What do you use to keep your ground foam(grass) on your layout? I’ve tried white glue with equal parts water with a drop of dishwashing soap, but some of the foam still falls off. Anyway what do you use to keep your foam down, something not to wxpensive though.
Thanks for any replies. 
Some always falls off no matter what you do.
Some times hair spray works, super cheap, super hold.
3 parts water to one part glue and spray it on until it is saturated. Other people have better luck with this than I. Some recomend spraying first with wet water.
My personal touch is to put the ground cover on the layout where you want in, then dampen the area with wet water, then using a mixture of 50% glue , 25% water, and 25% alchol. this mixture is to thick to use in a sprayer so I use an empty glue bottle. Let it completly dry and if needed use more ground cover or more glue mixture. I seem to go through a lot of white glue. When I am done the ground foam is hard, not spongy, and it will stay in place. Mike
Matt medium mixed with water 1 to 4 ratio. Add about 10% rubbing alcohol if you are going to spray it on. A quart may seem expensive at almost ten bucks but it goes a long way.
Spray surface lightly with 70% alcohol, spray or pour on diluted matt medium, spread with old paint brush. You can add a spritz more alcohol if the medium doesn’t spread well.
Sprinkle on foam. Overspray it with a mist of alcohol. Add a bit more medium to thicker spots of groundcover if you like.
The purpose of the alcohol is to make the medium spread out and touch or permeate all of the groundcover. Let it dry. Do NOT try to push it around to cover missed areas - it will clump up and look unnatural. You can add more later. After it is completely dry you can overspray with cheapest maximum hold hairspray. Hairspray works on trees too.
Good luck,
Karl
Karl, Good tips! Just wondering, what is the advantage of Matte Medium over plain ol’ white glue?
A number of years ago, an NTrak club I belonged to was ballasting modules using diluted white Elmer’s glue. We found a white residue on the surface of the ballast in some areas after the glue mixture had dried. I don’t remember the glue:water ratio. We may have used too much glue in the mixture. In any case, we switched to diluted matte medium and saw no residue after it dried. I can tell you from personal experience that you should pre-wet the ballast (especially fine N-scale ballast) with wet-water or rubbing alcohol before you apply the adhesive mixture. If you don’t, the fine ballast will form balls because of the surface tension of the glue mixture and look terrible. It’s problably also good to pre-wet ground foam ground cover before applying the glue mixture as suggested in the above posts.
Hope this helps,
Bob
I have just finished placing ground foam on my second layout. The surface is hardshell, essentially plaster, and it will want to absorb any moisture that it can get. So, if your hardshell, or plaster cloth, or even sculptamold, is dry, anything you spray it with will have the liquid content absorbed quickly leaving the ground foam high and dry. So, you have a couple of options. If you paint, sprinkle the ground foam soonest thereafter. If you use hardshell, and it is well shaped when you have set it, use the glue solution within 3/4 of an hour. If you don’t pre-wet, or use already wet surfaces with plaster, et al., the glue will be lost, and your ground foam will not be fixed to the surface. I had to go back and spray all my hardshell liberally with water before I could even think about spraying the glue solution.
Jack, the advantage of white glue over matte medium, from what I’ve read in other posts, is that if you need to take something up, with white glue, all you need to do is resoak it with water. I don’t think you can do that with matte medium.
Thanks Jack.
For me it is a combination of factors. 1) The Medium is sprayable, 2) The wife is using most of the white glue for her eight foot long real shale ledge, 3) I think that the medium penetrates ground foam and ballast a little better, particularly when mixed with some alcohol, 4) I wanted something that was not very water soluable because I do scenery in layers, 5) The price is about the same as white glue by the quart and I can use it for trees foliage too. I learned about it (and acrylic paint) from a professional artist friend.
White glue is fine for most purposes (except maybe spraying). You might want to try some glue and some medium on the same area and see which you prefer.
Karl