"May-Brith Nilsen" wrote in news:452de471$ snipped-for-privacy@news.broadpark.no:
When I use MDF for jigs I finish them with shellac followed by paste wax. For MDF shop cabinets I prime them with an oil-based primer followed by a coat or two of spray enamel. I have used polyurethane varnish on MDF (several coats) with good results too. Hank from NY