Case Study

Case

Length: 235 cm Width: 114.3 cm Depth: 32.2 cm

Cabinet wood: Book-matched walnut veneer

 

Case Description: Rounded case cheeks, angled tail, three column legs, decorated with three rings, a stretcher connects the two front legs and also supports the pedal lyre. The case is simple, elegant and without ormolu decoration.

 

Case finish: French polish using Graf's unique spirit-varnish formula. The cabinet was originally stained with a dark reddish brown "dragon's blood" stain. The stain has been bleached out in some areas by exposure to sunlight.

 

Pedals: Five pedals and maple trap work levers operate, from left to right: 1.keyboard shift, 2. bassoon, 3. dampers, 4. moderator, and 5. janissary. The janissary pedal includes the soundboard drum, tambourine (missing) and bells.

 

Damper system: Viennese Stiefeldämpfung

 

Damper Range: The top 11 dampers have been deactivated from g''' to f''''. The bass dampers 1-11 have lead weights; 1-47 dampers glued to red beech blocks, the rest are of linden wood. Dampers 1-37a have double leather-covered wooden wedges; the treble dampers are made of Karsch.

 

Stringing: The instrument has triple-strung unisons throughout the range without wound bass strings. Unisons 1-10 are missing the original brass wire. Unisons 11-73 are triple strung with high-carbon iron wire.

 

Graf's original string gauges are marked on the bridge as follows:
1 FF 7/0 (Brass wire starts here)
2 FF# 7/0/2
3 GG 6/0
5 AA 6/0/2
8 C 5/0
11 D# 5/0/2 (Iron wire starts here)
14 F#
4/0
19 B 4/0/2
25/f 3/0
32 c' 3/0/2
The mute string over the belly bar brace is number 37A
38 f#' 2/0
45 c#'' 2/0/2
52 g#'' 0
59 d#''' 0/2
65 a''' 1
70 d'''' 1 1/2

 

Provenance: The earliest, documented location is the village of St. Agata NE of Florence.

 

Owner's Name, Address and Phone: Brooke Allen

 

History of the Instrument: The early history of the instrument is unknown

 

Bibliography: The instrument is described in: Deborah Wythe. Conrad Graf (1782-1851) Imperial & Royal Court Fortepiano Maker in Vienna, Vol. 2, pp. 496-97.

{tab=Tech Data}

Action Type: Viennese capsule action.
Keyboard range: FF-f'''' (six octaves)
naturals: ivory
sharps: ebony veneer over stained hardwood blocks.
key fronts: ivory
key bushings: Front rail key mortises bushed with brown leather. Balance rail buttons unbushed.
Hammers: Pointed hammerhead moldings covered with 3- to 4-ply brown leather. The hammers are graduated in size. Pear-wood hammer shanks; brass capsules inserted in hardwood blocks. Pear-wood prell levers with spring guides and brass springs. Original beak leather with sämmisches gegerbtes mountain-goat leather beaks.

Keyboard and key frame: Spruce key levers with lead weights throughout; 2-part ivory covers for the naturals. Three-rail key frame with the key-stop rail above the back rail.

 

Inspection of the Instrument in Florence, Italy on: March 15, 2007

 

The piano is still in original condition, containing most original parts. Four oversize tuning pins were used when broken iron strings were replaced at some point. Rodents have damaged some of the original treble hammers. Hammers from the bass were moved to the treble to fill in gaps in the scale.

 

Woodworm, rodent and moth damage: There is extensive moth, woodworm and rodent damage. Moths have eaten virtually all the action cloth. The following parts need to be remade and replaced: hammer rest felts across the keyboard; laminated key-stop felt; laminated prell-rail felt; the moderator felt; back-rail felt; balance rail felt punchings; all the felt bumpers in the pedal trap work; the string-web; the under-string felt on the hitch-pin rail; the rest felts for the damper rack; the felt pads under the music desk; the pedal rest pads. Moderate woodworm damage is evident throughout the instrument. There is reason to believe that the woodworm infestation is still active. Rodents have eaten channels between the keys. Rodent droppings are evident in the key-bed and on the soundboard and hitch-pin rail. Rodents have found building materials for their nests by eating away some of the action parts. Some of the red-beech hammer moldings have been completely eaten away by rodents. As the instrument has a closed bottom, it was impossible to see possible woodworm damage under the soundboard.

 

Cabinet: The cabinet has its original spirit-varnish finish. It is very dirty and will require careful cleaning and repolishing. There is moderate woodworm damage in the pinblock, top, yoke, sides, legs and pedals. The soundboard does not appear to be infested. The third section of the top is broken at the left hinge. There is some broken and loose veneer, but the cabinet is basically in good, original condition.

 

Legs: There are three legs. The two front legs fit into mortises in the pedal stretcher. The castors fitted to the bottom leg blocks are not original. The threaded wooden dowels that attach the legs to the cabinet are in excellent condition. The legs are dirty and will require careful cleaning.

 

Music Desk: The original two-piece music desk is still extant and in good condition. It slides back and forth across the yoke, guided by two pins that may not be original. The music desk is not attached to the cabinet.

