Transom Cap Issue

M

Montana Kev

New member
My 1998 22 cruiser is stored under a full cover but much of the snow is dumped right into the motor well or on top of the transom cap. I was scooping out the snow to add a tarp cover in this area when I noticed the black transom cap has separated in one area. We have had freezing and thawing so I know a bit of moister has gotten in between the cap and the fiber glass. I have dried everything out wth heat. It looks like the only cap covering the transom top is the black plastic cap. Or is the black cap glued on top of a fiberglass top cap? Picture is in my album. I believe it’s more than just gluing the black cap down but I am not sure how the cap is constructed. Maybe someone has had the same issue and can provide advise.

Thanks,
Kevin
 
I've noticed that ours is also seperating, although not as bad as yours. I've thought of sealing it w/ 5200 and clamping it but haven't done it yet. The edge of ours seems to have been routed to remove the lip that extended very slightly off the stern/transom side. The seperation is where it was routed out, on the starboard side. The port side seems OK though.
 
I went and got some black Permatex RTV silicone seal at the auto parts place and plugged the cap separation on Journey On. It's held and (we can only hope) solved the problem. Certainly there's no more crack for the water to in leak.

Boris
 
I have not noted any separation, but have noticed that it looks like it was routed off on the outside edge of that cap too. Possibly for the engine mounting. I like the idea of the black permatex, and think I'll try that, especially if there is no separation.

Thanks for the idea,

Harvey
SleepyC :moon
 
My 1996 CD 25 (the last of the original 6 built by the Toland group) has this problem also. I noticed the plastic cap popped up last summer and looked under it to find that the only fiberglass-related stuff on the top edge of the transom appeared to be gelcoat. No glass, no mat, no resin, no nothing except a paint-layer thin coating that was stuck to the plastic cap and not the transom. I cannot for the life of me figure out why someone would build that way. A piece of plastic glued onto .025" thick layer of something brittle is all that protects the balsa core in the transom? A balsa core that is by now certainly ruined.

And while we're trying to figure out why things are built as they are, why is the transom cored at all? Only thing I can guess is for flexibility. It would only add a few pounds of weight to make it somewhat more solid and much stronger. It is a rather important part of the boat. When I looked at the thing and the black soggy wood in there, the first thought that came to mind was removing the cap, thereby exposing the entire top of the core, and then digging out all the wood from the top and refilling the cavities with some miracle foam crap that one of you fine folks would recommend. The transom, at least at the top where I can see, appears to be in two sections with a glass divider wall in the middle. It is structurally a pretty sound design; it just needs something to fill the voids that won't rot.

There. I said it. Now tell me why it needs to cost $5k ($5300 for an identical transom on another member's original CD 25) to rebuild a transom that is built plenty well but needs the filler material replaced? I have no doubt I can remove all the wood without cutting the whole back of the boat off.
 
Mike - I have not had problems with the cap on two 22's I have had. And since I never inspected how they built the transom, always assumed that marine grade plywood was used or end grain balsa, all encased in plenty of fiberglass. Someone on this site has the facts and should share it. Does end grain balsa have the same capillary action as plywood which will transport water between the glue lines. I don"t know. Can remember finding all kinds of balsa bobbers in rivers and lakes that seem to resist moisture penetration, i.e., they are not saturated.at all, only on the surface.

John
 
Dr. Bob of Thataway would be the most knowledgeable on this, but here is my take on the spread of moisture between balsa core and ply core:

1- The right angle grain of the balsa core resists the spread of moisture parallel to the fiberglass surface.

2 - Until the cut ends of the balsa core become separated from the surface fiberglass, at which time the surface parallel leakage will spread rapidly, especially in the sun where the moisture steams and expands the defect.

3 - Spread of moisture in any of the plywoods is usually greater than in the Balsa core since it can spread at any level of the wood or fiberglass interface.

4 - The old boats I've torn apart and rebuilt have had the worst damage from the old foam cores, in which situation the entire bonding surface between the foam and outer fiberglass seems to rapidly disintegrate.

5 - What leaks I've found and repaired in balsa cored hulls have shown more limited spread, but will spread more in broad, flexing areas where the end-grain bonding of the glass to the wood is taking more strain and pounding.

6 - In any of the cases, routine examination for and repair of openings will give you a reliable performance life.

Also, of course, one must be certain that all hull fastenings are in epoxy beds within the balsa core and it helps to fasten a synthetic mounting board on the stern to hold below water accessories, etc., w/o invading the hull.


John
 
There is a product out there that can be poured into the void of the transom after the wood has been removed. I can't remember what it is called, but it looked like it might be perfect for the transom of a C-Dory.

If I can remember the product name I'll post the information.
 
I have no apparent rot issues inside the transom, the wood under the cap looks clean and dry. I believe the cap let go from the ice hat formed in the space between the cap and the fiberglass. You can wedge a credit card into the space between the cap and the fiberglass in most places. Seems this should have been caulked or a better glue job during prouction. Strange that the black cap replaces the finished fiberglass work like on the older model transoms.

Kevin
 
This is what I was trying to remember- Seacast

L13.jpg


http://www.transomrepair.com/catalog/pages.php?pID=4

You remove the wood core, and pour in the material. Looks messy, :shock: but saves cutting the transom out.
 
Yes, SeaCast is the pour in place material for transom repair after the wood is removed. On a 25, I might do a bit more surgery, because of our findings--see below. On a 22, the pour in place should work fine. But replacing the plywood and re glassing/gel coating the transom should not take 50 hours at $100 an hour (that allows $300 for materials).

