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Catalina/Capri 25/250 Sailor's Forums

Catalina 250 Specific Forum

Ballast Tank Damage

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slaedlein
1st Mate

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USA
51 Posts

Initially Posted - 01/24/2011 : 19:22:32

Does anyone know of a way to check for damage to the ballast tank? Before pulling out our 1997 WB, my son placed the vacuum exhaust hose on the ballast vent tube while I waited for the bubbles. I was the bubbles, but about the same time, heard creaking and possible cracking from somewhere in the hull.

Needless to say, we stopped what we were doing and proceeded to pull the boat out. No water in the bilge, but a fair amount of water out of the hull bottom drain. More water than I expected considering we did have bubbles. I suspect the vacuum was producing too much volume for the process.

Scott
HuBeStu
1997 WB
Hull# 250

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Stinkpotter
Master Marine Consultant

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Djibouti
9080 Posts

Response Posted - 01/24/2011 : 20:11:17

If you had too much pressure, thereby pushing the water out at an "unnatural" rate, you might have created a vortex, like a little tornado, at the drain, allowing air to flow down and out through the water. You can see something similar if you have an improperly vented drain in your house--at least I have--where water is being sucked down by a siphon force... For starters, with the boat out, I'd fill the tank and then watch the bilge. My guess is you're OK.

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bear
Admiral

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USA
909 Posts

Response Posted - 01/24/2011 : 22:23:39

I think your OK as long as the valve was opened all the way before using the vacumn hose, bubbles doesn't mean the tank is empty. The level is down far enough for air to escape. Also tank will start to
re fill if your not quick enought to close the drain valve. I have used the reverse vacumn hose many times but still drain quite a bit when pulled out. Bubbles coming out tells me the pressure in the tank is reducing. Fill em back up and observe for leaks is what I would do.

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britinusa
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USA
5404 Posts

Response Posted - 01/25/2011 : 11:41:11

An interesting point. There is never anyone in our cabin when we blow the ballast (2005model)

Even at the bow, the sound of the bubbles is pretty substantial.

Not sure what the pressure of the vacuum exhaust is. We use a colman electric air pump (the kind used to inflate an air mattress.) to blow the ballast and to inflate our dink. When inflating the dink, the pressure gauge never gets up to 1psi, so I assume the pump is very low pressure. (We have to top up the dink with the hand pump to get it up to 3psi)

Paul

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bill bosworth
Navigator

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USA
172 Posts

Response Posted - 01/25/2011 : 21:43:00

Scott,
I use a foot pump to blow the ballast. It takes about 7 minutes to see bubbles. When we haul the boat we always get a lot more water draining out of the bottom hole. My guess, your ok.
Bill C250wb Serendipity on Kerr Lake,NC

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slaedlein
1st Mate

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USA
51 Posts

Response Posted - 01/26/2011 : 19:43:06

Thanks all. I will fill the tank and check for leaks. But suspect that my paranoia may be greater than the symptoms warrant. However, it will also be good to rinse the saltwater out. I have used a small portable camping pump in the past, but it took a while to get any air out the bottom. The portable hand vacuum I used this time (without the bride's knowledge) worked much quicker. PSI is low, but volume is high. took about 2-3 minutes to get bubbles.

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Oldsailor
Deckhand

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3 Posts

Response Posted - 11/21/2011 : 10:36:48

Do I have ballast tank damage? When filling the ballast tank, water is entering into the bilge. When valve control is closed, no more water enters the bilge. When ballast tank is drained, the bilge also drains. Is it possible the air vent connection to tank is leaking? If so, how do you get to it? All very confusing and looking for help.

Ron
2002 250 wb

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britinusa
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5404 Posts

Response Posted - 11/21/2011 : 18:33:28

Ron, I presume you are referring to the bilge as the area aft of the ballast tank and below the aft berth.

It has been mentioned several times on this forum that water can splash into the bilge when the boat is launched down a ramp. The water splashes from the tube that the center board haul line passes from the cabin to the turning ball at the back of the center board trunk.

However, if the water drains when you drain the tank, then it's not that.

