I'm told that the pre-1920s Bechstein grands (all models) had very thin plates and are prone to cracking. Is this true???

I don't know about thin plates, but it is true that they are prone to a crack just in front of the pin block, right up in the treble, on the bar parallel with the front.
Don't discount them on this though. Check the piano in question. They are fine instruments.

Greetings,
I have been told it is more a problem of brittleness in the iron than thickness of the plate. However, I am quite leary of taking on a Bechstein that needs the plate removed.
regards,

Just took the plate out of a 1895 6'6" Bechstein grand.

Small crack in one strut, treble side, just after the pin block.
Rest of the plate is fine. We will repair the plate.

We are thinking of modifying the design a little to support the plate. Some thoughts, no decisions on how yet.

I have heard comments reflecting Ed's post. Something to do with the metal itself.
The Original scale on this piano comes in at a little over 42,000 pounds tension.

At some point, I can post photo's if anyone is interested. What would you like to see in the plate?

It is a nice piano.

How about the crack in the plate Larry? Are you repairing using a stick weld? Maybe some photos of the process...

I've seen 3 such plates with these cracks. All open face blocks.

I guess it's very common.

There was a great PTG Journal article a few years back regarding the repairs of these.

Dan,

I have brazed three plates in the past (Hired welder, that is). The trick there was to heat a large area and after the repair was made, cool the metal very slowly. Dissimilar metals shrink at different rates when they cool. Cool too fast and ... crack.

After that, I look for a way to improve the plate support to help prevent further cracks.

Those three plates remain un-cracked.

I am hiring a plate repair guy from Worcester MA. He is well known for metal repair. I'll get the specifics on him and re post.

And .. yes, I'll take pictures of that repair process and post them.

Rod,
When were the articles or your plate repairs? I'd like to look them up.
Do you still have pictures you could post?

Thanks Larry,

It is a subject of interest to me because in a former life (1970’s) I was a welder/fitter, mostly 6011 dirty rods, aluminum electric wire feed, and some 7014 (jet rod).

Back then doing cast welding was really tricky using a stick, I tried a couple of cast iron manifolds out of older vehicles with some success, but the process was really slow like you have stated, the metal could not get too warm or there could be contraction problems. And of course when you are doing arc welds the heat is tremendous; it can be thousands of degrees at the point of arc…..

I know from talking to a welder who does aluminum castings (with a stick now), that a lot of the processes for casted metal have changed and improved, along with the improvements in the sticks and brazing materials….. so I guess I am being a little selfish, I wanted to see how much the processes have changed over the years.

Might be a source of interest for some other members too hopefully……to see a plate repaired…

Larry,

I flipped through 4 years of Journals hoping I'd see a cover that points to the article. No Luck. If I find some time I will flip through the pages and see if i can find it. It could be a article I read 5 years ago.

I have no pictures of any repairs like that.

Darrell Fandrich has a guy close to him that did an amazing job on a plate using a titanium rod. It looks perfect and has had no problems since it was done a few years back.

Darrell has explained the process to me a few times but I could never explain it like he can.

I'll be seeing Darrell on Monday at out meeting and I'll ask him if he remember the Journal article I first mentioned.

Thanks Rod and Dan,

The Bechstein plate will get repaired. I can do it anytime and I have time to plan it. It would be nice to hear about other experiences.

Dan, you know the challenges first hand. It is tricky business!

Rod, It would be nice to hear about Darrell's thoughts if you don't mind giving us a run down here.

Thanks,
Larry

Well I poured myself a cup of coffee and started flipping pages.
Because my brain is what it is I was not sure when I saw the article. It seemed like just yesterday I read it.

Well is was not.
It was March 1997.

But even better, as I flipped I found an Journal that was almost
exclusively about plate welding and repairs. Nov 2000.

The only problem now for me is I found around 14 articles I want to review from the past 12 years.

And who said membership in the PTG is not worth it!!!!!

I've got journals going back to July 1968 in that one an interesting story about Posey Sitka soundboards saying at that time 70% of all the pianos made in the U.S. use their boards.
Around 140,000 boards each year and employing 125 workers!!!!!!

I bet they wish they had that buisness volume today.

Coming to this late...
When I lived in UK saw a bunch of these grands with cracked plates...but the larger..I think 7.6" didn;t have the issue.
I had one fixed by a local engineer by means of a key....he drilled a series of holes at right angles to the break..plate out of course....very close together...and a key which mirrored this pattern was either welded or just plain driven into the key holes and the crack closed up...seemed to hold and with the usual jiggery pokery I smoothed off the surface and it looked good as new...never did break again (as far as I know).
Now this was a fair amount of time ago and I may be delusional, but that's how I remember it :-)