Background: Traditionally the Forest Service (FS) tree marking crews have used solvent based cleaners such as mineral spirits to clean-up and store their tree marking paint guns in. Recently the FS is in the process of switching over to a water clean-up type of paint for tree marking. Crews in Region 6 (R6) have been able to use this paint for the past year. The FS has also recently directed that solvent based cleaners not be used anymore for paint gun clean up or storage to reduce the exposure that marking crews have to the solvents.
On the Applegate RD, marking crews traditionally have worked in the field marking timber sales year round due to the low elevations being accessible during the winter months. The problem then became how were the paint guns going to be stored during times of freezing weather to avoid damaging them from storing them in water.
Findings: One possible solution was to use an antifreeze mix to store the paint guns in. Currently the water clean-up paint has propylene glycol (an ingredient in antifreeze) in it though the FS is already developing alternatives to this by using citrus pulp instead. So it seemed that using the antifreeze mix (propylene glycol) was not totally risk free to hazardous material exposure. I spoke with Frank Duran in the R6 office about this matter and asked if he had any recommendations. Frank referred me to Jim McGilvery on the Okanagon NF whose crews were using vegetable oil as a paint gun clean up and storage material.
How does it work? On the Applegate RD the tree marking crews have given the vegetable oil a try this winter and found there is no offensive smell or fumes. The vegetable oil appears to go through the paint guns easily and helps keep the leather parts within the paint guns lubricated. The vegetable oil also keeps the paint guns clean without the paint drying up in them and clogging them. The vegetable oil does not freeze though it does get thicker when the temperature gets below freezing. The vegetable oil also works well for clean up and storage with both the new water clean-up paints and the older petroleum based paints. The vegetable oil is readily available locally (I had purchased gallon containers at a local Fred Meyers grocery store).
Applications: Use of vegetable oil appears to be a good alternative for marking crews to use in the clean up and storage of their tree marking paint guns. The use of the vegetable oil reduces the marking crews' exposure to hazardous materials (such as solvents or propylene glycol) yet still allows the use of the tree marking guns during the colder winter months without damage to the paint guns.
Submitted by Bob Schroeter; Applegate RD; 541-899-1812