You might want to put the boat in the water with the tank valve closed, then dry out the bilge so that you know it's not tube splash. Then you could put blue paper towel along the after edge of the tank where it mates with the open bilge. The blue towel easily and quickly changes color to a much darker blue when it gets wet.

You might also place some towel along the seams of the tank where it mates to the port and stbd sides of the hull in the two lockers and under the galley cupboard removable deck panel.

Then watch the towel with a flash light when you open the valve with the boat in the water.

If you can post pictures of any areas of concern that will elicit a lot of responses here.

Welcome to the forum

Paul

Edited by - britinusa on 11/21/2011 18:35:04

Arlyn Stewart
Master Marine Consultant

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2980 Posts

Response Posted - 11/22/2011 : 08:11:47

It is not uncommon for some water to exit the shaft hole for the valve rod and end up in the bilge. Some owners complained that the hole was close enough to the edge of the tank top that the rubber washer meant to seal the valve shaft did not have a flat surface on which to seal. You should check for that.

Water draining from the bilge when draining ballast tank... has me perplexed however as that would dictate a hole along the bottom edge of the rear of the tank. Such a hole would surely flood the bilge quickly.

There have been some reports of pin size holes along the rear of the tank that can be repaired quite easily through the bilge access port as Paul outlines using the paper towels to discover. These generally let a small amount of water into the bilge. I can't imagine such draining the bilge however.

I'm more inclined to think that the bilge water is simple moving to forward areas such as under the galley and side lockers due to the trailer angles.

Bilge water usually means an issue however, but most of the causes are minor such as tank pinholes on the back of tank or the rubber grommet sealing at the valve shaft. Someone posted once about a flooring screw being too long.

Edited by - on

Oldsailor
Deckhand

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3 Posts

Response Posted - 11/23/2011 : 08:10:07

Thanks for your input Paul and Arlyn. I hope to checkout some of your suggestions next week and get back to you with my findings and additional details as they unfold.

Ron

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britinusa
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5404 Posts

Response Posted - 11/23/2011 : 14:28:20

Another option would be the possibility of water ingress from the top of the hump under the lower stair tread that houses the tank valve. We had a slight leak of water in through the hole that the valve spindle passes thru. In our case, I rebuilt the top of the hump adding thickness to the top and then embedding a stainless washer on which a large rubber washer mates neatly. Reducing the leak to almost nothing.

Paul

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zebra50
Captain

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USA
408 Posts

Response Posted - 12/02/2011 : 13:12:41

There is a link in the archives somewhere about this issue and the repair of the misaligned "through bolt" in the hump. Paul has it correct. I had same problem a couple of years ago and did the same fix. It worked.

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dmpilc
Master Marine Consultant

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4593 Posts

Response Posted - 12/06/2011 : 13:56:34

Dry the bilge completely. Close the drain and pour a bottle of green food coloring into the ballast tank and start filling it with water. If you get green water in the bilge, odds are excellent that you have a ballast tank leak that needs fixing.

If you don't want to alarm the neighbors, wait until St. Pattie's Day to do this and make up a story to explain why you have green water pouring out of your boat and running down the street!

Edited by - dmpilc on 12/06/2011 14:01:26

Oldsailor
Deckhand

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3 Posts

Response Posted - 01/02/2012 : 06:10:33

Analysis of the previously mentioned ballast tank and bilge water problem resulted in the following findings:

Inspection through the aft bilge access with light and mirror indicated two major breaches in the aft end of the ballast tank.
The breaches are where the tank is sealed to the hull. One is on the far, port side and is about 4 inches in length. The other is on the starboard side and is about 3 inches in length. In both cases, the L shaped tank -to -hull seal shows a lifting of the outer edge of the seal from the hull for the length specified. (Seal integrity is maintained on either side of the breaches which suggests inadequate construction in the problem areas. Ballast tanks have always be drained after use, therefore freezing/expansions should not have been a factor)

Unfortunately, the bilge access is insufficient to permit reaching the areas needing repair. I am looking for ideas to provide that access and information about any structures in the area that must be avoided (aside from the hull of course). I have thought of installing sealable access ports in the floor above the breach areas but that is hardly minimally invasive to say the least. Also any information about tools, techniques and materials would be greatly appreciated.

