Long-Term Finish Storage
Test Results

Finish Storage Test: Overview

As most of you know by now, I have always done a lot of testing and research in my studio on tools, finishes and various woodturning protocols. I’m constantly striving to find a better technique at the lathe, mix a better finish, or find a new way to use an old tool. So it is today, testing and research is still a big part of my studio work and it always will be -- if I have anything to say about it.

This idea for this particular test came about the first year I opened my studio. I had purchased a ton of various finishing products to get my studio initially stocked. As the years went by, I kept accumulating a lot of finishing products, since I would always buy any new products that came along for testing. As the mountain of finishing products in my storage room grew, I began to wonder just how long I could store them without any degrade. Humm, sounds like a test is called for…

Finish Storage Test: A Test is Born

After mulling over the possible testing parameters, I segregated a large number of finishing products out of my open stock and began the initial work to set the test up. For this test, I wanted to test various kinds of finishing products both brand new in the can (never opened), as well as some that were opened and partially used, then stored away. Much like you might do with some of the finishing products in your studio.

To make the test more realistic, I also included some finishing products that were half used, some that were three-quarters used and a few that had their lids left off overnight before being resealed. I’m sure none of you have ever left a lid off a can of finish overnight accidentally -- nah, no-way, never, who me? Numerous types of products were included in the test like various oil finishes, pre-mixed shellac, wax finishes, blended finishes, water based finishes and many others.

I wanted to have a good sampling of products, but I did not want to break the bank, since most of the products used in this test were purchased for use in my studio (a few were gifts). As time went on, I added some new products to the test, as my budget allowed. In total, seventy-five products were eventually included in the test.

Finish Storage Test: Five Years Turns to Ten

The best laid plans of mice and men… The length of the test was originally going to last five years. However, after reaching the five-year point, I was so busy in the studio that I decided to put the test on the back burner until I had a wee bit of free time. Well, time has a way of slipping away as they say and five more years passed. At this point, I was so busy in the studio that there was no way I could devote the time to finishing the test and recording the results.

Once again, I decided to put this test on the back burner, vowing to complete the test as soon as I possibly could. Fast-forward to today and fifteen years have passed since I first started the test. Wow! This was a classic example of the “out of sight, out of mind” excuse. Time sure flies when you’re having fun. The products included in the testing ended up ranging between ten and fifteen years old, with a scant few in the eight to ten year age range. That’s a long term test for sure bruddah!

Finish Storage Test: Thin-film Polymerization Testing

To assist with evaluating these finishing products I performed a thin-film polymerization test at the start of testing. This involved taking a large sheet of glass and marking grid sections on it approximately two inches square. Each section was numbered and each number was assigned to a particular finishing product.

A tiny sample of each product was then applied (from a container that was not included in the testing, to preserve the integrity of the unopened cans/bottles) to the appropriately assigned grid section with a Q-tip. The sample was then applied to the square until the sample was approximately the size of a silver dollar. Once all of the products were applied to the sheet of glass, it was allowed to cure for several weeks.

The resulting films/finishes were then observed for lustre, resistance to scratching (fingernail scratch), colour and overall appearance. Unfortunately, I was unable to get a photograph of the thin-film test glass, as no matter how many times I tried to photograph it, only a few of the finishes (darker coloured oils primarily) could be readily seen. The test photos looked like a sheet of clear glass with a grid section marked on it. Many of the finishes were just too clear to show up in the photo, especially when applied in such a thin film.

Finish Storage Test: Crash and Burn

When I began this test, I knew some of the finishing products would not survive to the end of the test. Half and three-quarters used cans of oil finish usually do not last long, as I’m sure you have found out in your studio if you left a partially used can stored for several months. Many oil finishing products will begin to cure in the can, using the air inside the can once the finish is removed -- if stored for long periods.

Other finishing products in the test settled out, with the thicker ingredients settling to the bottom of the can or jar. Some of these could be stirred and were ok to use, some never incorporated correctly again and were useless. I decided to include some products in the test (partially used) that I knew would not be useful at the conclusion of the test as a baseline metric.

Finish Storage Test: Winners and Losers:

Note: This article will concentrate on the results of the oil and wax finish tests. Future articles will cover the rest of the finishes including shellac, water-based finishes, waterborne finishes, specialized finishes, artists' oils, water colour paints, acrylic paints, rattle can finishes and more.

Through the years, I often wondered about those finishes sitting in the long-term test shelf. Much as I wanted to, I did not peek or sample any of them before the official end of the test. What I learned surprised me… The results below represent a sample of the products in the oil and wax test, since including all of the products would make this article as long as a book.

Some of the finishes (unopened cans) of the oil finish were just like new when opened at the end of the test. You could not see any difference between the older finish in the test can and a new can fresh from the store. Thin film polymerization testing showed no significant performance difference in many of the oil finish products that were stored vs. new finishes.

This was a bit of a surprise for me. I had originally thought the unopened cans of finish would fare better than those that were opened, or partially used and resealed for obvious reasons. However, I did not think that a can of oil finish that was fifteen years old would be still be useable. Note: I should mention here that I do not recommend storing finishes for long periods of time, as you may well end up with a can of unusable product later!

