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Old Mason & Risch ex-player 57 inch.

I have never come across this one. Oh sure I have drilled through to the rear with the linesman’s bit or the old fashioned way; the bit and brace, but this one I am questioning the viability of repair.

Usually the pin block separates from the rear plank. In this one which is not lag bolted all the way through, the top of the rear plank has split about 2 inches below where the top board attaches and the top of the plank is migrating forward.

Eventually this will break the plate. I am not sure this one can be rescued.

Initially I was thinking to install the lag bolts and use big washers stacked up to cover over the split, but I don’t think it will prevent movement.

Next up I was thinking about a 1/4 or 3/8 inch steel plate bolted to the rear and drilled through at the top, then lag bolted, but over time the tremendous strain attached to the front by way of tension on the strings would bend the plate over.

Third, I thought of turn buckles. I took some out of an old upright that did not have back posts; it had giant
turnbuckles; the buckle is a foot long and the stems are 5/8 thick. But again would this prevent 20 tons of weight on the front side from pulling the plank along with it?

I am thinking now to drill down vertically into the top of the piano about 6-8 inches and installing the giant carriage bolts I took out of another old upright, then drilling through the front and doing the usual lag bolt and nut.

This one is remote; a 5 hour trip on two ferries so I want a solution prior to attending.

I have asked the owner to send photos so they are coming and we can have a look here….

Looking for some other suggestions. Comments and opinions please.

Sounds like an interesting one - definitely need to see some pictures...!

The obvious question; is this worth it?

Coming as soon as they arrive. Could be 24 hrs or so…..



They live on one of the remote Gulf Islands. To haul another instrument over is $600.00. which I have set as the limit for repair.
Probably get this one done for less than that.

Dan,

As discussed per PM: being a beginner, I didn't want to appear cocky by posting this in the tech forum, so I checked it by PM first. Here goes:

If one installs large carriage bolts vertically, as you suggested, these would be subjected to a horizontal shear force at the plank's split. The top half of the bolts would be pressed forward, the bottom half towards the rear. I would expect that over time, the walls of the holes would gradually be crushed by the screw threads, making the holes oval. In the top part of the plank, the rear half of the screw hole would be crushed, while in the lower part, the front part would be crushed. All of this would allow some horizontal creep at the split.

Seeing that the objective is to prevent any such horizontal creep, could one not supplement your lag bolts with some large, sturdy positioning dowels, made of hardwood or even steel rod, e.g. 3/4"? In this way, the lag bolts (screws) would serve mostly to keep the split closed, but the thick dowels would do the actual work of preventing the top half of the split plank from moving forward. The more closely the split is kept closed, the better the dowels can withstand the shear force, without bending or breaking.

And seeing that the dowels don't have any screw threads, there is a snug fit between them and the pinblock material, which prevents hole elongation.

I.e., my suggestion is, to release string tension completely, let the top part of the plank spring back into its original place (or clamp it into place), then drill holes from the top, alternating them for lag bolts and sturdy dowels. The lag bolts would only thread into the lower part of the plank, so that they pull the top part down, to close the spit.

If one angles the holes for the dowels a few degrees towards the back, i.e. the top of the dowel slightly towards the rear of the piano, then any shear force would actually assist in pulling the split closed.

Then, when the two parts of the split plank are re-connected vertically, insert horizontal lag bolts all the way through, possibly even using a steel apron across the back, as you suggested.

I hope this post can make a positive contribution.

Mark

Hi Mark,

I was thinking about the shear force being applied and like the idea of dowels down into the plank. Of course glue would be forced into the split before cranking it closed; that was my idea of using the large carriage bolts. Then once the glue dries drill for the dowels or steel rods.

I am not sure this one can be saved. I would like to see photos of how far apart the split is, and then go from there. Lots of good observations and ideas in your posting, thanks.

Here are photos of the rear plank and the horizontal split. The problem with drilling through from the front is the bolts will locate above this crack line.

photo set

I am not certain whether this indicates a problem with the pin block, or if there is a plank at the top of the block which has moved with changes in humidity. If it is the latter, it is purely cosmetic and will not affect the functioning of the piano. Or there could be a plank behind the block which has warped a bit, and that would also be cosmetic.

What matters is on the other side of the framing: The block itself, the plate, the soundboard and bridges. Is the plate actually bending? Is there a loss of bearing? Is it impossible to tune the piano? If there are no symptoms other than what you see, I would just ignore it until it becomes impossible to ignore. It looks like the piano has survived at least 70 years with this problem, so things are not happening quickly.

I added some more photos to the album that show the split better. I would agree that this has been there for some time. Definitely the rear plank has failed but whether it is going to effect the tuning or structure into the future is the unknown.

Probably end up observing this one through a couple of seasonal changes to measure the movement if there is any.

I couldn't tell from the photos if there is any separation of the sides. It looks to me like the part of the piano back at the very top was subject to some sort of shear stress perpendicular to the back. Moving damage?

I wonder if it would affect the function and stability at all?

I don't suppose you have any pictures of the inside of this thing.

From what I see in the pictures you did post it looks more like extreme moisture (or the lack of it) damage than stress damage.

I'd like to see the inside.

ddf

Hi Ed,

The sides are intact with no separations visible. I also wondered if the piano had tumbled off a dolly on the back side and connected with the ground at the top backside. That scenario would create the shear force mentioned for sure.

Hi Del,

I don’t have any photos of the inside top area of the instrument. I have sent a message asking for more photos. Will post when received. The humidity factor is a good observation as this instrument is located on one of the Gulf Islands.

I just received some photos of the interior and posted them to the album.

Looks like the top board may have to come off. Doesn't look like the plate has moved yet.

photo set

It looks like there are two boards that have warped. One is at the top back of the piano, horizontal behind the pin block. It has shrunk. A second is vertical at the back of the piano under the first board. The back is veneered over those two boards. The first board has shrunk inward. The second board has warped outward, particularly on the bass side of the piano.

I think it is cosmetic, rather than structural. The tearing of the veneer makes it look worse than it is.

Hello Dan, back of pianos sometime bow that way, the plank that cracked in reaction is not structural in my opinion.
Now if the rows of pins have lowered in the plate bushing holes, the pinblock is really turning.

Yopu have yet the screws location, possibly install longer screws if you want to be reassured, but the whole pinblock section seem to be in one piece there.

the pinblock can only pivot on the plate lip. if you take out a front screw you may see if there is space and how much.

It happens that the pinblock does not touch well the plate and that everything is secured only by the bushings in some locations (bowed upper plate)

SO even if you see some space it is not absolutely the sign of a defect.

That external small plank often is damaged when the instruments are in unfair conditions. If the sides of the pînblock are still glued to the sides of the piano I believe there is no big trouble.

Thanks for the additional comments Isaac and BDB. I will have to check all of this out when I am there in a couple of weeks.