 

Prop Stick: The original prop stick is attached to the underside of the top. It is in excellent condition.

 

Pedals: Five, original brass-covered iron pedals are attached to the stretcher. The pedal pins for the damper and shift pedals are worn and the pedals wobble. All five original pedal rods are still extant.

 

Frame: The tail of the instrument has twisted and lifted slightly, but there is no sign of breaking or damage to the case and frame joints.

 

The Action: Rodents have caused some minor damage to the key levers. The front of the action frame has bad glue joints on both the treble and bass ends. The key pins are dirty and corroded. The hammers are out of order with some large bass hammers serving as replacements in the treble. Some treble hammers have been completely destroyed by rodents. There appear to be five missing treble hammers. Because the hammers are out of order, it was not possible to do a complete inventory of missing hammers and hammer shanks. Some new pear wood hammer shanks and red beech hammer moldings will needed to replace missing parts. Six original broken shanks, four fragments of treble hammers, one bass hammer, one intermediate hammer and some fragments of brass wire were hand carried to the United States in a plastic box.

 

Conditions of the Dampers and the Damper Rack: The damper rack appears to be in good condition. The parchment and leather guide loops are all intact. There are three broken damper-block stems and one missing damper cap. The leather and Karsch damper material is original. The Karsch dampers have some moth damage. The original leather dampers in the bass and treble sections appear to be in good condition

 

Condition of the damper guide loops: good

 

Pedals and pedal trap work: All five pedals and pedal rods are still extant. There is wear on the shift and damper pedals and the pedals wobble slightly on the hinges. All the brass is corroded and needs to be cleaned and polished.

 

Condition of the moderator and moderator batten: The batten and trap work are extant. The cloth tabs and the moderator have been completely eaten away by moths.

 

Condition of the soundboard: Spruce soundboard with the grain running parallel to the spine. There is a small crack in the treble. The soundboard is dirty and stained by some minor spills. As is typical of Graf instruments, there is no finish on the soundboard.

 

Bottom board: The bottom is completely closed with a spruce bottom-board.

 

Bridges: The strings are supported by a single bridge: 2.0 cm high by 1.9 cm wide, running straight to the tail. There are front and back bridge pins and the bridge is notched in the front.

 

Key wobble: Very little

 

Back rail felt: Destroyed by moths

 

Balance rail felt punching: Destroyed by moths

 

Front rail punchings: none

 

Condition of the ivories: All the original ivory is still extant. Some ivory is loose and needs to be re-glued. In the middle of the keyboard the ivory is scalloped indicating that the instrument was frequently played. The ivory is dirty, stained from spills and in need of thorough cleaning.

 

Condition of the ebonies: Three ebonies are missing their original ebony veneer. Much of the ebony veneer needs to be re-glued.

 

Bridges: Single bridge: 2.0 cm h x 1.9 cm w. running straight to the tail. Front and back bridge pins, front notches in the bridge

 

Hitch-Pin Rail: The hitch-pin rail is in excellent original condition. It does not appear to have pulled forward in the treble.

 

Stringing: All of the brass bass strings are broken, but there are coils of wire around the tuning pins from which the wire diameters can be measured. Most of the iron wire is still original, very dirty and corroded. The understring felt has been eaten away by moths as has the string web. All of the wire gauge sizes are written on the bridge. All but four of the original tuning pins are still extant.

 

Tuning pins: The tuning pins, with oblong heads, are not pierced with holes for stringing. The wire coils are attached to the tuning pins using the pressure-wrap system. Four or five of the tuning pins are replacements, pierced with holes and with oblong heads. Each of these pins is attached to a non-original string.

 

Pin block: The original pin block is bowed upward slightly, but considerably less than usual. The nut bridge which guides the strings and marks off their speaking length is original and in excellent condition. There is a single, iron belly rail brace in the center of the keyboard.

Restoration

The Graf fortepiano arrived in the restoration workshop in the condition already described in detail in the report written by Ed Swenson. The case:

I began restoration of the case by addressing the woodworm damage. The lid and front lid had suffered the most damage. I cleaned the woodworm holes with compressed air to remove wood powder and woodworm detritus, including eggs. I then injected woodworm-specific poison into the same holes. Finally I closed the holes with beeswax.

 

During the entire time the Graf was in my shop I never saw any evidence of the insects (Anobio puntatum).

 

I reglued all loose veneer using animal hide glue, prepared according to my recipe in the traditional style.

 

I conserved the original finish and repolished it using my recipe, in the traditional style, based on shellac (free of wax) in pure alcohol (200 proof) with the addition of other essences. The portion of the case which had suffered serious woodworm damage I filled with Gesso di Bologna and colored earth, after which I lightly sanded it and stained with Dragon's Blood (my recipe), completing the process with a repolishing using the same shellac recipe.

 

I returned all screws and hinges to their precise original location.

 

The soundboard: The soundboard had two small cracks in the treble area.

 

I removed all the strings and put them in numbered order. Then I cleaned the soundboard and bridge, and removed all the understring felt. Everything was saved and labeled. I filled the soundboard cracks with red spruce from the Val di Fiemme, well-seasoned, using no glue. I put in new understring felt, in the yellow color typical of Graf, from Vienna (probably from the same manufacturer that provided felt to Graf).

