Clearing pond/lake ice can get -- interesting.
There is the whole issue about the thickness of the ice, of course. And by that, I mean the solid, clear ice, not the frozen slush (which is full of entrained air). What often happens is that the surface starts to freeze and then snow starts accumulating on top. Or sometimes, the surface is not yet frozen, but a significant snow falls, floats on top and then the bottom slushy layer freezes. 5" or 6" of clear blue ice will safely support a tractor. 5" or 6" of frozen slush will not. Simply drilling down will not tell you what kind of ice is present, you need a core sample. I use a chainsaw to hack out a block and check the layers.
If there are springs, a bubbler or other running water in your pond you may have thin spots. Bubblers are particularly concerning, because the bubbles can travel hundreds of feet under the ice. A number of snowmobilers have been killed well off-shore where a dock bubbler installation thinned the ice.
Ice itself is plastic. Floating plastic. It will form a dome where you have cleared as the weight of the snow pushes down on the parts you haven't cleared. Some of that uncleared snow will be that which fell there naturally, some will be what you relocated there with the snowblower. That can lead to thin ice in the centre of your rink, if a bubbler is present.
Not only is the snow weighing down the ice, it is also insulating the ice, preventing it from freezing deeper and thicker. This can lead to a hidden and unexpected layer of slush between the ice and the snow that wasn't there before the latest storm, as the weight forces the ice down and water comes up through cracks and around the edges to penetrate the boundary layer. Not only does slush not blow particularly well, tending to freeze in the chute, but if your tractor hits that and gets stuck, you have a limited amount of time to get that tractor out of there before it freezes in place. Not a good place for your tractor to be next spring when things thaw out again! So go slow and have a recovery plan in place, just in case...
That layer of water can eventually seep to your cleared rink, ruining the surface. Stomping down the snow around the outside of the rink -- even with snowshoes -- destroys the insulation value of the snow under your footprints. This can help freeze that creeping layer to form a barrier around your rink and help preserve it. Just think how deer tracks become raised bumps in the spring when things are thawing.
Speaking of the spring thaw, get off and stay off once the temps start fluctuating above and below freezing regularly. The cycles cause the ice to crystalize into vertical channels making formerly strong ice weak.
I've been blowing a rink off for the kids (and now grandkids) for many, many years. It can be done, but avoid my mistakes!
