View Full Version : Styro qestion

03-10-2008, 03:39 PM
When making decor out of styrofoam, instead of using 2 part epoxy to seal after concrete is applied could I just take some silicon and brush it all over it? or is it to thick to work with?

03-10-2008, 03:46 PM
You could always just simply use aquarium silicone if you'd like.

03-10-2008, 03:50 PM
I just thought about it, because its too expensive for the 2 part epoxy where I live, and silicon is so cheap. It would seal it up good and keep everything in, but would it effect the look of my concrete?

03-10-2008, 07:59 PM
Nobodys tried this?

03-10-2008, 08:04 PM
The silicon would dry with too many brush strokes I think, which would really show up after the algea started to grow on it. Plus it would take a lot of silicon for full coverage. I think it would peel of easily as well.

03-10-2008, 08:12 PM
Anyone know of anything else I can use besides 2 part epoxy?

03-10-2008, 08:25 PM
i dont know if this link would help but hes done a good job with the styro:14:


03-10-2008, 08:33 PM
He didnt use anything to put on as a sealant over top the cement! Wonder if it will hold up forever in water??

03-10-2008, 08:36 PM
sorry it didn't help,:ssad:

03-10-2008, 08:41 PM
No man thanks! Makes me think I dont even need to use anything but styrofoam and cement!

03-10-2008, 08:45 PM
oh good glad it did help,his design looked good :22: good luck with youres will be nice to see some pictures when your finished,:19:

04-22-2008, 03:14 AM
Yeah, I have seen many people across the net that did not use any epoxy in the end. I probably will not either. Don't know how it will hold up over long lengths of time, but we will see.

His design did look great. Very nice 3d sculpting.

06-24-2008, 02:00 PM
Try with transparent acrilyc i do on my own diy backgroun, after the cement i apply the spay the i let'm dry about 2 Days then soak in to water for 1 week and thats it
No problems until now

03-01-2009, 08:05 PM
Wow pal, think again!
It may hold up for a days, weeks, maybe months...but not years for sure! It all depends on how well your concrete cures. When concrete cures, surplus water moves to its surface, leaving behind a network of interconnected capillaries. Concrete is more porous than Swiss cheese typically 12% to 18% air. You will want a sealer for sure!
I also recommend using a Hydraulic Water-Stop Concrete from Quikcrete.

03-02-2009, 01:21 AM
I have a rectangular piece of foam siliconed to the back right corner of the tank. I used aquarium silicone to seal it. That was about a year ago and there is no deterioration of the foam what-so-ever. However, the top is covered by play sand and the sides are hidden by rocks. I haven't noticed any breakdown of the foam.

03-02-2009, 04:49 AM
the foam won't break down as much as the concrete will leak which can cause problems. If its a simple background and your not worried about your fishes too much then sure go ahead and don't fill the poures in the concrete