Warning on Chlorine in Ballast tanks

moonie · Post by **moonie** » Sun May 29, 2005 11:57 am

I have found out the hard way that chlorine is highly corrosive to stainless steel and bronze. I have added small amounts of chlorine to the ballast tank as I keep the boat on a berth.The first bronze air plug corroded away,I then changed to a rubber stopper with a stainless steel bolt which corroded away in

8 days.
I'm concerned on how chlorine effects the fibreglass. Anybody have any knowledge on the subject and what other ideas I can use for an air plug without changing the existing system.

moonie

Divecoz · Post by **Divecoz** » Sun May 29, 2005 1:06 pm

Measure it and I would think a cup or two would work fine .
I say this knowing that we all use chlorine in one form or another in our holding tanks on the island. We don't for the most part use bronze or brass or Stainless anything talk about $$$$$$$$$$$$$$$
I have yet to replace anything in either tank in 6 years now . Floats that turn the pump and the city dibble I mean water on and off are basically cheap toilet ball float valves .

Catigale · Post by **Catigale** » Sun May 29, 2005 4:48 pm

Chlorine will attack natural rubber pretty hard - maybe a synthetic polymer stopper would work better?

Jack O'Brien · Post by **Jack O'Brien** » Sun May 29, 2005 8:33 pm

Stick a cork in it. Very resistent to most anything.

Post by **kmclemore** » Mon May 30, 2005 6:08 am

Hmmm... very odd... because using chlorine tablets is precisely what MacGregor recommend in the original Owners Manual:

14. PREVENTION OF ALGAE IN THE BALLAST TANK

If you leave the ballast tank full of water for long periods, drop in a few swimming pool chlorine tablets to prevent a bad case of algae. Be cautious when handling the chlorine tablets. Follow the directions on the chlorine tablet container very carefully. Don't put chlorine in the galley water tank.

Catigale · Post by **Catigale** » Mon May 30, 2005 7:12 am

Chemist in me makes me wonder if this is a salt vs. fresh water issue...

macsailor · Post by **macsailor** » Mon May 30, 2005 7:33 am

I've kepy mine at a dock for six summers in fresh water and I never put anything in the tank. I replaced my stopper a couple of years ago, but thought it was just getting a bit too corroded for my liking, but wasnt leaking. The water smells a bit when its dumped, but not a big issue I dont think., Beats having the chlorine eat away at the stopper plug and have 100 gal of water in the cabin..Just my thought.,

moonie · Post by **moonie** » Mon May 30, 2005 9:06 am

I'm concerned about the transom valve being damaged as well.I'm taking the boat out of the water on thursday to check up on this.
Is the ballast tank on the transom fitted with screws or adhesive?

Divecoz · Post by **Divecoz** » Mon May 30, 2005 12:36 pm

Transom valve sure looks like pool parts to me . Salt water and chlorine hummmmm never thought of that one, does anybody know for sure ?

KRV · Post by **KRV** » Mon May 30, 2005 3:18 pm

Blue Water Yachts recommends using a couple cups of bleach. I would like to hear from those that use bleach and does it work?

CFCassidy · Post by **CFCassidy** » Mon May 30, 2005 3:59 pm

I put a couple of cups of bleach in every year in my 1998 X. I keep the boat in a saltwater slip from May to October. No problems with the transom valve. I did have to replace the vent plug at the beginning of last season.

Scott · Post by **Scott** » Mon May 30, 2005 6:25 pm

I put in a clorine "pool" tablet a couple times per year. Never had to replace anything.

Pouw Geuzebroek · Post by **Pouw Geuzebroek** » Tue May 31, 2005 4:06 am

Moonie, with what sort of water did you fill the balast tank. Could it be waste water from some sort of chemical plant? Is it save to swim in? I heared of guy once that lived near an chemical plant and his car corroded within 1 year.

moonie · Post by **moonie** » Tue May 31, 2005 4:31 am

Pouw Geuzebroek wrote:Moonie, with what sort of water did you fill the balast tank. Could it be waste water from some sort of chemical plant? Is it save to swim in? I heared of guy once that lived near an chemical plant and his car corroded within 1 year.

Pouw
The water was directly from the Med.
I have been reading up on the chemical reaction of chlorine and different metals. Chlorine does corrode metals especially stainless (irrespective of grade) and bronze at a rate which depends on the quantity of chlorine solution. I put a couple of small pool tablets into the tank which was obviously too concentrated.I have now flushed the tank three times and put fresh water from the supply on the berth.No more chlorine for me,I'll just change the water often. The fumes were bad enough when I opened the air valve under the forward birth.

Pouw Geuzebroek · Post by **Pouw Geuzebroek** » Tue May 31, 2005 4:39 am

Ahh ok Moonie, I leave mine in a slip for 6 months each year and never add anything to the balast tank. But I am on a lake with sweet water, I do not know the effects of salt water as balast water. But you have now sweet drinking water from the marina, so that should be OK. I hate the smell of Chlorine, reminds me too much of swimming pools, I hope you get it out of your boat quickly.

MacGregorSailors.com

MacGregorSailors.com

Warning on Chlorine in Ballast tanks

Warning on Chlorine in Ballast tanks

How much did you use??

Vent Stopper

Transom valve sure looks