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Zahid Naqvi
04-07-2005, 4:39 PM
First of all I would suggest changing the name of the forum from "project finishing" to simply "Finishing", the project part is a given.

Here's the stupid question. Over the last couple of years or so of my woodworking adventures I have run into several brew recipes, and am guilty of using some. The question is what benefit do these provide over the ingredients used in isolation. Ease of use is the only thing that comes to mind.

To give an example a very common recipe is to use; 1/3 any oil (BLO, Tung), 1/3 thinner (naphtha, mineral spirits) and 1/3 poly. With poly included in the mix and if I were to apply two coats of such a mix, what's the point of applying oil on top of poly (which is 1/3 of the first application). Why don't we apply an oil, wait a couple days and then apply 2 to 3 coats of poly as needed.

Jim Becker
04-07-2005, 7:13 PM
The "brews" simply alter the effect you get--a "custom" finish, if you will. The oil/thinner/varnish mixture (so-called "Danish oil") results in a "softer" finish, both in look and physical properties. It still cures which is why you can put multiple coats on, although it cures slower due to the increased oil component. It buffs up beautifully, too, and that's one of the reasons so many turners use it. (Either their own or commercial) And making your own wiping varnish by thinning "regular" varnish yourself 50/50 can save you money. Why pay the vendor to sell you a thinner mixture for more money?? ;) And you can vary the formula to suit your preferences, including naphtha for the thinner for a quicker "dry" between coats, etc. (Not always a good idea, to my understanding, depending on application method)

Also, the effect you will get with applying oil first and then coating with varnish is different in look many times than the one you get with using the mixture over multiple coats.

Frankly, for most furniture projects with the species I use the most (cherry or walnut) I prefer one or two applications of BLO, a seal coat of shellac (usually garnet) and then an appropriate clear coat for the needs of the piece. That's the look I like the best.
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Please notice that I used the term "varnish" above rather than "poly". Polyurethane varnish is just one kind of varnish. (The one that the marketing folks cram down the store's throats--something my friend Steve Mickley terms "polyoneverything") There are also alkyd-based varnishes (Pratt and Lambert #38 is an example) and phenolic-based varnishes. (Waterlox is an example) The latter two types usually look much better on projects as they offer a lot of clarity and are all hard, durable finishes. Poly has a slight edge on heat resistance and because it's softer and formulated for better abrasion resistance, it's a good choice for that kitchen table top. The others will look better on most other furniture, however.

The type of oil used will also affect the look. The products made with soya oils (P&K #38, McClosky Heirloom) are much lighter in color than those made with BLO or Tung as the oil base. (All those oils become polymerized when the varnish is "cooked" at the factory and are no longer what they were in their raw state, however). The impact of this is in the degree that they tint the wood amber. If you want a lighter result, use a soya oil product. That goes for brushed straight out of the can or used in a "home brew"...

Jeff Sudmeier
04-08-2005, 8:31 AM
I have tried using Blo Separately and then a Wiping varnish of my making. The reason that I prefer the Brew is that it is so easy! You can do all of the steps at once. It goes on SUPER thin, so you don't have near the sanding between coats. (Most of the time, none).

You do get a slightly different look when you use a brew, rather than the components of the brew alone. For now the brew is my favorite finish, but I have only used a few.

Jim Becker
04-08-2005, 8:41 AM
Jeff brings up a good point about sanding. Do remember that if you use a polyurethane varnish in your "brew", you must sand lightly between coats if you let them cure for more than a few hours. If you do not, you will not get a good bond to the previous layer...the scratches are necessary to get "bite". This is not an issue for the other varnish formulas, only poly.

Zahid Naqvi
04-08-2005, 9:25 AM
Jim,
That was really good information, thanks.

Bob Winkler
04-08-2005, 10:05 AM
Thanks for the question Zahid. I recently used the "brew"on a maple/cherry bookcase I've been building. I loved the look of the first coat, which popped the maple curl very well.

But while applying the second coat, I questioned the integrity of applying more "brew". My worry was the oil component on top of the varnish component. It didn't "feel" right when applying it. So I stopped and applied further coats of just homemade wipe-on varnish (thinned normal varnish). That felt "right" and I liked the overall look.

Maybe I'm thinking and "feeling" too much ;)

Bob

Zahid Naqvi
04-08-2005, 2:12 PM
Thanks for the question Zahid. I recently used the "brew"on a maple/cherry bookcase I've been building. I loved the look of the first coat, which popped the maple curl very well.

But while applying the second coat, I questioned the integrity of applying more "brew". My worry was the oil component on top of the varnish component. It didn't "feel" right when applying it. So I stopped and applied further coats of just homemade wipe-on varnish (thinned normal varnish). That felt "right" and I liked the overall look.

Maybe I'm thinking and "feeling" too much ;)

Bob

I agree, because if you really think about it once the poly in the first coat dries it should make a non-permeable coat. But I have tried the brew on a box I made late last year, and if I remember correctly, I applied three coats. The first penetrated quite a bit, but subsequent coats dried very slowly and no matter how thin I applied them I still had to wipe off excess. But the finished result was real nice in that it did not have the glassy finish of a poly and felt like an oil only finish, was real smooth but not very shiny.

Jim, Dennis and some of the others who have recommended a brew are very experienced WW'ers so there must be some chemical logic to the method which would explain the success, I just don't have it figured out yet.

Dennis Peacock
04-08-2005, 5:04 PM
Z,

I use a brew because it provides the type of finish that both looks and feels good to the eyes and hands. Don't get me wrong here, I have used straight oil on bare wood, then topcoat with dewaxed shellac and then applied a shellac finish. I've also used a lot of lacquer which really does well on various piece of furniture. My favorite finishes are Lacquer and Shellac. My next favorite finish (especially for turnings) is a brew of sorts. Sometimes we just need to experiment with finishes so we can obtain more knowledge about finishes, how they are applied, how they act when applied, how they look to us, how they feel to the hand as well as what we can and cannot do with finishes.

The finishing aspect of woodworking is a whole 'nother science and there are as many ways to finish a piece as there are woodworkers in the world. Some people like Oil and Wax finishes while others like Epoxy finishes (the two extreme's in my book). Each person has their way of finishing and choice of favorite finish material. But....I like to experiment with all of them. :D