Tuesday, May 12, 2009

French Polish

Some time ago I made a business decision that I think many more furniture makers should consider; to become friendlier to ourselves and to the environment.

One of the greatest leaps forward in this department is considering what material gets used as a finish on the furniture.

I used to use a pre-catalyzed lacquer that went on smooth and looked reasonably good (about as good as any mass produced furniture with a sprayed finish) however the ease in application was overshadowed by the dangers in using highly explosive, highly toxic material with a huge amount of VOC’s that off gas even months after the furniture is completed and delivered to the client.

I started searching for a finish to replace lacquer in my shop. It had to fill two major rolls;

- It had to be non (or nearly non) toxic

- It had to look great

I decided to adopt shellac as a finish, and not just ordinary shellac, but shellac applied with a technique called ‘French Polishing’.

This is the undisputed king of finishes, and has been for several centuries.

There are countless texts describing the various ways to apply a good French polish finish, but one thing that is true of all of them is the ingredients; Shellac flakes, Alcohol, and Oil

The shellac can be purchased easily at most well equipped finish suppliers, the oil, (olive, or in this case mineral oil) can be purchased at the local pharmacy, but the alcohol is a different story.

Because in Canada alcohol is heavily taxed, manufactures of grain alcohol must add a toxic element to the alcohol to sell it as non-potable alcohol, thus eliminating the need to pay taxes on it, and eliminating the possibility of people consuming it.

The most common form of toxin added in Canada is Methanol, which if ingested causes blindness and potentially death. It also has a nasty habit of migrating through protective gloved and passing through the skin, making it difficult to handle. One other nasty habit of it is that it also passes right through gas masks and gets absorbed by the body through the lungs.

I set out to find a product that was denatured with chemicals other than methanol, and I did find it after some serious searching.

So finally, on with the finish...

The one point that defers between the Italian, English and North American techniques of French polishing, and the TRUE French polish is that only in the true French polish is oil applied to the bare wood before any shellac.

I start by using a cheese cloth and liberally apply mineral oil the surfaces to be finished.

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I then wipe the surface immediately with paper towel to remove any oil not absorbed by the wood.

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I then take the ‘pad’ and add some 2lb. Cut shellac and some alcohol and begin by rubbing the pad in small circular motions all over the surface. Once the pad begins to dry out I add more shellac and more alcohol (always more alcohol than shellac)

When the rubber begins to drag on the surface I place a drop of mineral oil on the surface and use it to lubricate the pad.

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All the while I am adding just a light dusting of pumice (4F grade) to cut the finish and shine the surface.

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I keep this technique going for at least two days, and when I think the shellac is built up enough I slowly start to reduce the amount of shellac I use when recharging the rubber.

I also begin to scale back on the pumice and eventually I switch to a new pad with no pumice on it, and begin to use rottenstone.

For the final polish I use the tiniest drop of alcohol and polish the surface to a very high gloss finish using up every last bit of alcohol in the pad while at the same time removing every last trace of mineral oil.

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If all goes as planned I'm left with a very high gloss flawless finish.

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Now if I don’t want to have a super high-gloss finish on the furniture, I will rub out the gloss with 0000 steel wool impregnated with 4F pumice to leave a pleasing satin finish.

Thursday, March 5, 2009

The wonder tool

One of the most used tools in my shop is one that costs only a few dollars, but lasts virtually forever, is easy to sharpen and easy to use. It produces a surface that is flawless, out performs sand paper every time, and requires no electricity.

Yup, it’s a card scraper.



It is sharpened to a square edge, and then rolled over to produce a burr. It takes a few minutes to dress a brand new one, and occasionally needs to be redressed to restore a nice edge, but it takes just seconds to repair an edge that is becoming dull.
One thing to watch for is that a card scraper should never produce dust. The shavings should look like (and feel like) the shavings you’d expect out of the finest smoothing plane.



This little card is used as a final touch on boards that are almost ready for finish.
Its final and most impressive attribute is that no matter what type of figured wood it’s used on, it will not tear out the grain.

All this for just a few dollars.

Saturday, February 7, 2009

Hand Cut Nails

Occasionally I get the opportunity to use materials that don’t get a whole lot of use in the shop. For instance it's not often I get to use true hand made cut nails!

Cut nails have been around for centuries, and are still very useful for furniture that requires a fastener in a visible area, or just as decoration on an otherwise somewhat plain surface.

In hard maple it's advisable to pre-drill before driving the nail.

These nails have more of a blade shaped tip than a point, and it's important to orient the nail so the blade slices the fibers of the wood rather than forcing them apart (and possibly splitting the wood).

Once I'm happy with the placement of all the nails, I simply hammer them home.