| transom repair/ gudgeon replacement #271047 04/02/14 02:39 PM 04/02/14 02:39 PM |
Joined: Jan 2007 Posts: 160 North Carolina abbman OP
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Posts: 160 North Carolina | I've started to repair the transoms on my 16 and replace the old style gudgeons with the newer ones. I had asked for advice on this forum and others and I appreciate everyone's advice on how to repair them. Long story short, my gudgeons failed while under sail during Ya Gotta Regatta down in Myrtle Beach. Some of the ss screws sheared off inside the starboard transom. I'm very inexperienced with fiberglass repair and was initially told to drill out the old ss screws, since they were likely seized into the aluminum plate (which they were). I didn't use the right tool for the job (a left-handed drill bit) and ended up having a really difficult time drilling out the steel. I buggered up a lot of the surrounding glass and aluminum. I also sheared off some of the screw heads on the other transom and basically doubled the work I am having to do. After looking into several options (install ports and thru-bolt, install helicoils, fill and drill, etc.) and talking with many folks about it I have decided to go the most drastic route and remove everything down to the aluminum plate and build it all back up. I just couldn't stand the thought of installing ports, especially when that area of the boat is often underwater when resting on the water and in between races. So far I have gotten the aluminum plate out of the port hull. I should be getting new aluminum plates in tomorrow. I figured I would post some pics of my progress for feedback from you guys as well as to show the anatomy of the 16 transom. I'll continue to post my progress. Wish me luck. I'm storing the photos here: http://s1319.photobucket.com/user/jsautry/library/?sort=2&page=1Feel free to tell me what you think or offer any advice.
Last edited by abbman; 04/02/14 02:40 PM.
James 1983 Hobie 16'
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271049 04/02/14 02:51 PM 04/02/14 02:51 PM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | Good Lord, man...chop chop. The last Ya Gotta Regatta was at least four years ago!
On a more serious note, be sure you taper out where the new fiberglass meets the old on the transom so you have a large contact area for the new resin to bond to. You typically want a 10:1 taper (or more) if you can manage it...so if you've cut 1/8" into the glass, you should taper out the seam between old and new about 1.25".
Jake Kohl | | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271051 04/02/14 03:32 PM 04/02/14 03:32 PM |
Joined: Jan 2007 Posts: 160 North Carolina abbman OP
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Posts: 160 North Carolina | Yeah man. I'm pretty ashamed of myself. It's been too long and I miss sailing and racing with you guys. I was really starting to sail well back then too. There has been a lot going on in between, (I married the girl that came with me to the 2010 Duck Cup, moved about every year, and was pretty strapped financially) but the real reason is that I was intimidated by the repair. I'm hoping to be back on the water soon. I definitely want to do Duck Cup this year as well as several other regattas.
Thanks for the advise, Jake. I'll keep posting pics of each step and feel free to keep the advise coming to help me make this a quality/lasting repair.
James 1983 Hobie 16'
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271052 04/02/14 03:39 PM 04/02/14 03:39 PM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | If you have access to it, a side-angle grinder with a flapper sanding disk makes short work of tapering out that repair. The main point is that you don't want to have the sharp 90 degree edge that you would have if you just repair the hull as it sits right now. That would load the seam between old and new almostly completely in shear and there will be minimal contact area to carry the load. You want lots of contact area.
Also be sure to bed the new aluminum plate with some thickened resin (preferably use cabosil filler {fumed silica}) so it makes full contact with the inner skin of the hull and around it's sides. Also coat some thickened resin on the outside of that plate before starting to build up your glass so the plate has very good contact all the way around it with everything it touches. It may work loose if it has gaps around it.
This really shouldn't be a tough repair...the boat is very solid in this area and you can't mess it up to the point that it can't be fixed. Don't sweat it and have at it!
Jake Kohl | | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271054 04/02/14 03:45 PM 04/02/14 03:45 PM |
Joined: Jun 2002 Posts: 1,658 Florida Suncoast, Dunedin Caus... catman
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Posts: 1,658 Florida Suncoast, Dunedin Caus... | You could have cut holes in the deck to work inside and glued the cut-outs back in. Would have been much better than cutting into the outer laminate as you've done. How you plan to repair it from here? Hopefully your rudders kick up easily because if you fix that the way I think your going to that transom will peel off.
