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T O P I C R E V I E W
Posted - 02/21/2021 : 12:50:13 In an effort to assist others, and in an absence of a clear procedure I wanted to contribute this food for thought to everyone here in hopes that others with this condition will have a guide to help them with the project.The original bushing to my 2004 C250 WB (Hull #781) is/was a fiberglass bushing that was inset into a hole in the centerboard. Over time, because this is a high load point, the bushing broke free from the centerboard with a net result that the board then effectively rattled around on the bushing. This then made the hole oblong and generally a mess.
From the bottom looking up at the pivot point
With the board out you can see the mess that it is...
The board then was free to rattle around the trunk, make lots of annoying noise and make the boat difficult to steer as it would tend to never go straight as the centerboard pivoted port or starboard literally acting as a second rudder amidships. A condition that is no fun at all and worse potentially dangerous. Fortunately it can be relatively easily fixed and made better than new in my opinion. There are some tricky situations that one encounters doing this job and hopefully this will give others a good reference as to the key points of the job. Iím not going to go into specifics on removing the centerboard as everyone has different facilities available to them to get the boat raised up. My marina only has a telelifter and straps so we lifted the front end of the boat while it was on the trailer the 16 or so inches required to slide the board out. Takes less than 20 minutes to do it. (note to those with the tongue extension - get it out of the way before lifting the boat first!)
Note that a floor jack is helpful raising and lowering the board
There are a few important things to note about my boat and this job Ė my hull, #781, came with the Ďnewí keel hanger casting kit that apparently is wider than whatever was originally chosen earlier in the production run. That kit, as mounted in the hull has a 2 Ĺ inch gap where the board goes sitting on its bronze pin. That was good news for me as I chose to replace the bushing with the C-25 Keel Pivot Pin Bushing Part #: E1985 for $9.95.
As soon as I removed the board from the trunk I reinstalled the hanger and checked the bushing to see if it fit. It did perfectly.
Checkout this mess that is the old bushing and the new bushing
That said, the tolerances are close so going into this project I knew that I needed to have a high level of precision. While I didnít measure things, I do enough other mechanical projects that I could tell that thereís 1/8Ē or less that Iíll have to work with so things need to be done right.
The job at handÖ Once you get your centerboard back to your shop or wherever youíre going to work on it the first thing youíre going to notice is the hole for the bushing is right at the transition area between the flat part of the upper board and where it starts to taper the foil. Further, if your hole is an oblong mess like mine itís going to cause you a lot of stress trying to figure the situation out. Fortunately itís just not that hard, with simple tools you may have or have access too; like some scrap 2x4 wood, painters tape, C clamps, a drill press, and of course epoxy, you can do the job yourself.
Step 1 Ė I used two sawhorses to lay the board down horizontal. Clean off any bottom paint with an orbital sander so you have just gelcoat around the hole. I would also recommend cleaning out the hole in the centerboard and making sure there is no residual anything in there. Wipe it all down with acetone or other solvent and get it clean and dry on both sides of the board.
Step 2 Ė This was my hardest partÖ The width of my centerboard is about 2 ľ inches, maybe slightly more. I have no idea how precise Catalina made centerboards but thatís what mine is. That said, the bushing is 2 Ĺ inches so we have less than ľ inch that we will have to be very precise with. So the task becomes figuring out how to perfectly center the bushing into both the hole in the board and then centered again to equally straddle the board so it sticks out each side equally. Seems daunting. Itís actually not that hard.
Letís get the measurementsÖ You need a C Clamp and a very straight smooth piece of (in my case) scrap 2x4. I had one about 18 inches long sitting around in the barn. Clamp it on the underside of your centerboard with the end of it sitting under the hole. Next set the new bushing on the board and centered in the hole. It will stick out the top side of the centerboard and should look something like this
You need to measure how far it sticks up between the flat side of the centerboard top and the bushing. I used some dial calipers that I have and recommend that you do as well. So in my case I have a measurement of just over 3mm.