In addition to the major problem, the ballast fill control needs a new hull gasket. A source for getting a replacement would be appreciated.

Ron

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Stinkpotter
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Djibouti
9080 Posts

Response Posted - 01/02/2012 : 08:49:06

Ron: What does Catalina's warranty say about hull integrity? If it's 10 years, your 2002 should be covered (barely), especially if you have evidence that the cracks were there earlier. IMHO, this is clearly a hull integrity problem--it's letting seawater enter your hull as well as compromising the ballast that keeps you safe. Start with Frank Butler and let him figure out the best approach.

Edited by - Stinkpotter on 01/02/2012 11:08:43

dmpilc
Master Marine Consultant

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4593 Posts

Response Posted - 01/04/2012 : 12:16:40

If warranty is no help, any chance you could spray the joint with several coats of something like Flex-Seal(TM) or similar product for fixing gutter joint leaks. Just a thought.
https://www.getflexseal.com/?tag=im|sm|go|tm&a_aid=011&a_bid=a4cc8494

Edited by - dmpilc on 01/04/2012 12:18:33

Stinkpotter
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Djibouti
9080 Posts

Response Posted - 01/04/2012 : 12:58:11

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by dmpilc
 ...any chance you could spray the joint with several coats of something like Flex-Seal...<hr height="1" noshade id="quote"></blockquote id="quote">I'd have two concerns about that: (1) A repair like that should be done from the inside of the tank, so the water pressure pushes the sealer into rather than out of the crack. (2) When it doesn't work, it will likely have created a mess that will complicate a "real" repair using almost anything else.

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britinusa
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Response Posted - 01/05/2012 : 04:48:21

Ron, from your description of where the leaks are located, I'm wondering if you can access them via the actual drain valve opening, tight is an understatement here, but I venture to suggest it's possible.

Another, dreadful idea, option might be to cut out the hump under the lower step, it would be comparatively easy to reattach.

The hump does have the benefit of being central and so provide access to each side.

Once the hump was out of the way then pressure washing the area via an extension tube should be feasible. Then drying and finally cleaning with Acetone.

With a lamp and mirror you should be able to reach the full extent of the aft tank bulkhead where it attaches to the hull. Putting a large lamp up from the bottom and pushed forwards should maximize your view. (I realize that you would be working remotely as the lower step 'box' would be a major but not insurmountable restriction.

Roughing the surfaces prior to glassing over the area concerned would be the toughest part, I doubt it would be possible to just reach in with a electric sander (start thinking of some ventilation to blow the dust out the drain valve hole)

But if you can get that far, then glassing over the area would be a comparative breeze!

Difficult- absolutely, but Doable.

Fixing the issue via the bilge aft of the tank would be possible if there were an access port on each side of the aft berth as far forward as needed. At least you would be able to reach the repair area by hand.

If you do work on this, I hope that you take a gazillion pics to help others should it every crop up again.

Not something I would venture to do during the hot summer months, ventilation would be really important. But I would suggest this is a weekend project with the boat on stands.

Paul

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John Russell
Master Marine Consultant

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3444 Posts

Response Posted - 01/05/2012 : 07:31:44

I'd at least call my insurance company.

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dmpilc
Master Marine Consultant

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4593 Posts

Response Posted - 01/07/2012 : 10:20:51

Ron and Scott, call Frank Butler and see what guidance the factory folks can offer.

Re: Using Flex Seal, Dave, I was half-way kidding!

Edited by - dmpilc on 01/07/2012 10:32:56

zebra50
Captain

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USA
408 Posts

Response Posted - 01/07/2012 : 11:38:35

"It is not uncommon for some water to exit the shaft hole for the valve rod and end up in the bilge. Some owners complained that the hole was close enough to the edge of the tank top that the rubber washer meant to seal the valve shaft did not have a flat surface on which to seal. You should check for that."

