Finishing Discussion Point 1: "Protection"?

In the same spirit that Mark introduced design-oriented discussion threads in the Design Forum, this thread will serve as the first talking point for SMC's new Finishing Forum. Please participate and express yourself!
-------

So...whenever folks talk about finishes, the "P" word often gets bantered about like it's some absolute. "P" word being "Protection". It's often closely associated with the current retail (and hobbyist woodworker) trend for what my friend Steve Mickley calls, Polyoneverythane...yep, another "P" word. (Steve moderates the finishing forum at another site and does wonderful work himself)

We apply finishes on most of our woodworking projects for a number of reasons, including coloration, highlighting the special characteristics of the wood, etc. and, of course, for protection. (And just to keep things honest, "no finish" is also a finishing choice) All of these reasons can sustain a health conversation on their individual merits, but the last one is probably the one that gets talked about in detail the least. I'd like to change that.

Ok, Protection. From what? That clock on your mantle. Is it in danger from spiders with steel-toed claws? Will you be handling it a lot or is it's primary job to sit quietly...well, maybe not aways quietly depending on the kind of clock it is...and bring you great joy in just looking at it from time to time, as it were? What about that jewelry box you painstakingly made from exotic veneers with custom ebony knobs and all? Will it also be used as a step-stool and need to handle the pitter patter of little feet or will it just be supporting your responsibility to foot the credit card bill from the jewelry store? Hey, what about that end table in your formal living room? (for those of you who have houses that still have formal living rooms) What do you expect it to endure? Really?

All (hopefully humorous) sarcasm aside, "Protection from what?" is a valid question that we each need to ask ourselves when we begin to consider what finish to use on our projects. There are so many great choices (and some horrible ones), but sadly, most of us, especially when starting out in this woodworking thing, get conditioned by advertisements, TV shows and the home centers to think that there is only one finish worthy of our purchase, no matter what the purpose of the project.

While I'll likely comment further in this thread, the rule of thumb I use for choosing finishes is pretty much, "What is the least amount of "protection" I can afford to embrace while maximizing the beauty of the wood?" If BLO and wax will give me the silky-smooth finish I love without materially endangering the longevity of the piece...that's what I like to use. Decorative items get this almost exclusively and so did my recent mantle project. It's a renewable finish, too. If BLO followed by shellac will give me the clarity and pop I want while providing a nice (and easy to apply) film finish that is generally resistant to spills and general use, that's what I'll use. In fact the tables in our TV room are finished that way. If I need something more physically durable, such as the kitchen cabinets I built and installed in 2003, I use water bourne acrylics sprayed on. (Target Coatings usually)

My kitchen table? BLO to pop the teak and then it has about 15 coats of wipe-on polyurethane varnish. Yes, I used the evil poly! (It's even Minwax if I recall accurately) And I'm sure I'll be happy that I used that particular finish type on that particular table once the kids arrive. It was the right thing to use for that particular project.

This is important because finishes materially affect how your completed project will look, both initially and after time passes. There is a great deal of difference in appearance between a penetrating oil finish and a thick film of "whatever". Over-protection might cause an awesome project to be merely really nice.

Now it's your turn. What are your thoughts about "protection" and how do you choose a finish for each of your projects? Are you only using one finish or have you made a pact with yourself to try new products and techniques? If you're only using one product/method, why?

Jim ---

You exactly parallel my thinking about finishes. My current set is:

* Bartleys Gel Varnish or the "Maloof oil". I use this on pieces which don't need much protection, and especially on pieces which will be touched.

* Emtech 8000 "varnish" and 8800 sealer. This is a waterborne polyester/acrylic finish sprayed with HVLP. I use it on objects which require medium protection like kitchen cabinets, or dining tables in adult households.

* Brushed on poly. I use this for really abusive environments, like floors or furniture for kids

Jim,

Even on my Wenge dining table I only have Tried and True. Probably 4 coats...Faint rings may appear and then dissapear...but, it feels and looks like wood ...the sheen you observe is from the smoothness of the wood not from a plastic coating which was layed on top....when you do that, you might as well use laminate..it doesn't feel like wood anymore. Like when you go in a Lexus, BMW, Mercedes....I always wonder "is it wood?" they say it is! Not too many years ago they used wood contact paper in cars...or real cheap plastic...now the chrome is plastic...let wood look and feel like wood and let the true color come out...