 

The wrest plank and tuning pins:

 

The wrest plank was in good condition, free of cracks. Most of the tuning pins were original. I removed them, organizing them in order to be able to return them to their original holes. The bass tuning pins were 6.2mm in diameter; the treble, 5.7mm.

 

To replace the 19 tuning pins which were not original, I made replacements by forging and tempering as per the originals, using iron CA 40 (40% carbon).

Parts

The Strings

For the most part, the strings were original. I reproduced the original stringing scale using the original numerical notations on the bridge. I reproduced the original coiling, using 8 or 9 turns. I used English wire (Malcolm Rose), brass and English iron type C in the following sequence:

Brass: 1.07; 1.00; 0.95; 0.90; 0.85, strings #1 through #13.

 

English iron: 0.90; 0.85; 0.80; 0.75; 0.70; 0.65; 0.60, strings #14 through #74.

 

All notes are trichords, individually looped. The loops were in the French style. Beginning with string #46, the loops became progressively smaller.

 

I stabilized the tuning at 425Hz.

The dampers:
I was able to preserve the first 37 dampers which were constructed of wooden wedges covered with lambskin. In some of these dampers I inserted a thin strip of lambskin, without glue, to improve the damping.

 

The remainder of the dampers were felt. I removed and save the originals, and replaced them with a very soft French felt.

 

I repaired some parts of the mechanism by the addition of small new parts of pear wood. Some of the damper caps, of red leather, needed to be replaced; I used new red calfskin. The interior mechanism needs only to be cleaned.

 

The keyboard:
I carefully cleaned and buffed the keytops, which were ivory. I cleaned and polished the key pins. I welded the one capsel that was broken. The extreme bass and treble keysticks were impregnated and stained with mouse urine. I bleached these parts with a light solution of 100% peroxide mixed with water. The sharps were capped with ebony; three of these needed recovering, for which I used new African ebony. The balance punchings were completely ruined. I repaced them with new ones of the same thickness (1.00mm), shape (square), and color (white). The key stop rail felt—in this action design, attached to the underside of a rail at the rear of the keys—was completely ruined. I replaced it with new material of the same thickness and construction: a strip of parchment and three strips of 1.00mm bushing cloth, yellow sandwiched with white, sewed together. I glued the parchment to the rail with animal hide glue. I replaced the hammer rail cloth as well, using the same three cloth layers as the back rail cloth. The damper spring leathers were in good condition. Only two needed to be recovered; I used creamy yellow goatskin. The back rail cloth was destroyed except for a few fragments. I replaced it with new material using the following construction: three internal strips without glue, and one wider exterior strip glued only in front and back.

 

The pedals:
I put the pedals into perfect condition. I recovered the bassoon stop with parchment—nothing remained of the original parchment. I adjusted the una corda pedal so that it worked smoothly. I recovered the moderator with new yellow cloth; again, nothing remained of the original. The Janissary stop moves three registers: The bells now work perfectly. The cymbals were missing; I rebuilt them and they now work perfectly.

The bass drum stop was not working. The mechanism was inaccessible without destroying the case bottom, so I left it as is. According to previous reports, the bass drum was functional; I presume that the mechanism is intact in the case, but that the mallet felt has been destroyed by insects.

 

Action

Some of the hammers had been moved from the extremes to the center to replace the broken ones. I reordered the hammers back to the original pattern, and made new hammers and shanks as necessary using well-seasoned maple of the same density as the original. I chose to use maple rather than pear because the maple was well-seasoned and stable. I refrained from staining the maple to match the pear to make the new pieces easy to see.

I replaced the beak leathers as necessary with elkskin. Four of the prell parchments were broken; I replaced these without damage to the remaining, intact ones. I replaced the regulating cloths with cloths of equal thickness (1.00mm) and regulated them by inserting paper shims of varying thicknesses as necessary. I replaced the prell cloths with the same material, using the same construction as that for the key end stop rail—parchment and three layers of cloth, yellow sandwiched between white. I replaced all the prell spring leathers, using elkskin. (I preserved the originals.) I replaced prell springs as necessary using raw brass wire of diameter 0.70 and 0.60mm.

The hammer leather was brown calfskin, tanned with oil, tapered from 1.00mm in the center to the thin edge where the calfskin was glued to the hammer. I replaced some of these as necessary. I replaced the backcheck leather with brown calfskin as per the original. The brass clip for the backcheck rail was missing; I replaced it with the same material.

{tab=Considerations}

I used only animal hide glue (recipe) for all gluing operations.
For the French polish I used traditional recipes and techniques transmitted through generations of work on historical instruments.
Any cloth, felt, wood, leather, metal, etc. not kept in the piano was saved and labeled.
To replace leather I always used leather from the same animal, tanned with natural methods.
Any action parts, case parts, etc., which had to be removed in the process of restoration I returned to their identical original location.
I examined all original materials in order to be able to replace them with as exact a match as possible. Some interventions were necessary because of musical exigencies.

Because of this, this restoration cannot be considered 100% conservative. However, all interventions have been thoroughly documented and are completely reversible.