transom / motor well trim separating and leaking oil

F

ferret30

New member
The top edge of our transom where it drops down to meet the motor well has a sturdy piece of hard plastic trim capping it. It looks like it was originally glued down, but now it is separating from the transom top and there's at least 1/8" gap all the way through for maybe 8". Shining a light inside it's hard to tell what the actual transom top is made of underneath. It looks kind of unfinished, like the fiberglass/core sandwich was just covered with resin.

Is this something I need to take care of as far as allowing water in? Or is it well protected underneath and the cap is just a bumper?

Also, probably a subject for another thread, but I noticed tonight as I was finishing the transducer block project that the large pan head hex drive screw at the bottom of the motor (just above the lower unit) was seeping oil. I'm glad I noticed since I haven't checked the level since I first got the boat. I'm guessing this is the drain plug, and it is already very tight, but it's leaking. Bad sign?

I'll post pictures of both issues tomorrow when the phone's not dead.
 
I am not a mechanic, but my understanding is that the gasket on that oil drain plug needs to be changed each time it is opened, and if it isn't you stand the chance of a leak. That's from my mechanic, and I believe I have seen that addressed here on the site.

As to the other question, I would have to defer to everyone else first. Good place here, there are folks who do know.

Harvey
SleepyC :moon
 
There are o ring seals that fit under the heads of the machine screws that close both the vent(top) and drain/fill(bottom) openings in the lower unit. The o rings are inexpensive and easily removed and replaced. Water can enter the gear case though the same leak the gear oil is coming out of. Water in your lower unit can lead to wear and corrosion.Gear oil should appear translucent similar to new unused motor oil. as water gets mixed into gear oil It will becomes opaque/milky. My 2 cents worth of advice would be to locate the part #'s for the o rings, purchase a fill adapter(hollow bolt that threads into fill/drain hole and attached plastic tubing), and change the gear oil and o rings before running your engine.
 
JRassier is giving good advice I think. You mention the leak is occuring "above" the lower unit but if it is the gear case vent that too is part of the "lower unit". The lower unit being everything that drops out with the drive shaft when the water pump is changed. You might want to post the picture for us to be sure we understand what you are talking about.

If it is a gear case lube leak, the advice to change out the lube and replace the vent and fill washers is sound. Then carefully monitor for new leaks by checking for visable oil and by draining the gear case after one use to look for either water (it will be the first thing to drain out) or the milky looking lube mentioned. Mercury makes a nice pump filler bottle for its synthetic gear lube (which I highly recommend) which includes the fill adaptor JRassier mentions. Browns Point Marine will have the gear case washers. Wally World carries the gear lube filler bottle - oh I mean "wal mart"
 
Falco is right, Drain that lower unit....and replace the gear oil and the washer...it should be renewed every time the oil is changed...any Marine Store should have the washer...it is standard practice to replace it so it will be close to where you find gear oils... at least it is at West Marine..where I buy my gear oil.

I absolutely would address that void in the transom quickly before it gets any worse .. take it to someone that works with fiberglass boats as a profession.

Joel
SEA3PO
 
The plastic cap is "glued" down with either Bostic or urethane sealant. The top of of the transom probably does have resin on it. There should be layers of fiberglass--and resin. This is where the hull to deck joint is covered on top of the transom. There can be leaks, and breakdown of plain thickened resin. On the 25 I redid the transom on, this was a problem.

In your case, I probably would pull the cap, check to see if it is fully intact on the top, and then put the cap back on with black 4200. (This is what we did on the 25, after glassing over the top of the transom.

Agree, with new gasket on each oil change. There is a drain, a fill and and overflow for the lower unit. There is a drain for the oil--but I recollect it is higher than you describe.
 
We had the same problem on Valkyrie, a 22 cruiser, but the crack came from under the rub rails (aft) and ran under the transom "cap". When I had a local shop evaluate it they found that the top of the transom was not finished or sealed with resin or cloth, but the void was filled with gelcoat!

I contacted the factory, with pics, and they told me to have it fixed, under warranty, and they would reimburse me, which they did. There are NO dealers anywhere near Ohio to handle the problem. I know of three other 22's of the same vintage which had the same problem.

Nick
"Valkyrie"
 
It seems like the transom is under attack from all directions! Just so I have a rough idea, how much would it cost to have a decent shop do a transom rebuild if a below-waterline penetration leaked or water seeped in under the cap? I'm guessing the whole core needs to be replaced at once, not just a localized area...

So, is it on the order of $3k? Are rebuilt transoms as reliable as the old ones? Might be worth knowing just in case I have a problem in 10 years, or end up buying another boat, etc.
 
In our case, water intrusion was not an issue, so I can't really address that, but our repair was $1200 five years ago.

Nick
"Valkyrie"
 
There is a crack running around one end of the black plastic cap on Journey On's transome. 2 ea comments.

1. I called the factory and they told me some type of Locktite sealant was used. Also, it would be tough to remove.

2. I had a local fiberglass "expert" look at it and he felt that it was a stress crack, caused by water intrusion from under the black cap. His advice was to seal the cap and fill the cracks. BTY, the gentleman said he did Bert Rutan's composite work, which was interesting. Spent some time discussing that.

No guarantee on either comment, but I'm going to follow 2. and see what happens.

Boris
 
I have not been to c-brats site for a long time ane decided I would today. Guess why? I discovered a transom problem this spring. What a surprise to see this issue being discussed.

