Caring for Oiled Furniture

This week’ question comes from Hope. She writes:

Around 5 years ago or so a friend of mine built me an incredible bed out of mahogany. It is such a beautiful piece and I feel it will become an heirloom. My problem is that I have lost touch with my friend and she did not put a finish or stain on the wood she only oiled it. I went to a lumber place to ask for some oil and the guy told me that I need to know what she used on it initially before I reapply more oil. Is this true and if so how can I ever know? Or what are my other options? I really want to take good care of this bed and I don’t want to mess it up. HELP

And here was my reply:
“Have no fear Hope. Fortunately, your lumber guy is wrong. Never send a wood seller in to do a wood finisher’s job. :) Actually, his concern is valid, since finish compatibility is sometimes an issue with certain finishes. But oil finishes are usually not a problem. Since 5 years have gone by, the oil is fully absorbed and cured. This means you can pretty much topcoat it or re-coat it with anything you want. So lets talk about what you want out of the finish. If you like the way it has looked over the last 5 years, and you just want to “refresh” the finish, then you can simply apply another coat or two of oil. If you want to add a bit of extra protection that a straight oil will not provide, you can go with a simple oil/varnish mixture. This mixture will give you the best of both worlds, with a very natural looking finish and some added protection from the varnish. Either way, the process is the same. Even if you don’t have any wood finishing experience, this process is a breeze.”

“First we have to prep the surface. Start by sanding the entire surface with 320 grit sandpaper. I am only talking a very light sanding here. Just a few light strokes in each section. This will help “clean” the surface and smooth everything out. For a bed, if you spend more than 35-30 minutes sanding, you are sanding too much. So once everything is nice and smooth, wipe the whole surface down with a rag soaked in mineral spirits. This will remove the dust as well as any surface oils from the last 5 years. Give it a few minutes to dry. Now you are ready for your new oil finish.”

“If you just want a straight oil, I would recommend a classic boiled linseed oil finish. Home Depot and Lowes sell this stuff in small cans. Make yourself a 50% solution of boiled linseed oil and mineral spirits. This will make it easier to spread the oil. Use a rag or a brush to coat the whole bed liberally. This might get messy since you are really trying to flood the surface. By the time you finish coating the whole bed, you will be ready to start wiping off the excess from the starting point. Just use some clean rags and wipe until there is nothing left standing on the surface. Wipe down the whole bed this way. Over the next 8-12 hours, check on the bed every hour or so. If you see oil bleeding out on the surface, wipe it off. After about 16-24 hours, you can add another coat if you want.”

“For an oil/varnish mixture, you do pretty much the same process, only you use an oil/varnish mixture instead of oil alone. I recommend a pre-made product called Waterlox. Its one of the best out there. I would dilute that mixture about 10% with mineral spirits and apply in the same fashion as the oil finish. The more coats you do, the more sheen you will get. But if you like the natural look, you may only need one or two coats. Good luck!”

And just a quick safety note. Oil cures by means of an exothermic reaction. This means the reaction produces heat. So a folded up oily rag can very easily burst into flames as the oil cures. Its best to lay your used rags out in a single layer on concrete and let them dry thoroughly. Once dry and stiff, the rag is safe to dispose of in the regular trash.