Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum original soundboard recrowning

Thank you gentleman: DBD. Woodfab. And Larry Buck of Lowell Ma. for your encouragement, to ingnore some of the silliness. I guess I am about fifty years to late. I wish I could go back to 1957 when this all started. And save all the fine pianos that went the standard cut out and replacement rout.It is a shame. We will soon have some pictures for viewing. If this method we have invented here, had been adopted then, it might now be standard practice.Pianos done this way would be more valuable than new. Like some other vintage musical instruments. I wonder where this notion of the deteriation of internal cells came from,It's like some computer virus, only of the human mind. If someone could present some scientific evidence, then that would be proof of this condition. This soundboard thing we do is not fantasy we have the proof it is routine here.They are in homes,except for two, one is in the Iron Horse music hall in Northampton Ma.for 22 years now with no problems yet.There is an Steinway A-3 1920 in Florida, I am trying to find the technition who takes care of it and ask for his opinion, and see if he will join in this forum, This one was done in 1994. I found out the owner died 8 weeks ago. Bummer. My second question for you all is going to be. What exactly is the finish on these SB's And dont bother to say shellac. I myself feel it was Sandrac,Dammar, or Mastic, varnish, I will post this question soon. please wait until then.

Are there high quality recordings (not nesessarily professional - I know a hobbyist who does great work) of your re-crowned pianos? If we could hear them it might help us judge the vaildity of your efforts.

Yes, I know the problems with making an assessment this way, but it would be a something to consider. If a picture is worth a thousand words, surely a recording is worth that many (probably many more judging by how many have already been written here).

Mr. Blaisboard,

I think what you are doing is great. I would love to see pictures of your process and more detailed information. All the best.

I find this process interesting, but one question keeps standing out in my mind:

How does the process take a collapsed board, with no crown, and has lost its support, and simply by reassembling, end up with a board that has crown and adequate support, without adding any new material? The only difference I can see between the original and recrowned board is that cracks have been shimmed and glued, and not even with new wood, but with wood from other collapsed boards. Where is the additional crown, and more importantly support, added into the system?

The only way I can think is to shape the original ribs into a crowned shape, and reglue, but I don't believe you have mentioned this as part of the repair.

I am not trying to discredit this method, but I haven't seen an answer to the above question.

Granted, I am not a rebuilder personally, but I have worked on many rebuilds myself, including soundboard replacement, and have read as much as I can on the subject.

Respectfully,

Mead piano: In our first attempt, we took a length of copper tubing and flattened it on one end and tried directing it to the SB to rim joint. This did not work at all I ended up burning face and hands, and damaging the rim. Then tried a length of small diameter p.v.c. tubing, drilled it full of little holes, placed it topside and covered it with cloth to hold the steam, this failed also.Then we got some solid round rubber cord one inch diameter, placed it where the SB meets the rim, running the steam into the space where the round does not fit,using stainless steel tape to protect the veneer and this worked, but it did loosen veneer from the case, and had to spend time to glue back veneer in those areas.We did this to a couple of boards. We now use flat rubber about 2 inches wide wide 1/2 inch thick, with a shallow channel cut in center on one side,this works great. I still use the round stuff to unglue the SB mouldings on the long side, and on the treble side,these are reused also. And yes pictures are coming.

Mr. Kinline: Not that I know of.

Mr. Dowell: The entire soundboard is lifted out from the case. After which the ribs and bridges are steamed off. The panel now can be repaired where necessary, and the ribs repressed into a SB press, just like you would if you were using all new wood,resulting in a compression crown. Steaming off bridges took some thinking, They are steamed off from the back side of the board, yes the steam goes right through it, it takes about an hour, and it falls off, like bones out of well cooked chicken.

That is very interesting! Thank you for your explanation it helps a lot! I have more questions but I think pictures will answer them so I will wait and see.

Thanks!

-Daniel

Richard,
Do you dry the board down before gluing on the ribs?

Bill: Yes, Of cours. We maintain the temp of 110 degrees Farenhight. We have a 1940's Weston moisture meter it has two batteries, a 67and1/2 volt battery, to power a vacum tube for moisture resistance between the needles, and a D size battery for the indicator. It is extremely accurate. moisture content drops down to about 4%. The panel shrinks about 1/4 inch.

Bill: I mispelled (course) I am very tired we moved four large grands today.

I would think that if the panel shrinks 1/4" and then creates a crown after rib installation, then it is functioning similar to a new board.
Do you recap the bridges? I think it would be difficult to set bearing without some form of adjustment for each section of the piano.

Bill: Of all the ones we have done, only one, has been troublesome. I over did it, and ended up with way too much crown. I should have unglued the ribs again, and corrected this, but that meant repressing, I did not think it would be a problem, but it was serious. I had to set the acoustic dowels as high as possible. And put thick shimming material under the plate nuts,and even under the duplex bars, even with that,it was pretty scary. And I ended up recapping the bass bridge. Yes it was a lesson learned. If the manufacturer did their job correct,the bridges return to their original height,I kid-you-not, honest.This was on an A-3 1902.You know if some is good,then more is better, well not on crown height, that is for sure.How this happened? We are on third floor of an old mill building, when the heat comes on, the humidity drops to below 25%,and with heating the SB, and ribs to 100 degrees+,dropping the moisture content down to about 4%,and it would have been normal,except on this one, I made my press cauld's too deep, pushing them into the "dish" more than the others before this one.Thus ending up with over-crown. The temperature was correct, the moisture content was right, but too much curve.I don't know if any body else does it this way,well anyway, I threw this set of caulding away,about a three dollar loss in material.We use three quarter inch M.D.F. to make these.You see, I don't think this is conventional either?There is no concave "dish", I put more crown from fourth octave up than in the bass. I am familiar with the standard giant, thick, go bar decks.Our pressing equipment is made of steel.And between pressings it just stands in the corner.No go bars. One cauld for each rib,cut on a band saw.After I am done with them, I bundle them up, tape them together, and write on them the piano model, and serial number,and use them again and again. The caulding I made for the cir,1900 M&H we did 2 years ago, was pulled off the shelf,and reused for this 1913 M&H I pressed this past winter.The bridge and the curvature was exactly the same, only not as wide in the bass,It saved me some time in making new ones.Once the caulding is made,say for a B Steinway it can be used over and over.M.D.F.is fantastic in that is cheap and has no grain to deflect the band-saw.It takes about 5 or 6 hours to make these and that is it.

