Mbuna Condos, concepts for a African Cichlid tank

[OnlyGenusCaps]

You, my dear, are a bad influence!

You sound like my mom when I was a kid. And my friends. And my wife. Hmm... I'm beginning to sense a theme here.

 

[eatyourpeas]

You sound like my mom when I was a kid. And my friends. And my wife. Hmm... I'm beginning to sense a theme here.

And I am probably old enough to be your mum.

 

[madmark285]

One tidbit, when I make certain sculptures I use silicone mats (placemats) to bend and form before pouring the material. It helps with areas where I want it to be smooth. Not that you would want smooth for your strata, but I am full of useless information and it has to go somewhere.

Nope, keep the ideas coming. Actually my next prototype is to make a rock face form using a piece of metal flashing. Cooking Pam works well as a mold release and beside, I want a rough face and the Mbuna may love eating any leftover Pam . My concerning with the 'break the concrete in two" method, the straight edges may end up looking like a bunch of brick top on each other. With a flexible form for the rock face, I can make curves and coves.

For eliminating the smooth cement issue, brush the cement before it fully hardens.

BTW, can I please have one of those lantern dudes to keep my gargoyle Thelonious company?

Absolutely but you have to pay for shipping

 

[madmark285]

BTW, can I please have one of those lantern dudes to keep my gargoyle Thelonious company?

My all-time favorite Haunted Hayride prop was inspired from the movie, The Green Mile. It was the electric chair scene where he forgot the wet sponge and the victim head caught fire.

The prop had a telephone for the Governour call (it was Geico instead, I just save on my insurance), the single light bulb which dimmed when the juice was on and a fog machine behind the chair... fog would come out of the victim's head! Not very scary but very funny...

No hayride last year due to COVID but I ready for this year!

 

[eatyourpeas]

That sounds grand!

Absolutely but you have to pay for shipping

Ok, maybe I need to reassess the situation... It is only fair, but I forget how heavy cement is.

The last time I dressed up for Halloween (about two years ago) I made a little kid cry. I was kindly asked by my daughter to not dress up again. I like going overboard

 

[madmark285]

OK, more prototyping. I decided to make a rock face mold using silicone caulk purchased at a Dollar store (Red Devil brand). While searching for techniques using caulk reminded me of an old engineering saying: "The wonderful thing about standards is there is so many to choose from". I found so many methods and tried a few which didn't work of course (didn't try the Dawn soap one).

So what I learn, the critical ingredient on using silicone caulk for molds, add liquid glycerin to the mix. Silicone needs moisture to cure, the glycerin adds the required moisture and my first test cured in 4 hours. So my recipe is:

2 fluid ounces (50 grams) 100% silicone caulk
2 fluid ounces (40 grams) corn starch/flour
~1 fluid ounces paint thinner (25 grams) (100% mineral spirits)
1/4 teaspoon glycerin
a few drops of acrylic paint, acts as a mixing guide.

First, making the rock face:

Using heavy duty aluminum foil, I apply a thin layer of polyurethane gorilla glue inside the black lines shown above. Using a spray bottle, I misted the glue with water which acts as a catalyst for the glue. I added double stick tape to seal up the glue. The idea here, once cured the glue will harden my rock face template. I folded the top piece over then crumpled up the foil. Next lay it out shown below:

I build a small box using plywood with metal flashing attached to the side and put the template inside the box shown below:

For a mold release, I used petroleum jelly (vaseline). So after a heavy lube job, fill with the silicone mixture:

I add some small blocks of wood for support, I want to bend the mold to make curved rocks. So here how it came out:

It is very soft, my guess it's hardness is Shore A: 25. It will bend very easy, hopefully I can make more realistic rocks using a mold. So for my first test on making a rock....sorry but it's cliffhanger time, that's my next on my list. So stay tuned...

 

[OnlyGenusCaps]

I love this! Reminds me a bit of a friends lost wax casting work (obviously a bit different as well). You are an artificial rock production machine!
Thanks for including your recipe and experience! That makes this far more useful for others interested in the technique. No me mind you. I'd make an epic mess trying though!

 

[eatyourpeas]

OK, more prototyping. I decided to make a rock face mold using silicone caulk purchased at a Dollar store (Red Devil brand). While searching for techniques using caulk reminded me of an old engineering saying: "The wonderful thing about standards is there is so many to choose from". I found so many methods and tried a few which didn't work of course (didn't try the Dawn soap one).

So what I learn, the critical ingredient on using silicone caulk for molds, add liquid glycerin to the mix. Silicone needs moisture to cure, the glycerin adds the required moisture and my first test cured in 4 hours. So my recipe is:

2 fluid ounces (50 grams) 100% silicone caulk
2 fluid ounces (40 grams) corn starch/flour
~1 fluid ounces paint thinner (25 grams) (100% mineral spirits)
1/4 teaspoon glycerin
a few drops of acrylic paint, acts as a mixing guide.

First, making the rock face:

View attachment 134245

Using heavy duty aluminum foil, I apply a thin layer of polyurethane gorilla glue inside the black lines shown above. Using a spray bottle, I misted the glue with water which acts as a catalyst for the glue. I added double stick tape to seal up the glue. The idea here, once cured the glue will harden my rock face template. I folded the top piece over then crumpled up the foil. Next lay it out shown below:

View attachment 134250

I build a small box using plywood with metal flashing attached to the side and put the template inside the box shown below:

View attachment 134251

For a mold release, I used petroleum jelly (vaseline). So after a heavy lube job, fill with the silicone mixture:

View attachment 134252
I add some small blocks of wood for support, I want to bend the mold to make curved rocks. So here how it came out:
View attachment 134255

It is very soft, my guess it's hardness is Shore A: 25. It will bend very easy, hopefully I can make more realistic rocks using a mold. So for my first test on making a rock....sorry but it's cliffhanger time, that's my next on my list. So stay tuned...

This reminds me of my visits to the creature shop!!! Can't wait for installment number two, I am already envisioning the reverse image for the rocks!

 

[madmark285]

Clearly this project is turning into a learning thing, I never made a silicone mold for casting nor have I used cement for making things. I have a rather boring bucket list of things to do

One problem with the mold, it is shrinking as predicted by someone on the web, the mineral spirits are evaporating. Not an issue for me, 2.5" to 3" rock faces will work for me.

Adding glycerin to silicone is a handy thing to remember, add a few drops to a big glob of silicone and it will set in a few hours instead of days.

 

[Rockfella]

Ingenious. First I thought you will simply glue the rock on the PCV pipes then I see you are going ninja on the pipes too. Thanks for the great ideas.