FIberglass for plywood tank

[CJH]

So I got my estimate today. They were basing it off of 80'Sq I told them, which I overestimated to be on the safe side. My actual coverage I would need is closer to 66'sq, but I wanted to account for unexpected errors. They were reccomending a thickness of 80 mils. Anywhoo, 2 x 5 gallon PermaDri Pond Coat (trowel) 210.00 420.00
Estimated freight 90.00
TOTAL = $$$510.00

Unfortunately, that's too rich for my blood...

I'm sitting around waiting for a delivery with nothing else to do and I got to thinking about this more.

Even if your tank was 80 sq. ft and if Pond Coat is 75% solids (educated guess), five gallons would give you a dry mil thickness 75 mils.

I'd email them back and clarify their position that you need ten gallons. It just does not add up in my mind. But I have not been getting much sleep recently so I may be missing something.

If it were my tank and only had 66 sq. ft on the interior I would not hesitate to "only" use five gallons of Pond Coat.

 

[Buckdog]

Buckdog, AMAZING build. Hope you don't get mad if I steal your stand idea. That would definitely get my girl's approval

Hey, knock yourself out. Lets see what you get. The best thing is to keep it simple and stick with it. My stand started out one way but ended up another way after I "changed horses in the middle of the stream". I had to work around my screwups.

 

[Buckdog]

One company I have not dealt with but have heard good things about is Raka. Likewise, the company that Buckdog used has a good reputation.[/QUOTE]

Thanx CJH. They're called Polymer Composites and the one thing I like is that you can call and talk to the chemist (he's really busy so email may be the best way) and he'll give you the straight talk. The knowledge that guy has on all this kind of stuff is insane. He convinced me to fiberglass the outside of my tank. If you do correspond with them, mention your project is on MFK.

 

[CJH]

One company I have not dealt with but have heard good things about is Raka. Likewise, the company that Buckdog used has a good reputation.

Thanx CJH. They're called Polymer Composites and the one thing I like is that you can call and talk to the chemist (he's really busy so email may be the best way) and he'll give you the straight talk. The knowledge that guy has on all this kind of stuff is insane. He convinced me to fiberglass the outside of my tank. If you do correspond with them, mention your project is on MFK.[/QUOTE]

Thanks for clarifying. I couldn't remember the name and did not want to back out of the reply function to follow your link.

I read about one other plywood build on this or another forum and they said the same thing you did about the company.

 

[greenterra]

So I got my estimate today. They were basing it off of 80'Sq I told them, which I overestimated to be on the safe side. My actual coverage I would need is closer to 66'sq, but I wanted to account for unexpected errors. They were reccomending a thickness of 80 mils. Anywhoo, 2 x 5 gallon PermaDri Pond Coat (trowel) 210.00 420.00
Estimated freight 90.00
TOTAL = $$$510.00

Unfortunately, that's too rich for my blood...

Liquid rubber is not cheap here either. I sent them an email with my tanks dimensions and asked for a quote and whether it would be suitable to water proof the tank. I had already built my tank but I was curious to see the price difference and what they had to say.

This is the reply I got.
Quote:
Hi Brenton,
Thanks for your enquiry regarding Liquid Rubber products for your project. Liquid Rubber Zavlar would be suitable for your aquarium as will also be safe to the fish. You would require a 20L drum of Zavlar ($ 359.00) and will need approx 14 L/M of geotextile cloth @ $ 2.50m = Total $ 394.00 + $25.00 freight

Application is simple and requires 3 coats

1/ Paint corners
2/ Install cloth (make sure no wrinkles)
3/ Paint in cloth
4/ Allow to cure for 24 hrs
5/ Paint 1st coat over entire structure allow 24 hrs curing
6/ repeat step 5 twice more and you should have a waterproof tank

Please note ZAVLAR is only available in black, We also have coloured top coats if required. (4L = $79) Any questions please give me a call

Cameron Macfarlane

Liquid Rubber Australia
P: 07 5576 5322
M: 0449 250 936
cameron@liquidrubber.net.au
www.liquidrubber.net.au
End quote.


This quote is just to do the inside so i wasn't impressed with the price. It was cheaper to fiberglass it in epoxy. For just $200 more my tank was glassed inside and out. Liquid rubber may be easy to apply but the price plus its very ordinary surface finish and the fact they state it SHOULD be a water proof would be enough to make me steer clear of it.

 

[imusuallyuseless]

80 mils??? Holy smokes.

By any chance did they say that was wet mill thickness or dry mil thickness? And is 80 mil thickness also recommended for the brushable grade of Pond Coat?

Let me do some calculations and get back to you about epoxy.

