Plywood tank epoxy

[salty55]

I'm in the planning stages of building a large plywood tank. Im currently trying to decide which epoxy I want to use. It seems like west system sweetwater epoxy and pond armour seem to be the most popular choices. Has anyone had any experience with this product? https://pentairaes.com/epoxy-paint-kits.html
It seems to be a good bang for the buck. Especially with the amount of product that you get.

 

[CyclistMT]

Epoxy paint can work well, especially for smaller tanks. I used epoxy paint on my 150 years ago. If you have something bigger in mind, you might look at US Composites. That's what I used 8 years ago on my 300 and it was inexpensive and has held up well. 635 resin with slow hardener and color.

http://www.uscomposites.com/

My thread has links to many other plywood builds too.

CyclistMT's 300 Gal Plywood and Glass Build

 

[salty55]

Thanks for the info, cyclist. Did I read your thread correct? You didn’t use any fiberglass, just the epoxy pour method?

 

[CyclistMT]

Correct, no fiberglass. I used the "pour method" for the epoxy instead of brushing it on. Takes longer but WAY better I think. Will give you like a 1/4" epoxy layer on the inside of the tank and a lot of peace of mind.

 

[outssider]

Correct, no fiberglass. I used the "pour method" for the epoxy instead of brushing it on. Takes longer but WAY better I think. Will give you like a 1/4" epoxy layer on the inside of the tank and a lot of peace of mind.

Way back in 1969/70 (when I was a teenager) I built a 50 and 75 gallon plywood tank using finishing resin and blue pigment, poured one side at a time ...worked great !!

 

[salty55]

thats one of the many decisions that are plaguing me. some people don't use fiberglass, some fiberglass the entire tank, some some people only fiberglass the corners (which I don't fully see the benefit of the latter)

 

[salty55]

I guess I should share a little info on my intended tank build. The tank is going to be 92" long, 48" deep and 24" tall. It will be a "dropoff" style tank with the shallow end being around 16" deep and with a span of 3' of the tank. The tank will also be placed on a short stand appx 12" tall so the tank can be viewed top down, along with viewable from two sides.

 

[CyclistMT]

This is why I don't think you need fiberglass. (If you can't see the photo, you might need an extension for Chrome that shows Photobucket items.)

If you pour the epoxy (in 3 coats) you can get a nice thick, bulletproof layer. Even if your tank is 48" deep in the drop off, I don't think you'll have any problems. You can pour the corners too like I did. If you could see this in person you'd understand. There is no need for the mess, fuss, and extra work of fiberglass.

 

[salty55]

How many gallons did you use to achieve that thickness?

 

[CyclistMT]

Looking back at my calculations, I was going for a 1/8" layer so 5 gals resin and 2.5 gal hardener. Obviously that particular pour was a little more and I think I ended up getting another gal or 2 of epoxy by the time I was done. At any rate, here is the calculation.

Conversion for cubic inches to gallons is 0.004329004.

So for my bottom it worked out like this:
48*60= 2880 square inches
3880*.0125 (1/8" pour) = 360 cubic inches
360*0.004329004 = 1.56 gals