3-D cement cure time?

[chopinrockwood]

For those that have built a 3-D background, How long did you wait in between each coat of cement? Did you keep the cement moist in between also?
I am thinking about airbrushing acrylic paint for some depth and highlights after my last coat.
Thanks

 

[wildroseofky]

Dry cement will not stick to other dry cement. Let each coat just barely set up before adding the next layer. Anywhere from 15 minutes apart to an hour depending on how wet it is. Once you get the thickness you want, let it cure for 48 hours before painting. It is also a good idea to soak in water for a week or so to limit the effect on PH. Cement has limestone in it and limestone will raise PH. I coated my final piece with clear acrylic spray paint but I am told you do not have to.

 

[chopinrockwood]

Thanks. I have 4 coats on it now and the 3rd and 4th coats I tinted each one a little darker to get the rock look without having to mess it up with paint. I don't think I need a fifth coat but I am glad its in 4 parts as this is getting pretty heavy. I will keep it moist by spraying it down a couple times a day for 3-4 days just to make it as hard as possible.

 

[chopinrockwood]

Disregard the dirty tank. I might as well let it cure in the tank. Next topic will be the new stand that I am going to build

 

[wildroseofky]

Wow, your background looks great. Can't wait to see it when you get it done.

 

[Krissycakes]

Wow, that is pretty creative. I am inspired

 

[chopinrockwood]

Thanks. Its easy once you get at it. Like I said before the hardest part is the clean up and getting the colour you like with just 2 cement colour pigments. I think this project adds the most WOW factor to any tank. It sure beats the plastic photos of rocks that I had on the tank before. I also carved out 8-10 little caves inside the "rocks" just deep enough so fish can escape and hide out. My last tank had caves made up of about 120lbs of lace rock and the only time I could really see the fish was at feeding. I am hoping this way they will still feel safe but out in the open.

 

[mleissac]

Was ur base just a large piece of styrofoam? And is it necessary to seal acrylic paint?

 

[chopinrockwood]

yes it was one piece 32"X48" 3" thick. I cut it into 4 pieces so it wouldn't be as heavy and I also have a center brace. I carved the rocks to overlap the joints so that the joints will be hidden when I slide it together. As for you question about the sealer I am not sure. I was looking for a clear sealer to speed up the Ph cure time. I used coloured cement instead of paint. I would even put clear epoxy over the cement but Its a little expensive from what I hear.

 

[gimmethatfish]

I have read that acrylic paint is safe for the fish (I don't know this from personal experience, just from reading 1,000 DIY project journals). However, it's really prone to flaking off. What I have read/heard a lot of people do is mix acrylic paint into white latex-based Drylok. Drylok IS definitely aquarium safe, and it will help bind in the acrylic so it won't flake off.

 

[chopinrockwood]

I also heard that you can mix the cement tints with the drylok and colour the background that way also.