aquarium cement like stuff

[firefly]

I am working on making a prototype of a feeding tool, and I am wondering if there are any cement like compounds that are aquariumsafe. SOmething I guess like clay, but that will air dry and be safe in the water. I want it to sink, doesn't really have to look stoney.

Emily

[bethany]

One choice is marine epoxy. It's two parts which you mix together and they hard to an inert cement. Some are very stiff like a putty, others are a bit more fluid. Some set up & cure quickly, other more slowly. I have a fluid slow setting kind. If I need it to be stiffer and set more quickly I heat it (on top of a hot compact fluorescent light) until it is the consistency I want.

Several companies also make a two part epoxy which is a true putty for use in aquariums. You need to knead the two parts together to mix them. It advertised as ideal for building cave, walls and such out of various materials. Generally they set up fairly quickly. I don't remember how long it takes but the stuff I have did harden promptly.

[chrisajohns]

Go to WWW.garf.org They have some very good articles about something they call agrocrete under the heading "how to pages". They use it to build artificial live rock for saltwater tanks. It is very cool and will help raise the ph in your tank. Just be sure to cure it for long enough before using.

[snailboom]

half an hour for the epoxy. better than waiting for sealant to dry, but not so easy to make water-tight.

[firefly]

Thanks for the replies! I don't really need anything to be water tight, just safe for use in the water. Some of the epoxy stuff sounds good, as does the agrocrete type stuff. I"ll check out that garf site too. Could be interesting.
Sometime, after christmas, I'll look into getting some of this stuff and experimenting.
Emily

[angelcobb]

Sclupey clay could be an option. Its easy to mold and cheep. I use in my aquariums for decorations that I build myself. It sinks. I get mine at walmart. You build what you want and then you bake it in the oven till its hard. You can get it in different colors or paint it.

[ookami_meggle]

Is sculpy clay safe for submersion? I have heard it leaches into the water and isn't good for them. I am new to this so I may be wrong.

[pbgroupie]

Never used the stuff in my artwork so did a bit of research. I personally probably would not use it but read these articles and make up your own mind:

http://www.bellaonline.com/articles/art33912.asp

http://www.sculpey.com/faq/qna/faq-159

http://www.sculpey.com/faq/qna/faq-138