standing water in dimples aft of shaft log and aft of rudder stock

[Michael]

Some posters (as a side issue in the "water in the hull" thread at http://c34.org/bbs/index.php?topic=1441.0) say the problem of standing water aft of the shaft log can be solved by filling with resin or foam. I am thinking of filling the depression there and a similar depression aft of the rudder stock but would appreciate your thoughts first.

1.  Is filling these depressions a good idea?
2.  Would you fill with epoxy resin, foam, or something else?
3.  If foam, what sort of foam should be used?
4.  Does anybody think our boats could be gaining some of their overweight (see the "displacement" thread, http://c34.org/bbs/index.php?topic=2200.0) from water seeping into the fiberglass hull from these standing pools?  They appear to be in areas that are rarely painted so I suppose the glass might absorb water more there than from, say, the bilge.

My thanks in advance for your thoughts.

[Stu Jackson]

Michael,

1.  I personally don't think so.  I'd like to know WHY water is there in the first place.  I'm in the process of checking my rudder fiberglass shaft.  I think it's a good "telltale." (Could you modify your post and include the "LINK" to your referenced article? Just copy & paste its URL into the text of your message.  Thanks.)

2.  If you're going to fill, find something that'll look like it wasn't "pasted on."  Foam may be harder to smooth out than epoxy.

3.  White.

4.  No, absolutely not.  That area is what, maybe 30 square inches?  The displacement issue is basic, the boats were built heavier than advertised, and so what?

Let us know what you decide to do.

[Michael]

Thank you for your feedback, Stu.

I like the way you see these water collection points as telltales.  Seen that way, the fact that there are several of them (bilge, aft of shaft log, aft of rudder stock) is actually helpful in identifying where water might be coming from.  I had only been seeing the water as a bad thing in its own right (seeping into the hull as I mentioned) whereas I suppose the real issue is the one you mention - "Where is the water coming from?"  For now anyway, I am going to sponge the water out of these aft depressions and watch them like a miner a canary.

I've revised my first posting to include URLs for the referenced threads. It was useful that you asked me to do that as I was unaware that an existing posting could be modified (notwithstanding that the system makes that pretty obvious) and unaware that threads could be referenced by URLs.

[Stu Jackson]

Thanks, Michael, the links wwere very helpful.  The telltale idea is like painting your engine (white).  The cleaner it is the more likely you are to see leaks.  As far as the water goes, please let us know what you find, and I'll do the same.

[Michael]

Stu, I will report on Hali's rogue water sources...if I ever locate them.

It seems to me that you have been on the hunt for a leak near your rudder stock for some time, as I believe I came across a posting of yours (in 2005?) when you were already after that culprit.

Prior to joining c34.org, I had no idea that part of every detective's training should be to own a boat.




   

[Ron Hill]

Michael : First determine if the water is fresh or salt.  Think you may be surprised and find that it is fresh!!
If I over fill my aft tank I have the same water collection.  I've checked the fill hose, vent hose and the drain hose.  The tank has NO inspection port, so I suspect that the factory may have put a screw into the top (somewhere).  Just haven't gotten around to pulling the aft cabin panels removing the tank thru the aft cabin.  Yet another project!!
A thought.   

[cjenson]

I have the same problem with standing water in the same spots. Hull # 40 no aft water tank.

[Robert Mann]

My boat collects water in dimples that are visible when the aft starboard locker cover is lifted.  This caused by the design of the swim ladder on Mk II boats I think.  As a swimmer exits the water the tendancy is to twist the ladder and eventually unseat the compound under the hinge bracket on the swim platform.  These need rebedding and tightening quite regularly if you use the ladder.

[Michael]

Ron, I was surprised to see that you have never taken out your aft water tank.  It was your writing about taking out your fuel tank and cleaning it with acetone that gave me the courage to do that job. (Except that it took us hours to take out the fuel tank instead of the one hour I think I read it had taken you.  But I will write more about that on your fuel tank - or another - thread and not here.)  Once the aft water tank is out, the whole aft end of the boat is wonderfully accessible.  Things like changing the cockpit and propane locker drain hoses, replacing the engine vent and air lines, and wire brushing the rudder quadrant become relatively (that is a relative term) easy.  You are quite right that there is no inspection port on the aft water tank (at least on #1352 there isn't), unlike the quite decent inspection port on the forward tank.  We still have the aft water tank out and are thinking of cutting an inspection port into it.

Robert, your comment about the swim ladder torquing the screws through the swim platform and causing leaking rang a bell with me.  With the aft water tank out, I can see under the swim platform.  The platform is of quite thin fiberglass (at least on Hali - don't inquire as to how I know) yet there is ample room to glass backing plates there.  I am going to put two fore and aft backing plates there: one to pick up the two screws on the port side of the ladder and one to pick up the two screws on the starboard side of the ladder; and at the same time change the screws for bolts and nuts.  The decision to do this is largely to address the problem you discovered, which hasn't occurred to us yet but will because we stern tie at our dock, with fender lines tied around the swim ladder right at the through-deck screws.  At the same time, I am going to glass another athwartships backing plate between the two for and aft plates -- to provide something to clamp the drain hoses to.)

Cjensen, I guess from hull #40 to hull #1352, and maybe on for years to come, our c34s will have these depressions where water collects.  After Stu's posting, I see them as good things.  Although I haven't had a chance yet to follow Ron's advice about checking whether the water there is fresh or salt, but I am pretty sure it will be fresh water.  The depression aft of the rudder stock is - I think - above water level.  With the aft water tank out, you can see down through a reasonable size hole (in the fiberglass ledge that supports the water tank) to the depression that is between the shaft log and the rudder stock.  The fiberglass in this depression was not originally painted at the factory.  Although it will be like painting by mouth, I am going to try to paint with a brush down through that hole.  Anyone thinking of doing this will need first to recover all the miscellaneous tools, screws, and odds and ends that have accumulated down there.  On Hali, there was an assortment of interesting "droppings" in that depression.

We have had dry weather for a few days since I sponged the two "water holes" dry.  They have both filled about half way since then. I suspect the water is entirely fresh water...from washing the boat down.  But where that water gets into the boat from is a bit of mystery...unless that small hole I drilled by mistake up through the corner of the swim platform has something to do with it.

Cheers and thanks for the advice.

[Saribbean]

Hi Michael,

I just realized I have the same problem with standing water aft and forward of the rudder stock. Did you ever find where the water was coming from? Did you fix the problem?
I saw water dripping forward if the rudder stock, it was just below where the rudder stock meets the hull.