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01-02-2007, 02:07
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#1
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Registered User
Join Date: Jan 2007
Location: Cape Town
Boat: 47 foot Shuttleworth Catamaran
Posts: 4
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I have bad tasting water - advice needed
My boat a 14.4 meter custom built catamaran Shuttleworth design has recently been launched. The water tanks are integral and finished with a product called Isophthalic Flo Coat. I have been using the tanks for a month or so now but the strong after taste of the Flo Coat still persists. I have flushed them through 4 or 5 times now. The builders cured the tanks before filling and the coating certainly seems cured. Any advice on how to treat the water or to get rid of the taste would be most appreciated.
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01-02-2007, 04:36
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#2
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cruiser
Join Date: Nov 2004
Posts: 4,525
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Just some ideas...
I wouldn't drink out of the tanks until you can't smell that smell. I don't know what Flo Coat is made out of but there are probably VOC's included in the ingredient list for drying purposes. You want to avoid drinking those.
Next, is there a way you can empty the tanks and secure ventillation? Maybe you can put a fan on an access port/hole (if you have one) and blow air continuously into it for days/weeks to make sure the tank is dry? The air you blow in should be able to vent out your vent tube. Just keep air flowing past for a long period of time and try again with filling with water and smelling the water at the tap.
I'd start there, rather than treating the water.
Later, you can install an inline filtration system to remove other impurites and junk. Although my filter (Culligan brand) takes out the VOC's, I'd still want to be sure the water going in was as pure as possible.
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02-02-2007, 00:17
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#3
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Registered User
Join Date: Feb 2006
Posts: 367
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You could ask the builders. If they are using that technology to construct the boat, they should be able to tell you how to make it work.
It sounds like the material did not cure completely. In that case, it will just re-contaminate anything you put in the tank.
__________________
Mark S.
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02-02-2007, 00:55
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#4
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Registered User
Join Date: Jan 2007
Location: Cape Town
Boat: 47 foot Shuttleworth Catamaran
Posts: 4
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All very good inputs - thanks very much. I have 4 seperate tanks so I'll immediate dry one out and "fan" it for a few days and see what happens. I agree that it sounds like the curing is not complete.
By the way Mark, the builders used the Flo Coat on the advice of the designer so they had not used it before hence they have relatively little to offer other than to say they cured the tanks for the requisite number of days per the Scott Bader (suppliers of the flo coat) recommendation.
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02-02-2007, 01:31
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#5
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Senior Cruiser
Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
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ISO requires a minimum of 3 hrs at 80degC. Sorry I don't know what that is in F. That is a minimum time. Longer is better. Don't go any hotter though. I suspect the taste is styrene. There are no other harmfuls in the cured plastic, providing it is cured.
If extra curing and ventilation does not help, you have two choices. One is to use a water filter capable of removing chemicals ot the other is to paint a potable water barrier coat over the resin and seal it.
__________________
Wheels
For God so loved the world..........He didn't send a committee.
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02-02-2007, 01:51
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#6
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,138
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Odour and/or taste, in potable water, may be indicative of some form of contamination of the water ,or of malfunction during water treatment, storage, and/or distribution - and should not be accepted without knowledge of the exact cause. The unusual taste or odour might be an indication of the presence of potentially harmful substances.
Isophthalic Polyester Flowcoat is a protective waxed gelcoat , typically applied to the inside surface of (male mold) fibreglass laminates. It should cure to a hard, tack free surface when fully cured. Most polyester resins are viscous liquids consisting of a solution of polyester in a monomer, which is usually Styrene.
Styrene Monomer is a colorless oily liquid with a sweet aromatic odour. The average taste threshold reported for styrene in water at 40 ̊C is 120 μg/litre, and reported odour thresholds for styrene in water range from 4 to 2600 μg/litre, depending on temperature.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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02-02-2007, 11:34
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#7
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Registered User
Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 7,145
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f=9/5 C+32 if I remember my high school math.
Therefore: 80degC = 176f.