Have Fun
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271057 04/02/14 04:30 PM 04/02/14 04:30 PM |
Joined: Jan 2007 Posts: 160 North Carolina abbman OP
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Posts: 160 North Carolina | My basic plan is to first remove the aluminum plates. I wasn't able to get the screws out successfully, some of them are still in the plate. That will leave me with the inner glass. I am then going to patch the holes from the existing screws on the inner most layer of glass. I definitely plan to grind to a taper a good size portion of the outer fiberglass to get good contact with the new glass. Then, glue in a new aluminum plate. Fill in any gaps with thickened epoxy. I'll then likely cut out a new piece of plywood to glue to the back of the plate to keep the brittleness of that area down. I figured an area that thick of just thickened epoxy might be prone to cracking under stress. Correct me if I am wrong there. Again, keep in mind I don't really know what I am doing. I'll then fill in any gaps. Then, I would start to lay glass over that, laying it up in to the tappered section in layers and possibly wrapping around to the side of the hull. Grind/sand everything back to where it is supposed to be and then finish with gel. This is my first time doing any significant fiberglass work, so I am totally open to thoughts and suggestions. I've got to learn how to do this stuff sometime or later.
James 1983 Hobie 16'
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271060 04/02/14 05:26 PM 04/02/14 05:26 PM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | Aaa...Ok. I see what you've got. I didn't realize that we were still looking at the aluminum plate in the hull. I agree that it would have been easier to go through the inspection port thing - even if you reglassed the hole...but it's not a big deal with what you have.
I haven't been inside a Hobie 16 at the sterns....is there actually a layer of glass on the opposite side of the aluminum plate?
Jake Kohl | | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271064 04/02/14 07:31 PM 04/02/14 07:31 PM |
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Posts: 160 North Carolina | There is. It appears to be about 1/8 thick from what I can tell. From the inside of the transom to the outside it is: 1/8 in. glass, a 1/4 in. aluminum plate, 1/4 in. plywood, 1/4 in. glass, gelcoat. I'm pretty sure the plywood is cut to the shape of the transom and glued in there. I'm not sure how it all goes together exactly. You can see in the pictures I added that there is some separation between the inner layer of glass and the deck/lip of the transom. I figure I will fill everything in there and probably lay up a little glass first before I glue the new aluminum plate back in. http://s1319.photobucket.com/user/jsautry/library/?sort=2&page=1I really did consider putting ports in the sterns, but I just hate the thought of water getting into the hulls. I had problems with delamination in a previous set of hulls and I can imagine that ports in that curved area of the hull could possibly lead to some delam. I also thought of cutting into the hull to thru-bolt and repairing the deck, but if something were to work loose later that would be another round of having to gain access to the inside of the boat. I figured replacing the aluminum plate, plywood, and layers of glass would bring it back to a more "original" state. I will also have the option of removing the gudgeons if that is ever necessary. This will also give me all new stuff to drill and tap into, so hopefully I can keep everything in place and water-tight.
James 1983 Hobie 16'
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271075 04/03/14 08:04 AM 04/03/14 08:04 AM |
Joined: Jun 2009 Posts: 524 Petten Netherlands northsea junkie
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Posts: 524 Petten Netherlands | In order to make it strong enough for a rip-off the next time that you hit the sand with your rudder, I would suggest the following:
You will get the necessary strength only if you laminate the complete transom surface with an overlap on the inside side of the hull!
So there you have to taper the laminate to not disturb the streaming flow of the water too much. Very important is to round-off (before) the angle between the steep end of the innerside and transom itself; so make a round edge. Use the complete thickness of the sandwhich hullplate. (Otherwise you get troubles with laminating)
After that laminating, you can add two or more layers laminate(tapered) on this inside which has to put out straight, passing the transom. The space (niche) which you have created this way, you can fill with thickend epoxy.
That's the normal way to make an edge. You can even make this as sharp as a knife.
For the gudgeon I remember you that Hobie has complete one-piece gudgeon plates on the market for the upper and lower pin together.
