I recently made my first attempt at using ground goop. The recipe I used was;
1 part celluclay
1 part vewrmiculite
1/2 part brown latex paint
1/2 part white glue
1/2 part water
Two days after putting this on my layout some areas are still not completly cured. The thin areas are hard. But the thicker areas (1/4 to 3/8 inch thick) are dry to the touch but are still mushy under the skin. Hopefully this will eventually dry completely and harden. If I want this to dry quicker what changes should I make to the formula? Thanks for all answers.
The relative humidity will affect drying time. If I were to modify the ingredients, I would cut back on the water which may or may not speed up the drying if humidity is high. You could also apply it in thinner portions or build it up using thin layers.
Some materials take longer than others to dry, and itās always dependent on ambient humidity and air movement. I have a feeling that your goop recipe, or the way you compiled/mixed it, is a bit short on plaster-like material. Iāll explain:
I use a recipe proposed by Joe Fugate on this forum when he was active here 12 years ago. I may not recall it precisely as he posted it, but I use the following:
a. Four parts āfineā vermiculite;
b. Two parts Plaster of Paris;
c. One part Portland Cement; and
d. A pinch of two colours of masonry dye powder (āmesaā and ābrownā).
You should see that my/Joeās concoction contains about three parts gypsum-like material to four parts of the ārebarā analog in vermiculite. I can use a wood drill and drill holes for armatures in the goop and for telephone poles, etc.
This may all be by-the-by and irrelevant to you, but in case you are finding your concoction a little friable or soft after you deem it to be ācuredāā¦
I have applied gelled gloss medium over a water course and found some wave tips taking over a week to turn from whitish to clear. When I use my goop recipe, and run a dehumidifier in the room, my goop batches dry in about 20 hoursā¦ish.
Itās an alternative ground covering created by Lou Sassi if I remember right. Itās mentioned often in MR as heās a frequent author. He does very good work and his scenery is very nice.
Not being very fluent in āground goopā use my belief is you use it as base material similar to Sculptamold or plaster and then use your scenic materials over it. I donāt think it is or can be used to make things like rock molds.
Personally Iām happy with the results Iāve always gotten with Sculptamold and plaster. I donāt mind experimenting with new materials when I see a benefit but GG doesnāt appeal to me.
I think part of the original appeal of ground goop was that it would be cheaper than other ways and lighter than some of the plasters that were being used. I would guess that sculptamold would be more expensive than ground goop. Since starting this thread I decided to speed the drying process in the thicker areas by using a small nail to punch holes in the skin of the still soft areas. Then I went a step further and turned on one of those utility lamps with the big metal shades and set it down on top of the offending area. Everything is dry and solid now.
So I have decided that the ground goop experiment was successful and will continue to use it with some modifications: maybe less vermiculite for areas that I want a smoother finish, definitely less paint in all future batches since the first batch dried very dark. I will also experiment with the ratio of water and/or glue that I use. Thanks for the replies.
Iāve used Lou Sassiās formula to excellent effect a number of times. I find it has certain specific advantages over the alternatives listed above.
Texture: the vermiculite gives it a rougher texture that better models the unevenness of actual ground
Consistency: using paint and white glue as the liquid elements of the mixture gives it that muddy āgoopā consistency that I find easier to spread and sculpt. Also, it adheres to other surfaces, like wood or foam, better than plaster, which just sits on top.
Color: itās certainly possible (and desirable) to color plaster before applying it to your layout, but ground goop already has the color factored into the formula. This means that if you have to cut or drill into it, you donāt get the unsightly white that plaster often leaves.
Durability: the latex paint and white glue give the goop a slight elasticity even after curing that holds up to the abuse of time better than the alternatives. This is especially important for modular layouts that get moved a lot.
Workability: this mixture is a lot more forgiving than many plasters. Hydrocal is notoriously sensitive to the amount of water you mix it with. Too little and itās unworkable; too much and it gets brittle. Where plaster is like baking, ground goop is more like cooking: you can kinda eyeball the ratios. As the OP noted, it does take its time drying, but also gives you some extra time to work it, so you can do big batches.
As with anything, you do you, but I find this stuff easy, effective, and satisfying to work with.