Notable Test Results – Oils and Waxes

Finish Storage Test: Oil Finishes

Unopened Minwax 209 - This is one of my favorite finishes… Tested finishes were ten, or fifteen years old and each one passed all of my tests. Three of the quart cans of 209 were used on several recent projects in my studio. No differences were evident during initial application of the test finish, or after final buffing with a cloth wheel once the product had cured. From this side of the keyboard, that’s amazing. This finish has a low percentage of solids, which may be one of the reasons it fared so well. Nonetheless, it passed all tests with flying colours.

Partially Used Minwax 209 – For this test, I used a small amount of finish from the can, enough to coat a 10” bowl three times -- over the course of three days. The balance of the finish was left in the can and the top was reapplied after cleaning the rim contact area thoroughly. No adjuncts (like Bloxygen) were used to forestall curing in the can.

The results were the same as those in the unopened can of Minwax 209. Of course, there was still a significant amount of finish left in the can after finishing the bowl, but the test fulfilled my objective – open a can, use a small amount and reseal it and then store it away.

Unopened Livos Meldos Oil – This light oil finish did well in testing. There were no problems noticed in application or subsequent buffing with a cloth wheel and white diamond compound. No differences in viscosity or colour changes were noted in the finish.

Partially Used Liberon Finishing Oil – This is one of my all time favorite oil finishes. It’s a heavy bodied oil that builds very quickly. In testing, no differences were noted in application, or subsequent buffing with a cloth wheel and white diamond. This oil finish remains at the top of my list of preferred products when a medium coloured oil finish is acceptable.

Partially Used Liberon Pure Tung Oil – This is a 100% pure Tung oil finish that I use occasionally for making up some types of custom finishes. The test can came through all tests without any problems. No differences were noted in overall drying time either, which is lengthy -- just as you find with fresh product.

Unopened Robson’s Varnish Oil – This is a very interesting high viscosity finish that I really enjoy using from time to time. The test can was unopened, just as it came from the factory. No differences were noted in testing. This is a very nice finish for certain projects.

Unopened Robson’s Danish Oil – This is another excellent oil finish from Robson’s that is less viscous than their Varnish oil. I use this occasionally as an intermediate finish, using my blended oil finish protocol. Results from testing mirrored Robson’s Varnish oil, no problems were noted. Both of these products are excellent finishes, but the need to be applied in thin layers for best results.

Finish Storage Test: Paste Wax Finishes

Note: All of the wax finishes in the test remained useable after testing. Most of the paste waxes in push top metal tins experienced a bit of wax creep. Seepage of wax from a sealed tin is known as "wax creep." Some tins were more resistant to this creep, which could be an important consideration if you want to store your paste waxes over a long period. For an in-depth discussion of paste wax creep, check out this article.

Unopened Renaissance Wax – This paste wax was fared very well in testing, with no creep and no shrinkage due to solvent loss. This wax has a screw on lid with a liner, which no doubt helped to keep the product fresh. This is my favorite wax bar none, regardless of cost considerations.

Partially Used Briwax – This carnauba based paste wax is a long time favorite of many woodturners. The version I used for testing was the one with Toluene solvent. This paste wax did experience some creep, but not too much. The wax itself did not lose any solvent during testing. This wax performed flawlessly.

Finish Storage Test: Liquid Waxes

Unopened Livos Liquid Beeswax – This product comes in a glass jar, with a screw on lid. There was no creep whatsoever, but the product did settle out. Once shaken, it was ready to use. In use, it was superb and no differences were noted in testing, versus fresh new product. This is a great light Beeswax finish that has many uses in a woodturning studio.

Partially Used Liquid Wood Wax – This liquid wax comes in a metal quart can with a screw-on lid. There was no creep noted and the wax performed well in all tests. Other than a good shaking before use, there was no difference in the test sample and new product.

Finish Storage Test: Semi-Liquid Waxes

Partially Used Williamsville Wax – This semi-liquid wax scored very well in the test. No creep was evident (screw-on lid) and there was no separation in the wax finish at all. In use, the wax performed flawlessly in all respects.

Partially Used Craft Supplies USA “Lemon Oil Wax” – This product is offered in a plastic container with a screw-on lid. There was a slight bit of creep noted, but the wax itself performed flawlessly. This is one of my favorite waxes for some wooden bowls and other treen products. The lemon scent is an added bonus!

Finish Storage Test: Closing Thoughts

This test has turned out to be very interesting to me… Some of my preconceptions about long term storage were proven false and others were verified. Look for additional articles on this subject next year with the results of other finishes. Another article will explore various products and storage containers that help to preserve your finishes during short, medium and long term storage.

Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.

Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments.

Steve is also the current and founding President of the Lone Star Woodturners Association, Inc., an AAW member chapter. The LSWA is a 501(c)3 non-profit educational organization dedicated to teaching and demonstrating the art and craft of woodturning.

Steve is also a featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his articles covering technical topics, or project based articles in an upcoming issue.