How can I avoid blotches when staining pine?
First, Minwax wiping stains are inferior...so is there conditioner...in fact the only thing they do well is marketing. Step up to Sherwin Williams BAC or Old Masters and you'll never look back. Having said that, in this case you need a gel stain. Second, conditioner although indispensable when working with soft woods, will only get you so far. With a quality piece like your door you really need to start with a sprayed alcohol based dye stain, then conditioner, then gel stain (not wiping or penetrating). Once you're satisfied with the color, seal it with a good sanding sealer that's compatible with your ultimate finish. At this point if you choose you can add a glaze, but make sure it too is compatible. In particular if you plan to use a Sikkens varnish you'll want to avoid glazing. Now it's time for finish. I personally like a pre-cat lacquer but occasionally we spray conversion varnish too. If you don't have a booth you'll probably want to stick to varnish or poly-urethane which can be brushed on easily. If its for exterior use, use a spar varnish or Sikkens (bearing in mind the compatibility issues). Cheers!