This is the first time I have used waxed sand.

We pulled our bobcat traps Saturday. At one location we had 6 MB-650 traps set since the beginning of the bobcat season on 12/21. There was snow on these traps all season. Each day we would shovel or sweep the snow off - sometimes exposing the pan, and re-cover with fresh waxed sand (1/4" +/-). Traps were bedded in waxed sand that I made this summer-using Bob Jameson's recipe. (as a side note, I tested the sand several times - leaving a cup of sand with 1/2" of water in it for a week and the water did not penetrate. I also did several freezer tests as well with the sand and it did not freeze or absorb water) Polyfill was used under the pans. There were 2 traps that would not fire due to the polyfill being a solid block of ice. The traps, however, were not frozen-in. The waxed sand was not frozen at all - it was loose and appeared dry. I guess moisture somehow migrated throug the sand (from above or below??), and was absorbed by the polyfill and froze.

Any ideas what happened?

Maybe I should have put nothing under the pan and used a coffe filter or similar pan cover instead of the polyfill.

Maybe I should have removed and re-set the traps during the season, but I figured they were isolated/protected and should have been ok. When cleaning the snow from the top of the traps throughout the season, none of the sand we brushed off was ever frozen and never appeared wet at all. We did use light peat moss covering of the sand, which was ususally wet and sometimes frozen.

Its better to use a pan cover or screen of sorts for long term traps set in the ground. Nothing that will absorb or hold moisture. Bone dry sifted peat I have used successfuly under the pans at times also. I always bed in dry sifted peat moss layer. Keeping that void under the pan is critical besides the jaws freezing down.

There is certainly nothing wrong with your quality of sand but I’m suspicious with how the trap was bedded. Properly waxed sand or dirt as your is will not allow water to permeate through it unless the barrier is broken. It’s been my experience that a lot of trappers skimp when using waxed sand or dirt in the trap bed and they will pay the price for being cheap! So picture this, your trap should be completely encapsulated by the waxed sand, If when you bedded your traps a corner or a part of the trap poked through into the bed. Or, your trap chain created an avenue for water to seep into the trap. Or, when bedding you created thin spots in the waxed sand, thin enough to allow water in the bed to seep through into the trap. ETC!

Good advice and trouble shooting by Seldom.

Any/all moisture will "migrate" to take the place of air (water is heavier than air) so the fiber fill method is a very poor material to use under a trap pan in freezing/thawing then hard freezing conditions. Also coffee filters are very poor because they "absorb" water (coffee) and then stay wet until the freeze when the temps go below the magic 32 degrees (any one ever seen a wetted then dried coffee filter in January?) Nuff said..... So if you want to set a trap in early Dec. and have it in working condition until March, you will have to use a NON-ABSORBIVE PAN COVER!!!!!!! That is granted you have moisture + low temps and the moisture moves either up or down in the surrounding trap medium (soil, sand, mixtures, etc.). Grass, straw, hay etc., even peat will buy time and if suspended above or protected some way from contact with soil it can keep the mechanical parts of a trap working. Been at this in Great Plains weather/soils for over 40 years and waxed soils or coal shale are the only mediums I will use for bedding and over the pan to depend on a trap set operating in these soils and conditions. My experience. ............................ the mike.

Thanks for the input. It makes sense that moisture got to the polyfill. I must not have had enough waxed sand beneath the trap. Moisture likely came from below and could not escape thru the sand on top of the trap. It would have been stopped by the pan anyway and condensed there.

What could have been used as a cover? Plastic or metal screen? It seems that screen would keep out enough sand to allow the pan to move downward.

I will need to do some experimenting in the back yard when I return from a trapping trip to North Carolina-where deep freeze is usually not an issue.

I usually use dry sifted peat moss and may go back to it.

I cover with wax paper

What Seldom said. Use enough waxed dirt / sand that the moisture has no path into the trap. I use polyfill under the pan and bed well in waxed sand with no frozen traps. That's assuming your waxed sand is properly mixed with enough wax. Test it by pouring a little water in a depression in it.

Here's your tip for the day from my peanut gallery: long long time before COVID I used powderless latex and/or nitrile gloves stretched (or cut and layed) over the trap pans as cover to prevent my soil covering from sliding under the pans. COVID caused the availability and price to skyrocket so I went back to the old "faithful" waxed paper ---- BUT---- the synthetic gloves were cheaper and required less handling and stored in their boxes much better then (I am LAZY)..... No one else used them to my knowledge back then (late 1990's-2015) and I had no issue even using the other light weight kinds of disposable gloves used for food handling/serving. It made my preptime easier for land sets. Have not went back to them due to the above reasons but could set a trap in Dec. and it would function until I pulled in March if I had no takers. My experience. ....................the mike