My carvings are made from dead trees that I find in the Montana forest. I make every effort to find and use wood that is well seasoned. I do soak my carvings in penetrating oil, allow them to dry, and then apply several coats of polyurethane varnish with a final coat of sparr varnish. I use this process to allow the carving to cure out slowly to minimize cracking. If there is a natural crack already in the wood I position the crack on the backside of the carving. If a natural crack has not started I often make a cut on the backside to relieve the drying pressures as the wood swells and shrinks due to weather and humidity. Some cracking will occur and is normal.
I highly recommend that especially for the first year that you try to keep your carving out of hot direct sun or near a fireplace. The extreme heat is hard on wood. If you follow my recommendations for upkeep and still have trouble with large cracking I will replace or repair your carving at no charge.
Solar Light Moose
Close up of Mountain Man