The Ultimate DIY Rocks!

[Insane Reefer]

Ah, I see you removed the Isreal bit, lol.

<a href=showthread.php?s=&postid=10537900#post10537900 target=_blank>Originally posted</a> by mr.wilson
The brown building sand will render a grey colour, not a brown colour as some would speculate.

Mixed in, yes, I agree, but it has been my experience that whatever color your casting sand is, will still be that color when the rock is done - some sand sticks to the outside when you use sand to cast into, and this sand is plainly visible once the rock is done. So if you use brown sand to cast into, you will have brown sand stuck to your rock when you are done...
That is why I have been enjoying the blasting sand - it is finer then sugar fine, and almost disappears into the surface of the cement - grey or white.

I believe Izshoker took the "playsand" ingredient in the recipe as meaning any playsand, and not the "Southdown playsand" that is commonly used.

If southdown or anything like it was still left in the US, I think this conversation would be moot - that's what we would all be using. However, because of trade restrictions, you won't see much aragonite in the hardware stores. I believe there is just one plant in the whole US that packages it, and it is supposedly available in the PA area and possibly surrounding states. Otherwise, it is the small, expensive bag from the LFS...

 

[SNTLewis]

Fumed silica...

Fumed silica...

HobbyTown may have it as there are several "fillers" used in resin products, some are really nasty (like milled glass fibers, etc).

I've had better luck at the marine boating stores. Go online to WestMarine.com... look up #406 collodial silica.

Also aluminum powder is #420 aluminum powder... not so sure about this one's usability.

 

[Insane Reefer]

Re: Fumed silica...

Re: Fumed silica...

<a href=showthread.php?s=&postid=10537974#post10537974 target=_blank>Originally posted</a> by SNTLewis
HobbyTown may have it as there are several "fillers" used in resin products, some are really nasty (like milled glass fibers, etc).

I've had better luck at the marine boating stores. Go online to WestMarine.com... look up #406 collodial silica.

Also aluminum powder is #420 aluminum powder... not so sure about this one's usability.

I'll definitely look into that - we have a couple of boating stores locally, so will check there first, but from what I can find, powdered aluminum is powdered aluminum. I'll ask the Nick, cement guy in england if he thinks that will work...

Thanks for the info!!!

 

[mr.wilson]

You're right IR, the casting material will stick out like a soar thumb, making the rock brown.

 

[Insane Reefer]

I love eBay.
:inlove:

http://search.ebay.com/aluminum-powder_W0QQfnuZ1QQfsooZ1QQfsopZ3QQxpufuZx

The boating place had it for $20 a pound. eBay has it for half the price...

 

[Insane Reefer]

Neptune - would you be willing to part with 5# of that silica? I'll gladly pay the shipping, and 1/5th of the total after tax.

PM me if you will
Thanks!

 

[Neptune777]

PM sent.

<a href=showthread.php?s=&postid=10538352#post10538352 target=_blank>Originally posted</a> by Insane Reefer
Neptune - would you be willing to part with 5# of that silica? I'll gladly pay the shipping, and 1/5th of the total after tax.

PM me if you will
Thanks!

 

[Insane Reefer]

Sweet
Thanks!

 

[cayars]

<a href=showthread.php?s=&postid=10538153#post10538153 target=_blank>Originally posted</a> by Insane Reefer
I love eBay.
:inlove:

http://search.ebay.com/aluminum-powder_W0QQfnuZ1QQfsooZ1QQfsopZ3QQxpufuZx

The boating place had it for $20 a pound. eBay has it for half the price...

I think I missed something. What are you using the aluminum powder for? I wouldn't intentionally add metals to my rock and worry about it leaching in the tank. Aluminum is one of the metals you have to watch out for because it becomes toxic at low levels.

Carlo

 

[Insane Reefer]

Sorry, Cayars. Let me clarify. A while back, while looking for other ways to get really porous rock, I found something called "powdered aluminum" - it reacts with the cement during hydration and produces a ton of microscopic bubbles. I asked Nick about it, and this was his reply:

b) Use autoclaved air-entrained concrete, the stuff full of bubbles also known as aircrete, used to make lightweight blocks. This is made using aluminium powder which reacts with the alkaline cement mixture to give hydrogen, sort of like making bread. The aluminium content is fairly low - there is more in the cement than in the powder overall.

