Background Help

[charles]

Fake rock wall background!

Hey guys.
I am making a fake rock wall background for my spotted who's only 10 months old. This background won't have any water near it so I am guessing I don't need to use pondite?

So I have read heaps on diy backgrounds but I still need help. I'm a novice to all this handyman work so I do not understand all the terms.

I have started my background by cutting out my desired look out of polystyrene.

From here, as I understand it, I need to get pva and mix it with water to coat the polystyrene so i can paint it. Is this correct so far?

I want to use the dry paint method by mixing in dirt etc to create that certain look. Once i have coated the polystyrene 5 times with the pva and water, Can i know start painting over it all?

Do i add the dirt to the paint to get that look or do i add the dirt to the pva and water mixture..

Thank You.

 

[saximus]

You still probably want to use pondtite just so not excrement can soak into it. In that case you could just mix the sand/dirt into some clear pondtite

 

[jack]

you can coat it with most water based products as they do not dissolve the polystyrene, PVA is easily sourced and has the benefit of being somewhat elastic, which means the finish is less likely to crack as can happen with cement finishes

 

[J-A-X]

Seeing as your not using a cement or grout to coat the polystyrene you'll only need 2 coats of pva+water on the foam, all its used for is to help the paint stick to the foam. Do the same to seal the paint to make it easier to clean.
You won't need to seal it against soakage because your not rendering/grouting it. Remember that by only yang paint you won't have any great strength to it so be gentle when you wash it- or remove it if it's not fixed to the tank. Given its a spotted going in there it won't need to be overly strong, but still don't get too rough with it

 

[saximus]

I thought PVA went funny when you wet it though?

 

[J-A-X]

It does, but a quick wipe to clean it won't affect it