What did I do wrong on background

[Tuskugee]

I used styrofoam for the background. I carved and glued pieces accordingly to make the design I wanted. I then grouted it with non sanded grout. I did about 5 coats of the grout. After the grout I sealed it up. Now it's finished and when I put pressure on the background it dents and the grout chips off easily. Does that always do that? Do you want thin coats of grout on? Did I just not wait long enough for grout to dry? Please help me out.

Thanks

 

[Doesj]

first of all, you want to coat in increasingly thicker layers of grout.
The first one should be like olive oil, the second a bit more solid, the third even more so and the fourth and final layer should have about the consistency of toothpaste.

Secondly, if you put pressure on it on a small surface (like the tip of your finger), it will allways dent, even after 5-6 layers. That's because you can put multiple pounds of pressure on your finger. A beardie weighing only 1 pound will never put 15 pounds of pressure on your background

 

[Tuskugee]

What kind of sealer did you use?

 

[JeffSimpson]

first of all, you want to coat in increasingly thicker layers of grout.
The first one should be like olive oil, the second a bit more solid, the third even more so and the fourth and final layer should have about the consistency of toothpaste.

FWIW, I've never followed this method. I generally start out pretty thick, and then get a bit thinner. My first coat starts off like thick peanut butter, as well as the second, and then a little thinner for the 3rd (and final) coat. The thinner coat allows you to make some subtle markings to give it a textured look. I waited at least 8 hours in between coats, and then 2-3 coats of mod podge.

Did you use premixed grout, or did you mix it yourself? If the latter, what was your process for mixing it? Did you let it set after it was mixed? I've never really had an issue with grout 'flaking' off, so something definitely isn't right there.

 

[Tuskugee]

I use sanded grout and just mix a little water with it.

 

[Tuskugee]

I honestly think it was my sealer. It kind of sucked. I need mod podge