Giant storage tank

[Dune]

So I am at a local boatyard, and I notice this giant tank, which I calculate at six thousand gallons. It is fiberglass, and I can most likely get it for free. Is this thing just way too huge or what? Now I am thinking it may be a good starting point for a methane generator.

 

[pybyr]

bigger is better with storage..., but you may have found the "too big"

How on earth would you ever get a vessel of that size within a well-insulated space? Also, some, but not all, fiberglass can handle the temperatures involved in thermal storage. It'd be a bad experience to find 6000 gallons of hot water suddenly telling you that this particular tank isn't up to the temperature....

but maybe if you can confirm this tank could handle the temps- you might have one heck of a "seasonal storage" if you could build it into a basement

 

[Dune]

Trevor, thanks for the input. I am planning on buried, super-insulated storage. I am connected to a spray foam insulation company. Are there any known formula, rule of thumb etc. to calculate ideal storage size versus cubic feet of house size? I am a fabricator, and can make this tank into other (smaller) sizes. For instance, I could cut the two ends off and make a round tank, less than 1000 gal, or if I were better off with larger, I could include some of the cylindrical section. Thanks for any expertise.

 

[carbon neutral]

A word of caution about fiberglass tanks. Many, in fact most, epoxies have a polermization temperature of about 140 degrees. This is the temperature that the epoxy will soften. I know this from building a composite airplane. Sometimes it is necessary to post cure a part. This innvolves bringing the part up to 160 degrees for several hours. During this process the part has to be well supported.
Once post cured the parts will not reach a polermiztion temperature until about 260 degrees. Post curing is common in the airplane business where strength to weight ratio are important and where temperatures can easily reach 140 degrees, think about a plane parked on a ramp in Arizona during the summer. If it ain't post cured or painted white it will "melt". Anyway I would seriously doubt the 6,000 gallon tank you are looking at has been post cured.
Also a 6,000 gallon tank is too big IMO

 

[steam man]

Insulate the inside and put a epdm liner in it. Just think of the bragging rights you'll have around here. LOL!

 

[Dune]

This tank is an old gasline storage tank. It is not made from epoxy, but rather modified polyester resin. It can easily withstand 200f. It will also be easy for me to modify, as I am well equipped to do so. My house is 60 feetx 24 with a partial second floor. I am replacing baseboard with radiant suplied by wood boiler. I have a couple I" mixing valves. What size tank would be Ideal? Is there a point of diminishing returns? I understand the concept of keeping the tank inside the heat envolope, but serious insulation must suffice. Any ideas on sizing a tank?

 

[free75degrees]

Let's say for your house, you need an average of 2 full loads of wood per day over the course of the winter. With no tank this might mean 1 in the morning and 1 at night. With a large enough tank this could mean a few hundred loads in October and then you are done. An intermediate might be 14 loads starting Saturday morning and ending on Monday. Once the tank gets large enough to prevent idling, adding any more size only gives you some leeway on when you need to fire it up. I personally don't think the routine of 14 loads on a weekend is any easier than burning 2 loads every evening. I think a daily routing is probably easiest, but maybe a 6000 gallon tank would be nice if you plan to be away from the house often so that you can avoid burning fossol fuel for a period of consecutive days.