Building Fiberglass Fresh Water Tanks

[cat man do]

Originally Posted by Stevens 47

The Jeffco product that complies with this standard are epoxy resin 1405 with a 4105 bb hardener or a epoxy resin 1409 and a 4102 hardener. http://www.jeffcoproducts.com/

I use these guys because they are local for me.

Jack

At the end of the day it's another epoxy resin and hardener.

Does this one have a non-toxic hardener, or is it just the peice of paper that protects you?


Dave

The NSF/ANSI regs really only come into play if I ever sell the boat, but it is likely that the chemical make up of the jeffco product is different than West Systems.

[Stevens 47]

I suppose that Jeffco has had it certified to meet that standard. I am not a chemist so can not comment on the chemical differences. Jeffco does have allot of different resin systems and yes at the end of the day they all do much the same thing get hard. Unless you are building really high tec parts some of the resins could be over kill. I have been using the 1310T which is a good vertical laminating resin does not drain out the way the west system resins do. I will probably buy the stuff they recommend for my tanks.

Jack

[Alan Wheeler]

Ummmm, well actually the chenical make ups can't be different. The are differences in formulation yes. It is the Hardener that does all the tricks, but the base product is still the same. It has to be as it is a matched chain(hardener) to the epoxy chains so as they cross link. There is no other chemical compound that does the same thing. If there was, you simply would not get Epoxy. It would become something else entirely.

[soul searcher]

just a thought but for seven tanks could you build a mold and build the tanks out of just glass and save a lot of weight?

[Steve Rust]

I don't think a solid fiberglass tank would be lighter than a ply/epoxy tank not to mention higher material cost with the additional resin and cloth needed. And then of course how do you get the mold out of the tank? I remember reading about one particular nasty method of making a mold out of styrofoam and then after cutting in your access port you pour in gasoline to melt the styrofoam. Lots of fun.

[Alan Wheeler]

I suppose you could make two halves and then simply glue the two together and tap the seem. That would solve the mold prob. Or you could use an inflatable shape and deflate and pull it out of the filler hole.;-) :-)

[GordMay]

Building Tanks with WEST Epoxy ~ Wood/Epoxy composite tank guidlines http://westsystem.com/ewmag/18/pdf/tanks.pdf

Each tank is a completely different size and shape, so molds are not really practical for me. I did consider this, and even making the molds so they could be adjustable, but it just doesn't pan out.
Wheels, interesting. I would have thought the chemical make up would vary from one manufacturer to the other. If the product is exactly the same, what is the difference between different products?
Gord, great link. Thank you. It looks like the same article Cat-Man-Do posted.

And procrastination sets in. Just had to sail this weekend, so the tanks wait another week

[Alan Wheeler]

Sorry mate, I never saw your question above.
So what makes epoxies different?? Well big question. It is what is put into the epoxies to make them do what we want them to do.
There are literaly thousands of Epoxy mixes out there. Each one specialising in some role. However, the basic chemical formula of the epoxy and hardener itself, is the same in all of them.
In the role of Glassing or sheathing epoxy, the Resin is usually close to pure epoxy. Sometimes a few additives can be added to make the epoxy do a specific job. Much like we use the laminating Resin and add Talk or silica or wha have you to make fillers and glues etc. Such additives the manufacturer will add will be Viscosity reducers, wetting agents and maybe colour, especially in relation to a few new mixes available that change colour to show they are mixed correctly. But the Hardener tends to have the most tricks in it. These are colours once again, adhesion promoters, wetting agents and of course accelerators which is the most common difference. These additives all alter the way the epoxy performs, but the resultant cure remains the same. It goes hard.
The basic principle is a chemical reaction between two chemicals called Epichlorohydrin and Bisphenol-A. However, there is a little smoke and mirror majic done with these and NaOH that can manipultate the complexities of the chains that are formed. Thus making differing strengths and Epoxies that can withstand heat and so on. Normaly the more complex the chain becomes, the thicker the viscosity tends to be. And the most coplex chains with ans many as 25 molicules making p a chain is basicly solid at room temperature and has to be heated to melt it so as you cam mix it.
I won't go too much further, basicaly as I imagine your eyes are rolling over and I am fast approaching the deep end of what I know. I want to paddle back to the shallow end now if I may, before I get myself in trouble.

Being a visual learner, you are correct. At first, the eyes started to go blank, but your description hit a few nerves, and the pictures started to appear. I get it.

[Boracay]

A good water tank storey can be found at :-
POISONED AND DYING IN SIDEA
and at :-
Dire Straits

I have met people with Heavy metal poisining. Not something I want to experience. Still haven't got anything done on the tank. Wood's bought. Epoxy's bought. Now all I need is a couple extra days off each week

[Sheetbender]

I would not at this time leave an epoxy finish on the inside of a drinking water tank. Do a search for Bisphenol-A. Not good.

Epoxy can be coated with a good iso gel coat. West Systems says that good adhesion can be obtained when overcoating epoxy with gel coat.