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02-02-2007, 13:35
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#8
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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IIRC you can use carbon and resin filters to remove any "organics" that are in the drinking water from the tanks. These are sold in most hardware stores for installation in home water supplies, typically two "arm" sized cannisters and some hookups to go under the faucet plumbing.
If they need 176F to cure, air-drying a tank won't help, you'll need to carefully add some heat source in it. Perhaps hanging a couple of large light bulbs or a hair dryer into it, with due care against fire, would do.
Time to contact the designers and suppliers to ask them about curing it and drinking it.
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02-02-2007, 14:06
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#9
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,138
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I think the 176 Deg F is, technically, a "post-cure".
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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03-02-2007, 12:07
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#10
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Registered User
Join Date: Jan 2007
Location: Cape Town
Boat: 47 foot Shuttleworth Catamaran
Posts: 4
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Thanks for all the inputs. I am "curing" one tank at the moment using a hairdrier. Lots of "smell" wafting out so I'm hoping.... Will post the results. BTW the surface is certainly not tacky and feels very dry but (as I've said) the odour is quite strong.
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03-02-2007, 12:31
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#11
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cruiser
Join Date: Nov 2004
Posts: 4,525
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Quote:
Originally Posted by markvanniekerk
Thanks for all the inputs. I am "curing" one tank at the moment using a hairdrier. Lots of "smell" wafting out so I'm hoping.... Will post the results. BTW the surface is certainly not tacky and feels very dry but (as I've said) the odour is quite strong.
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Very good sign with the odor wafting out. You are certainly getting whatever part of that chemical wasn't quite done out of there now.
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03-02-2007, 17:50
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#12
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Senior Cruiser
Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
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Yes the 176F is a post cure. Polyester is different to epoxy in that it can't really "not" cure if ratios of the catalyst have been screwed up. Polyester is always in a state of cure, even in the tin. It has a limited life. The addition of the catalyst simply starts a fast reaction and speeds up the process. So technicaly you don't actually need the heat to make the material stronger as required with epoxy, the heat simply speeds the cure process to an even faster rate.
__________________
Wheels
For God so loved the world..........He didn't send a committee.
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03-02-2007, 19:50
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#13
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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I wonder...if it needs 176F to cure (or post-cure, all the same from a geological time scale<G>) that would also mean that pouring BOILING WATER into the tank would do a nice job of making sure it was all nicely hot. And, dissolving out anything that was water-soluble as well. Maybe after the chemical stink from the hair dryer stops, it would be worth boiling up vats of water and pouring them in for a "final post-cure" ?
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04-02-2007, 03:24
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#14
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,138
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Post Cure:
Tanks should be heated on the interior to a temperature of about 180º to 200º F (80 - 90 C). for 4 hours. To avoid the potential of inducing flaws in the laminate from thermal shock, increase the temperature slowly, and do not exceed the maximum recommended target temperature (ie: NO boiling water).
A hot water wash is only then used to remove styrene, grinding dust and foreign matter from interior surface of tank. After tank installation and before putting the tank into service, attention to the following procedures is important:
(1) After tank installation, steam-treat or steep it with hot water for 8 – 16 hours at 160º - 180º F. This should remove all residual styrene from the interior surface.
(2) Rub a small amount of clean Acetone on the laminate surface until the Acetone evaporates. If the surface stays dry and hard, it is properly cured.
(3) Wash the tank with detergent and rinse thoroughly.
* Merely relying upon an ambient thermo-set of the resins results in some degree of uncured components (styrene, alkali, and others). As soon as these un-cured pockets are exposed to any moisture, a hydrolytic reaction takes place.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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04-02-2007, 10:07
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#15
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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Gord-
"(ie: NO boiling water)." Shucks, sounds like the debate over "how hot should coffee be when it is sold to customes?"<G>
OK, no actually brewing coffee IN the tanks. But surely, by the time you drag the freshly boiled water over to the tanks and pour it in...it will cool close enough to <200F? If you walk slowly?<G>
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