Jim,
Thanks for posting this. It was a great read and a good reminder that one finish does not cover it all! Currently I am building furniture that will be used, so it is all getting witches brew. I want to get back to some mantle clocks, etc. At that time I will be expanind my finishing horizons, so to speak :)

Jeff...think about your witches' brew a moment. What's in it and in what proportions?

I'll make a simple assumption: let's say it's 1/3 varnish, 1/3 oil and 1/3 thinner...a typical formula...for..."danish oil". When you mix varnish and oil you end up with a softer finish after curing because you've effectively increased the ratio of "oil" to "resin"--very simplified and not quite chemically correct, but that description serves our purposes here. (The thinner merely makes it easier to apply by wiping with the only negative being more coats needed to reach the same film thickness) The resin (varnish in this case) is what cures to the harder part of the finish film--it's a chemical reaction. The oil you add, at least in the initial coat, penetrates the wood and "enriches" the color and grain. It also cures, but separately from the varnish since they were not cooked together to form a single reactive stew.

What is the impact of this? Well...you've just proven that you don't need a 3" thick slathering of plastic to "protect" your furniture from normal use...as long as general care and maintenance is taken care of, of course. You know...cleaning up spills in a reasonable amount of time, etc. In fact, I honestly think that your furniture is easier to care for since the bumps and dings may be less noticeable since the finish is a little softer and can "bounce back" rather than chip off. That's really good because it also means you can use a finish that enhances the beautify of the wood, rather than covers it up.

Your "brew" is actually quite nice in that you can vary the proportions to change the "protection" properties a little while still having an easy-to-apply finish...at a lower cost than buying some vendor's overpriced thinned down varnish/oil combination.

Having little kids makes the "p" word(s) necessary. I'm getting ready to make a cabinet for our main dining area (breakfast room). Its purpose is to look nice in there while hiding the kids art supplies. I have been using General Arm-R-Seal poly. It's easy, pops the wood nicely and protects well, but looks a little too plastic for me. I am looking to expand my horizons a little on this project. That will probably involve buying a conversion gun.

Obviously from its purpose, this one is going to require protection. The finish will have to withstand water (possibly tinted with watercolor paints) and the Mr. Clean magic eraser at a minimum.

While I like the look and feel of a minimal finish, at this point I cannot have a furniture surface that is not water resistant. It's amazing where I find half full sippy cups at the end of the day. A power ranger sticker can also do some serious damage to a finish, especially when a little milk is also involved :rolleyes: . A jewelry box or clock would be a different story.

Jay

Jay, have you considered some of the really excellent water bourne acrylics? They will work very nicely over oil used to pop the grain (if that's something you want), have wonderful clarity and can wear like iron. They also don't have that lingering smell, so you can use them inside and outside of your entire project if that is appropriate. Jamie mentions just one choice from Target's lineup. I'm only asking this question to point out that there are alternatives that result in the same degree of "kid" friendliness...

Quote:

---

Originally Posted by Jim Becker

Jay, have you considered some of the really excellent water bourne acrylics? They will work very nicely over oil used to pop the grain (if that's something you want), have wonderful clarity and can wear like iron. They also don't have that lingering smell, so you can use them inside and outside of your entire project if that is appropriate. Jamie mentions just one choice from Target's lineup. I'm only asking this question to point out that there are alternatives that result in the same degree of "kid" friendliness...

---

Jim, that's what I've been thinking. I do plan on using some nice grain that will need poppin on this project. Have to excercise that new cutterhead after all ;) .

I do have some research to do on the actual WB product I want to use (and gun for that matter).

Jay

Quote:

---

Originally Posted by Jim Becker

While I'll likely comment further in this thread, the rule of thumb I use for choosing finishes is pretty much, "What is the least amount of "protection" I can afford to embrace while maximizing the beauty of the wood?"

