I purchased this initially because I read that MDF must not be primed with a water based product. Zinsser Shellac based primer was recommended. I was a bit sticker shocked. One gallon was over $40.00! However, as I began to apply it, it became clear that one gallon goes a LONG way. This product is quite thin in consistency. Even the neatest painter will want to use a drop cloth and have a clean up rag ready. Clean up solution is either denatured alchohol or equal parts of ammonia and water. You must ensure good ventilation. This primer is very strong, as is the cleanup solution. That being said, the primer does a great job of sealing MDF. It absorbs nearly on contact and dries very quickly so be ready to catch drips!  My particular project (framing out an opening and adding pedestals & columns) was constructed using paint grade pine, MDF and drywall. I was very impressed with how the primer conceals knots in the wood and seems to unify all the materials. It really looks like all select grade wood.

Recommended: Yes