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leeflan
Fireman

USA
2441 Posts

Posted - 03/26/2005 :  12:47:02 PM  Show Profile
Hey, Eddie,

Great progress, man. The bridges look great with the landforms. I like using natural rocks, when embedded into the plaster they look real good. I've also used rolled up bits of the WS plaster cloth, which looked pretty good for river rocks. Besides, it's a good way to recycle the stuff.

Regards,
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leeflan
Fireman

USA
2441 Posts

Posted - 03/26/2005 :  12:47:02 PM  Show Profile
Hey, Eddie,

Great progress, man. The bridges look great with the landforms. I like using natural rocks, when embedded into the plaster they look real good. I've also used rolled up bits of the WS plaster cloth, which looked pretty good for river rocks. Besides, it's a good way to recycle the stuff.

Regards,
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MikeC
Administrator

USA
21584 Posts

Posted - 03/26/2005 :  4:56:20 PM  Show Profile
Eddie, John mentioned aquarium gravel/rock. You can buy natural rock, either polished or unpolished, in 25lb bags at most fish shops, but it's expensive. About $12-$15/bag.

Have you thought about making your own rock molds and using them to cast plaster rocks? It's very easy and relatively cheap. All you need is a real rock with an interesting "face," a jar of liquid latex mold compound, and a cheap paint brush. I have a couple dozen molds that I've made over the years from rocks I found in the Ozarks. I try to use ones that are only about hand-sized.

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MikeC
Administrator

USA
21584 Posts

Posted - 03/26/2005 :  4:56:20 PM  Show Profile
Eddie, John mentioned aquarium gravel/rock. You can buy natural rock, either polished or unpolished, in 25lb bags at most fish shops, but it's expensive. About $12-$15/bag.

Have you thought about making your own rock molds and using them to cast plaster rocks? It's very easy and relatively cheap. All you need is a real rock with an interesting "face," a jar of liquid latex mold compound, and a cheap paint brush. I have a couple dozen molds that I've made over the years from rocks I found in the Ozarks. I try to use ones that are only about hand-sized.

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belg
Fireman

USA
4503 Posts

Posted - 03/26/2005 :  8:21:18 PM  Show Profile
Ed, as Mike said the method is pretty cheap and does work well but be patient and let the coats dry thoroughly and between third and fourth coat add a gauze layer to give the mold a little more strength. I believe it is also recommended to thin the first coat to make sure it goes into all the nooks and crannies. Pat

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belg
Fireman

USA
4503 Posts

Posted - 03/26/2005 :  8:21:18 PM  Show Profile
Ed, as Mike said the method is pretty cheap and does work well but be patient and let the coats dry thoroughly and between third and fourth coat add a gauze layer to give the mold a little more strength. I believe it is also recommended to thin the first coat to make sure it goes into all the nooks and crannies. Pat

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MikeC
Administrator

USA
21584 Posts

Posted - 03/26/2005 :  9:01:52 PM  Show Profile
As an alternative to the thinner first coat, I spray "wet water" on the rock facing just before I paint the latex on. It helps the latex to flow into all the cracks and crevices.

As Pat advised, it's best to allow each coat to thoroughly dry before adding the next. Usually 24 hours will do it. Instead of gauze, I usually use an old T-shirt (I have lots of those) that I tear into pieces and layer into the mold between the 6th and 7th coat.

And here's another tip: when your mold is ready (I usually apply 10 coats of latex), dust it thoroughly with cheap talcum powder before removing it from the rock master. The powder will keep the mold from sticking to itself during removal. (It can take up to several weeks for the latex to fully cure, so the talcum powder is a necessity.)

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MikeC
Administrator

USA
21584 Posts

Posted - 03/26/2005 :  9:01:52 PM  Show Profile
As an alternative to the thinner first coat, I spray "wet water" on the rock facing just before I paint the latex on. It helps the latex to flow into all the cracks and crevices.

As Pat advised, it's best to allow each coat to thoroughly dry before adding the next. Usually 24 hours will do it. Instead of gauze, I usually use an old T-shirt (I have lots of those) that I tear into pieces and layer into the mold between the 6th and 7th coat.

And here's another tip: when your mold is ready (I usually apply 10 coats of latex), dust it thoroughly with cheap talcum powder before removing it from the rock master. The powder will keep the mold from sticking to itself during removal. (It can take up to several weeks for the latex to fully cure, so the talcum powder is a necessity.)

