1200 gallon insulated storage tank for $595 Pic added

[Bad Wolf]

That’s what it cost me to build mine.

My tank
$ 71 Pool sides
$280 EPDM liner (25’ x20’)
$140 (12) pieces Styrofoam for bottom (8) and top (4)
$ 74 (2) Rolls Insulation for sides (4’ x 100’ 1 ½” thick)
$ 30 Misc stuff (spray adhesive, hardware, plastic sheeting, spray foam)
$595 Total

Construction:
52” high x 7 ½ foot diameter tank:. This was brand new swimming pool sheet metal sides. I got a 24 foot round and cut 1/3 of it off. Measure the exact distance you need hole to hole and drill matching holes to the ones already there and bolt it together with ¼-20 hardware.

Base: I put 4 2x8 pieces of Styrofoam together and cut a 7 ½ foot circle, repeat. Stack on top of each other and you have an R-20 base. Could have gone with 3 layers and lose 2 more inches in height.

Liner: Bought from pond supplier, cut a 16 ½ by 16 ½ piece. I put mine in square but if I had to do it over I’d cut it round so I don’t have to trim it afterwards. Place inside and pull up over the sides. You have to do some pleating of the material but it’s not too hard. I held it in place with duct tape.

Cover: I took another 4 pieces of foam board and this time cut an 8’ circle. Glue edges together and lay an 8’ diameter piece of left over EPDM on it and contact cement it in place. Cut holes for any pipes. R-10 (flip it over, the EPDM side goes down)
UPDATE: Heat and contact cement don’t work well together!! Liner is starting to detach from foam board. Its not going anywhere though, it’s supported in the middle and on the edges. My project for next summer is to find a better way to glue it up.
UPDATE: People are telling me that the pink foam will not hold up in the long run. I did a test by putting some in the oven at 190 to 200 and placed some weights on it to simulate loading. After 4 hours I couldn't see any change. Now that was only 4 hours I have no idea how it will fair over 6 months. I'll check in the spring and maybe add some of the foil covered foam.

Seal top to side with Dow Corning high temp sealant

Wrap tank with insulation. I used 6 layers for 9 thick. R-26
Cut four 8’ diameter half rounds, place on top for 2 layers or another R-9.

I wrapped the whole thing with plastic sheathing just to make it look nicer and add a little protection. Looks like a giant cake.

This is roughly the same as the STSS 1200 gallon tank that they sell for $2560 (plus shipping), and theirs is only R-14.

I had to buy more material than I needed so I’m selling what I have left over at my cost.
Sheet metal pool sides: I paid $212 so I’m asking $75 for the piece that has the holes in it at the other end and $70 for the piece with no holes.
Insulation. I bought 6 rolls for $222 and only used 2, so I’m asking $37 each, Johns Manville brand 4’ x 100’ rolls


So far its working great, temp was up to 145 over night before I let the fire go out. I'll try to get it higher tonight.
UPDATE: Its been up to 172 consistantly with no problems. The bottom only gets to 155.

Email me
Greg H

 

[Justburnit]

Nice,
When I did mine I used strips of the plastic decking planks and sent 6"stainless screws up trough to hold the upper liner.

 

[88rxn/a]

pictures?

 

[tom in maine]

Sounds like a great job.
It sounds like you used Styrofoam (extruded polystyrene) for the top and base. These will start to melt when exposed to temps
over 140-160F. You should monitor them. It the tank gets up past those temps, the foam will slowly start to look like someone put a torch on it and melt into a solid mass. There should be enough liner to accomodate this on the base, but you will lose your insulation value when this happens.
Be prepared to replace the cover at some time since this will go sooner.

You need polyisocyanurate. This is the foil faced foam that they sell at most places like Home Depot. MAKE SURE the foam is yellow.
They are now selling foil faced expanded polystyrene, which is a cousin to Styrofoam and will also melt at similar temps (this is white).

Hate to be a bearer of bad news, but this is something to watch out for. Not a catastrophy, but an issue.

 

[Justburnit]

A 1" layer is enough of the foil faced foam to protect the Blue or Pink stuff generally.

 

[Bad Wolf]

Oops!! I didn't know that. I'll keep an eye on it. The tank was at 160 this morning, probably higher earlier since the house had been calling for heat for a little while and the fire was out. I've already mapped out some improvements that I'll do in the spring it it can wait. Sounds like I'll need to drain the tank, cut out my coils and put in unions (which I probably should have done n the first place) and replace the foam on the bottom and fabricate a new top.
As long as it doesn’t let go and flood the place I guess I can wait.

Thanks for the heads up.

Greg

 

[Justburnit]

I would try to keep the 160° as an upper limit for the season and give it a look in the spring. That should be a sufficient temp to operate with.

 

[Bad Wolf]

Here's a pic of the tank. I have more of the finished installation.

 

[Dave T]

Greg H I don't know a lot about storage tanks but I am a commercial roofer and use EPDM and contact adhesive almost daily..The way your post reads you tried to use contact adhesive on DOW board, the glues used in commercial roofing (contact adhesive) will disenagrate(spelling) styrofoam much like gasoline, when EPDM is glued down the insulation it is glued to is paper backed we call it isoboard (Polyisocyanurate) I threw in a pic or 2 for fun, nice lookin storage tank..Dave

 

[Bad Wolf]

Thanks Dave.
The first contact cement I used, I tried out on a scrap piece (I ain't no dummy) and sure enough it melted it. I found a spray on adhesive that didn't dissolve the DOW board. Unfortunately it didn't hold up to the heat. Some time when the tank is cool I'll try reaching in with some plastic strips and stainless screws and tack it up. It's sealed at the edges and I have a support in the middle so it can't sag too badly.

I'll try a few more pics of the finished tank later.

