fake rock background??

[Josh1321995]

Hello guys,
I have started making a fake rock wall background and have completed the first step in making the shapes out of styrofoam and fitting them on, along with a little 'expanda' foam. After this step i intend to use perma-stone (with some amount of colouring) to get the rock hard effect covering all of the foam, then adding whatever colours to finish up and once dry sealing it.
Now when i seal it i am not entirely sure of what sealant to use or where abouts to get the sealant?:? Soo any suggestions?
Also has anyone used perma-stone before if so what benefits or disadvantages did the stuff have?
thanks guys any help/advice is greatly appreciated, oh and go ahead and post me some pics of your backgrounds and ill post some of mine later.

 

[saximus]

Seal it with pondtite/pond sealer. You can get it in clear so it won't ruin your hard work with painting.
I haven't used perma-stone before so can't talk about that sorry. Most people on here use grout or cement render for the base layers.

 

[Josh1321995]

ok ill get my hands on some pondtite, do you know where i can get it from, we have bunnings and mitre 10 so im guessing they would have it? and also i have decided to go with the grout but still a little confused, should i get the powder form and mix it myself or buy the stuff in the bags/tubes but it seems pretty thick?

 

[J-A-X]

Bunnings have pondtite, grout Powder is cheaper than premix and if you get a neutral colour you can colour it with cheap acrylic paint, my local mitre 10 has a better range of grout powder than bunnings