[FoxHound]

Hi everyone,

I wanted to stop in and ask a quick question about the way I sprayed my new viv's background. I used The window and door Great Stuff.

My question is whether or not it is okay to have the GS touching the tank bottom. I plan on using a hydroton false bottom set-up but I am fairly positive I can make it work. I like the way it is sprayed so I would really like to not have to cut any off of the bottom. I included a picture so everyone can see what I am talking about if it doesn't make sense. The reason I am trying to get quick answers is I am trying to do the silicone/substrate tomorrow.

Please let me know ASAP.

-FoxHound

P.S. Sorry for the awkward angle of the pic but I had limited space to stand back.

 

[fieldnstream]

It touching the bottom won't hurt anything.

 

[Okapi]

It should be fine. the substrate that sits on that section of gs may be a little dryer than the rest, but micro-niches are good. All in all, your false bottom will just hold a little less water because of it.

 

[kickedinthevader]

Shouldn't be a problem. But if it isn't gonna get seen (covered by substrate) why not just cut it away??

 

[FoxHound]

WOW you guys are amazing! Thanks so much for getting back to me literally within (what seemed like) the first minute of posting this!

PHEW!

I get your point about it not being seen I'll have to give that some thought.

Finally got all my ducks in a row so I have been itching to get to it.

Thanks so much again,
-Fox

 

[DendroRachel]

I would be worried that it would soak up some of the water and rot quicker. Even if you cover it with silicone I'm sure there will be some tiny nookes and crannies for water to soak into it

 

[jacobi]

Its plastic. It cant rot.

 

[cyck22]

Fox,
Shouldn’t be a problem as everybody else has indicated. The only thing I want to caution you on is your application of coco-fiber. Once the gs is covered in silicone, consider leaving the silicone bare just below the line that the substrate will come up to. If coco-fiber covered silicone extends from the drainage layer to the substrate, it can wick water from the drainage layer up into the substrate and saturate everything.

 

[cyck22]

Its plastic. It cant rot.

Good point Jacobi! And this isnt the first time I've heard/seen misconceptions about PU being able to “soak up” moisture..

"About Polyurethane
The secret of Polyurethane is its closed cell structure. This makes it very stable and keeps moisture from migrating behind coatings. Moisture migration causes serious problems in wood building products (such as wood beams or molding), promoting paint failure and rot. Because of the closed cell structure of Polyurethane, paint tends to last longer and not be lifted off by moisture.
Since the introduction of Polyurethane architectural features nearly thirty years ago, their usage has increased dramatically. When we began making these products at Barron Designs, we would not consider making simple, straight run moldings in Polyurethane. Instead, we concentrated on features which would be very labor intensive and costly if made in wood.
Polyurethane is a petrochemical-based material that substitutes for fiberglass, rubber, latex, silicone, epoxy, and many other natural and synthetic materials — it is preferred in various applications for its high performance characteristics, reasonable price, environmental compliance, and manufacturing efficiency. In an increasingly competitive global economy, manufacturers who can reduce their production, handling, or material cost even slightly while retaining or improving product performance can gain an advantage sufficient to increase market share. Polyurethane products, including polyurea, polyaspartic, and other subcategories, are increasingly found to be cost-effective due to their durability and physical properties, and the demand for this versatile family of materials is growing. Polyurethane chemical composition can be altered to achieve specific physical properties necessary to satisfy product design requirements. The liquid chemical compounds are sprayed, poured, or cast into molds, and the heat generated by the chemical reaction fuses them into Polyurethane products of various densities, textures, and strengths.
Polyurethane is a unique material that offers the elasticity of rubber combined with the toughness and durability of metal. It can be manufactured in a variety of hardness, or durometers, ranging from rubber band soft to bowling ball hard. Depending on the durometer, urethane can elongate up to 800% and returns to its original dimension without a significant loss of memory. Polyurethane can replace either rubber, plastic or metal to create the ultimate material in abrasion resistance and physical properties. Polyurethane is one of the toughest, most wear and abrasion resistant material available today.
"

Ref - About Polyurethane

 

[Raf]

I use PU foam myself BUT it will degrade when constantly submerged!!
It's not that it's useless for our goal.

Frequently Asked Questions - General:
14. Is this foam water resistant?

Yes, but with the following caveat. The foams that we sell are considered closed-cell, which means that each cell that makes up the foam structure is completely closed off from surrounding cells which prevents it from acting like a sponge. It is completely safe for this foam to be in contact with water for hours/days/weeks and even months with no adverse effects. However, it should never be submerged in contact with water permanently. Over a period of years the water contact can begin to soften the foam and cause it to lose its closed-cell status. This foam is designed primarily to be used as an insurance policy in case of damage/holes that could cause a vessel to lose buoyancy. Pinhole sized openings would essentially have no effect on the foam since the amount of exposure is so minimal but you should always make repairs as soon as possible to keep the foam effectiveness as good as possible. This will be the case with all after market closed-cell polyurethane foams and even manufacturer installed foams.

 

[parkanz2]

I would compare it's longevity to that of cork. Give it long enough and you'll have problems. But when you compare it to the average life of a tank, it should outlast it no problem.

You could always cover it in epoxy

 

[Raf]

Yep it's not a big problem and for our goal it's very useful.
I'll see within a couple of years how the materials degraded when I'll redo my viv.