#3 portland cement

[Bendalat]

Hello guys,

 

I'm planning to build some special rocks for my tank?

Can you show me where to buy #3 portland cement?

Also, I never do this before, can you give me some pointers?

 

Thanks,

 

Khanh,

[Origami]

Check your local Lowe's. Or, go to their website (www.lowes.com) and search for "portland cement."

[Guest thefishman65]

I have some White Portland Cement I think it was #2 that i used. You have to buy about a 70 lb bag (i found mine at a brick company near Manassas). I can sell you some if you like. I also have left over perlite if you are using that in your mix.

[Coral Hind]

Go to GARF.org page below and see the links for aragocrete. The old Eddie Postman link is where I learned to do it.

http://www.garf.org/navagation.html

[Bendalat]

Thanks Origami2547, thefishman65, and Coral Hind.

 

thefishman65, I just bought some portland cement from Lowes to do the test.

I will ask you for some with cement when I do the "real" work.

 

Thanks again,

 

Khanh,

[Bendalat]

Guys,

 

I bought a 10 pounds bag green-grey Portland cement from Lowes and made some rocks;

I don't know if it was Portland #3 or Porland #2.

Does it matter?

 

I will cure them with vinegar, and then cook them as we cook dry rocks for about 2 weeks.

Do you think its good enough, or do I have to do something else?

I don

[Guest thefishman65]

I thought vinegar was bad. IIRC it weakens the concrete. I thought soak and change water until the PH was below 8.4 and then into the tank a little at a time.

[Bendalat]

I followed the link that Coral Hind sent me

 

http://www.garf.org/news15p3.shtml#EGGS

 

Step Six

Remove plugs from egg carton by just popping them out from the bottom. If they are stuck together just break them apart using your hands or a chisel.

 

Step seven

 

Curing: to cure the plugs put them in a water tight container and let them set in white vinegar for 24 hours.

[Guest thefishman65]

Hmm I think what I read on reef central said to avoid the vinegar. Maybe plugs don't need to be as strong since they don't support a lot of weight. This falls into chemistry and what happens to the structure so it is beyond me.

[BowieReefer84]

I followed the link that Coral Hind sent me

 

http://www.garf.org/...15p3.shtml#EGGS

 

Step Six

Remove plugs from egg carton by just popping them out from the bottom. If they are stuck together just break them apart using your hands or a chisel.

 

Step seven

 

Curing: to cure the plugs put them in a water tight container and let them set in white vinegar for 24 hours.

 

 

Put the plugs in the back of your toilet where the clean water is. Flushes will replace the water, and eventually you can use them without negative effects..... So I hear.

[tecsavi]

Using vinegar in the curing process will make the concrete brittle. This is like using vinigar to clean coraline algae off of pumps. In the case of frag plugs this might be something you want. I use to use this method when making frag plugs myself because I liked to be able to crumble away the disk when I wanted to mount it.

 

If you are using this mix to make rock for your tank then you dont want to use vinigar. It will be brittle and break easy. Cure your rock in water and change the water every few days. Test the ph of the water before you put your rock in it. Your rock is cured once the rock no longer raises the ph of the water after sitting in it for three days. Typically this can take from 6-8 weeks so don't rush it. You can aerate the water to speed up the process slightly.