I am in the process of finishing a flintlock kit. In the past I have used LMF Permalyn Sealer with either Tru-Oil, Chambers or Dem-Bart as the final finish. I was recently told not to use LMF Permalyn Sealer due to the fact that it is polyurethane based and is subject to cracking and shrinkage to changes in humidity and weather. I was advised to use an oil based sealer which would have more flexibility when humidity conditions change. The previous guns in which I used Permalyn Sealer had had no problems due to weather changes and have been pleased with the results, however the guns are only 2 years old. Any comments would be appreciated.