Back to the problem--and Dr John explains the issues with the woods well, and TyBoo hits the jackpot as to the problem.

The way that most boats this size are constructed is that the hull to deck joint is formed on the top of the transom; the splashwell is part of the deck mold, and the hull has the core molded into the transom. Core material is used to decrease the weight aft. A 1 1/2 to 2" solid glass laminate would weight twice as much as a one cored with 2 layers of 3/4" ply, and almost 3x as much as one with balsa core or a foam composite.

Our newer 25 (2003) was built with a plywood core--very possible that balsa was used in the older "cruiser 25's". The problem was two fold--one was that the plywood did not go all of the way out to the transom, so that the thrust of the motor was taken structurally by the splash well. In our boat there was insufficient glass on the top of the transom and in the splash well. The sides of the transom were thinner than the center core, and could flex some (not visiable). We resolved the problem by reglassing the top of the transom, and putting several layers of 18 oz trixial cloth in the laminate of the splash well. After glassing over the top of the transom, we re attatched the cap with black 5200. In our boat the plywood core only had some minor rot in the area of the trim tab screws and the depth sounder transducer screws. As in TyBoo's boat there were no glass over the top of the transom core, but just resin.

A paradox is that balsa is a hardwood by classification--that is it has short cells, and channels for water migration, thus water does not migrate in the wood grain far. Fir or pine (material which most plywood core are made of) are softwoods, with longer cells, and no canals for water migation, and thus water migrates in the wood much more easily. Rot occurs faster and more extensively in the softwood plywoods. (There are hardwood plys such as Gaboon marine ply, often used for cold molded or stitch and glue boats)

In this case, if there is no evidence of water intrusion (moisture meter on the transom, and ice pick into the top of the wood), just reapply the cap and be sure it is well sealed.
 
This thread scares the crap out of me. As the owner of a 1996 22' Cruiser, with trim tab and transducer screw-hole penetrations, drain cock, livewell, and wash-down pump penetrations in the transom, am I sitting on a rotting transom core time-bomb?

I'd like to see a post from Scott regarding this issue, and what the factory might offer or propose as a fix as well as what I could expect to pay.

jd
 
nimrod":2ipzpqwu said:
As the owner of a 1996 22' Cruiser, with trim tab and transducer screw-hole penetrations, drain cock, livewell, and wash-down pump penetrations in the transom, am I sitting on a rotting transom core time-bomb?
Click to expand...

Perhaps, plus there's a parallel (though arguably less serious) situation with the core in the hull itself - penetrations from fuel tank cleats being an obvious source of water intrusion.

The good news, as Dr Bob said, is that it's possible using a moisture meter to quickly - and non-destructively - determine if a boat has a serious problem. Moisture meters aren't a perfect science, but you will have better information about your particular boat.

Along that line, I have an Electrophysics GRP200, plug-in remote, and calibration plate that I would be willing to lend out to C-Brats if I had some assurance that I'd get them back.

Moisture readings aren't normally absolutes - rather, you measure known good areas to get a baseline, and then measure other areas looking for significant deviations. That said, it might be worthwhile to get a set of readings from a number of boats - I would expect that boats with similar production characteristics would have similar values.

As for "the factory" doing a repair, remember that the current factory is not the one that made your boat. And this issue is by no means unique to C-Dories - so there are many, many shops capable of doing any necessary repair work.
 
You have several choices--but first I would check the intregrity of the transom by bringing the motor up and then putting your weight on the lower unit. If the transom flexes, then you may have a problem, and should investigate further. As for the screw holes, and drain plugs, these are usually limited areas of water intrusion. You can either let it go, or remove the screws and see if there is any moisture present (moisture meter, or just put a shop vac on the holes.) If moisture is present, then you may want to route out the area by first removing about 3/8" of glass and then use a Dremel tool to remove any core. Fill the bad core with thickened epoxy, and then build it back to flush, the last coats: epoxy with white pigment to get close to what the original gel coat was. You can then either screw the transducer back into the epoxied area of the transom, or screw/5200 a piece of Starboard or poly ethylene cutting board and then screw the transducer to this board.

If the entire transom is rotted, then it is a much bigger job, but the C Dory 22's transoms do not have a history of rot, as some other boats do.
 
I understand where you're coming from regarding the factory repair work. The only reason I mention it is because Scott has indicated that they want to do this kind of work, not just on CD's but all boats, and also because of their unique expertise.

jd
 
nimrod":36ttepf9 said:
Scott has indicated that they want to do this kind of work, not just on CD's but all boats, and also because of their unique expertise.
Click to expand...

For you in Mount Vernon, taking it to just north of Bellingham makes a lot of sense. It would make even more sense if you wanted them to do things like refasten the rub rail, upgrade the fuel tank surround, repair the gelcoat, and so on. In fact, rogerbum (the previous owner of the boat I just purchased) did exactly that, and it was certainly a factor in my decision to buy that particular boat.
 
Great feedback everyone. An original search on the Transom Cap topic yielded little result for the transom repair information I was looking for. This thread is coming up in the search result from the forum page/Google search and I hope it will be useful in the future. Repair with 5200 was the original suggestion from Scott at C-Dory. Nice to hear from others who have been down this path.

Thanks,
Kevin
 
I've been reading this thread and am a little confused. What is the "transom cap"? Is it the horizontal piece that goes across the back of the transom?
 
Back
Top