HELP! Poly water tank - How do I plug these holes?

SydneyChick

BuiDoi wrote:

...

Quote:

I appreciate what you're saying BuiDoi. I really do. I'm going to try again today to get in touch with a plastics welder who can do the job without costing an arm and a leg

My welding job cost about what you were quoted.. he is at Bankstown, and I can give you his number.. and his work is now proven.. and he has material to do the work, BUT, you would have to deliver and pick up in order to keep the cost down..

Quote:

But it also means I'll have to build a special base to accommodate this "cone" shape

No.. you will have to bury in suitably shaped sand and wash it under to further shape and compact..
I built a shaped base from timber to.cause the central depression .. your depression is inbuilt.. sweet.. :headbang:

..
PETER

PS.. I would. Assume. The shed floor is bricks over dirt.. I would remove a circle of bricks and fill with builders sand to give you the shaping.. this would have the advantage of dropping the total height, a little..
..

Would love that number BuiDoi!

The sand base is a great idea! I was thinking of covering the base in plastic and sitting it in concrete encased in a frame to make a mould of the tank base profile - but your idea is better and less work.

SydneyChick

Called seven plastics welder a this morning. None of them willing to do the job. Most say they don't do rainwater tanks because of the pressure from the water causing repairs to fail! :cry:

Gunagulla

That's a pathetic excuse, your 1m deep tank only has 10kPa, or about 1.5psi pressure at the bottom. I put >30 X that much pressure into my mountain bike tyres.

If the weld can fail at that tiny pressure, they aren't properly welded!

coachchris

I filled mine with an epoxy resin that a friend who does fiberglass brought over.

Stuart Chignell

SydneyChick wrote:

BuiDoi wrote:

..
Fourty bucks.. For not sign ificantly more you could get proper stuff professionally welded..
..
.

Right now forty dollars is sounding like a bargain. The closest plastics welder I have found so far is in Penrith and even if you take the tank to him his minimum charge is $100 :upset:

Peace of mind is invaluable in AP. Might be the best $100 you spend on AP.

Stuart Chignell

SydneyChick wrote:

I think BuiDoi is just saying that since the former top of our rainwater tank rose up to a point sort of, when it's inverted it will slope down to a point which is very handy for solids collection.

That is not how round tanks work though. For the slope of the bottom of the tank to concentrate solids in the center the slop on the bottom must be 45 degrees or MORE.

You tank might have that on the edges but not to the center. To get the solids to collect in the center you have to get the water to swirl.

SydneyChick

Stuart Chignell wrote:

SydneyChick wrote:

I think BuiDoi is just saying that since the former top of our rainwater tank rose up to a point sort of, when it's inverted it will slope down to a point which is very handy for solids collection.

That is not how round tanks work though. For the slope of the bottom of the tank to concentrate solids in the center the slop on the bottom must be 45 degrees or MORE.

You tank might have that on the edges but not to the center. To get the solids to collect in the center you have to get the water to swirl.

Duly noted Stuart. Swirl is always good when planning a SLO

SydneyChick

I had a bit of a win today! Was trying to think out of the box on what I could use to seal the 29cm inlet hole.

Found a guy selling big plastic HDPE barrels (food safe contents) and he gave me one of the lids!

The second "lip" inside is a perfect fit. It even come with a rubber O ring that I can use.

Still going to use the HDPE chopping board and gasket rubber on the inside of the tank - but between these two we should have a high chance of making this puppy watertight! :headbang:

Backyard Aquaponics A place to discuss aquaponics

HELP! Poly water tank - How do I plug these holes?

Backyard Aquaponics
A place to discuss aquaponics