3d Background - Styro or Poly?

[Tomiam]

Quickie question.
Im about to start work (once Ive got the correct material) on a 3d background for my 6ft x 2ft x 2ft tank. Ive been searching high and low for styrofoam and have yet to find any.
I have however found a supplier of Polystyrene sheets at 8ft x 4ft. My understanding is that styrofoam, compared to polystyrene, is slight more dense.
Im 90% certain it would be ok,, but thought Id ask the professionals (you folks!) first

My question would be: Is it essential to use styrofoam, or can I use polystyrene instead please?

My thanks in advance.


Link to 3d backgrounds. http://www.thecichlidgallery.com/article_styrobackground.htm

 

[dskidmore]

I'd think the only problem would be a less dense foam would be more prone to float. Just secure well to the back.

 

[Tomiam]

Thanks.
Yep, thats the same thought as what I have at the moment.
Will probably take a trip to B&Q to get a sheet early tomorrow so that there arent many people staring at me in the carpark as I cut it to fit into the car

 

[kaz]

doesnt all styrofoam float? how u keep it down in the back without floating? I looked at the article and he didnt cement the top or background would that hurt the fish with styrofoam starting to despence out into the water?

 

[Tomiam]

In all articles except that one I have seen the 'creator' silicone the back ground into place.

Hope this link helps show it in more detail.
http://www.catfishheaven.net/moreday4.html

I dont believe that the styrofoam dispenses into the water. The cement on the surface of the foam does, hence the need for a lot of time, patience and water changes at the very start.

Another side note:
I can get a polystyrene sheet (150mm thick - 8ft x 4ft) for £19.38
If I want that same size in Styrofoam Im looking at more than £100.00 and this is from one of the very very few places in the Uk that seem to stock it. http://www.craftfoam.com/buynow.asp

Can someone point out my mistake here please? It just seems that the articles Ive seen dont lend me to believe that creators have paid that much money for such an item.

Thanks, as always, for any advice

 

[dskidmore]

Maybe it's just not as common over there. Use what you can find.

I've also seen some sets of instructions paint the whole thing with a waterproof epoxy so there's no chance of the water mixing with the styrofoam.

Yes, all foam floats, but the lower the density, the greater the force it exerts when forced to sink.

 

[Tomiam]

Just an FYI if anyone else is looking for a supplier of Styrofoam in the UK.
The best place I could find was in Bristol at a place called CSManufacturing. 0117 9773388. I found out that Styrofoam (the blue type) is damn expensive. Polystyere comes in about 5 different densitys. The density of the polystyrene is determined by how much steam the little balls get during manufacture. (Small bit of useless info ) So obviously I needed to get either the Extra Dense or the Dense polystyrene in order to lose as much bouyancy as possible and also to help with the carving process.

NOTE: This is not an advertisement for them - merely a piece of information saying "they do it and here is a guide to the costs".

Styrofoam - 8ft x 2ft x 100mm thick = £78.00 + Vat each.
Dense Polystyrene - 8ft x 4ft x 115mm thick = £41.99 + Vat each.
Extra Dense Polystyrene- 8ft x 4ft x 115mm thick = £50.60 + Vat each.

Please note that those are the prices I got for going in and picking it up. They do not included any delivery etc.

 

[dskidmore]

Wow, and from what I recall of the exchange rate, that's crazy!

Are the thinner sheets any cheaper per cubic foot? Many sets of instructions call for adhering several thinner sheets together.

 

[Tomiam]

Sadly dskidmore nope
The cheapest way for me to get the amount of styro / poly that I need is to purchase it in one sheet. ie: Purchase an 8ft x 4ft (115mm thick) sheet and then cut it in half, glue it together, to give me a sheet 230mm thick.
I need a sheet 6ft x 2ft so the last 2ft of the 8ft could be cut off and used to build up the end sections (if that made sense ).

Im truely amazed at the price difference between UK and overseas on this. Still... I guess I'll just have to cram in some overtime at work and get some extra £££ lol.

 

[dskidmore]

Could it be a diffrence in enviromental laws? We produced alot less styrofoam after the problems with CFCs were discovered, but it's mostly a public pressure thing rather than a regulation. It may be alot harder to make styrofoam where there are stricter enviromental laws.