PSA - Dont Use MAX ACR - the stuff just dont hold up

[Arkangel77]

Just a heads up, if you are gona build your own tank. Don't use MAX ACR. I used it on my 400G build, after 3 years its a total FAIL. I did everything as they said and even did twice the coats they said to use. Its just cracking and splitting. Just FYI - stuff is Junk

 

[thebiggerthebetter]

Can you link the thread to your original build, please? Maybe consider elaborating, if you will.

 

[Arkangel77]

https://www.monsterfishkeepers.com/...gallon-mostly-pics.697145/page-4#post-8335155

The coating has split and cracked. I fixed a few small cracks I found around the glass lids and I originally assumed I did something wrong. At this point I believe the Epoxy just dont hold up long term

 

[stempy]

I used it on my 540 with zero issues, tank was up for over 5 years. When I tore the tank down the wood under the max acr looked brand new. My next build (whenever that eventually happens) will absolutely be with Max acr. Sorry you did not have luck with it. Epoxy is not the easiest stuff to work with.

 

[twentyleagues]

I've heard good stuff and bad about max acr but have not used it. I've also heard good and bad on pond shield, I've used that for various things. I wonder if you were getting some minor shifting in the wood from water pressure. That's alot of pressure to hold back with no reinforcement structure. It looked beautiful. I have been researching plywood builds for a couple years now off and on. I really want to build one in a particular spot but don't want to waste space with a 2×4 frame. I'm not sure a double plywood structure is going to be strong enough or last a lifetime. If I built it without frame it'd end up being around 400g with a frame about 100g less. I don't trust 300+ gallons without support from the research I've done.

I've got a old friend that built a huge tank in his basement years ago with a steal frame (he's a welder....or was) he will be disassembling it this summer. I plan on helping him, he's 75 and his family is gone. It's a shame it's been up for 20+ years. He says he's just to old to keep it up. He used max acr on the original build. I was thinking this would be a great time to learn how to weld and work with steal. I'd be able to build my tank where I want it with reinforcement at a fraction of the loss. Cost would probably be prohibitive with steel though.

 

[Arkangel77]

I really dont think there was any FLEX in the structure. I don't know that for a fact but i dont see any evidence of it. I wish I knew for sure cause that would make next step decisions a Lot simpler. I wont be Using Max Acr if I attempt to repair this tank. Feels like It might have worked out had I fiberglassed the entire interior, But that was never stated as a requirement when I was researching years back. Saving the current tank will be tuff but building another is not an Option for me. I will figure something out soon!

 

[stempy]

That wood is under an immense amount of pressure. On my 540 the 1" thick window bowed more than I would have liked it too so there is most likely flex in there even if you don't see direct evidence of it That's the main reason I overbuilt the crap out of my tank, was not worth the risk as wood does warp/flex/shrink/expand with different humidities, temperatures, etc. which does not play nice with something as rigid as epoxy, unfortunately.

 

[Arkangel77]

That wood is under an immense amount of pressure. On my 540 the 1" thick window bowed more than I would have liked it too so there is most likely flex in there even if you don't see direct evidence of it That's the main reason I overbuilt the crap out of my tank, was not worth the risk as wood does warp/flex/shrink/expand with different humidities, temperatures, etc. which does not play nice with something as rigid as epoxy, unfortunately.

SO do you think its not salvageable without an external Frame? BTW - I remember looking over your Build when I was researching =)

PS - once there is even so much as a pin hole, for sure water will get into the wood , cause it to swell and then epoxy starts to split

 

[twentyleagues]

SO do you think its not salvageable without an external Frame? BTW - I remember looking over your Build when I was researching =)

PS - once there is even so much as a pin hole, for sure water will get into the wood , cause it to swell and then epoxy starts to split

I think it's possible that as you filled the tank the wood flexed under the pressure then anytime you drained the tank it would relax. Then as you filled again the same would happen. Sooner or later the epoxy will crack. Epoxy is strong but it can be "brittle". Then micro cracks appear and like you said water gets in. It's just a theory. I've seen the no support builds in the larger sizes have some of the same failures. I've also seen lamination fails when the epoxy was improperly applied. There seems to be a "sweet spot" in the application time between coats that if you miss it either way could cause adhesion issues in the next coat. Seems most epoxy manufactures are a little vague on exactly when the correct time is to apply the next layer. Of course temp and humidity play a role also. Seems like most of the tank fails in the braced ones are of a error on the part of the builder that was missed or ignored i.e. things not fitting correctly, or a delamination of epoxy from improper application.

I started messing around with epoxy in my 3d background builds. I've seen where I messed up in application and got delamination. I've built 10 different backgrounds and had 2 with flaking of the layers. All so far have been pond shield (or is it armor? I always screw up the name) the rest have been pretty much bullet proof. In fact the one I built for my ex was the strongest but design was not the greatest. How do I know it was the strongest? It took me forever to destroy it and get it out of the tank. Lol. The one I built for my 180 was done differently then the previous ones instead of painting and then covering in clear I used black and then painted with krylon. The manufacturer said krylon would stick if the epoxy was deglossed. The paint started flaking within a year. The epoxy was strong and solid under.

My carpentry skills are sub par at best, I worry that my build will be a colossal waste of money, time and effort because of this. So I've slowly been working on them building random things needed in my house or hobby. I will most likely "over build" the structure. Because of space limits where I want to put the tank I'll probably need to move the build to another spot. No sense in building a larger tank if it's not actually going to end up that much larger then what's already there.

I think I've spent to much time researching this topic. And not enough time actually getting my hands on it.

 

[Arkangel77]

I want to thank Everyone for there Input and Help. After talking this over with lots of folks here and elsewhere I have decided NOT to repair this tank. I will be ordering a Acrylic tank next week.

While I totally believe it is reparable and there are a few Options for that repair (a Pond liner probably easiest way). Just cost plus labor and peace of mine for 15 years from now - I am not going to mess with it.

Again - Thank you all for the Help.