Last spring I was anchored in the Columbia for that mythical fish. I pulled out my ice chest to get something behind it at the transom. I noticed a drop of water running down and started looking closer. An old screw hole up on the transom near the junction of the motor well stucture was weeping some drops of water, or rather metaphorically my tears. The screw hole had been a former attachment point for an electrical wire. Being in an upper location I was satisfied to put asmall dab of polysulfide caulking on it. Seeing the single drop of water I picked the polysulfied off and a few more drops weeped out. At this point I had that feeling that had just shifted from denial to post kick to the.....

This fall I trailered the boat to a professional for an opinion. The first thing he pointed out was the beginning of some delamination of the fiberglass at the upper edge of the inside of the transom port and starboard just before the transom trim starts going vertical. With hard thumb pressure you can get the fiberglass to work/spring approx. 1/16-1/8 inch just in the corners demonstrating the delamination. He showed me corresponding subtle short hairline stress fractures in the gel coat on the outside of the transom corners as well. He used a hand held meter to detect water within the transom. I think the most definate concentration he found was near the motor bracket on the portside. He thought the water was getting into the transom through the delamenation described above and not likely the motor bracket bolting holes. He thought the delamination and gel coat stress fractures were a result of motor torque producing flex within the transom. Part of his take on repair was to not just solve the point of entry leaking but to stiffen the transom with fiberglass to prevent the flex. He also suggested a single rectangular washer to span the distance between motor bracket bolts to help distribute the transom stress. He talked about enlarging the holes where the motor bracket bolts go through the transom. If I remember correctly he would use a hole saw to make large holes then fill in with some combo. of epoxy/fiberglass or resin. Then new bolt holes would be drilled through the new synthetic cores so if water ever leaked into the bolt holes in cannot migrate as easily to the plywood. I think he also said the synthetic cores do not compress like plywood does.

The estimate was 2800 to 3200 assuming things are not more advanced damage once we know more, and that it could be less, if I take off the motor so he can concentrate on the skilled labor.

I took the boat for a second estimate and this fellow was more just get the motor off ,tent in the transom area and apply lights to get it dryed out. Once you get it dryed out he thought I could take off the transom trim and cut out a trough within the plywood core area the entire length of the transom in the top edge of the transom approx.2-1/2 in. deep then I could laminate in this core with fiberglass and resin. I'm assuming doing this was his fix for further water entry not so much for controlling the transom flex. He also agreed with the rectangular washer suggestion from the first estimate.

He was not so much interested in an estimate at this point as getting the motor off to see whats going on and if necessary I can drill holes at the inside of the transom where it meets the floor to help drain water if necessary and promote drying. He said the holes did not have to be large in diameter. He said to put tape on the drill bit to create a determined depth to drill so I would not drill through the exterior transom. He said if I did the glass work he could do the paint work. Guessing 600 to 800. He suggested I call the manufacturer to ask about the trim removal.

I called the c-dory manufacturer and the guy who I talked with wasn't sure what my trim was glued with (1999 boat) but suggested I not take it off unless a last resort. Thought a heat gun may be necessary and likely would ruin it. He agreed with tenting and drying out the transom and drillling holes to drain water if water is concentrated. Regarding the delamenation he said he would just put some silicone on those areas to prevent water entry. He thought it was unlikely the water was entering the upper transom and more likely the motor bracket holes.

As of this date I have everything disconnected from my honda 90 except the steering cable. Then I will lift and suspend the motor with block and tackle from my boat port rafters which I reinforced with some vertical supports. As to what to do with the transom we'll see? I am not sure yet? Your suggestions would be much appreciated.

Tom
 
Tom-

You have three very good, if somewhat diverse, opinions and sets of advice to follow up on.

Take a very good look at what you have, investigating the damage throughly. Drill at least a few investigative holes at the bottom interior of the transom to see what you have there in terms of moisture. Probe down into the top of the transom to see how far the damage to the wood and the fiberglass separation goes. Remove damaged material as necessary. Probe around the motor bolts to see how much damage is there. You may have to repair/replace damaged core and fiberglass layers. The advice you have is good as far as it goes. Let us know if you find something different, or something unusual.

Now for the encouragement: You're doing the work yourself, so the labor is free, so there's plenty of room for doing it right as far as the material costs are concerned. Do a totally through job, replacing and reinforcing as necessary. You really can't over do it, making it too strong, but you certainly can leave it too weak, asking for further trouble. Make it both super strong and as waterproof as possible. If you're not sure how to proceed, take pictures, post them here, and describe everything throughly and you'll get lots of advice in return, all for free.

Make an aluminum plate as suggested to bridge the area between the motor bolts, using at least 1/4", preferably 5/16" aluminum plate. (You could also use stainless, since you already have aluminum in the motor and stainless in the bolts, but stainless is harder to work with and not really necessary.)

Don't rush, discover what you've got, and take some time to think about it. It's easier to do it right the first time after some thought, etc.

Good Luck and let us know what you find out!

Joe. :teeth :thup
 
Thanks Joe

Much appreciated and useful advice. It reminds me of what a friend used to say when nerves got a little tight on the construction job, that he learned from a horseman out of Montana. In a deep, calm voice, he'd say, "STEEAADDYY"

Thanks to the other previous posters as well. Montana Kev, your link to a prior discussion, Jan. 2011, is right on!

I will report as things develop.

Tom
 
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.
 
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
 
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
 
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
 
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
 
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