---

That's exactly the thought among luthiers, at least according to what I've seen and read. You want to protect the wood but leave it free to vibrate. In other words, you want the wood to sound like wood, not finish. Yet a guitar or other instrument will be handled a lot, with the associated wear and tear. Nobody will be putting drink on it without a coaster, but the human body produces oils and moisture. I seem to remember on "Handmade Music" that they typically seal with shellac, then spray lacquer.

ProtectionYears ago my aunt Elaine bought a beautiful blue curved sofa...too protect it she had a company cover the beautiful , comfortable fabric with see through plastic. It really worked! Not only did it protect the sofa....no one sat on it since it was so uncomfortable sticky and hot....which made it last even longer!
Like Mr. Robinson said, "One word....plastic"

How can the wood breath?
In studing architecture there is a famous question that has served many well....Louis Kahn, one of Americas greatest architects asked..."What does the brick want to be?......This really simplifies the answer for me.

Quote:

---

Originally Posted by Jim Becker

Jeff...think about your witches' brew a moment. What's in it and in what proportions?

What is the impact of this? Well...you've just proven that you don't need a 3" thick slathering of plastic to "protect" your furniture from normal use...as long as general care and maintenance is taken care of, of course. You know...cleaning up spills in a reasonable amount of time, etc. In fact, I honestly think that your furniture is easier to care for since the bumps and dings may be less noticeable since the finish is a little softer and can "bounce back" rather than chip off. That's really good because it also means you can use a finish that enhances the beautify of the wood, rather than covers it up.

Your "brew" is actually quite nice in that you can vary the proportions to change the "protection" properties a little while still having an easy-to-apply finish...at a lower cost than buying some vendor's overpriced thinned down varnish/oil combination.

---

Jim, you have summed it up well. I have found that the witches brew is easily repairable too. I acidentaly put a pretty good ding in on of my finishes. I sanded out the ding and put a few more coats of witches brew on. You would never know there was a ding in it.

I do actually adjust the content of poly in the brew, to offer more or less protection, depending on the project. Also, the first coat of the brew contains more blo, to really POP the grain. After that, the BLO softens the finish, but doesn't really pop the grain, so I decrease the amount of BLO in the brew.

Jim - all good points so far, but there's another kind of protection worth mentioning. Protection from excessive expansion/contraction or checking due to big humidity changes and the ability (or lack of it) of a finish to provide a vapor barrier. Somewhere at home I have an article that did a pretty good job of comparing various finishes for this. It may have been in FWW, but was maybe 5-8 years ago. If I can lay my hands on it, I'll plug in some of the info. Maybe someone else remembers this who doesn't have a Hiroshima filing system and can find it quicker? I seem to recall shellac coming out pretty good in this respect, and penetrating oil finishes towards the bottom, with poly's somewhere in between, but without the article to refresh my memory, I could be wrong.

Because of Badger Pond and SMC, and the information I've learned has led me to appreciate and accentuate the natural beauty of wood, mostly by increasing use of BLO, wax, and sometimes shellac. And the best part is that these "tried and true" finishes are time tested and even easier to apply than the "hard" finishes.

Bob

Quote:

---

Originally Posted by Doug Shepard

Jim - all good points so far, but there's another kind of protection worth mentioning. Protection from excessive expansion/contraction or checking due to big humidity changes and the ability (or lack of it) of a finish to provide a vapor barrier. ...~snip~... I seem to recall shellac coming out pretty good in this respect, and penetrating oil finishes toward the bottom, with poly's somewhere in between, but without the article to refresh my memory, I could be wrong.

---

Shellac is one of the best moisture barriers available--and one of the easiest finishing materials to use, once you learn that it is NOT varnish and can't be applied in the same way. (Keep in mind that there is a difference between "moisture", meaning ambient moisture in the air, and "water", as in the glass of clear stuff your three-year-old just spilled on your antique table)

One thing you need to consider when worrying about the moisture barrier properties of a finish is, "where is the finish going?". In theory, if you put what is effectively a moisture barrier on only one side of a panel, you get uneven moisture penetration...and potentially a warped panel. Therefore, in a sense, on many projects that only get a finish on one side of the components, a more "imperfect moisture barrier" may be desirable. That said, when it comes to movement...it's more of a matter of using the right joinery methodologies to accommodate movement. The finish only minimally impacts movement.