I do have a question, they want me to do a small test area, if I mix a small portion of the liquid chalk [Tru Mark's SwitchBack Double Play Liquid Chalk] with an equal part of water and do a demo, can I use what I've mixed at a later date or will it dry out and not be usable? [This is an application using an airless field marking unit on a synthetic turf sports field.]

For the unused pail of liquid chalk (not yet diluted) you should reseal the lid securely for the next use. Just remix the liquid chalk in the 5-gallon pail before you go through the next dilution process. The key is to keep the lid sealed, not just sitting on the top of the pail. Always add the chalk/paint to a pail/container of water. Never add water from a hose (especially with the hose end exposed to the air) into a pail of chalk/paint as you will add air to the diluted mixtures causing pump performance issues.

Put the diluted liquid chalk in a container that you can closed. You can reuse this, however in most cases the solids will settle out over time. During the next use process I pour out the majority of the liquid into another pail for remixing. I then use a putty knife to peel off the solids from the bottom of the pail, then add a little water and stir with a paint paddle to get the solids back into suspense. I use this previously diluted chalk for the next mix cycle with a new batch of undiluted liquid chalk.

For test purposes I would try and use one gallon of liquid chalk with one gallon of water to make two gallons of diluted liquid. This will be more than enough for a couple test strips since you should get up to 300 linear feet out of one diluted gallon, depending on how fast you walk with the line striper.

Check with the facility manager and apply two test strips, one a single pass, and the second a double pass (try and let the first pass dry (give it 10-15 minutes if possible between passes). This will be a good test, especially in a high traffic area, e.g., entrance to the field or facility. Try and let the material dry for an hour if possible. If it is outside with a breeze and sun it will dry pretty well in 30 minutes. Once it dries you can then perform the scuff/broom/removal tests. I would have a pump up sprayer (or battery powered backpack sprayer) with water in it to help remove the dust following the scuff/broom/removal process, especially if this is indoors.

If the line striper pump has a pressure regulator you want to dial the pressure down to minimize the amount of liquid chalk that goes deep into the turf fibers. Otherwise, the faster you walk the more you minimize the “over application”.

Those without an airless field paint striper should consider the aerosol chalk solution. This is applied just like aerosol field marking paint, yet performs similar to dry powdered chalk used on baseball and softball fields. The different colored (red, yellow, and blue) aerosol chalk solutions has been popular for many club sports programs.