joining rocks with rods... what type is good?

Chin_Lee · #1 10-04-2006, 04:27 AM

I am planning to joing rocks together by drilling rocks and inserting plastic rods.

Does anybody have any recommendations on what material rods I should use? I am looking for something that is strong yet slightly flexible and not brittle. PVC, ABS, Acrylic, other???

And what size rods should I consider using? 1/4", 3/8", 1/2"?

dirtyreefer · #2 10-04-2006, 04:32 AM

Chin I've heard of using plastic ties to join the rock. I think Fudge did that with his rock.

trilinearmipmap · #3 10-04-2006, 05:09 AM

I've heard of using acrylic rods, I think there is information about this on Reef Central, I have never done it though.

mr_alberta · #4 10-04-2006, 06:03 AM

Titanium rods!

J/K. I think 1/2" rod is a bit overkill personally unless you are stacking huge rocks together. 3/8" and 1/4" is probably good enough.

Tarolisol · #5 10-04-2006, 06:36 AM

Could you heat and bend acrylic rods to form arches and stuff?

Nate · #6 10-04-2006, 06:51 AM

Hey Chin Lee,

For my new 150 gallon, I decided I could not go without a sandbed, so I put an area sectioned off by 3 inches of glass, in the middle of the tank. I put sand around the tank, and in the middle of the tank, I built a small, oddly shaped structure made out of 1/2 PVC as it bends a bit, but is still fairly strong. The structure I made is kind of odd looking, but with the rock on top, it looks fantatsic...

Now I know what you are thinking...detritus buildup in the middle section...

Well, to counter act that, I have done two things. I have left holes, in the live rock, just a couple, where flex tubing and a powerhead could easily push the detritus out, and I drilled holes along the bottom of the "support" pvc, and have it rigged so it is a closed system with a maxijet 1200 shooting out these holes.

I dont really think this is really what your question is, but I was also toying around with the idea of running one of the sections of 1/2 inch PVC out for an arch, but found taht I was able to create a really nice one, without.

I would suggest 1/2 inch PVC, its cheap, easy to work with, and can be found anywhere.

G/l and let mek now if you have any questions.

Nate

Chin_Lee · #7 10-04-2006, 07:02 AM

Thanks Nate. Interesting idea with the sand sectioned off.
I thought about using 1/2 sch40 piping but I would need to buy at least a 5/8 masonry drill bit to fit that into the hole. Since I'm probably going to throw away the very rust masonry drill bit later, I'm tempted to go smaller (the bits gets much more expensive as you get beyond 1/2").
What I want to do is build some arches and I would like to support the bonding of the rocks with zap straps and rods and then maybe epoxy the joint slightly to make it look smoother. But I'm just not sure what material rods I should use.

Nate · #8 10-04-2006, 07:27 AM

how much of an arch ar eyou going for?

My tank is 48 X 30 X 24...and sits lengthwise into a room. The overflow is on the back in the middle of a small panel, and the rockwork is done as an island that connects to the back of the overflow and tank wall. What I did was use one rock with a large opening underneath, and put it in the front corner before I started my rockwork. Started building up the rock to the front corner, as my glass for my sandbed is only 33 inches from the back, and cut it off and headed one direction with it. I built straight up on he rock in the sandbed, and then used a large rock adn corals to connect to the main body of the rock work. Looks decent in my opinion, maybe I will try to get handy tomorrwo nite, adn take a picture for you...

kwirky · #9 10-04-2006, 08:03 AM

i used plastic ties, and it's butt ugly. if you want to take the time to drill it, I'd do that. Or just build a rack to set the rocks on top of, letting gravity do it's thing.

But a note, I don't think solid rods will be strong enough, I think you will need something like PVC. I used 1/2" PVC to hold up my rocks with enough strength. Most people online who drilled through their rocks used the same.

I didn't drill mine, because of the drill and bit required to make 1/2" holes in rock. I think I may down the road make a "pedestal" like structure out of PVC and elbows, and just set the rocks on top.

One piece of advice I have to give, is you can't really make your structure, then buy your rocks. You'd be going through hell trying to find rocks that will work perfect on your structure.

If I was to do it again, and had the tools, I would drill for 1/2" PVC. It would make me feel safe that it won't snap like acrylic rods. Thick enough acrylic rods to support the rock would be EXPENSIVE and not much stronger than slightly thicker PVC pipe. And I would buy my rocks, then build the structure during the curing process, having the rocks handy to make it all jive together.

Dave C · #10 10-04-2006, 11:38 AM

Quote:

Originally Posted by kwirky

And I would buy my rocks, then build the structure during the curing process, having the rocks handy to make it all jive together.

That's exactly what I plan to do. I've got 140lbs of Tonga coming this week from J&L and while it cooks I plan to pull it out and figure out how it will sit and drill it for PVC.

Some people use Thorite (by Thoroseal) cement to attach rocks together. The cement adds to the rock & becomes part of the rockwork itself. Then you don't need to drill or use acrylic/pvc or anything but the rocks & cement. It's reef-safe and can be found on many threads on RC.