anywhere on a boat will be a structural improvement as long as it's properly bonded to the surrounding area (which may not be a trivial task). G10 is pressed layers of fiberglass cloth and epoxy in an optimal ratio with no voids - it is very tough stuff. Not steel to be sure, but better than wood for all except termites.
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#23
IP: 199.68.38.6
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Here is my initial (rough draft) plan:
Step 1: Cut fiberglass skin in bilge and dig out all wood down to the fiberglass keel stub floor (same thing goes for the mast compression block). Sand all the area of the bilge with a rough grit sandpaper (e.g., 36 grit). This will be somewhere between 1.5 inches and 2.5 inches of depth of material from what I have read on the web from others doing this task. Step 2: Layer alternating woven roving and the heaviest weight fiberglass cloth I can find wetted out with epoxy across the keel stub floor and up the sides of the bilge (i.e., inside the boat). Do enough layers to get a thickness of one-quarter inch or so. Step 3: Make cardboard template of bilge floor and cut the G10 or FRP to shape, including holes for the eight keel bolts. The longest G10 or FRP I have seen is four feet in length, so may require two pieces. If two pieces are required, then alternate the seams. Lay the G10 or FRP into the bilge in a bed of thickened epoxy and weight down evenly, scraping off the excess thickened epoxy. Step 4: Repeat step 3 until approaching the original bilge level, making sure to sand the surface of each layer level so that there are no lumps to make voids in the next layer. This should take either three or four layers of one-half inch thick G10 or FRP. The mast post compression block in the bilge will be rebuilt in the same manner. Step 5: Layer alternating woven roving and the heaviest weight fiberglass cloth I can find wetted out with epoxy across the stacked up layers of G10 or FRP to make the new bilge bottom. Do enough layers to get a thickness of one-quarter inch or so. Step 6: This is where I am not quite sure I am following the conversation above. I think what has been pointed out is that at this point I want to make another cardboard template and then cut a piece of stainless steel to shape with holes for the eight keel bolts. Or, did I want this plate embedded down between the layers of G10 or FRP? Also, are we thinking that this plate needs to be one-half inch thick? This plate would get embedded down with thickened epoxy, evenly weighted. Step 7: Let everything harden up well - couple of weeks at least. Torque keel bolts to factory specs. Use stainless steel nuts/washers the length of the bolt. Step 8: I could also add additional stainless steel lag bolts at this point. Step 9: If the Dutton bilge arch becomes available, then add at the next winter haul-out. Opinions?
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1978 Catalina 30 |
#24
IP: 24.152.132.65
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It's interesting that Catalina's published remedy does away with the plywood shoe and replaces it with only glass work. It begs the question, what was the plywood shoe about in the first place?
You never know what lies beneath the line of vision once you start digging into the bilge. Be prepared for a plan B just in case. Here are a few pictures to disturb your sleep:
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#25
IP: 174.96.76.34
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Ok, thanks for the nightmare fodder, Neil!
To your point, yes, why was there a big plank of wood there? The Catalina factory fix makes me think it was just to save money rather than using more fiberglass. I am not enough of an engineer to know otherwise. Regardless, I like the idea of the metal plank. Can stainless steel be wholly encased in fiberglass? How about 3/4" or 1" aluminum? By the way, with your nightmare pictures, would you not be S.O.L., even if the Dutton arch was readily available?
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1978 Catalina 30 |
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