holding tank

[Capt. Mike]

Has anyone every built there own tanks I saw it done one time and I think I can do it, if someone else can do it then so can I. this how I have always lived my life. yes it has got me in trouble twice in the last 15 years (no not the law) But I do think I an do it.

I want a black water holding tank that holds 200 or more so I don't have to dump so often and now that I am painting my bilge this the time to do it

maybe I can pull this off or just learn from it but I will try and I will learn

 

[erikgreen]

Re: holding tank

You know how to weld aluminum? A black water tank isn't the worst place to have a leak, but it's far from the best.

I wouldn't recommend you make it out of fiberglass, because you'll really have to know what you're doing to not make it super heavy all by itself and still have it seal in the water and smell.

Speaking of weight, 200 gallons of clean water weighs about 1600 lbs, and blackwater a bit more. If you avoid dumping a lot, you'll be spending a lot of fuel to haul around a tank full of sewage.

Unless you have a really big boat (I'd say more than 50 feet) you'll definitely notice the extra weight in your boat's handling characteristics too.

If you have a really tiny tank now you can certainly up the size without too much problem, but I'd think twice about a 200 gallon blackwater tank. Plus for the small sizes it's cheap just to buy a plastic tank anyway.

Erik

 

[Capt. Mike]

Re: holding tank

I wanted to use poly but fiberglass would be easery then poly and cheaper.Yes I can weld aluminum, but I don't like aluminum tanks.

my boat is a 60 footer

www.bigwoodenboat.com

 

[erikgreen]

Re: holding tank

Poly and fiberglass are pretty much the same thing... fiberglass is the reinforcing material, poly is the resin. Same idea as epoxy/fiberglass.

Or do you mean poly sheeting? If you know how to work with thermoformed plastics, you're probably ahead of most folks here.

One thing - if you do use fiberglass, then use epoxy. Poly is slightly porous, as I recall, which over the long term will be a bad thing for your nose

Other materials if you don't care about weight... steel maybe?

I know some folks here have had custom aluminum tanks made... custom steel would probably be easier to make actually.

For fiberglass, there are several construction methods. You can form a female mold the shape of the tank with one side missing, polish it smooth, and do a layup in it like a custom hull.

Alternatively you could form a foam core using styrofoam, making it hollow if possible, and lay up the fiberglass around it like an external jacket. Use styrene liquid (sold as thinner and part of some brush cleaners) to dissolve the foam and leave you with a hollow shell. Add fittings and go.

What shape do you want the tank to be?

Erik

 

[erikgreen]

Re: holding tank

One more thought... with a wooden boat that size, you're probably not daunted by tons of work to make something

You could possibly make a tank the old fashioned way, using cooper's (barrel making) techniques.

Or, you could build a wooden tank into the boat, and line it with fiberglass to seal it.

Just a couple thoughts...

Erik

 

[flashback]

Re: holding tank

never done it, but if I were, I would get a block of foam that equates to the size I want and glass it with epoxy,, everything except one end.. then tear the foam out after it cures, then close the end....should work...

 

[Capt. Mike]

Re: holding tank

The more I think about it and read what you guys say. fiberglass will work best for me epoxy like west sys. is over kill and over rated. I will build the bottom and sides first and inter walls to stop the splashing around. I will take many photos.

thanks guys

www.bigwoodenboat.com

 

[Gary H NC]

Re: holding tank

Man that thing is huge Capt.Mike! What a nice boat!

 

[Capt. Mike]

Re: holding tank

thanks .... but also huge amount of work

 

[Gary H NC]

Re: holding tank

Looks like it will be well worth it! Keep us updated with some pics...
We all love pictures!