Didn't read through everything they sent me, and i'd like to just post it all up here, but I'm not real sure how to post PDF files to the forum. Will be more than happy to forward them to you via email if you want. Was able to convert one of them to text only though:

Pond Coat: Brush, Roller or Spray applied.
Ideal for the following applications: plant containers,
earthen ponds, lakes, reservoirs, spillways and other
water features.
Waterproofing ponds and other landscaping water features
has never been so easy. Materials include a Geo-Textile cloth
and Pond Coat which is a water borne, (no VOC) coating.
Spraying Pond Coat is easy compared to working with
compared to heavy single ply membranes. The custom low
pressure/high volume spray equipment is available from Pond
Coat dealers or call 1-800-279-5604. Spray coating creates
a smooth seamless membrane, without overlaps, that are a
notorious failure point with conventional membranes.
Pond Coat’s Membrane is Thicker
Providing Better Protection
Factory membranes are usually 40-45 mils and are heavy
and difficult to install and hard to maintain. Pond Coat’s
spray-applied membrane is typically 80-120 mils. The greater
thickness provides better protection. Pond Coat also provides
the architect or applicator greater freedom in design. When
coating concrete planters by using a brush or roller, thickness
is easily achieved, due to the high building formula.
Safe for Fish and the Environment
> Monolithic (seamless) fluid applied membranes
> No seam failure possible
> Fast drying
> Irregular shapes are no problem
> Fish & people safe water borne chemistry
> Brush, roller or spray application with customized equipment
Applying Pond Coat
Lay out geo-textile fabric, pin it into place with galvanized
fasteners and spray Pond Coat to a depth of 80-120 dry mils of
coating. The substrate must be prepared of smooth sand, clay
or concrete acts as the proper base for the application of fabric
and coating. A perimeter trench of minimum 18”x 18” on the
outside of the water feature serves as the anchoring point for
the fluid created membrane. The fabric is wound around a 2”
PVC pipe at the bottom of the trench or a 2”x 4” is used for
the same function. Spraying is done from the lowest point to
the highest point in sections no larger than 30’x 30’ to verify
the thickness of the membrane. For smaller ponds the PVC and
2”x 4” are not necessary. The trench can be backfilled with
gravel to hold the geo-textile in place.

EDIT: Got it(I hope)

 

[CJH]

Didn't read through everything they sent me, and i'd like to just post it all up here, but I'm not real sure how to post PDF files to the forum. Will be more than happy to forward them to you via email if you want. Was able to convert one of them to text only though:

I skimmed over that and I don't believe there is all the information necessary for me to make an exact calculation.

But I can tell you that five gallons of any sealant will coat 66 sq ft. with a wet mil thickness of 121 mils.

Calculating the dry mil thickness then requires multiplying by the percent solids by volume (not weight). For example, a 100 mil wet film thickness will shrink to 75 mils if the percent solids by volume is 75%.

So even if Pond Coat is as low as 50% solids by volume you'd still be left with a dry film thickness of 60 mils, which is pretty darn thick. And I doubt the percent solids by volume is that low, but it might be close given the percent solids by weight is 53% to 58%.

There are some situations where a sealer or paint will shrink less than expected but never more than expected, so the 60 mils is a worst case scenario.

So my point in all this is that if the Pond Coat appeals to you then make your choice based on five gallons. I think if you went over the math with the company rep he or she would agree.

If you do, specifically ask what the percent solids by volume is AND what they recommend for a DRY film thickness.

If you want to compare it to epoxy, then I would first decide if you're willing to forgo fiberglass as some companies recommend. As you say, you're confident in your framing. If that's the case, you could get away with as little as one gallon of epoxy for a dry film thickness of 20 mils.

 

[imusuallyuseless]

If you want to compare it to epoxy, then I would first decide if you're willing to forgo fiberglass as some companies recommend. As you say, you're confident in your framing. If that's the case, you could get away with as little as one gallon of epoxy for a dry film thickness of 20 mils.

No lack of confidence in the structure of the tank I'm planning, and at that glassing just the corners would help w/the structure. In any case, my concern is obviously in the sealer, and more importantly, it's impact resistance. I'm not dead set on fiberglass, BUT is 20mils of epoxy going to hold up to a falling rock w/o cracking???

 

[Buckdog]

No lack of confidence in the structure of the tank I'm planning, and at that glassing just the corners would help w/the structure. In any case, my concern is obviously in the sealer, and more importantly, it's impact resistance. I'm not dead set on fiberglass, BUT is 20mils of epoxy going to hold up to a falling rock w/o cracking???

Tip: Thin the epoxy down a bit with acetone AFTER proper mixing. This will allow the epoxy to seep into the wood and "bite". Obviously, this will give you a bit more coverage because you've stretched your mixture. It's the same thing a stain does on bare wood. After cure you can decide if you want to add more layers and/or fiberglass, etc. I've dropped stuff in my tank (dry) and all I get is a little dent. But I also have two layers going - no fiberglass.

One of the reasons (as this was told to me) some say forgo the fiberglass on the inside is because most common fiberglass contains a silane that is toxic to fish. The silane helps the resin or epoxy wet into the fibers better. The theory goes that if the fibers are not completely encapsulated by the medium then there is the risk that the silane will leach causing problems. The flip side is that there are plenty of tanks here that are inside glassed and I dont remember any complaining of fish getting poisoned. Yet.

 

[imusuallyuseless]

Tip: Thin the epoxy down a bit with acetone AFTER proper mixing. This will allow the epoxy to seep into the wood and "bite". Obviously, this will give you a bit more coverage because you've stretched your mixture. It's the same thing a stain does on bare wood. After cure you can decide if you want to add more layers and/or fiberglass, etc. I've dropped stuff in my tank (dry) and all I get is a little dent. But I also have two layers going - no fiberglass

Thanks for the tip. What kind of ratio are we talking about here? How much acetone would you be adding to the mixed epoxy?