I'm almost done refinishing my mother's kitchen. This blog details some of the work, some problems, and some of the solutions.
The doors were dirty with hand marks and other stains, and that was the impetus to start a refinishing everything. She was not happy with the dirt, and wanted to get it cleaned or removed. The handypersons painting the house suggested either painting or staining the cabinets a dark color. That wasn't going to happen, according to her. So, she figured out that Gojo or Goop, petroleum-based hand cleaners used by auto mechanics, worked to soften the grime, and allow cleaning with a detergent and warm water. After the cleanup, the wood looked pretty good. I didn't think new varnish was necessary, but she insisted.
I started off by buying some clear gloss polyurethane, Varathane brand, and sanded off the front of a drawer (plain old 150 grit paper). Nearly all the old polyurethane came off, and I then painted it. It looked okay, but a bit pale compared to the rest of the wood in there. The old polyurethane had yellowed, giving everything a yellow tinge. This wasn't bad, because the tile and fixtures are also yellow (a 1961 house), and it made things look good.
There were other problems. First was that some of the wood had been water-damaged, and was darker than the rest of the kitchen. Second, the old finish had been damaged in places, and had crackled in many places. The previous finishing job, which I did around 30 years ago, wasn't very good: there were lots of drips, sags, and wrinkles, and low spots where the finish wasn't thick enough. Not bad for a 10 year old, but not good for an adult.
So I proceeded to remove all the doors from the lower cabinets. At that point, my mother flipped out, and said all she wanted was a fresh coat of polyurethane on everything. I was totally against that, because the old finish wasn't well done, and the water damage was ugly. Besides, the test on the drawers looked pretty good; this new finish material was a lot nicer than the old material.
We eventually cut a deal: I'd fully redo the lower cabinets, and she could just do the upper cabinets, which were not so dirty.
This newer water-based stuff is great. It cleans up with soap and water. It's pre-thinned, so you get a nice, thin coat. It dries in two hours, and you can paint another coat without sanding, so you can do up to three coats a day without much trouble.
If you remember the old stuff, which you'd thin with mineral spirits, have to clean up with more solvents, and took a day to dry, you will really appreciate the new materials. You'll also save your liver from the stress of removing the VOCs from your bloodstream.
I bought a random orbital sander from Sears. Not the latest and greatest style, but it worked great, and had a dust outlet that connected to the Sears 2-gallon wet-dry vac (the best little vac I've owned). Sticking the vacuum onto the sander is key - it allows you to sand quickly with almost no dust. It's amazing.
I never used a power sander before, and I swear, it's totally worth the money. You can sand down a cabinet door in around 2 minutes, or less once you get good at it. Hand-sanding the remaing corners and trim is no big deal. Just use a small sanding block and you're done. Work outside, and there's no dust at all.
The interior got sanded too. That was done in an hour, and I wiped it down with tack cloth (put some expired, dead shellac on an old lint-less rag, and squeeze it around until it feels pretty dry; it'll work ok). Then, I gave it one quick coat of polyurethane.
The water stained parts went red, and the wood grain really became vivid. Areas exposed to more water and food were slightly darker than the rest of the kitchen. And the areas by the range sanded down almost to white, and when varnished, were off-white. This wasn't going to work.
After doing some web-research, it looked like the solution was to first put down a thin layer of polyurethane on everything. Then, layer some poly+stain mix on top of that, to darken the wood. Then finally cover with one or two more coats of clear gloss.
So, I bought a poly+stain mix. It was the right tone, slightly red, but darker than I needed, so I mixed it, 1/3 poly+stain, and 2/3 clear. Then, I put a very thin layer on the cabinet, to glaze it. Then went back over and added thicker layers of color where I needed it darker.
After it dried, some areas needed more darkening, so I glazed it with another coat. Generally, I did a mediocre job because I put it on too thick, and there were wavy variations and some drips, but in the end it was OK. If I were doing it again, I'd use a really thin glaze, and plan on doing up to four layers of poly+stain. Once it's thinned out, it's a very subtle effect.
All the doors also got this stain treatment, so the colors would be more even. It worked pretty well, and it was also an opportunity to fix the doors so the overall color within a door was more uniform. At the same time, the stain helped bring out the grain a little bit more, and the color made the wood look nicer, in general.
The first layer of clear gloss poly is necessary to seal the wood. If you don't do this, the grain will be too contrasty, and it just won't look right. (Learned this on the internet.) The second layer is the stain+poly mix, with additional layers if necessary to even out the colors.
The third layer is clear poly, to protect the stain layer, which can easily scratch. I discovered a good way to get a more glassy layer. First, paint the polyurethane on across the grain - perpendicular to the grain of the wood. This helps force polyurethane varnish into the visible pores of the wood. They're sealed now, so the polyurethane won't soak into the wood.
Second, holding the brush vertically, drag the tip of the brush across the varnish in the direction of the wood, pulling the excess varnish across the wood and probably pushing some back into the brush. You'll see some brush marks, but they will flatten out in a few minutes. You can then check to see if you missed any spots, and repeat the process if necessary.
You won't fill all the pores, but you'll get many of them, and the finish will start to become glass-like. If you're perfectionist, you can go past the third coat with a fourth or even fifth coat. Just lay the material on very thin. With each drying, some pores will re-emerge, demanding another layer, but you will definitely see progress pretty quickly. I didn't go far enough to get a flat surface on the doors, using only three or four coats in total, but it was looking pretty shiny. I wanted to see some grain, but also have some of that plastic look too - this is a 1960s house, not an antique (yet). Moreover, I wanted it smooth so it's washable.
(Don't paint the stain layer against the grain. You'll create visible stains and boost the contrast. With the stain blend, always go with the direction of the wood.)
I didn't do any sanding between most coats. The second coat had some crud in the finish, so I used some 1500 grit I had around, and that smoothed things out. It probably just broke the chunks free. I've read that 220 grit is fine. I suspect 400 or 600 would be better, because you don't risk sanding away the stain as much.
The job didn't demand perfection because it's a kitchen - it's going to get a little dirty. Besides, the house is 50 years old, and it would be cool if the original wood looked a little old. These things are going to be seeing some soap and water. There's not much reason to push to make it totally glassy. If it's necessary, I can scuff it up, and add a few more layers of polyurethane varnish.
The project was easy and fun, and I'd do it or a similar one again. I'm already looking for an unfinished table, to use up the remainder of the materials.