My new 2600 gallon plywood tank project

[Ozkar]

The liquid rubber might cost you the same as the pond armor that you are using but what you are using right now isn't working. I would get 5Gs of Zavlar and coat the inside of the tank as many times as you can until the bucket is empty. The stuff is great to work with and I am confident it will take care of your leaks. Whichever you decide, good luck!

Nolapete has the same problems with the Zavlar right now. Go figure.

 

[Inglorious]

Nolapete has the same problems with the Zavlar right now. Go figure.

True, but how much would it hurt to add a different product as the top layer? In the future would it be better for everyone to layer PA, sweetwater, fiberglass, and other waterproof agents in layers instead of just multiple layers of one product? Can anyone explain why it woVLDuld be better to use just one product or to layer different mediums to get the desired result? I really feel for VLD having so many problems with one build, and am wondering if the fix would be as simple as another layer of a different type of sealent? I know pond armor was chosen for a reason, but at this point is it worth looking at sweetwater and other options?

 

[jefferymoorhead]

wow what an amazing build. I just spent the last 2hrs reading through the 1500 and the 2600. I hope you get the leak problems fixed and hope to see the tank up and running. Great job so far

 

[lil_pendejo]

I've been watching this build since I was in Afghanistan and can't wait to see it finished and filled.

 

[MonsterPeacock]

Smoke'n Job! Must be frustrating as hell though to be so close and continue to be dealing with small leaks!! Keep up the good work and hang on to that positive attitude you seem to have!! It will be worth it in the long run and you'll know you conquered the hell outta it!!!

 

[VLDesign]

Thanks.. It's tough to stay positive when the leak appears to be moving.

Before I took the windows out it was leaking around the 20" mark. After the windows were re-installed the leak dropped to 13". Just makes me crazy when this happens.

I find it hard to believe that after removing the windows, redoing 2 more coats of PA under the window, then resealing the windows that this could still be the source of the leaking. Can't rule it out though.

So my next plan of attack which should make me even more crazy is I now have a 1" band that I know the tank leaking in. (12" it doesn't leak and 13" it does leak.) I am going to sand a 4" strip on the sides and back wall that will cover the 12-13" area. I will then use even more pond armor ( should be here tomorrow) on this band around the tank. Let it harden over night, and leak test again (Friday).

I have a feeling it will continue to leak at the same 13" mark just to taunt me. And at that point I will be gasing up the chainsaw. lol

 

[Zari]

So do you still think pond armor was the best choice for this over say fiberglass and marine epoxy resin?

 

[imacskye]

Yeah it leaked again this morning at 13".

There is no way in hell the tank is flexing at 13". I could build a box w/ 1/2 ply with no other support and not have it flex at that height.

And it was a 5" area from a depth of 13" up to 18" at the leaking was present.

Leaked more at 17" which suggest multiple leaks.

Going to have to cosider my options at this point. The liquid rubber is going to actually cost me the same as pond armor so I might as well stick with what I have been using.

I think it's safe to assume the floor of the tank isn't the leak since it holds water up to 12" without issue so I won't bother recoating that. And the leak is in the back of the tank 10' in from the left side of the tank. So I think it's also safe to assume that it's not the side walls as well.

I know you don't want to hear this, but I'm just trying to help, I don't want to see you waste your time and money. I build and repair boats for a living so keeping water at bay is what I do.

Just because it doesn't leak up to a certain point and leaks above a certain point doesn't mean the leak is between those two points and when you say that filling the tank more produces multiple leak all that says to me is that the cracks are opening up more and more and allowing more water out.

I think you are very naive to say there is absolutely no flex in the tank, no matter how heavily built a structure is the is always flex, especially in a wooden structure. Just the sheer weight of water is enough to compress the wood enough to open the seams up. You would be amazed how much you can compress softwoods.

Another possibility is voids within the plywood, all though I don't think you would see any evidence of these for quite some time.

I understand your frustration, but 'glassing is the only way to guarantee a water tight tank, you could have the whole thing done in a day, and it will last forever.

I wish you the best of luck in whatever course of action you decide to take.

 

[jeepn4x4]

I know you don't want to hear this, but I'm just trying to help, I don't want to see you waste your time and money. I build and repair boats for a living so keeping water at bay is what I do.

Just because it doesn't leak up to a certain point and leaks above a certain point doesn't mean the leak is between those two points and when you say that filling the tank more produces multiple leak all that says to me is that the cracks are opening up more and more and allowing more water out.

I think you are very naive to say there is absolutely no flex in the tank, no matter how heavily built a structure is the is always flex, especially in a wooden structure. Just the sheer weight of water is enough to compress the wood enough to open the seams up. You would be amazed how much you can compress softwoods.

Another possibility is voids within the plywood, all though I don't think you would see any evidence of these for quite some time.

I understand your frustration, but 'glassing is the only way to guarantee a water tight tank, you could have the whole thing done in a day, and it will last forever.

I wish you the best of luck in whatever course of action you decide to take.

I agree that there is no way that the tank is not flexing. with that amount of water and the size of the tank it is flexing.

 

[VLDesign]

I appreciate the help and I am not discounting it at all.

Voids in the plywood are a very real possibility as to what is going on and has been discussed in great detail around the house.

I know there will be some flex when the tank is full but at 12" of water it's only .5 PSI at best. Actually it's .4somthing but I rounded up. And I said there is no way it's flexing with only 13" of water in it and I still stand behind that statement. It's impossible that a foot of water is flexing the tank as a whole.

If this next water test fails like I suspect it will I will have to consider something drastic anyways.

Considering that I do still suspect the voids in the plywood at ths point (Those could easily flex/collapse) I may either lay down another layer of 3/4" plywood on the back wall and 1 side wall (the one with the bulkheads is already 3/4" ply) then doing those walls again in pond armor. Or fiberglassing is another good option.

Do I still think PA is a good choice? If the leak is pressure related and due to the voids in the plywood walls then Yes I do.

That would mean I am having a hardtime because of bad decisions I made and nothing to do with the pond armor. Infact I have said all along that I am unable to locate anything obvious that would make me suspect the PA even today. It's worked for me in the past so it must be the underlayment that is causing me grief.

In fact I will be going over the tank tonight and if I don't see something obvious I may just lay down the new plywood on top of what is already there and start again on the 2 walls.

Only reason I would hesitate on the fiberglass is the smell that would overpower the house. Can't really have that. The Bondo was bad enough on it's own.