At last I would consider not to make holes with bolt-thread in your aluminium plate, but to mount and fix the bolts with laminate and epoxy reversed under the laminate. So that the threaded part sticks out for mounting the gudgeonplate. ( Be sure that they cannot turn if you snug the nut on the outside) In that way you have completely sealed off the transom.
Last edited by northsea junkie; 04/03/14 09:08 AM.
ronald RAIDER-15 (homebuilt)
hey boy, what did you do over there, alone far out at sea?.. "huh....., that's the only place where I'm happy, sir.
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271087 04/03/14 10:58 AM 04/03/14 10:58 AM |
Joined: Jan 2007 Posts: 160 North Carolina abbman OP
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Posts: 160 North Carolina | Thanks, Ronald. I had thought about leaving the threads out as you mentioned, but from my research the problem with that is that it will interfere with the lower rudder casting on the H16, preventing full steerage.
There is a part of me that is thinking about removing the entire transom down the the innermost glass. Basically bringing it back to a flat surface. That would give me about 1/2 in. or more of the hull sides glass. I could then glue the plate in. I could lay glass over that and have the whole inside glass to laminate it to. I would then fair all of that down flat again. Then, glue in new plywood to match the shape of the entire transom. I would also glue it to the sides of the hull. Then I could lay fiberglass over the entire new plywood and interior sides of the hulls and build everything up again. It seems to me that this would be the strongest repair, and probably bring everything back to a more original state. It would give me the most surface area for new glass/epoxy puttty. Again, if my thinking is wrong here don't hesitate to let me know.
I am planning to install the one-piece gudgeons.
Is this kind of what your were saying, Ronald? I definitely want to make this a strong repair.
Last edited by abbman; 04/03/14 11:00 AM.
James 1983 Hobie 16'
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271092 04/03/14 12:04 PM 04/03/14 12:04 PM |
Joined: Jun 2009 Posts: 524 Petten Netherlands northsea junkie
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Posts: 524 Petten Netherlands | Okay James, with regard to the reverse mounting of the bolts, you are quite right. I sacrificed indeed maybe 10-20 degrees of steerage range on my homebuilt cat.
If I understand you correctly, you seek support for your rebuilt on the interior sides of the hull. In fact you estimate that you have 1/2 in.or more working distance there. In my proposal I searched for this working space a place on the outside of the hull which could give you a larger area.
Nevertheless we both do realise that the solution has to deal with the shifting-force when the new transom is charged with pulling-force (ripping off).
It isn't clear to me if you are planning to laminate inside the hull against the inner sidewalls too. Do you have enough "flesh" overthere, especially because you have to make a "fillet" (I don't know the english) in the corners in order to laminate up against the innerwalls?????
If my understanding of this is correct, then I hesitate.
Last edited by northsea junkie; 04/03/14 01:02 PM.
ronald RAIDER-15 (homebuilt)
hey boy, what did you do over there, alone far out at sea?.. "huh....., that's the only place where I'm happy, sir.
| | | Re: transom repair/ gudgeon replacement
[Re: abbman]
#271172 04/05/14 03:05 AM 04/05/14 03:05 AM |
Joined: Jun 2009 Posts: 524 Petten Netherlands northsea junkie
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Posts: 524 Petten Netherlands | Rodger, it is cristal clear that working from the inside through a port is the most obvious solution.
But try to think (literally) more out of the box.
We have on the beach where I sail in summertime swimming lines to keep the swimmers away from the breakwaters. About 6 years ago, I sailed with an old P15 by accident over one of these lines . The line got stuck between the transom and the rudderblade of one of the hulls. I was pushed by a wave and the transom teared off. Within 20 seconds my hull was completely filled with water.
So, problems to return to the beach with a limp cat, not to mention the difficulty to pull the cat single-handed on the beach again.
It was in the middle of the season, I had no time for an extended repair. I just pushed everything back and laminated over the transom till 5 inches overlap on the sides. It was rocksolid (though not a beauty solution).
That gave me, amongst other reasons, the confidence for my momentary cat which has no interior at all. The hulls are massif and filled with foam.
So every possible repair has to be done from the outside.
ronald RAIDER-15 (homebuilt)
hey boy, what did you do over there, alone far out at sea?.. "huh....., that's the only place where I'm happy, sir.
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