how to remove harp/plate?

Posted by: berninicaco3

how to remove harp/plate? - 07/01/13 01:05 AM

Ready to remove!

We're looking at it, and how it might come out, and it looks tricky.

There in the upper right of the photo is a steel post with a threaded rod inside of it, that comes up through the plate.

Is there a way to remove that? I see 2 flat spots on the post (between soundboard and plate) and can turn it a little, before it stops. Haven't put much torque on it. Tried putting vise grips (with padding!) around the threaded portion, and it doesn't turn.

The reason being that you can see, in the lower left of the photo, that there's a nice chunk of cast iron wedged under a wooden overhang. To ease the plate laterally out from that overhang, we need that bolt out first-- or it'll stop on the bolt.

I can't see that the bolt passes through the bottom. It seems to terminate in a solid chunk of bracing wood under the case.
What's the best way to remove that bolt?
Or of course if there's another way to get the plate out without removing that bolt.





on a side note, a single screw that went from the plate into the pinblock, broke off in the pinblock. Bad metallurgy (you can see the porosity!). Worth extracting and replacing? There ARE 24 screws there, so maybe unecessary.
Posted by: Adypiano

Re: how to remove harp/plate? - 07/01/13 02:56 AM

I would cut the overhanging block out of the case, remove the frame etc. then fit a new block after re-fitting the frame (in fact, I'd wait until I'd strung the piano just in case there's an unforeseen problem that means you need to remove the frame again!).

As for the screw - yes, renew it... While you're looking for a replacement, it would be worth getting a few spares just in case another screw breaks during final assembly.
Posted by: berninicaco3

Re: how to remove harp/plate? - 07/01/13 03:07 AM

It's not overhanging by a lot. Like, 3/8 of an inch. But a critical 3/8", that combined with a bolt in the spot it is in, means it won't come out.
I do not at present have the woodworking experience or equipment to cleanly chop it off and refit a new one, let alone match the finishes correctly.

Is there really no way to remove that bolt? That really seems the simplest way!
Posted by: Olek

Re: how to remove harp/plate? - 07/01/13 06:42 AM

You will probably need to cut in the block, if the rod does not come from below.

You are lucky you do not need to do that on both sides.

There are some electric saw that allow to do that easily.

The finish will be the least of your problems if you are able to repair the rest.
Posted by: Johnkie

Re: how to remove harp/plate? - 07/01/13 07:26 AM

Unless this particular piano is a very unusual design, you should be able to release the rod from the top. The rod is there to anchor the stretcher bar so as to arrest any form of bending when the frame is under tension. The frame sits on the post and the round domed piece that's showing above the frame is the part that unscrews. Can't see clearly from the photo, but there are usually slots in the 'nut' that allow removal.
Posted by: Olek

Re: how to remove harp/plate? - 07/01/13 07:42 AM

Originally Posted By: Johnkie
Unless this particular piano is a very unusual design, you should be able to release the rod from the top. The rod is there to anchor the stretcher bar so as to arrest any form of bending when the frame is under tension. The frame sits on the post and the round domed piece that's showing above the frame is the part that unscrews. Can't see clearly from the photo, but there are usually slots in the 'nut' that allow removal.


On most of the ones I have seen the plate strut sits on a recess, that make the pulling out of the rod impossible. Or you are talking of something else.

The rods come from the top, once the plate is out, generally.
square tuning pin shape at the bottom allow to turn it with a sort of T hammer. I do not remind being able to unscrew any of them from under.
Posted by: Ed Foote

Re: how to remove harp/plate? - 07/01/13 07:59 AM

Greetings,
That is a nose bolt through the plate. They usually go into beams, but sometimes into a removable block attached to a beam. There is often enough slack in the angle, the plate will lift if on the proper tilt, with the treble end higher than the bass. (the nose bolt determines bearing pressure and flex on the plate, so you will want to know exactly how high it originally was).
If the plate won't angle out, you may need to break the joint and remove the side piece. I would use a razor cut around the pieces to keep the veneer tear off to a minimum. Sometimes the older hide joints will break free under a sharp, and I mean sharp, rap with a hammer and hardwood block.
Regards,
Posted by: David Jenson

Re: how to remove harp/plate? - 07/01/13 08:26 AM

Rebuilders look for these aggravations before tearing the thing appart or even thinking about it.

Leave the nose bolt in place as Ed instructed. Concentrate on removing the music desk block assembly, and be prepared to reproduce it if things go badly. Take a LOT of measurements.

'Fun huh?
Posted by: Ed Foote

Re: how to remove harp/plate? - 07/01/13 10:48 AM

Greetings,
One small observation; a scrap of thin, industrial, carpet placed on the key bed will allow all manner of tools to be laid there without damage to the soft wood. I try to keep something soft between my tools and any part of the piano that they a placed on.
Regards,
Posted by: berninicaco3

Re: how to remove harp/plate? - 07/01/13 10:51 AM

All 3 bolts go into the wood from the top (crawled under the piano with a flashlight), and do not appear below.

