Bass bridge on John Brinsmead "Spinet"

[Sandy McLeay]

Having acquired a moth-ravaged but otherwise remarkably well-preserved John Brinsmead and Sons upright (s/n 85840, which seems to put it in the 1950s), after replacing the various bits of missing felt (fortunately the hammers and backchecks were ok), I discovered that the bass bridge is cracked for the full span of the double strings for notes 19 - 30.
The style of the piano is what would be called a "spinet" in USA. I wonder if a helpful soul who is familiar with these pianos could offer some advice. I am taking my terms from Reblitz, some of which will no doubt be different from what would apply in the UK.
The bass bridge is on a shelf which is screwed to the soundboard from the back with 3 countersunk screws, with a spacer between the shelf and soundboard.
Here is what I propose to do:
Loosen the 18 single and 24 double strings which are attached to the bridge, lift them off their hitch pins and get them out of the way.
Remove the bridge pins.
Saw through the bridge logitudinally with a fine pull saw held parallel to the soundboard (to get a pattern).
Cut away the remaining part of the bridge with a router down to the level of the bottom of the existing bridge pin holes (or the bottom of the crack).
Make up a new bridge (or deep bridge cap, if you prefer) to match, from an excellent piece of hard rock maple which I have, fitting new bridge pins.
Epoxy this new bridge into place.
Re-fit the strings.

Here are my questions:
1. Could I expect to encounter screws between the shelf and the bridge, or would the two just be glued together?
2. Which way should the grain run in the new bridge? Reblitz talks of "... the grain of the main body of the bridge oriented vertically.", which I take to mean that the growth rings (and medullary rays) would be perpendicular to the soundboard . The lateral forces imposed on the bridge by the bridge pins would then be applied to the bridge in the direction in which the wood is most easily split. Is this right? The bridge pins for the double strings are spaced at about 7.5 mm. centres, thus there is not much more than 5 mm. of timber between each sucessive pair of bridge pins, not much to prevent splitting.
If the bridge were oriented with the growth rings parallel to the soundboard, the bridge would be less likely to split. Reblitz seems to imply that this orientation would cause the tone to suffer, but would this be significant?

[PianoGuy]

If the bridge were oriented with the growth rings parallel to the soundboard, the bridge would be less likely to split. Reblitz seems to imply that this orientation would cause the tone to suffer, but would this be significant?

You'd never notice the difference on one of those, Matey!

[pianotechman]

The Bridge will almost certainly be screwed from the underside of the bridge 'skirt' if it is not directly glued and screwed to the soundboard from behind, so the router cutter may be damaged. It may be best to try to remove the whole bridge from the board to effect a repair. The top surface of the capping must finish up slightly above the frame height, before you replace the strings, othewise the tone will be weak if there is no 'downbearing' on the bridge. Also remember the placing of the pins is most important to get the right amount of 'side draught' on the strings, so mark one row first from a paper pattern taken at the outset, then use a sliding bevell to mark the correct location of the pulled over pins. I would use laminated beech for the job, but rock maple should be OK if well seasoned.
Good Luck. David

[Sandy McLeay]

Pianoguy, thanks for your input. I thought there might be a bit of contempt for this "spinet", but it's appearance is nostalgically rather "Festival of Britain", the rosewood case is almost unmarked and quite pretty (if you ignore the ridiculous cabriole legs), and the Schwander action is not bad for an upright. The bass is about what one would expect, but the rest doesn't sound too bad!

David, thank you kindly for your technical advice. If I unscrewed the shelf, do you think I would be able to break it away from the soundboard along the glueline without splitting off bits of the soundboard? If so, what would be the best technique? A series of sharp blows along the edge of the glueline with a wide bluntish chisel?
I would much prefer to do this rather than messing around trying to rebuild the bridge with it still in the piano, but I didn't want to spread the damage further. I have a feeling that any attempt to weaken the glue first with heat or water would be extremely foolish!
Could you also advise if it would be wise to loosen all the strings, rather than just those passing over this bridge, before I lift these latter strings off their hitch pins?
My piece of rock maple has been in the merchant's enclosed store for many years (here in South Australia we have a very dry climate) and is very close-grained, so it should do the job.
Regards
Sandy

[PianoGuy]

Pianoguy, thanks for your input. I thought there might be a bit of contempt for this "spinet", but it's appearance is nostalgically rather "Festival of Britain", the rosewood case is almost unmarked and quite pretty (if you ignore the ridiculous cabriole legs), and the Schwander action is not bad for an upright. The bass is about what one would expect, but the rest doesn't sound too bad!

OK!

I think I know the model. It can only be classed as a 'spinet' if it has a remote operated dropped action btw!

In my experience on these small pianos it is perfectly possible to drop the tension on the bass brige without touching the strings on the main bridge.

[Sandy McLeay]

G'day once more, Pianoguy. It has a dropped action, but a bit different from either of those shown in Reblitz (second edition). I find that the action has to come out to allow practically any regulating adjustment to be made, so it's been in and out many times, and of course the drop action adds 88 x (1 centre + 1 "sticker" washer) in moth food! Actually only a very few centres needed re-bushing, fortunately.
All the best, Sandy