Closed-cell polyethylene or r-tech styrofoam?

[KRG]

I've read a lot about both of these for use under a tank. Which is better? I have 1/2" styrofoam but it doesn't compress as much as I though it would. The tank is empty right now and I am considering swapping out the pad. Are the sleeping bag mats (3/8" closed-cell polyethylene) more forming and softer? What have you guys had the best luck with and have any of you tried both?

 

[Grey Legion]

Styro will compress with water in the tank, getting something to soft will not be a good idea, as it will compress to the point that it is as hard as the surface it is sitting on and offer no support..

 

[KRG]

getting something to soft will not be a good idea, as it will compress to the point that it is as hard as the surface it is sitting on and offer no support..

I agree 100% however I'm not so sure the polyethylene is too soft. I also read on Fenner's site that the softer 1/4" fan fold insulation is highly reccommended as well. I'm having a hard time trying to figure out the pros and cons of each. I know the styrofoam is probably the most widely used however I've read some good posts on this site from people that swear by the sleeping bag mats. The problem is that nobody has explained in their posts why they believe the mats are better than the styrofoam. (I think I searched "closed cell")

 

[dnjan]

Which is more stable when exposed to the inevitable saltwater spillage? I use cut sections of the sleeping pads under my pumps, and have been disappointed how they have compressed (even where not loaded) after being submerged in saltwater for a while.

 

[Scooterman]

I haven't had problems with it under my tank, the spots that got wet dried & seemed to be as good as before. It doesn't compress much, really doesn't need to unless your tank is way off level.

 

[KRG]

From what I understand, the sporting good stores sell it as a moisture barrier insulation for underneath sleeping bags. Is it not water proof or is it only after the edges are cut to fit the tank that it becomes non-water proof?

 

[dnjan]

I expected it to be completely waterproof, but the pieces I used in my sump (continuous exposure to saturated conditions) are only about half as thick as originally. I don't know why ...

 

[KRG]

I found a website that sells all kinds of foam sheets! I copied the descriptions from their website below (wasn't sure if I should insert the link to the company)


[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular]Polyethylene : Polyethylene foam is a strong and resilient closed cell foam . Ideally suited as the material or part of a material required in products requiring a shock absorbing, this closed cell foam padding is also a great way to diminish the effects of vibration and dampening. Polyethylene is available as closed cell foam sheets that are well-suited for use as insulation, barrier or buoyancy component, and as a material for cushioning products in packaging applications. Polyethylene foam's excellent buoyancy allows it to be used in flotation equipment, and other nautical products. [/FONT]

Polystyrene[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular](A.K.A. EPS or Styrofoam): Polystyrene foam is lightweight foam that is very popular for countless craft projects, and it's easy to work with. EPS's unique closed-cell structure, available in Styrofoam sheets , allows almost total resistance from moisture & water vapor and will not rot or attract fungi or mildew. Also, EPS has a superior R-value, so it will insulate and keep heating or cooling inside a particular room. [/FONT]
[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular]1LB Density: Construction use, insulation, arts & crafts and cake interiors. [/FONT]
[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular]2LB Density: Hot tub covers, construction use, Insulation and arts & crafts. [/FONT]
[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular]3LB Density: Hot tub covers, construction use, Insulation and arts & crafts.[/FONT]

[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular]Volara: Fine-celled, irradiation cross-linked foam that offers aesthetic appeal as well as an outstanding range of performance characteristics. Like polystyrene foam , this material has a smooth surface. Additionally, like neoprene foam, Volara has excellent consistency, gauge control, superior physical and chemical properties, low water absorption and vapor transmission make Volara ® foam a versatile, dependable solution for a host of demanding applications.[/FONT]
Minicel[FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular]: Extremely fine-celled, chemically cross-linked foam that is ideal for applications which require thicker foam. It combines a smooth, aesthetic feel with superior physical and chemical properties. Minicel is the ideal solution for a diverse array of applications where thicker sections of closed cell foam are required. [/FONT]

Neoprene [FONT=Verdana,New Font Name,Helvetica,Geneva,Swiss,SunSans-Regular](AKA Monarch, Everlastic): Flexible and durable sponge rubber that provides good thermal & moisture insulation and form fitting which is able to resist ozone, sunlight, oxidation, many petroleum derivatives and chemicals. Neoprene foam can also resist breakdown by water, and can become temporarily stable because water & air can be come isolated in its unique molecular structure. Some of the many uses of neoprene include sports gloves, waders, wet suits, insulated can-holders, knee & elbow pads, expansion joint filler in masonry & concrete and filler support sealant in traffic bearing joints.[/FONT]

 

[lizardarm]

i'm gonna tag along on this one, i just bought a camping pad for the new 120, would like to see what people's opinions/experiences are.

 

[Detri]

Hello,

Styro foam won't compress very much at all! On a tank that is 36"x24"X26" (100g) there is only .78lbs per square inch pressing downward on the foam. That is over 1000lbs sitting on top of it. Sytro foam is only really ment to help level the tank out, support the bottom and give some sort of shock absorbtion.

Even the white messy styrofoam compresses very little. I wouldn't sweat this subject to much

 

[Scooterman]

The stuff I used works really well, I think it is perfect even though I had a very level surface it was nice to use & see how well it works!