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belg
Fireman

USA
4503 Posts

Posted - 03/27/2005 :  07:07:28 AM  Show Profile
Wow, Mike that makes for a huge investment in time to get any pulls out of this type of mold. I stopped after 6 coats and found out the hard way about letting it cure in between coats. I was not able to get my mold of in one piece. Don't you think that the wet water spray basically thin the first coat down a little to help it settle into place?? I'll give the t-shirt trick a try next time. Pat

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belg
Fireman

USA
4503 Posts

Posted - 03/27/2005 :  07:07:28 AM  Show Profile
Wow, Mike that makes for a huge investment in time to get any pulls out of this type of mold. I stopped after 6 coats and found out the hard way about letting it cure in between coats. I was not able to get my mold of in one piece. Don't you think that the wet water spray basically thin the first coat down a little to help it settle into place?? I'll give the t-shirt trick a try next time. Pat

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MikeC
Administrator

USA
21584 Posts

Posted - 03/27/2005 :  10:31:36 AM  Show Profile
quote:
Originally posted by belg

Wow, Mike that makes for a huge investment in time to get any pulls out of this type of mold.


Yes, it's a huge initial investment in time, Pat, but these molds can be used over and over, so I don't mind the time it takes. I still have (and use) molds that I made 15-20 years ago.

Another reason I like making my own castings is that castings from the same mold can can be turned at a slightly different angle or even completely upside down, and you have a whole new appearance to the rock face.

So, Eddie, have we convinced you?

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MikeC
Administrator

USA
21584 Posts

Posted - 03/27/2005 :  10:31:36 AM  Show Profile
quote:
Originally posted by belg

Wow, Mike that makes for a huge investment in time to get any pulls out of this type of mold.


Yes, it's a huge initial investment in time, Pat, but these molds can be used over and over, so I don't mind the time it takes. I still have (and use) molds that I made 15-20 years ago.

Another reason I like making my own castings is that castings from the same mold can can be turned at a slightly different angle or even completely upside down, and you have a whole new appearance to the rock face.

So, Eddie, have we convinced you?

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Eddie Landreth
Fireman

USA
2714 Posts

Posted - 03/27/2005 :  12:38:08 PM  Show Profile
Well, almost, sorta, kinda. I have cast rocks with WS molds, but never made my own molds themselves. Right now, I just have 1 WS mold, which is a big rock basically. I'm thinking of heading to the LHS this week (tomorrow) to look at some more molds (need some more hydrocal as well). I want to get moving again now that I have my momentum going on this section of the layout - I hate sitting stymied, better to try and fail than not try at all. If it doesn't look right, I'll just rip it out again (like the cow pattie). [:-glasses]
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Eddie Landreth
Fireman

USA
2714 Posts

Posted - 03/27/2005 :  12:38:08 PM  Show Profile
Well, almost, sorta, kinda. I have cast rocks with WS molds, but never made my own molds themselves. Right now, I just have 1 WS mold, which is a big rock basically. I'm thinking of heading to the LHS this week (tomorrow) to look at some more molds (need some more hydrocal as well). I want to get moving again now that I have my momentum going on this section of the layout - I hate sitting stymied, better to try and fail than not try at all. If it doesn't look right, I'll just rip it out again (like the cow pattie). [:-glasses]
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MP Rich
Fireman

USA
1762 Posts

Posted - 03/27/2005 :  1:47:54 PM  Show Profile
Okay, mow if Eddie is ready, let's really try to confuse him!! Once you get the rock casting down and run out of rock types to copy, (as if that is possible) I have found some other things to copy. Eddie lives in an area that has a lot of pine trees with real course knobby bark. I picked up several bags of them thinking they look a lot like eroded limestone outcroppings when turned sideways. The bark itself turned out to be hard to get to the color I wanted. From there I went into making latex castings that I do like. You will find that the bark is made up of lots of small layers. These look like the layers of sediment laid down on the lake bottoms when the rocks were formed. I do like Mike and wet the bark and then go through waiting for several layers of latex to dry and then peel it off for the mold. Really quite easy and cheap to do with an unlimited variety of forms and sizes to make. If you gather up 8-10 to coat at a time you can get quite a bunch in a short time. The rocks then come out with the layers already built in ready to stain. One trick to make them easier to use is to wedge the rock bark or whatever you use for the master into something like the bottom of a shoe box. This leaves half the rock sticking up and you can coat up, over, and around the rock making a 1/2 inch edge around the master which holds the latex form in shape attached to the box for filling with plaster when it is finished. Works as a cheap, ready made holder as such. Richard
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