I'm thinking that this might be an excellent way to counter the microsilica's filling of the pores.
Plus, this stuff supposedly "expands", sort of like "Great Stuff", so this might be fun to play with...

 

[airinhere]

Hey guys, I have been away from this thread for a while, but I am opening a thread called, Lets see your ultimate DIY rocks!!!! I think it would be nice to showcase some of these pieces so other people can get inspiration about how to sculpt their stuff. (Plus I like to post pics)

 

[Insane Reefer]

Post it, baby

 

[cayars]

Insane Reefer,

If you happen to find any Portland that ends in an "A" you could use that too. IE IA, IIA. Those are air-entrained concrete.

Tried it and had mixed feelings about it. Not sure how to describe the outcome except to say the "pop marks" it creates didn't look right or should I say had a different look. I liked it, but didn't like it at the same time.

I was moving some fiji rock yesterday in my sump (yep got real rock to) and picked up a piece and thought (sh*t rock) but then when I flipped it over it had lots of pores (almost pop marks). The other side was almost completely smooth with no pores. I then looked at a few rocks and noticed patterns like this on some rock. Many rocks have different textures to it depending on the side you look at.

I'm not sure the point of me mentioning this except to say our rock doesn't have to have to have only one texture but could have a blend.

For example we could make a smaller then needed "pop rock" with the type air-entrained concrete and then go back and "drip" type I/II over top which will create some crevices and mounds, etc and still leave plenty of the "pops marks".

This would give a couple of textures and if you waited say a 7-10 days between stages the pH will drop a lot faster after the 2nd cement job since the "inside rock" has already hydrated a lot.

Just thinking out loud but haven't tried this. Gonna have to try this for kicks and giggles next weekend.

Carlo

 

[Insane Reefer]

Will keep that in mind, Cayars
For some reason, when I mix calcium chloride with the white cement, I can't do two-stage pieces :sad2: - the second stage always pops off. So I'd be more likely to mix two batches at the same time, and mix and match as I go.

 

[badfish03]

<a href=showthread.php?s=&postid=10537813#post10537813 target=_blank>Originally posted</a> by Insane Reefer
Really bad politicians?

From what I have seen ours aren't any worse than everybody elses

 

[Neptune777]

Well I talked with my local merchant again and as it turns out the have 100# bags of Micro Silica for epoxy called "Epoxy Sand" for $13.95.....Even better price than $20 for 25#....that they quoted before.

Here is an interesting page for epoxy additives that could also be used in cement (good info on Micro Silica)........look at the microspheres (these look interesting as well)

http://www.epoxyproducts.com/f_mixin.html

 

[badfish03]

<a href=showthread.php?s=&postid=10540692#post10540692 target=_blank>Originally posted</a> by Insane Reefer
Will keep that in mind, Cayars
For some reason, when I mix calcium chloride with the white cement, I can't do two-stage pieces :sad2: - the second stage always pops off. So I'd be more likely to mix two batches at the same time, and mix and match as I go.

Get some concrete glue the bottle that looks like elmers school glue paint some on where you are adding the new batch. Make sure loose material has been removed and you may want to add a bit more of the glue to the new batch.

 

[Neptune777]

Here is a great pdf on Silica Fume...loads of info!

http://www.ce.berkeley.edu/~paulmont/165/silica_fume.pdf

 

[Insane Reefer]

<a href=showthread.php?s=&postid=10541628#post10541628 target=_blank>Originally posted</a> by badfish03
Get some concrete glue the bottle that looks like elmers school glue paint some on where you are adding the new batch. Make sure loose material has been removed and you may want to add a bit more of the glue to the new batch.

Wouldn't the glue result in a more waterproof mix?

 

[Insane Reefer]

<a href=showthread.php?s=&postid=10541626#post10541626 target=_blank>Originally posted</a> by Neptune777
Well I talked with my local merchant again and as it turns out the have 100# bags of Micro Silica for epoxy called "Epoxy Sand" for $13.95.....Even better price than $20 for 25#....that they quoted before.

Hmmm. I would be leery - why is that so much cheaper than regular microsilica? The "sand" part makes me wonder if it is in a fine enough particle to do the same job as what is recommended.

You'd think places like ReefBalls would have been all over something like that, if it would work...