Sunday, March 10, 2013

Building an Early Lacôte Guitar - Part 4

My replica
The original 1823 Lacôte has a mahogany body with black lacquered neck. The peghead, which is a later replacement, is a light colored wood with an ebony top and back plates. Although I built my model in curly maple I wanted to retain the black lacquer scheme for the neck. This made the finishing procedure a little tricky.
1823 Lacôte

You'll remember that in my last post I explained that the neck and body had to be assembled before I could complete the purfling because of the latter's delicacy. I knew these would create a problem in finishing because the guitar body, varnished with oil varnish, would share a joint with the neck that would be sprayed with black lacquer. I decided to proceed in the following manner even though the two finishes are incompatible.

When I build an instrument in curly maple I like to  give it a strong stain of roasted chicory tea. The maple for this guitar is actually English sycamore - I use the term "maple" generically - is quite light, so it needs some color, otherwise it apppears too washed out. I boil several teaspoons of chicory in a small container with about 60 milliliters of water for as long as it takes to produce the intensity of color that I want. I apply the stain in one coat with a new white shop cloth. Since the stain will raise the wood grain it is necessary to prepare for this in advance. After each sanding session I raise the grain by wiping the wood surface with a warm damp cloth. After the last sanding with #600 paper I scrape the area next to the binding with a thin steel scraper to remove any dis-coloration.
I have always varnished my instruments with oil varnish but it  will soon be impossible to buy oil based products because they are being phased out for environmental reasons. Last fall, a large old family run paint supplier closed and I was able to buy two gallons of varnish.
I find that oil varnish dries slowly on ebony, rosewood and other exotics so I seal these a with several coats of shellac.
To prepare the varnish I filter it through fine cheese cloth and add 5% thinner. Using a 1 inch wide natural bristle water color brush I cover a quarter of the back at a time using strokes across the direction of the grain and then brush out with the grain. In the photo you'll see that I masked the neck heel. Since black lacquer will be sprayed right to the edge of the varnished side rib I made sure the mask was accurate and firm.

 I sand lightly between coats with #400 paper or #1800 Micro Mesh. Heavy brush strokes or sags are removed carefully with a sanding block. Three coats will usually be enough. This is left to dry thoroughly in a cheese cloth tent. The maple dried well but even though I sealed the purfling it proved to be absorbent and needed an extra separate coat of varnish.

I had removed the masking after the last coat had dried over-night but I waited three or four days for the varnish to harden. Then I accurately masked the side ribs and protected the rest of the guitar from over-spray. There is always the risk of bleeding under the mask with sprays so I sealed the joint with clear lacquer by spraying several light coats (misting) right at the joint. If this does bleed, the clear coat will protect the under-lying varnish and make the clean-up easier. I proceeded to spray light coats of black lacquer at about 15 minute intervals until I had built up a thick enough finish.

The peghead of the original 1823 Lacôte had been replaced by one with side mounted tuners. The peghead core was capped top and back with thin plates of ebony. A maple like wood that had developed a beautiful patina  contrasted with the ebony. Chicory stain when heavily applied will collect in the pores of the wood and create an unattractive appearance on broad surfaces. But on small areas like those visible on the peghead it has an antiquing effect. I followed the same procedure in masking the appropriate areas of the peghead as I did around the neck joint. I finished the lacquering with several clear gloss coats. After allowing this to harden overnight I fitted the elegantly simple Rogers tuners and strung and tuned the guitar and then allowed the finish to harden for a week or more.

I varnished the soundboard of the guitar separately from the back and sides and the neck simply for the reason that I find it less cumbersome in handling the instrument.  While three coats of varnish were necessary to cover the back and sides I think that is too much finish on the top. Some makers would criticize me for varnishing my tops in the first place but soundboards need protection and I believe this can be achieved without inhibiting the response of the top. I thin the varnish a little more than 5% with solvent. This allows the varnish to penetrate the soft porous spruce enough that it doesn't lie on the surface. It also makes it easier to brush around the bridge and embedded frets.

The second and last coat is thinned by 2-3%. In comparison to the varnish on the back and sides, the two thinned coats creates a thin flexible film. If my hand is steady and my eye accurate, I can apply a smooth even coat in spite of the obstacles the bridge and belly frets present.  When all of the finishes have hardened I rub them out with rottenstone lubricated with mineral oil using a firm cotton ball wrapped in cheese cloth.

Pat Bianculli's original 1823 Lacôte is a beautiful, lovely sounding guitar. I enjoyed every minute that I spent building the replica.


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