It has been a long time since I did this and I am now ready to start applying rock molds to the plaster inpregnated gauze support structure. Can I just wet the plaster impregnated gauze and apply the rock molds or should I put a thin layer of hydrocal down then apply the rock molds?
Thanks I nadvance
Ira
Ira,
Just apply your rock molds over the dry plaster cloth with hot glue, and then apply strips of plaster cloth, slightly overlapping the rock mold. This will make your look like it’s in the ground, rather than on the ground.
Sam
It depends if you are applying wet rock molds or dry castings.
I apply wet plaster molds, so I only spray the facing they will go on with water. (This prevents the facing from drawing out the water from the wet castings.) I also add a bit of salt to the water before I mix the plaster and pour the mold. Salt speeds up the setting of the plaster in the mold so I don’t have to hold it as long. (Add white vinegar to slow the setting if you need to.)
If you are applying dry castings, you need to ‘butter’ the facing they are going on with wet plaster so they will stick.
I use liquid nails foam safe adhesive. Then use sculptamold or hydrocal to blend in the edges. Very secure.
I approach this the same as Elmer suggests. For flat application of dry molds you can use any sort of adhesive, but I do like to apply a partially hardened casting w/ a small fresh batch of Hydrocal buttered to the back. Any oozing as you place and force the mold to conform can be left or carved at a later time as you fill-in the voids between castings. A good hint is to know your casting as the orientation and type of rock itself. This helps to avoid that patchwork look of different type and wayward strata. If in doubt as to the mold’s appearance, just cast a few, they will not go to waste (apply elsewhere or break apart for fill in of the Jigsaw). The “pre poured” castings will also help you in the layout of how to place the castings as you lay them up. I like to precolor the plaster w/ powdered masonry dyes, this helps in the final coloring, washes and will not show those “white” specks if it gets chipped.
Rock outcroppings can be just 1 or a few castings placed as the vegetation will fill in the “blanks”
[URL=http://s151.photobucket.com/user/bogp40/media/Layout%202011/DSC00
I use Sculpt-a-mold to bond my rock castings in place. I cast the rocks in the mold, let cure and then apply to the scenery base with the Sculpt-a-mold. I like doing it this way, as I can cast many rock castings at the same time. Also I find the Sculpt-a-mold easy to carve into rock faces, filling the gaps between rock castings.
Talk to twenty people about how they do this and it’s likely there will be 20 different ways of doing the process.
The Cripple Bush molds are great and easier to work with. They look good too. I also use plaster molds. A little hot glue to hold it in placeand ground goop around the sides to plant and lock it in place.
I just use hot glue and then a little Sculptamold to blend everything in. I have never really had good luck applying wet castings to wet or dry plaster so my advice is, do whatever works for you.
Harold, I used to have the same issues w/ applying that partially hardened casting, since found that a small “fresh” batch of Hydrocal buttered to the back worked wonders. Also that oozing plaster helped w/ additional placement of adjoining molds, scoop to fit the next or just remove, or if needed it can be carved or small broken “bits” can be placed for fill-in.
The advantage of placing a partially hardened ones is that hand pressure will allow you you shape and conform to even some of the most concave or convex situations. Some of the castings may crack or break, but found it can even add to the effect. If unsure, I will leave a mold on the area for a few hours, then carefully peel/ stretch as it is removed. Some molds may have fairly deep and craiged impressions making removal difficult. Broken pieces can be popped out of the mold and glued on or just wet and carve to blend. Note: dried Hydrocal will carve much better when wet.