Casting a stone wall.

[Sumpter250]

The under construction shot of the church show a pile of pebbles I placed in a row just to get a feel of how the finished scene would look. There will also be a similar wall that runs from the edge of the road along the driveway and end at the cemetery gate. I think I am probably better off making a wall in place as someone mentioned. I could make a frame with stripwood and pour in hydrocal I suppose and then hand carve once set up. This could be done on my work bench and then glued in place once stained/painted. This is the methodology I am leaning towards at the moment.
Matt

Hand carving, a project, but it would look good, although at this point, my decision to hand shingle the entire GCLaser Boat House, doesn't sound quite so "impossible dreamlike".
I will be waiting to see the "finished" pictures, it's a challenging project that could be a realistic, and attractive addition to the scene.

[Saltwater Cowboy]

Well I gave this a shot....I made a simple frame out of stripwood and laid it flat on a piece of wax paper. I sprayed the frame and paper with a light shot of food release. I mixed up a soupy batch of hydrocal and poured it into the frame. I set a few weights on top to prevent the plaster from leaking out under the frame. A little bit did anyhow, but no big deal. I waited a couple hours till the plaster dried and then pulled off the frame. Now I had a "wall". Here's where I caused a few issues. After a day, and to ensure the wall had totally cured, I took a piece of sandpaper to it to smooth out a few bits and former air bubbles. Pressure caused the wall to break in half. Not a big deal, so I glued it back together with Elmer's and attempted some more careful sanding the next day. Same result only it broke into about 4 or 5 pieces this time. (grrrr....) Glued everything back together and a day later began scribing stones with a #11 blade. It looked good but all the gluing of broken pieces made the wall structurally a pain to work with so off to the land fill it went! Now I learned a few lessons and have poured myself another wall and am waiting for it to set. This time I plan on no sandpaper! Any irregularities will be taken care of with a hobby knife; shaving at almost a 90 degree angle and I believe that might do the trick. Will keep you informed and post a pic or two if this works out ok!

Matt

[nachoman]

Well I gave this a shot....I made a simple frame out of stripwood and laid it flat on a piece of wax paper. I sprayed the frame and paper with a light shot of food release. I mixed up a soupy batch of hydrocal and poured it into the frame. I set a few weights on top to prevent the plaster from leaking out under the frame. A little bit did anyhow, but no big deal. I waited a couple hours till the plaster dried and then pulled off the frame. Now I had a "wall". Here's where I caused a few issues. After a day, and to ensure the wall had totally cured, I took a piece of sandpaper to it to smooth out a few bits and former air bubbles. Pressure caused the wall to break in half. Not a big deal, so I glued it back together with Elmer's and attempted some more careful sanding the next day. Same result only it broke into about 4 or 5 pieces this time. (grrrr....) Glued everything back together and a day later began scribing stones with a #11 blade. It looked good but all the gluing of broken pieces made the wall structurally a pain to work with so off to the land fill it went! Now I learned a few lessons and have poured myself another wall and am waiting for it to set. This time I plan on no sandpaper! Any irregularities will be taken care of with a hobby knife; shaving at almost a 90 degree angle and I believe that might do the trick. Will keep you informed and post a pic or two if this works out ok!

Matt

You could try adding a "reinforcement" to your wall. Pour about half the plaster, then lay down something like a piece of gauze or nylon window screen, then pour the rest of the plaster.

[tetters]

I like the idea of gauze or some metal window screening in there to act like a re-bar of sorts. You also mentioned air bubbles and I wonder if they could also be trapped in the pour and causing some weak spots. I wonder if you could try to lightly vibrate the mold to get all if not most of the air bubbles out if that might help make the wall more structurally sound.

[Bob C]

SWC - I'm curious, as Hydro-cal" should be VERY strong - it's die-maker plaster, so fine-grained and hard as stone - how thick a piece did you make ? Careful filling of the mold, and some "bumping" of the mold/careful agitation will minimize air pockets/bubbles. Has your plaster been exposed to moisture in storage, compromising its strength ? I have used files and rasps on 1/4" thick un-reinforced plaster castings without breakage, then snapped 'em with my "Pointing" tool. :oops: Bob C.

[Saltwater Cowboy]

Hi Bob. The wall is off the top of my head about 3 scale feet in thickness... I'm using lightweight hydrocal which I don't like very much. I used to have a 50 pound bag of denser hydrocal which I liked much better.

Matt

[Saltwater Cowboy]

Do you guys think cheesecloth or wedding veil material might work as "re-bar" for the lightweight hydrocal? Anyway, darn work is calling me back and I can't mess with this little project until Wed. a.m. and Thurs.

Matt

[yellowlynn]

In your first post of making the pour, you stated you made a soupy mix. A SOUPY mix is much more prone to breakage than a much stiffer mix. I haven't used lite-weight hydrocal, so that could be part of the breaking problem.

Lynn

[Saltwater Cowboy]

This is the 1st time I used WS lite hydrocal and do not like it. I used to have a 50 lb sack of hydrocal direct from U.S. Gypsum that was much better quality. Alas that is gone and I don't seem to be able to find any more in the area. Later this week I will try good ole plaster of paris and see how that turns out. I will also use a denser mix of the WS stuff and pour some rock molds with it to see how that turns out in comparison.

Matt

[Russ Bellinis]

If you are having trouble finding Hydrocal, check to see if there is a potter's supply store in your town. A lot of those companies carry various types of casting plasters including hydrocal in addition to clay.

[MasonJar]

If you do find a good source of Hydrocal, please enter it in our Hydrocal & Casting Plaster thread in the Equipment and Supply forum.

Thanks!

Andrew

[Saltwater Cowboy]

Well. I made the wall. Didn't use plaster of paris. Tried a new concept. I followed the mixing instructions on the WS hydrocal. How 'bout that idea?!? Anyways, I sprayed my frame with wet water this time and poured in the properly mixed plaster. I decided not to use any simulated re-bar.



I let this sit with some weights on it for 24 hours then carefully separated it from the frame.



At this point, I cleaned up the edges with a sharp blade and a very light sweep of fine sandpaper. Very little pressure applied.



At this point I got ready to scribe the stones. In this pic you can see the hobo came by from the campfire to see how he measured up. The scrap of HO scale embossed brick paper was just there as a visual reference as to how to size my stones. I think with a project like this we can easily make the stones too big and backfire on the realism.



I decided to do the scribing of stones on the ends and the top. Ignored the bottom and left that flush.



Now the tedious part began. Scribing all those stones! This took about 45 minutes but seemed longer. I used the point of the ole no.11 blade to scribe. With all the twisting and turning of the knife, I learned it was easy to twist the knife in such a way as to use more of the blade and not just the point and create gouges instead of crisp clear lines. Here's where a dental pick might have worked a little better. But I was careful to not do that too much and a little gouge here and there couldn't help but add to the effect in a positive manner. Most stone walls have some loose and missing areas anyway. Hopefully these pics will turn out ok. I'm not a photo expert by any stretch of the imagination!



Now it's time for lunch and after that I'll head back down to do the other side. Then the fun part begins; Adding color and details. We will soon. And if this project turns out junky, then I will go buy a wall and be done with it and may this thread spend eternity in the netherworld of cyber graveyards!

Matt

[nachoman]

I did similar, but carved mine in place on the layout. I sharpened a nail and stuck it in a wooden handle and used that for the carving. I was hoping to simulate rough cut or quarried stones.

[tetters]

Looking good so far Matt!

Your wall looks good too Kevin.

[Bob C]

Matt; the result so far, seems to be worth the ignominious and un-guy-like "instruction reading" - but none of US will tell on ya !!! Bob C.