Bill: Of all the ones we have done, only one, has been troublesome. I over did it, and ended up with way too much crown. I should have unglued the ribs again, and corrected this, but that meant repressing, I did not think it would be a problem, but it was serious. I had to set the acoustic dowels as high as possible. And put thick shimming material under the plate nuts,and even under the duplex bars, even with that,it was pretty scary. And I ended up recapping the bass bridge. Yes it was a lesson learned. If the manufacturer did their job correct,the bridges return to their original height,I kid-you-not, honest.This was on an A-3 1902.You know if some is good,then more is better, well not on crown height, that is for sure.How this happened? We are on third floor of an old mill building, when the heat comes on, the humidity drops to below 25%,and with heating the SB, and ribs to 100 degrees+,dropping the moisture content down to about 4%,and it would have been normal,except on this one, I made my press cauld's too deep, pushing them into the "dish" more than the others before this one.Thus ending up with over-crown. The temperature was correct, the moisture content was right, but too much curve.I don't know if any body else does it this way,well anyway, I threw this set of caulding away,about a three dollar loss in material.We use three quarter inch M.D.F. to make these.You see, I don't think this is conventional either?There is no concave "dish", I put more crown from fourth octave up than in the bass. I am familiar with the standard giant, thick, go bar decks.Our pressing equipment is made of steel.And between pressings it just stands in the corner.No go bars. One cauld for each rib,cut on a band saw.After I am done with them, I bundle them up, tape them together, and write on them the piano model, and serial number,and use them again and again. The caulding I made for the cir,1900 M&H we did 2 years ago, was pulled off the shelf,and reused for this 1913 M&H I pressed this past winter.The bridge and the curvature was exactly the same, only not as wide in the bass,It saved me some time in making new ones.Once the caulding is made,say for a B Steinway it can be used over and over.M.D.F.is fantastic in that is cheap and has no grain to deflect the band-saw.It takes about 5 or 6 hours to make these and that is it.

Mr. Mckaig.I never touched a computer until last Tuesday,I haven't typed anything since high school, 1971, but I'm learning, and I find it most interesting. I checked out your shop pictures. The question That intrigues me the most is, Why do you make ribs round on top "pre-crowned". And do you do this to Steinways? Is the perimeter glued down at 90 degrees where it meets the rim.? The 1913 M&H I'm doing has a convex board, right to the very edge, all around the perimeter. The node at the bridge is adjusted to compensate for this type of construction.If the manufacturer had used a compression type crown, with the edges glued flat. Thus one of the reasons for rib pairing,do you make the SB to rim jointing angled to the same curve as the roundness of the board.The sweet spot is in a slightly different place,as Chris Robinson demonstrated one time long ago.This is why there is a pulsator bar. And I dont know how to spell pulsator.

I've settled on a hybrid system to build my sound boards. This system uses a combination of arched ribs and compression to form a crown allowing me to dry the board down to 5.9 % instead of 4%. This gives an extra margin safety so that the spruce is less likely to be forced past its elastic limit (crushing force). I feel this gives the board a longer functional life. This hybrid system is not new. It has been used since at least 1900, probably earlier.

I've never found a need to modify the rim ledge. I don't think it helps or hinders the crown of a board. As I said earlier, a crowned board is a self-supported system, it needs a solid rim for a foundation for it to function properly, but the rim does not maintain the crown of the board (as in a buttressed arch).

Bill, Yes, I have a SB from an old Chickering upright from early 1900,that we junked, this had milled crown ribs. Also a Knabe 7'4" grand 1892, the ribs were two piece,joined horizontally, with the top half milled for the crown,That was very interisting.I kept one of them for show and conversation. And I saw a Chickering 6'8" from early 1900 that had only seven ribs, that was constructed this way also. But Steinway's always seems to be what is considered the standard example worldwide, why didn't they do this?

Forum followers,
We have tried to post some pictures from our last job. Computers seem to take delight in torturing me, and I can't seem to figure out how to post a link. I think...if the URL below is copied and pasted into a browser it might work. Please let me know if it won't.

https://profiles.google.com/105412259108667869462#105412259108667869462/photos

Thank you gentleman, for the response to my original question. Yes I've known for a long time that there are some who remove SB's from antique pianos,and reinstall them.The technique is different in that they don't use steam,just water.This would not be practical on most pianos after 1860 or so with wide glue joinery and 3/8 inch SB's.It would take a long time to loosen these glue joints. The ones I do know about are museum property,some are privately owned.And I will be happy to answer any additional questions anyone might have.

Richard,
The work your doing to these pianos looks very nice and clean and I do believe your restoring them back to a functioning piano. But the only advantage that I see of this procedure would be for historical or antique pianos. It really is less work to build a new board. That being said, everyone has their own philosophy about piano rebuilding and if your criteria is to retain as much of the original piano as possible, I think there's a market for that.