Rock & Foam Project

mamagoose45

Member
As promised, here are some ââ"šÂ¬Ã…"œthus farââ"šÂ¬Ã‚ photos and step-by-steps from the foam/rock overflow cover project that Brian and I have been working on for the last two weeks or soââ"šÂ¬Ã‚¦

As far as the process, we started by making an egg crate case that sort of slips onto the overflow. The frame will stick out farther at the bottom of the overflow to allow for a slope effect and also to help with stability. The main goal of this project and the new rock work is to allow for better flow and more open space for fish to swim about.

Anyhow, everything is just pieced together and held in place with zip ties (well said about the duct tape of the reef world, Brandon ââ"šÂ¬Ã¢â‚¬Å“ too true!!) After the form was made, Brian painstakingly dug through all the smaller rock pieces we had (thanks Wayne!!) and managed to put the rocks together on the frame like a puzzle. He left holes in the design which would become cave openings later on ââ"šÂ¬Ã¢â‚¬Å“ we simply snipped the egg crate out of these areas. There are a few overhangs to help with coral placement and to help create depth. Then came the Great Stuff. We really werenââ"šÂ¬Ã¢"žÂ¢t sure what was going to happen with it, so it was pretty much a spray and hope sort of process. We tried to fill in all the gaps in the rock work, making sure to cover all the snipped egg crate edges with the Great Stuff so that fish didnââ"šÂ¬Ã¢"žÂ¢t run the risk of getting scrapes and scratches swimming through any tight spots once itââ"šÂ¬Ã¢"žÂ¢s all in the tank.

First step - piecing the rock together...
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Back view after Great Stuff...
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Front view after Great Stuff...
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Close up of Great Stuff...
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After the foam dried, we started the process of covering the foam areas. For the resin coating, we used Bondo Home Solutions All-Purpose Fiberglass Resin. The original epoxy we wanted to use turned out to be slightly more expensive than we would have liked, and we would have had to special order it from a hobby shop. The fiberglass resin was much cheaper and readily available at Home Depot so we went with that.

As far as the material we used to cover, we aimed for a 50:50 mixture of crushed coral and sand, but we were less than scientific about that. :) We wanted the look of the crushed coral but were using the sand to fill in any of the space that the crushed coral left. We found out that the areas we put the resin on thicker seemed to work better, it helped hold the coral/sand in place. Also, oddly enough, the resin seemed to dry faster in these areas. After we let the first coating of coral/sand dry, we went back and put on a second layer to make sure to cover the foam completely.

Halfway through the coral/sand coat...
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**A note to everyone that may attempt to do this ââ"šÂ¬Ã¢â‚¬Å“ the resin gums up much faster than we expected it to, so donââ"šÂ¬Ã¢"žÂ¢t mix up more than you really need because you wonââ"šÂ¬Ã¢"žÂ¢t be able to use it all before it starts to solidify. This part of the project is definitely a two person job ââ"šÂ¬Ã¢â‚¬Å“ one person to ââ"šÂ¬Ã…"œpaint onââ"šÂ¬Ã‚ the resin, one to throw and mash the coral/sand into place.**

The pictures we have only go up to this point because the ââ"šÂ¬Ã…"œstructureââ"šÂ¬Ã‚ is sitting in a Rubbermaid container full of water in hopes of setting everything, getting any funk off of it, and settling any loose coral/sand to the bottom so as not into the tank. Weââ"šÂ¬Ã¢"žÂ¢ll post more pictures when we actually start doing the reworking of the rock and have the structure in the tank.
 
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Very very nice!

Can't wait to see the end results. It really sounds like the meeting at Wayne's next month is going to be a blast!

Quick question... how did you guys apply the resin? Both before the substrate and after? Just with a brush?

Brandon
 
Regular ole paintbrush. I recommend you use an old paintbrush that you don't care about throwing away. We didn't have any of the paint thinner to clean up the brush with when we did it, buy frankly...I don't see how there would be any way to salvage a brush after using for this stuff. It turns into a SOLID rock.
 
I will say that I was incredibly worried after we put on the Great Stuff (you want the red can) that it was going to look pretty ugly. However, once you coat it with resin it looks pretty natural.

You just have to make sure not to be too careful with any part of this process (i.e., this is a bad project for anally retentive perfectionist types). The Great Stuff looks better if it is all bumpy and uneven and doesn't totally swell to fill every hole perfectly. Likewise, when putting on the fiberglass resin, you want to get some on the rocks as well as the Great Stuff so that you can't tell where the rock ends and the Great Stuff begins.

Finally, think about weight. Even just this chunk which will cover about 3/4 of the overflow weighs an enormous amount. The Great Stuff and epoxy make it a lot stiffer/stronger, but it is relatively week in a few places.
 
man....nice to see someone local take a stab at it....you guys better be there at waynes to give us some pointers
 
John, I'm a little scared at the incredible hawk eye factor going on :)

That was Brian's Christmas present...

If it were only two hobbies...I wish!
 
I think the red can is the gap filler. You definitely do not want the black can, which swells up super big time. I think there is one other type that isn't any good either, but I'm not positive about that.
 
Fanof49 - Great Stuff is supposed to be inert once it has cured. I know quite a few people on the DIY forums have used it short-term with no detrimental effects. Finding examples that have been around long-term are a little more difficult, but according to a thread I read, the TotM this month used it. The general consensus is that the Great Stuff does deteriorate a bit with light exposure, so in addition to the epoxy and sand making the foam harder and more natural looking, it protects the Great Stuff from the light. That said, I take no responsibilty for anyone using it in their tanks, especially since it hasn't actually made it into my tank yet. I think if you give everything plenty of time to cure (say a few weeks) you shouldn't have any problems...
 
<a href=showthread.php?s=&postid=11833134#post11833134 target=_blank>Originally posted</a> by mamagoose45
John, I'm a little scared at the incredible hawk eye factor going on :)

That was Brian's Christmas present...

If it were only two hobbies...I wish!

John seems to have his eye on a lot of things lately.

:lol:

Brandon
 
<a href=showthread.php?s=&postid=11835469#post11835469 target=_blank>Originally posted</a> by DMBillies
Perhaps John accidentally got the black can... :eek2:

W...O...W!

:eek2: :eek1: :mixed: :eek:
 
That looks incredible! I can't wait to see pics of that in your tank!

OK, now it's time for a dumb question:
Is the Great Stuff the only thing holding the rock to the eggcrate?

When I finally get another tank going (been out of reefing for about 2 years) I definitely want to do this!
 
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