Water tank smell and taste...No good

First, let me say Richh, Wow! you definitely know your stuff. As I have been reading through, I did not see anyone suggest the water lines. I did see the fill hose mentioned, but you may have contamination elsewhere in your system. If not, have you considered inserting bladders into the tank? They seem to work pretty well, and they are getting cheap enough to be worth trying. That may prevent you from having to remove, cut, coat, glass, and modify.

[capt lar]

hey CSY guy - whats the verdict ? any solution ?
capt. lar

[CSY Man]

Yeah, I have sort of decided what to do:

First off all, I decided NOT to tear off the floor / cabin sole and then cut the tank open to coat it properly.

That would have been the best solution except for the horrific amount of work involved and the expenses.

As I am not retired and don't have a shop full of tools, I would have been forced to hire people to do quite a bit of the work.
The going rate around here is $55.00 per hour for marine mechanics.

So that solution is out.

Decided to sand the inside of gel coat surface as much as I could, using only the inspection holes, they are 5" X 5" and there is 4 of them.

I can get my arm in there and have started the sanding.
After the sanding and acetone washing, I will coat the gelcoat with West System epoxy applied with a foambrush.
I should be able to get 90% of the "floor" in the tank done and parhaps 80% of the walls and hopefully 60% of the top (roof).

Also cleaned off all old cauliking and sealents, and instead using chemical resistant rubber gaskets for cover-plates and plumbing.

In addition I will use higer "grade" filters on the drinking water system...Got one yeasterday that looks pretty promising: MATRIKX+CTO/2/ model 32-250-125-975.

The whole project should cost me about $50.00

IF I still have taste of smell after doing the above, then I will simply install a small dinking water tank and use the existing pump, hoses, accumulator, etc.
There is plenty of extra room on the boat for a 20 gallon tank, or even 2 x 20 gallon tanks, but that will eat into my storage space.
(Where the 8 cases of beer go for the long Exuma cruises.. )

I did consider inserting bladders in the tank, but due to the shape and the baffles and angles, etc It would not be practical.

I should be done in a few days and will report back.

[capt lar]

this far along, do you still smell the smell ?

[Talbot]

highly recommend that you replace the hoses at the same time, including the air vent.

[CSY Man]

this far along, do you still smell the smell ?

Nah, the smell is not that strong anymore now that the tank has aired out for a couple of weeks.

highly recommend that you replace the hoses at the same time, including the air vent.

Yeah, I will look into that as well.

[Alan Wheeler]

Now you probably know this, but be damn careful of using Acetone whilest head down in that tank. Or the last thing you may remember are little pixies flying around in the tank just before you go unconcouse.
And don't light a match. Or NASA will have another piece of space junk to have to track out there.

[Boracay]

To Alan's suggestions I would add using a good fan(if a suitable forced air respirator is not available) and to have a friend standing by as well.
Don't forget to brief the friend on the characteristics of flamable heavier than air fumes(no naked flanes, more than one person overcome etc.).
This is a dangerous activity and is best not attempted if you are not sure of how to mange it or you do not have the right equipment.
WEST Systems markets a sovent that is much more user friendly than acetone.

[Boracay]

The thought of using acetone as a cleaner in a confined space really worries me.
The reason acetone is used when bonding polyester fibreglass is to remove any residual wax, and to a lesser extent to soften the polyester.
The wax could have been added during manufacture to delay curing or from a polish that was applied later.
Have a look and see if there is any evidence of wax. If there is none then you may not need a solvent at all.
Contacting WEST System for further advice would be a good idea. Contact details are on their site at :- http://www.westsystem.com/
It is possible that the leeching effect of the fresh water has left a matt surface (with some residue from where impurities in the water have settled) and that the epoxy will form a strong mechanical bond to this anyway.
In a perfect world repairs would best be done with the boat out of the water.
Careful use of a hot air gun to get the interior of the tank totally dry combined with sanding, brushing and vacuuming where possible should leave your tank ready to coat.
Putting some time into making specialist brushes that will reach into odd corners and maybe using a mirror to enable more of the tank to be coated could be advantageous.
Don't forget that while Epoxies are much safer than acetone thay can still give off fumes that are dangerous in a confined space.
Reading the data sheet for your epoxy is also a good idea.
If you wait until the epoxy that you have applied is "green" or has "gelled" you could probably overcoat with a good primary (chemical) bond to help you build up thickness.

[CSY Man]

This is a dangerous activity and is best not attempted if you are not sure of how to mange it or you do not have the right equipment.

Yeah, thanks for the concern, but the danger of being overcome by fumes are not too great in this case as I can only get one arm into the tank and my face is therefore free and clear and in "fresh" air.

Yes, I usr a large fan inside the boat, not only to evacuate fumes, but also to keep the temprature down...(Hot Florida summer)

I am concious of the dangers of open flames, etc, being an ex-air-force fighter fighter, and also an ex tanker man who cleaned many a tank on 30,000 ton chemical tankers in the merchant marine.

What I am attempting to do here, coating the inside of my water tank with epoxy to seal of blistered gel coat surfaces is fairly benign stuff.....I hope....

[jimini]

This is a stupid question but I have to ask it - could it be the water supply being pumped aboard? The water itself before even entering the water tank....

Sometimes we look for the hardest things first and overlook the easliest.

jimini

[CSY Man]

Nah, not the water supply...The same kind of tap water I get in my house every day.
Got the boat in my back yard.

The cause now appears to be blisters inside the tank and the gel-coat braking down.

(As some folks concluded earlier on these pages)

The water tank is really the bottom of the boat with a "floor" 12 inches above it.
That is the tank, it stretches from underneat the setees on each side across with a big loop around the keel/bilge.
And from the galley forward to the mast.
Quite large and hard to get to all the corners and hidden angles.
Have been able to cover 99% 0f the bottom with epoxy and 95% of the walls, but it sure is slow going...A few more days and I can start putting it back together.
In the meantime using a hot lamp inside the tank to cure the epoxy properly, also going to water-scrub the surface before use.

(The hot-lamp and the scrubbing as per West System's web page
for coating water tanks....It is not "food grade" stuff, but it will do for now..There must be a lab out there that can analyze drinking water and find out if there is traces of bad checmicals in the water or not..?)

[Alan Wheeler]

Epoxy in it's liquid stage is bad news health wise. Once it has cured, it is very safe and should pose no threat to your drinking water. Just ensure you mix the ratios correctly. In other words, use exactly what the specs say of each part. Epoxy is kinda unique in how it works. You can basicaly look at it this way. The resin is a bunch of molicules that have a keyway in the side of them. The hardner has a key that fits in to the keyway and when this happens, the molicules are locked tightly together and become solid. The ratio is important in that their should be just enough Keys to fit all the keyways. Not enough and there remains unhardened Resin molicules, or too many and there remains unhardend hardner molicules. These excess molicles are locked within the hardened resin and you may not notice them physically, but they afre there and still cause a health threat. The same thing happens if the two liquids have not been thouroughly mixed together. So use the correct ratio and mix thoroughly.

[CSY Man]

Okay, thanks for the heads-up Mr. Alan, yeah I do pay attention to the ratio and the mixing.

Only use very small batches so mixing is easy.

THis project is dragging out and I am hoping to button it up next week or so,

Full report will follow.

[CaptainK]

Dear CSY Man,

So how's your water coming along. Did you ever finish fixing the tank?

And did you have to tear the floor up to get to all of the tank. Or did you managed to crawl in enough to get the job done?

Just wanted to ask. Cause I know that some time has past by since the last posting, of this thread?


Regards,

Kevin
CaptainK