A Question About Ground Goop

[jacon12]

 Let me say first off that I like the general qualities of what has become known as Ground Goop. The formula I use is as follows:

1 part paint (my basic scenery paint which is a kinda tan color)

1 part vermiculite

1 part celluclay (a paper mache type stuff)

About 3 to 4 ounces cheap white glue

and a jigger of Lysol to kill off the vermin.

I've noticed recently though that at the edges the GG covering, when I apply it, I'm getting whitish areas that I don't particularly like.  I'm suspecting the glue in the mixture, don't know what else it could be.

My questions are, if you use Ground Goop, have you noticed this?

Have you modified the formula in a way to correct it?

Have you tried matte medium as a substitute and if so what was the outcome?

Have you dropped the glue part entirely?

Thanks,

Jarrell

[gandydancer19]

 I have only tried Ground-Goop briefley.  I don't use any glue in mine, just paint with some small amount of water, plus the celluclay.  Haven't seen the white edges.  Can you just paint over it and sprinkle on some more ground foam?

[selector]

If I had to guess, Jarrell, it is mineral salts or gypsum powder.  I use Joe Fugate's forumula using Portland Cement, Plaster of Paris, and fine vermiculite, but I also added (not enough) masonary dyes to the mix before I added water.  I don't seem to have any "crystalization" or dusting forming at edges of the stuff.

-Crandell

[jacon12]

gandydancer19

 I have only tried Ground-Goop briefley.  I don't use any glue in mine, just paint with some small amount of water, plus the celluclay.  Haven't seen the white edges.  Can you just paint over it and sprinkle on some more ground foam?

 I think I'm going to try the next batch without any glue just to see how it works.  Well, I do have some matte medium and it's supposed to dry absolutely clear so I may try a half cup of that and see how it works.  The reason I was suspicious of the glue is that I've read where some modelers didn't like to use it when glueing down ballast because of the white showing, but I use it all the time for that application and haven't noticed anything.

Oh well, time to experiment a little.

Thanks for the reply!

Jarrell

[jacon12]

selector

If I had to guess, Jarrell, it is mineral salts or gypsum powder.  I use Joe Fugate's forumula using Portland Cement, Plaster of Paris, and fine vermiculite, but I also added (not enough) masonary dyes to the mix before I added water.  I don't seem to have any "crystalization" or dusting forming at edges of the stuff.

-Crandell

 

Can't figure out where the mineral salts or powder would be coming from.  When you say 'fine vermiculite', how fine is yours?  Mine isn't very fine, but I do have an old blender...  

Jarrell

[selector]

I initially bought two garden center three quart bags at Canadian Tire that was adverstized as medium.  It seemed coarse to me.  I found a large gardening specialty store and nursery that could order the fine stuff in bulk, so I purchased a 50 liter bag and it was quite a bit finer.  I'd say if you have a handy and inexpensive supply, your grinder will do nicely.

You may be right about the glue.  I suppose you could mix a min batch minus the glue, glop it in the same fashion as you have been using it, and wait to see if you find the same phenomenon.

Loved your moonlit engine in WPF...stunning!

-Crandell

[jacon12]

selector

I initially bought two garden center three quart bags at Canadian Tire that was adverstized as medium.  It seemed coarse to me.  I found a large gardening specialty store and nursery that could order the fine stuff in bulk, so I purchased a 50 liter bag and it was quite a bit finer.  I'd say if you have a handy and inexpensive supply, your grinder will do nicely.

You may be right about the glue.  I suppose you could mix a min batch minus the glue, glop it in the same fashion as you have been using it, and wait to see if you find the same phenomenon.

Loved your moonlit engine in WPF...stunning!

-Crandell

Thanks Crandell!  Today I think I'll grind up a cup of vermiculite and mix half of it with glue in the regular fashion and half with matte medium, spread them side by side and look for a difference.  It's the only way to know for sure.

Jarrell

 

[mekdall]

I just finished applying Lou Sassi's GG formula over about 30 sq. ft of my layout. (Lou Sassi's formula is 1 part of paint, vermiculite, celluclay and 1/2 part white glue, and of course a gigger of Lysol).  I could not find vermiculite but Home Depot recommended Perlite made by Miracle Gro.   I applied the goop directly to the plaster cloth covering over webbed cardboard shell.  I see little white flecks throughout my final product which is the plastercloth showing through due to incomplete coverage.  As I continue using ground goop, I will paint the plastercloth first before proceeding.  It still is not very difficult to go back and patch the little white flecks, but just adds a little additional time.

[ClinchValleySD40]

I use about the same formula you use and have had no problems like you describe.   I do use Elmers glue which I buy in gallon containers at Home Depot, not expensive at all.   Try it with some Elmers instead of the cheap glue and let us know if you still have the problem.

See ya.

Larry