Finishing Touch: Shop made finishes
Varnish (including polyurethane) by itself is a great finish. It produces a clear finish with a lot of depth; has superior water, abrasion, solvent and heat resistance, and it has good rubbing and polishing qualities. However, it can be finicky to apply if you’re not adept at brushwork, and it’s notorious for becoming embedded with dust – because it dries slowly.
An alternative, which might give you the best of both worlds, are shop-made blended finishes. The results they produce can be very satisfying. Basically, there are two types of these finishes – wiping varnish and oil/varnish blends.
These finishes are quick to make and very easy to apply – basically you wipe or rub them on and wipe them off. Clean-up is a breeze, and you only need to mix what you’ll use for the project at hand. They provide a natural look to your projects and are moderately durable and easily repairable. Best of all, they’re super economical to make.
Because both of these finishes employ varnish, your projects will end up with a slight amber tinge that darkens with age (the oil/varnish blends will darken the most).
Along with providing durability and protection from day-today use, these two finishes bring warmth to the wood they’re applied on.
Start With Precision
When starting out with mixing finishes take the time to use measuring devices, like this disposable mixing cup with gradations. Make a note of the ratio you use so you can make any necessary adjustments for your next project.
This is just about the easiest finish to make. Mix mineral spirits to any varnish (including spar and polyurethane) and you have a wiping varnish – essentially diluted varnish, which makes the finish easy to apply and relatively quick to dry. The exact ratio isn’t critical. I usually use a 1:1 ratio for the first few coats, and then I add enough varnish to the mix for a 1:2 (mineral spirits to varnish) ratio for the last coat. The 1:1 ratio will lay down a very thin coat of varnish, so you’ll want to apply multiple coats to build up the finish. On projects that won’t be subject to a lot of use, I lay on four to five coats (plus the final 1:2-ratio coat). If I expect the project to be handled a fair amount, I’ll lay on a dozen or more coats. Depending on the relative humidity and temperature in my shop, I can generally recoat after 90 minutes. Having said that, don’t recoat until you’re sure the previous coat has dried fully. You don’t want to use this finish for a dining room table or for seating, but it works well for carvings, turnings, trim, display cabinets and the like. The resulting sheen will be flat to satin.
If you’re looking for a more durable finish, an oil/varnish blend is the way to go. It’s a finish that is similar to the Danish Oil or Antique Oil Finish products on the market. It provides a higher level of wear, moisture, water vapour, heat and chemical resistance. Applying multiple coats will, of course, increase resistance. You can use either boiled linseed oil or tung oil, along with mineral spirits and any type of varnish, and here again, the exact ratio isn’t overly crucial. And, as with wiping varnish, you only need to mix the amount of finish that you’ll likely use for your project. I use a 1:1:1 ratio. Adding a bit more mineral spirits will make the finish easier to apply, but it will decrease its durability (in which case you can simply lay on more coats). You may have heard of the Maloof finish, popularized by the late furniture maestro, which uses linseed oil in place of the mineral spirits. If you decide to follow in the footsteps of Sam, best to use boiled linseed oil, not pure linseed oil, which takes forever to cure.
Both of these shop-made finishes are best applied by rag. After you’re finished sanding (I stop at 180-grit) raise the grain by wiping the surface with a damp (not wet) sponge or cloth. Once dry, lightly sand with one grit higher than the last grit you used in preparing the wood (I use 220-grit). I wipe on the wiping varnish finish and don’t bother to wipe it off. You’ll be surprised at how quickly it begins to dry out. For the oil/varnish finish I rub it onto the surface and then wipe it lightly in the direction of the grain. Once dry to the touch – about 90 minutes – I reapply, up to a dozen coats, depending on the intended usage of the object. I don’t bother sanding between coats.
A word of caution. Put used rags into a sealable oil-waste container, a bucket of water, or hang the rags out to dry, after which you can safely discard them. Oily rags can spontaneously combust while drying if they aren’t dealt with properly. Give one of these finishes a try on your next project. I think you’ll be pleased at how quickly and effortlessly you finish the project and how good it will look once you’re done.
Carl Duguay - [email protected]
Carl is a Victoria-based furniture maker and the web editor at Canadian Woodworking & Home Improvement.