Well-- two of them I can tell just bolt into the wood.
That one in particular, if it comes through, comes through under the pedal levers. I can unscrews them and see if I find anything behind them-- but frankly I doubt it.
There's a threaded rod that came through the top and there was a nut on the end that came off without difficulty.
Beneath the plate, the threaded rod goes into a post. This post has 2 flat spots that you can wrap a crescent wrench. They both spin together about half a turn. They aren't perfectly straight, and at that point kind of rotate into the plate and get stuck on it. I could muscle them around further however.
Now, if the post bit is in fact unwinding too, well, that doesn't work, because it'll try to screw-jack the plate upwards.
If however I can break the threaded rod free of the post, and wind it out separately, I'm golden. I wonder if it's designed to work that way?

Still really, really hoping I don't need to remove that overhang. There's a single smooth piece of veneer on top that would need to be sliced in half. I can't find any visible screws, so glued is a safe bet. It's a thick joint with a lot of surface area, and I doubt it will break cleanly unless the glue were already compromised/ or had never been completely glued.
There's still a chance that there's just enough play to angle it out without removing anything, but I won't know until I've already coerced 4 stronger friends to come to my house and help me really lift it. Myself, I can only tug on one corner or another.

There's also a support block under the left hand side of the pinblock. About 1/3 of this block also appears to support the plate. It ends early, however, and the thickness of the case wood takes it from there, so I might only get a little bit of extra wiggle room by removing it.
Posted by: Gene Nelson

Re: how to remove harp/plate? - 07/01/13 11:33 AM

Removing the overhang is easy.
Get a block of hardwood that is long, lay it against the overhang and rap it with a hammer. The glue joint should break, if not then the overhang will split and you can remove the remainder with a chisel. Adding some heat with a heat gun will help.
It is just a tapered block of wood that you can remake and glue on a new one quite easily if you destroy it.
I would not move the nose bolts if I were you. For one reason they could shift position in the vertical plane making them bind in the strut - removal and reinstall of the plate then becomes more difficult - especially if you are lifting by hand. The top of the nose bolt has a shoulder that is machined to fit snug against the bottom of the plate strut while the plate is secured with the perimeter plate bolts so that the plate is nuteral - not flexed.
If you move them, be certain they are lower than when you started before reinstalling the plate.
BTW - nose bolts are not threaded rods. They have machine threads that you can see on the upper part and threads that are large and are screwed into the large wood beams under the soundboard and they have a hex surface that is accessable to a wrench for turning.
Posted by: bkw58

Re: how to remove harp/plate? - 07/01/13 11:59 AM

While harp is out of the piano, we always stored blocked up on the floor - for equal weight distribution - level, exactly as in the piano. Measured everything and made templates prior thereto.
Posted by: Olek

Re: how to remove harp/plate? - 07/01/13 01:29 PM

Before banging on them, look at the front as the veener is may be glued on it.

Should be unglued, in that case, as the veener on the top, unless the finish is black.
Posted by: berninicaco3

Re: how to remove harp/plate? - 07/02/13 10:18 PM

well! it was all much ado about nothing.

finally got 4 other strong friends all together in one place, at one time, and in daylight; we lift up... and it angles right out.

it's at the body shop now to be cleaned up and painted.

It even fit in my station wagon! awkwardly.

i'm feeling a bit silly, but hopefully you can appreciate why I was concerned enough to ask, before I even tried to lift it.
Posted by: Ed Foote

Re: how to remove harp/plate? - 07/03/13 06:28 AM

Now, about that nose bolt height...
Posted by: berninicaco3

Re: how to remove harp/plate? - 07/03/13 07:39 AM

hah, yup, which I tampered with trying to remove it, before I determined that the threaded rod was not going to unthread from the body of the nosebolt. It IS threaded in, it's not a single piece, but it was not moving. Now that I have more to grip, there's a real chance I could separate them now, but there's not much point.
I think I know where it was before, it never even made one rotation... but I wouldn't mind being more certain than 'i think' (if it's important).
Posted by: woodfab

Re: how to remove harp/plate? - 07/03/13 08:06 AM

There's no need to remove the wood. the plate comes out very easily .
When lifting you just lift the right side first until it's above the bolt then you can move to the right to clear the wooden block.

I've done it about five times so far without any problems.

This is the same Model Kimball as yours.

Posted by: berninicaco3

Re: how to remove harp/plate? - 07/04/13 04:48 PM

yup, so i discovered to my great relief!

hijacking my own thread but not worth starting a new one:

So the agraffes are the 'nut' and the string passes through them, then up and over this nickel-looking bar, then to the pins.
I haven't torn apart any other pianos in my life, so you'll understand that I only just noticed that most pianos have a round insert there, with a felt backing underneath. Like the 2 metal rods that fell out from the capo d'astro bars.

Mine had just these shallow, broader steel bars without any felt.
Should there have been felt?
Actually, should there have been felt under the capo d'astro come to think of it?


Second question.
Local tuner who stopped rebuilding pianos, has some old but uninstalled 3/0 tuning pins that he'll sell for $60-- a few bucks cheaper than $115. They are the correct length.
Now get this: I measured many times and am quite certain. Bizarrely, 1/0 tuning pins are what came out.
The wooden hole inaccurately measures to .272",
the pins measure to .275"

2/0 is .282"
3/0 is .286"

Ok to jump up to 3/0, skipping 2/0? Maybe clean up with a drill bit so it's not too tight.