I use builder's sand from Lowes (50 pound bag for about $5.00) as ballast. It tested as non-magnetic. It is a light limestone color so I tint my diluted matte medium with acrylic craft paints to color it. I wet the ballast with diluted alcohol then apply the diluted matte medium. Since it is tinted it is very easy to see if the matte medium is soaking in all the way. And a bonus with the tinted matte medium is that with different tints I can easily alter ballast color so that mainlines are different from sidings or yards.
From many years of model building and track laying, I can relate one fact that has not been mentioned here so far and that is that diluted white glue will consistently leave a vaguely glossy finish to the ballast, or whatever it's applied to, as compared to the dead flat/matte surface one gets with matte medium. And, yes, WS liquid product does seem to be just diluted matte medium, but sold at many times the cost you could produce your own at by just visting your local arts & crafts store, buying a bottle of matte medium and diluting it yourself.. NYW&B
White glue all the way. No reason to spend a penny more for glue when this basic, available everywhere cheap product will work perfectly. As for the applicator. My club has a few very similar applicators that were gotten from a beauty supply wholesaler. I forget the name, but there is a national chain beauty supply store that will have them. The syringes are also often used by vets for liquid medicines and by pediatricians for liquid medicines, so a good drug store may have them or a pet supply store.
My applicator is real cheep ! Just use the orrigional glue squirt bottle ! Top opens and closes, and depending on how hard you squeeze, you can control the flow....Mike
Sorry for the late reply as I just noticed this. I will append my earlier experience with white glue by saying that my ballast was put down using the above process. Apparently ignorance is not the only reason white glue can fail over time.
I get my ballast/scenery materials where I want them, mist with 90% rubbing alcohol, and dribble on a 60/40 mix of "Aleene's Tacky Glue" ( found @ "Hobby Lobby" ), and water, with an about an oz. of the alcohol added to the mix. I wet the area down with glue mix until it's pretty white with the mix, and then carefully pat/dab up the excess with a large sponge. Works like a champ, I let it dry 24hrs., with a fan assist, and it's bullet proof.
