transom / motor well trim separating and leaking oil

[thataway]

First I would disregard the advice of anyone who said put silicone on the cracks--he does not understand the problem or the "cure".

If there is delimitation and weakness in the transom, the core needs to be replaced--you cannot "tent" and dry it out adequately. If the core is wet, and is weak, it needs to be replaced. The best way on the C Dory is to remove the motor and any other appendages from the transom. Then cut the fiberglass in about 2" from the outer sides all of the way around. Finally pull this glass, and then remove the core. Replace the core with a high density foam, and then reglass the outer transom, just in the way of the cuts around the outside--with gel coat over the area where it was faired in. You may want to put some more triaxial cloth with epoxy on the inside--but this will also require removing the fuel tanks.

The holes for the outboard should be bored out slightly and then undercut in the new transom--if the old transom is not wet or delaminated--then do that on the old transom--with epoxy, cabosil/high density filler, redrill the holes as advised. (Which should have been done --and rarely is--in the first place.

The problem with an aluminum or SS plate if the transom is already wet/delaminated, then it will just transfer the load to different areas--and that will still have a weak transom. (I did this once--and found out by experience that it does not work if the transom is really bad).

To find out if the transom is weak--delaminated--put the motor half way up and put full weight on the lower unit--if the transom flexes--it is bad.

A few wet places can be repaired locally. After you pull the motor, get a good marine moisture meter and check out the entire transom. Any metal (mounts, screws etc-) will give false high readings. So get the moisture readings early on. Drilling holes may or may not give the diagnosis--it probably will not "cure" the problem.

If the transom is OK--and just a few little stress cracks--V these with a dremel tool and fill with glass fibers, fair and gel coat. If the top of the transom is not sealed and not glassed, then that should be done, with a couple of layers of cloth/epoxy, or triaxial/mat/polyester.

[primative]

Bob
I had similar feelings regarding recommendation of silicone to seal out water entry at the transom.

I',m at the steering cable removal stage on my motor, so it's still bolted to the transom. Though since I have already disconnected elec. connections, I'll need to do the motor tilt manually,to do the weight bearing transom flex test. Glad you suggested it before it was too late for me to try. When you did it on your boat was flex obvious? Like at the upper edge of the transom or in the motor bracket area?

Can you clarify a bit more on the "bolt holes bored out slightly and undercut". I think I understand the big picture, it is to prevent water seepage into the core, but I don't understand some details. I think you mean to bore out original holes slightly larger, but how can that leave enough epoxy surrounding the bolt after the bolt hole is redrilled? I'm not sure what you meant by "undercut" in this process?

Regarding tenting the transom to dry out the core I assume you don't have faith in that unless the transom is opened up enough to evaporate off the moisture. That was my guess before getting the three opinions I wrote about in my original post. I think the 2nd estimater may have meant that since the top edge of the transom was dug out it would allow evaporation. But he never really was clear about this. Possibly he was thinking wait till the motor is removed and transom trim, then things will be better known.

When I asked the C-Dory manufacturing rep. how can the trasom dry out (tenting with lights to warm)with the transom trim in place and nothing but the motor removed and some small holes drilled through the transom glass on the inside surface, he said "it just does". If it does I don't understand it because if I have a plastic bag with a piece of wet plywood in it with a few small holes in the bag, how does the moisture escape? I guess warmth and time over weeks through those little holes?

Do you think the washer plate is a good idea after repairing the transom properly?

Thanks
Tom

[primative]

Hi Bob
Hope your holidays were special. Could you help with some questions, when its convenient, that I had in my last post?

I just noticed the change from Thataway to Thisaway. Nice name. I hope the shift in size suits you. I used to have one bigger before I had one that was smaller and now I like to say "its just right". Kinda like the "Three Bears Story"

Tom

[thataway]

Tom,
My apologies on not getting back to you sooner. You are correct, I did not have internet access for some time. I am sitting in the AZ desert--in view of two C Dory 22's, and my wife just got back from riding an ATV thru the desert!