Thatís all we have to play with here if we are going to keep things straight and level. And we need them to be so that when you reinstall the board it will be perfectly centered on the keel hangers and not scrape either side of the board on them. Likewise, we want it to be centered in the trunk itself and we donít want the centerboard canting either to port or starboard causing you tracking issues.
Step 3 - Getting ready for the job. Now that you have your measurement the challenge is to get the bushing centered on the board. To do this is actually easy. Take your measurement from step 2 and divide it in half. In my case about 1.5 millimeters. So what you want to do it take that 2x4 that you have C Clamped to the board off and you need a drill press and a 1 ľ spade wood bit (the Catalina bushing is 1ľ diameter). If you donít have one you probably have a friend that does. I didnít and have always wanted one so I bought a cheap one at harbor freight for this job. All you need to do is drill that 2x4 the 1.5mm so that we have a small indentation in the board lowering the bushing the appropriate amount. Remember that our straight 2x4 is already level with the top of the board so by doing this we are effectively extending the bushing out the side of the board. Youíll need those dial calipers again to measure. I managed to do it right the first time and it looks like this. So now go back and clamp that 2x4 back to the underside of the board and center it up. Put the bushing back in and check your measurements. As long as you have clearance on both sides for the keel hangers you should be fine. My board looked like this:
Step 4 Ė No doubt at this point you are saying what about the transition area, how do we deal with that? Well again, itís not that hard and we can have excellent results if we think about what epoxy likes best; a mold. Itís easy to create one. We just have to figure out how to close the rest of the hole off and keep the epoxy from dripping all over the place. Get some packing tape or other substance that epoxy isnít going to stick too. In my case its two side by side strips of packing tape stuck to a piece of plain paper then cut into a square. Take the bushing and center it on the shiny side of the packing tape and draw a circle with a pen. Then use an exacto knife and cut out the center. Now you have a template for the underside of the board.
Take blue painters tape and tape all around the gelcoat on the centerboard hole. I taped mine so that I didnít epoxy anything I didnít want epoxied. There were some rough edges that needed the epoxy. Once you have done that, center your Ďmoldí Ė the taped square, center over the hole in the centerboard making sure the shiny side of the tape faced up towards where youíre going to be pouring the epoxy.
It should look something like this minus the tape over the bushing. Tape it to the board. This picture below is from the top of the board and is what it should look like looking down into the centerboard hole on the underside. Lastly, recenter the 2x4, insert the bushing into the Ďmoldí template and itís ready.
Step 5 - Now it becomes an epoxy job. In thinking about how I wanted to do this and what I was working with I chose West 105 with 205 hardener and 404 high density adhesive filler. Among the many high stress points on a boat I would certainly count this as one of them. So I think the addition of the 404 is applicable here for two reasons, strength and I wanted to thicken the epoxy. Iím not going to go into how to use the epoxy, suffice to say read the directions and follow the ratios!
I wanted a consistency that would flow into all the crevices but not be so thin as to seep around the Ďmoldí template I made on the bottom in case my cutting of the template wasnít as round as the bushing. Just in case I think itís a good idea to use some saran wrap to wrap the board underneath so nothing sticks.
So, job ready and itís time to pour. I did all my mixing in a clear plastic cup and made sure I had all the epoxy I would need along with some flat wooden sticks to act as a spatula. On the top side, make sure that you have sealed the bushing so you donít get any epoxy in there that youíll have to remove.
Then begin your pour into the cavity around the bushing taking care to keep the epoxy where it belongs. In the end I had made a second Ďmoldí for the top of the board to contour the epoxy to the transition area. Just press it down with your fingers. It does a great job.
Once everything has hardened, remove all the tape and you should have a perfectly finished job.
