Making A Sump Out Of Clay?

[LWormy]

Hello! Since I wanted to make a sump for my 32 gallon goldie tank and I am kind of tight on budget, I thought about making them in clay. I joined a local art club that allow me to use their clay unlimitedly. The idea is that the sump will sit in between the aquarium and the wall, and there are only 5 inches so it is kind of tight. The dimension will be 24"x19"x5". I will fill it with gravel and grow lucky bamboo out of it. Will that work? I am kind of concerned about the clay breaking under the pressure since there are no supports on the side. Again, this goes behind the tank so I don't care what it look like. How thick should the clay be? Should I glaze the inside of the sump? How thick should the clay be so it won't break?

Help is appreciated!

 

[LWormy]

Hello? Any replies? I am new to this forum and really need some answers.

 

[Masha]

Guessing here... You would have to glaze it, otherwise it won't hold water. Make sure the glaze is lead free. Also keep in mind that clay shrinks when it's fired so it can be tricky to make something to precise measurements

Sent from my GT-I9190 using Aquarium Advice mobile app

 

[Masha]

Also can be tricky to make something with large, straight sides, the clay collapses easily under its own weight while it's still wet

Sent from my GT-I9190 using Aquarium Advice mobile app

 

[Delapool]

Emailed my brother. Will post if he knows anything. He's been working with clays for years but never tried anything like that.

I think you could experiment but say you did inch thick sides, that's 40% of your space gone...

 

[LWormy]

I was planning to have about half an inch thick clay. I am going to fire them and glaze them on the outside, but I dunno if I have to do the inside as well. Clay is porous so it will be good for the beneficial bacteria that will grow on it, but someone told me that water will seep out of the clay. The refugium will be in between the wall and the tank, so it should have some support. Do you think that half an inch is good? I don't want it to be so heavy that I can't lift it on the stand.

 

[Delapool]

Unfortunately no news here. Well, I mean the clay is free(?) so be interesting to try.

 

[LWormy]

Well, even though it is free if I mess up I will still be screwed because I will have 32 gallon roof water pumped to my floor and a bunch of fish jerky

 

[Delapool]

Can you test outside? Or maybe give it a few days in a sink or something and see if it leaks?

 

[LWormy]

The thing is, since I am going to use it for a long time, even if the clay doesn't leak at first it could still eventually break under the pressure. I wanted a sump that is safe for life, since I don't want to replace it every year or something. How about 2/3 of an inch thick?

 

[Delapool]

This was the answer back from my brother. He's being doing pottery for over a decade now. Perhaps someone at the pottery club has attempted similar? 1.5cm is slightly over half inch.


-----------
Hi,
This was forwarded to me as I'm a hobby potter. Will it work? In my non professional unqualified position, probably not. To make it water proof you will need to glaze it all over, ask the art club for a vitreous clay body and a clear stoneware glaze that doesn't craze. I think a single slab of clay of those dimensions is gonna warp and buckle when dried. And, will it even fit into the kiln to be fired? Dunno. Instead, make 3 sections, each 8" x 19" x 5". Dividing it into 4 sections would be better. I guess approximately 1.5cm thick slabs of clay would do. Look up slab building pottery techniques for how to build this.
This is gonna be a lot of work.

 

[LWormy]

This was the answer back from my brother. He's being doing pottery for over a decade now. Perhaps someone at the pottery club has attempted similar? 1.5cm is slightly over half inch.


-----------
Hi,
This was forwarded to me as I'm a hobby potter. Will it work? In my non professional unqualified position, probably not. To make it water proof you will need to glaze it all over, ask the art club for a vitreous clay body and a clear stoneware glaze that doesn't craze. I think a single slab of clay of those dimensions is gonna warp and buckle when dried. And, will it even fit into the kiln to be fired? Dunno. Instead, make 3 sections, each 8" x 19" x 5". Dividing it into 4 sections would be better. I guess approximately 1.5cm thick slabs of clay would do. Look up slab building pottery techniques for how to build this.
This is gonna be a lot of work.

Uh, first of all, what do you mean by "glaze it all over"? Do you mean I have to glaze the inside too? Also, what exactly is "a glaze that doesn't craze"? I am planning to make individual slabs of clay and then connect them with aquarium silicone after they are done firing. Will that work? I know how to build potteries and the art club I'm in have a very big kiln. You are right about them buckling when they are drying because of gravity, but if I separate the slabs when I dry them will it work?

 

[Delapool]

Uh, first of all, what do you mean by "glaze it all over"? Do you mean I have to glaze the inside too? Also, what exactly is "a glaze that doesn't craze"? I am planning to make individual slabs of clay and then connect them with aquarium silicone after they are done firing. Will that work? I know how to build potteries and the art club I'm in have a very big kiln. You are right about them buckling when they are drying because of gravity, but if I separate the slabs when I dry them will it work?

Ok, so below the dashed line in my reply was the answer back from my brother. I sent your first post to him and then copied his answer to that in.

Crazing I thought it best to look up in case it is an Australian word. Link below.

Reading his reply, to me all over would include the inside as well.

Would you like me to send your post onto him for a reply?


http://en.m.wikipedia.org/wiki/Crazing

 

[LWormy]

Thanks for the link! I don't think that the glaze I have will craze. Could you please send my post to your brother and see if he answer? I'll be really grateful. I want to build the individual slabs and stick them together with silicone after they are fired. I THINK that it will stick, since silicone work on tiles and stuff, but I am not sure.

 

[Delapool]

Lol - I was thinking it might of been some weird Australian term. Or we're just behind the times here.

Absolutely, I'll send to him.

 

[LWormy]

Thanks! Appreciate it!

 

[Delapool]

Sent on. Waiting, waiting.....

 

[LWormy]

Any news yet?

 

[Delapool]

Hi, sorry for the delay. Been flying over to see my sister and now out in the sticks with terrible connection.

All I got back was:

---------
'Just tell them to think about glass, perspex. The way they are going about it most likely won't work.'

 

[BillD]

The glass needed to build that, would only need to be 1/4" thick. I certainly wouldn't trust silicone to hold together 5 pieces of glazed clay. I would check around glass shops for scrap or salvage glass.