Does anyone remember where the link is to the fix for this? I fixed it once about 10 yrs ago and now it needs to be redone.
thanks

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Stinkpotter
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Djibouti
9080 Posts

Response Posted - 01/07/2012 : 13:43:17

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by zebra50
 Does anyone remember where the link is to the fix for this?<hr height="1" noshade id="quote"></blockquote id="quote">Check Mark Melchior's post in [url="http://catalina-capri-25s.org/forum/topic.asp?ARCHIVE=true&TOPIC_ID=747"]this thread[/url].

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Arlyn Stewart
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Response Posted - 01/09/2012 : 05:01:49

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by dmpilc
 Ron and Scott, call Frank Butler and see what guidance the factory folks can offer.

Re: Using Flex Seal, Dave, I was half-way kidding!

It would take multiple, thin coats and require spraying both sides to have any chance of success, and yes, it would make a big mess to clean up if it failed. Cutting an inspection port close to the breaks would also likely be necessary to sand the inside surface rough and spray that side.
The more likely scenario will be: 1. Cut an access hole that can be covered later with a watertight, screw-on/off cover plate. 2. Lay down 2-3 layers of glass cloth on both sides of the failed joint to seal the break permanently. Good luck!
<hr height="1" noshade id="quote"></blockquote id="quote">

Your suggestion might be a good one. If this area is the give area to normal structure expansion... a flexible repair might make good sense.

One of my RC model airplanes has a fiberglass fuselage... the method of choice to adhere wood structure to the glass is actually silicone adhesive. It bonds to the fiberglass tenaciously if the glass is roughed with a wire brush and cleaned with acetone.

A quality silicone adhesive has adequate strength and flexibility to survive the movement that might be the cause of the leaks.

If placing a light into the drain hole reveals that the leak area is accessible through the bilge port and the leaks are pin holes or minor crazing... I'd not hesitate attempting to seal using silicone.

Roughing would best be accomplished with a dremel tool with an end style brush. Then clean well with acetate and apply the silicone. Don't go overboard... more is not better... getting the surface prepared at the leaks and application only to those areas is the goal.

If the leaks are more than pin holes or crazing cracks... then glassing using build up would be my choice.

Edited by - on

Arlyn Stewart
Master Marine Consultant

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2980 Posts

Response Posted - 01/09/2012 : 15:29:41

Perhaps I should qualify my the above suggestion to consider a silicone repair to the ballast tank leak.

The ballast tank is below the water line except the raised section supporting the shaft for the drain stopper. The upper shaft gasket can only leak water into the bilge when the tank is full and the boat is heeling or in the case of one unfortunate C250, if flood waters bring the dock lines up short holding the 250 below her water line and the tank valve is leaking. In such a case, she has shown in the past that she will sink.

If the ballast tank valve is sealing, the tank is just a large in the hull tank and does not threaten the boat. Even if it leaks slightly and some of them might, the threat is minimal because the hand bilge pump can easily keep the bilge clear.

However, and this is my reason for clarification, if there is a minor leak along the back edge of the tank that is below the water line and the ballast tank valve does not seal fully, and the boat were moored or slipped unattended, then there is risk of sinking.

What I'm saying in effect is that a silicone repair I suggested above might not be the ticked for a slipped boat. In a way, I think this is a bit of a catch as it is very possible that the cause of the failures is the tightening of the ballast tank valve. All should know that when a nut is used in conjunction with a shaft to tighten or clamp something, it exerts a lot of force. When closing the valve, too much tightening is going to move some glass. That might be the cause of the leaks.

I guess what I'm saying is if you trailer sail, don't sweat a little bit of water leaking out the top of the shaft into the bilge when the boat is heeling. I've forgotten and left my valve open and had as many as a few sponge fulls of water in the bilge after a long day of sailing. It won't amount to much and isn't worth risking over tightening the valve. On the other hand, if one slips their boat, safety dictates the valve is closed and sealed so it is tempting not to tighten it well.

The valve can be inspected for its ability to seal simply by raising the boat with water in the tank with the valve closed and inspecting for any leakage out. It has a rubber seal around the valve surface but for a slipped boat that gets bottom paint... it is possible that the surface gets rough and the valve doesn't seal fully.

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