The flex in the transom was noticeable (this was in a Grady White 20 foot Overnighter, which I had a 225 hp (considerably heavier than a C Dory 22--and faster also). The flex will be in the motor bracket area--if at the top--it is very weak. (I also had a transom actually break on an inflatable, and I ended up "hand holding" a 25 hp outboard! When we opened the transom on the Grady White, it looked like tooth picks. The C Dory 25 transom only had localized wet areas. We cut all of the glass out in these areas, and filled with micro balloons and fillers--then reglassed.

We undercut the glass outside of the holes, with a dremel tool, for the motor bolt I use I 1/4" or 5/16" diameter cutter. Then pack in epoxy and high density/Cabosil filler, being sure it is against the glass in the stern and inside the transom. This will give a good bond. (assuming that there is no water in the core). then I just run a Dremel sander (fine grit) to clean up the epoxy--and this gives a solid and well bound repair. You can drill the original holes out--larger, but with transom bolts, this is not usually necessary. (more so with screw holes).

I have been working with osmotic damage in hulls for over 30 years, and have evaluated boats all over the world. It takes a long time to dry out saturated core. Currently there is a Kadey Krogen 42 in the Pensacola Marine Ship Yard, which has been under the dry process for over 2 years. This boat has a foam core, which got water into it. For over a year, they tried the heat lamps, tented, ground cover with plastic, and dehumidifiers--no decrease in moisture. For over another year, they have used the "hot Vac system. Where the pads which are heated to about 180 degrees are glued to the hull, and then a vacuum is applied to the hull surface (this is after a full 1/4" hull peel, and a number fresh water washes. It is still not completely dry. Also they tried drilling holes in the bilge of the boat, and using dehumidifier/heaters there. This is an extreme case--but where a boat had a peel before and it failed with recurrence of blisters. I know of another boat (Shucker 44) which has the same problems currently in our same area. This is slightly different than the transom, but not a lot--and the moisture issue remains the same. Drillilng holes did not help a lot with either of these boats. The small surface area of the upper transom or holes in the bottom (other than to drain water, under vacuum) will not have a great effect.

The washer plate would not hurt, but probably not necessary with a good transom.

Regards,

Bob

[primative]

The AZ. desert sounds nice right now from someone who lives near Portland OR. You mentioned two C-Dorys, would this be LK. Powell? A few years ago I took my brother on a tour up the Rogue R. by road not water using the boat as our "boater home" as Ken of Blue C used to say. It was a great road trip. I hiked down to the river a couple of evenings for Steel head fishing-no luck, but still a memorable trip.

If your on that ATV make sure your saddle is cinched well, I hear they have a mind of there own.

Thanks for your response to my prior questions. The comments on some of the drying processes at the boat yard was a jaw dropper. I looked up devil, money, and patience in the Oxford dictionary and you know what boat names came up.

To try and better conceptualize the "under cut" process around the bolt holes, Rene and I drew sketches of what we think you have described. Please let me know if my descriptions are correct. I would be using a Dremel tool with a thin I/4 to 5/16 inch diameter diamond cutting blade. I'm standing outside the boat. I insert the cutting wheel inside the existing bolt hole to cut away the plywood core that is in contact with the fiberglass skin without cutting the fiberglass itself. This is repeated from inside the boat. I assume you just keep cutting away at the core 360 degrees to enlarge the core area the complete thickness of the core material without enlarging the bolt hole openings.

How big should the diameter of removed coring be?

I don't own a dremel but generally know its a precision cutting, grinding, drilling, whirling dervish tool. I assume it must have a shaft long enough to penetrate the thickness of the transom working from outside and inside the boat?

Would you be alternating with a grinding type tip to help grind out core material (plywood in my case)?

When I put in the epoxy- carbosil filler it will fill the entire void including the bolt hole space. After it cures I will need to drill the bolt holes a slightly larger diameter than the bolts so the bolts can slide through?