Step 6 Ė Now is the time to check your work. Like I indicated at the beginning we donít have a lot of room to play with here but the steps I outlined should have given good results. In my case to check my work I went and removed the Keel Hanger castings off the boat and brought them to the shop. Below are pictures after reassembling them on the board and snugging them tight to the pin. The camera angle is a little off but you can see that I have the proper clearances I wanted so reinstalling the board should go smoothly after a fresh coat of bottom paint on the centerboard. Ė Kemp Fuller C250 WB #781
1) pivot pin and castings. You say that you did not replaced them. Did you looked at them or is it that you changed regularly the spacers which did that you never ended with some play and banging of the centerboard? There seems to be a little wear of the castings but not so much. As k3fuller states, 1/8 ® seems to be a good tolerance. And in my case its not more than that for the castings. I conclude that I should change only the pivot pin. In the process of removing the castings to get the centerboard off, I broke one of the nuts. I was lucky to have a competent mechanic to extract the remains of the bolt in the screw hole. I will have to replace that nut. I have read that the torque should be 15 to 20 ft/lbs in this article that I cited at the begining of the post. 2) bushing I had no bushing in my centerboard too. And I will install one. k3fuller technique is simple and well explained. In my case there was not so much play around the pivot pin but there was. I might have to drill the hole a little bigger to insert the bushing. I wonder if anyway it was not a good thing to drill the surface roughly so that the epoxy could tie itself better to the centerboard. 3) spacers On another catalina thread the author said that he just bought plexiglass disks to save some money. http://www.catalina-capri-25s.org/tech/tech25/sowind2.asp Is this a good idea? I have also tought about using some floor tile made of polymer, but what material should be used? At $86 US, there is some savings for sure, especially for a canadian like me. If this is a possibility with the plexiglass, it would have to be cut into circles with a whole saw. 4) keel pivot pin shims https://www.catalinadirect.com/index.cfm/category/107/pivot-assy.htm With the bushing extending out of the surface of the centerboard, I imagine that there will be no more place for the keel pivot shims. I have those presently.
Comments and suggestions are still appreciated. Thanks.
Posted - 03/29/2021 : 22:15:51
quote:Originally posted by francoisl
1) I wanted to buy the bushing, but it seems that I will maybe have to also buy the castings and pivot pin..
2) Concerning the spacers, how do you know that they are the fit is tight? Could there still be too much space between these and the sides of the drift well?.
3) I was wondering if I should not take the opportunity to check the centerboard hydrodynamics and rectify it according to the following hyperlink.
The spacers are not as important as you think. Catalina Direct has the spacer kit with different widths. Do the best you can. If itís too tight then it will be hard to lower the keel to the fully down position. Too loose and it will make a clunking noise when you tack. If you have 1/4 to 1/8 inch gap, then you should be fine.
The centerboard fairing is a funny story. The C22 was the original Catalina boat. The C22 is a racing boat, so every second counts. The keel was lead or case iron. When the keel was poured at the foundry, the form was horizontal. The top side of the form was flat. I know a guy with a C22 who had this problem and used the procedure you posted. As Catalina got better at build boats they fixed this problem.
Your C250 has a fiberglass centerboard. You do not have the same problem as the link you posted. When your centerboard is removed, you can check that the fairing is the same on both sides. Itís worth a try, but the problem is not as serious as the C22.
Posted - 03/29/2021 : 17:37:12 Very useful thread. I am in the process of doing the same repairs on my 1995 catalina 250 center board. Thus I understand from what you write that I have the old version of the castings. Though the hole in my center board was less worn, pivot pin and the holes in the castings seemed to have more wear than yours. As I did not found your post, I have made a new post. On the picture of the castings the wholes seem excentric somewhat.
1)I wanted to buy the bushing, but it seems that I will maybe have to also buy the castings and pivot pin. As the dimensions of my actual castings are exactly those of the actual catalog, I imagine that the must have been changed once. Maybe changing the pivot pin and castings every 10 to 15 years is not a bad practice. This is a photograph: https://drive.google.com/file/d/1IBUDahGq6sqTpo8eth3b_jloEb3lkJJz/view?usp=sharing Maybe I should measure it more precisely with a micrometer.