Greg

 

[Justburnit]

On my large storage tank I had about 40° stratification. yesterday I set up a 006 Bronze circulator drawing from the bottom and feeding back to the top. I now have 2-4° from top to bottom. A tank your size would need a half day run once in awhile to mix it.

 

[Bad Wolf]

Depending on how fast it came up to temp and how long its been there I get between 15 and 30 degrees stratification. I thought stratification was a good thing?

 

[Justburnit]

Well. if there is 30° difference between top to bottom so that would be 160 or so up top and 130 at the bottom compared to 160° all the way down. Stratification can be a sheer layer with a major change in temperature in a very narrow layer. It in not necessarily an even change top to bottom. We need one question answered. how much is at the high temp and how much is at the lower. It might only be the top 18" that is hot. But if it is all the same temp top to bottom, you have many more BTUs stored in there.

 

[Fred61]

I plan on building a tank and am trying to educate myself. I've never had an interest in a pool so I've never looked at the construction of one. It appears in the photo that you have no rails going vertical. Is all the outward pressure of the water being put on the 1/4-20 screws at the joint? If that works it is much simpler than the design I had in my head. If we were closer I would consider purchasing a side panel from you.

 

[Bad Wolf]

On my 24 foot pool in the backyard I have a piece of steel with holes in it as a backing piece but this pool did not come with one. If it will hold the 12,000 gallons of a 24' pool it shouldn't have any problems with a 7.5' one. There are 25 bolts and you probably can't tell from the photo but they get closer together toward the bottom where the force would be the greatest. Round is the strongest shape with the force equally distributed along the sides. 25 bolts in shear are amazingly strong. This is the same design that STSS has though I do see some strapping, I think they use aluminum sides, not sure.

One thing I did do was cut an extra strip of EPDM and tape it over the screw heads on the inside as added protection for the liner. If I have time between dinner courses I'll try to post some other pics.

 

[Fred61]

Thanks Greg for the quick response


Fred61

 

[NHFarmer]

Fred61 I built a 1000 gal. tank.I bought 4'x10' sheets of galvanized sheet metal.Heavy duty steel pop rivets,EPDM liner,2x6 stud walls on the outside,insulated with cellulose insulation.works fine.The sawdust insulation might work but I would be worried about fire as by boiler is close to my tank

 

[Hydronics]

Fred 61,
I see you used to own an Eshland Wood gun. Why don't you sell it?

 

[Fred61]

The Wood Gun was in my previous house. I didn't sell it, I junked it.

As I wrote in another post on this forum, Using it convinced me that if you were going to burn wood, gassification was the way to go, however the Wood gun had many negative "issues". After my experience with the Eko, I find that there were a couple good things.

I ran the wood gun for 10 years from the early 80s to the early 90s. It would eat itself up in one heating season. It ate (eroded) the nozzles. refactory on the doors and door gaskets. It would cost me the price of a years worth of heating oil each spring to repair it. Of course oil wasn't as expensive at that time.

Something I didn't appreciate at the time was that with the motorized, gasketed air inlet. I never had any boiler overheating during idle and did not get the amount of creosote in the wood chamber that I am experiencing with the Eko. I always got a good burn and there was no need for storage.There was no creosote in thr combustion area. The unit had fire tubes vs. just an open chamber. Unless I used wood with good "coaling" characteristics the fire would not re-light after along idle. If it short cycled it would have an explosion that blew the hood off the outside intake duct. Many times, I found it out in my backyard.

I also think the boiler plate wasn't as thick as the Eko. I had to hire a welder two or three times to repair leaks and he had alot of trouble welding the thin plate.

 

[Bad Wolf]

A few more pic as I get the hang of this.
My fully insulated tank, tank under construction, fabricating coils, and finsihed boilerinstalation. Thats about 10" of insulation

 

[TimCroft]

Hey Greg,

Wish I had done more research before springing for a 660 gal STSS tank. someitme wish I had more storage and may someday build a larger one. The Stss has pop rivets every 3 inches on the vertical seams. circular tanks has better ditributed of stress and all forces are shear, not thrust. This is the big difference between round and tanks of other shapes.

I am curious about your solar panels I have ordered 4 evac tube arrays to put in my yard. I want to run the PEG through a HE loop in my STSS but need to keep the Tarm excel 2000 warm during the summer also to prevent rust and condensation.

I would love to just tap into the primary circ. loop on the boiler and use the controller on the tarm to trip the primary loop at 165 deg. and run the solar heated boiler water horough the STSS BUT I have to have 50/50 PEG in the solar array and don't want to run 50/50 for the boiler water and my two zones.

Any thoughts?


tarm excel 2000
stss 660 gal unpress.
plumbed to tarm manual guidelines

 

[tom in maine]

Can't pass up the comment on round tanks versus other tanks.
Since I invented the round tank concept that STSS uses, and we are now building square tanks, I have a little bit to contribute on this issue.
You are right that all fasteners should be in shear and they are in most assembled tanks.

We came up with a simple way to make a very solid, rugged square tank that we are patenting.
Square tanks want to become round. If you build a strong enough square tank, it stays square.
The trick is to do it without being stupidly expensive. I think we accomplish that since our tanks are less expensive than others.

The nice thing about square tanks is that they fit into corners in square or rectangular basements!

 

[TimCroft]

Tom

My compliments on the simplicity of the round design . Just a little perturbed at the cost when I saw how little there was to it.

 

[tom in maine]

LOL, we do not make that tank. We used to make a round one.
The square one we make is less expensive and a lot beefier.

Do not want to make this into a commercial!

I admit that even our current tank is not cheap, but it is extremely strong and well insulated and offers a lot of convenience.

So much for not making this a commercial. I will stop now ;^)