Tom

[ferret30]

primative, check out this thread:

http://www.c-brats.com/viewtopic.php?t=17114

The process described there is similar to what you would need to do, and it also includes some cross section drawings that should help you visualize. Note that the cross sections were for smaller transom penetrations that don't go all the way through, but in your case you do have access from both sides, and your holes will be quite a bit bigger.

Here's one of the images:



The lighter yellow is the transom core and the darker orange/yellow is the epoxy "plug".

[primative]

Ferret30 thank you and Thisaway thank you.

The pictures helped me get the picture.

Bob when you repaiared the wet spots on the 25 is it correct you took off all the glass on the exterior transom but only removed localized wet/damagedareas of the wood core.

Tom

[thataway]

Tom,
We found that there was only localized wet wood. We cut that out, and filled with epoxy/filler, then regalessed. This was done from the external of the transom.



I also have put up a "project" showing the undercutting on my "Thataway" Album


Pages 5 thru 8 of the "Thataway" album shows various parts of the transom and cockpit repair, as well as other techniques for sealing voids, etc as well as using epoxy in the boat repair. Looking at these multiple photos may help visualize what we do with this type of repair, in both decks and transoms.

[ferret30]

I some images to my album showing the transom cap separation.

Bad side:




Good side:



The separation extends all the way around the corner and up the vertical part. I don't really know if I can take care of this without:

* breaking the trim
* removing the motor
* damaging good gelcoat where the trim is still attached

I could try and squeeze 4200 into the gap but I have a feeling it won't reach into the narrow gaps close to where it is attached, and it might end up trapping/accumulating moisture.

On the good side (port), the cap looks like it's glued down to a black piece that's embedded in the transom top. Hard to tell how it went together.

[primative]

Bob
I look forward to the review of Thataway album, pages 5-8. I finished the removal of the motor this evening. More of a deal than what I anticipated making a home made harness that I trust. Its laughable but safe. One of the lower motor bolts threads started galling about the last 1-1/2 in. of backing off the nut. Not sure why, the threads appeared fine before removing the nut?

Ferret30
Some of the same concerns I have. I removed the motor because as I mentioned earlier on page one I feel certain I have some water intrusion just not sure how much yet and I feel a need to get to the bottom of it.

Given what I've read so far I would try to remove part of the trim to know that the upper portion of the transom has been sealed properly. If it was sealed properly it would be peace of mind for me, then I would consider just gluing with clamping as described earlier. I think any gel coat damage done in removing the trim can be repaired. I do not have any experience with this yet but will soon enough. I have chips in other areas I would like to fix as well.

I don't know if the trim can be replaced if broken or its cost. Let me know if you find out before me.

Mines coming off broken or not. If its not replaceable I'll need to protect the upper edge with some other means. I've left the port side of the transom-motor well open ( no add on projects here) for off loading people and gear. Those same folks get back on unless its a mutiny. It gets a good deal of wear as a step here.

Tom

[thataway]

The transom cap material should be available--check with the factory.

If not, the best "repair" is to wrap the top of the transom in glass, and then either gel coat--or paint the repair. I like to put "non skid" on the top of the transom, so I would do a repair and then cap it with stick on non skid.

[primative]

I sent a couple pictures of the transom trim to the manufacturer yesterday. When I called a few days earlier he (Jeff) wasn't sure what I had even though I described it? He asked for pics.. No response yet.

The aggressive grit black non skid tape is what I've used on top of the trim and consider it essential for how it is used as a step in/out of my boat. I use it on my trailer wheel fenders too , I love the stuff.

Thanks for what to do if no trim is available.

Tom

[primative]

I called the factory and they (Scott) said they have the plastic trim. It comes in straight pieces. For a 22' C-Dory its 35.00. They develop the curves by using a heat gun then glue and clamp into place.

They use Loctite H3101 Speed Bond. The Loctite part # is 83006. He named the chemical compound its composed of ( I forgot the name) and said its very good for gluing the plastic.

Tom

[primative]

Also forgot to mention he said I could try to use the heat gun to help with removal along with chisel, flat bar etc.. but thought it would likely have to be destroyed in the process.

Tom