2) Concerning the spacers, how do you know that they are the fit is tight? Could there still be too much space between these and the sides of the drift well?
Also, the lifting cable got detached from the centerboard and as a consequence the bottom part dragged into the clay of the shallow part of the bay where my mooring is. I could not lift the centerboard to the uppe position. I will have to redo part of the exterior coating of the lower fourth or third of the centerboard.
Posted - 03/08/2021 : 14:19:42 Thought I'd post a follow up on the reinstallation of the board. Last Friday I got the board reinstalled with no trouble at all. We used the Telelifter again to lift the front of the boat up on the trailer. Myself and one of the marina hands muscled the board in place in the trunk and he and I held it there while I got the hangers into position and bolted down. Note to others, a face shield or safety glasses would be a good item to have in case a bolt decides to drop on you as one did on me. I used a new tube of loctite and new SS lockwashers on the bolts. It wasn't hard to do even though the tolerances were pretty tight. You have to get the board centered in the trunk to make it all work and the foot of the board is pretty heavy to muscle around.
All that done I took the boat to the storage area and proceeded to install the spacer kit. I was surprised just how much room there was in the trunk that needed to be filled. The catalina measurement method included with the kit is rather imprecise (paint stick with tape wrapped around it). That kit comes with three sizes of shims and from the measurement three on each side was a little much, or at least seemed like it would be. So I selected the two thickest ones and epoxied them in the appropriate places. I don't really like the epoxy that came with the kit but it was certainly sticky enough. I taped them into place and left the boat for 24 hours to cure both the loctite on the bolts and the epoxy on the shims. Added a little bottom paint in the places left uncovered on the centerboard and proceeded to rig her up and get her in the water. (by the way, Friday evening I called Catalina tech support and asked of there was a torque spec on those bolts and they said no. The factory just used loctite and lock washers.)
Late in the day Saturday with the rig up and basic tuning we went sailing. Hooray, no centerboard clunk!! Not a sound anywhere of it. I'll also note that the tracking of the boat was vastly better now that the centerboard was aligned and not floating around on the pivot pin acting as a second rudder. So all is well and fixed. Really looking forward to this sailing season.
Posted - 02/24/2021 : 07:21:11 Excellent questions! My board doesn't have any spacers and doesn't look like it ever did, or if they were there from the factory there is no residual evidence. I'm currently working with the marina to get the board back on using the telelifter. As far as spacers go, I have left the general area where I am going to put spacers sanded clean. Because I don't know how much space I'll need to fill I am planning on getting the board reinstalled in the hangers and then adding the spacers. It's not ideal, I'd rather have the boat suspended in slings and be able to raise and lower the board to be more precise but that option is not available to me so I'll have to do the best I can with what I have. It'll be far better than what was! The suspension hanger bolts have been thoroughly cleaned and I plan on cleaning the female ends in the hull before I put it all back together. I plan on using fresh locktite. The bushing came from catalina direct but I don't know what SS it is. My boat is in fresh water so no zinc. I can give you an after action report on reinstallation but the current plan is to use the same automotive floor jack to raise the board back into position once it's been manhandled into the trunk and secure it to the hanger assembly. It's going to take two of us to do that part.
Posted - 02/23/2021 : 11:09:32 Thank you for taking the time to document this excellent article and provide step by step guidance of this tricky center board suspension tube repair
Question... did you leave room for spacers between the hull and the 4 bolt hull suspension brackets? Did you use tight lock for the bolts?
Where did you obtain the new bushing and what type of SS is it made of
If your boat is on the salt did you add a self sacrificing zinc to the suspension bracket?
Did you need any help to detach and install the centerboard again?... any tools, props, braces needed?
Posted - 02/22/2021 : 08:24:50 Good article/post Kemp...especially since our boats are not getting any younger and sometimes require a little minor surgery.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.