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After stringing a piano do "You People" like to stretch them or let it happen on their own?

Ive heard through the grape vine that some techs use a
Rolling String Stretching tool and others just use a piece of wood.

I tried stretching a few times, and it didn't seem to make much of a difference. I do, however, do some minor pre-bending at the bridge, and a little lifting at agraffes. In my experience, those actions seem to help the string stabilize more quickly.

Greetings,
I string sharp by about 20 cents when I install them, (bass strings maybe 10 cents). By the time the last pin is hammered in and the coil tightened, the middle of the piano might be 20 cents flat. There is a lot of slack in the coils, behind the bridge, behind the duplex bars, etc, and the curvature on both sides of every bend is going to become flatter with time, though the greatest change is almost instantaneous. The newly strung piano will, over a couple of days, get two chippings, both of them to 20 cents sharp. I do this with no over pull, and I keep an eye on the ETD so that I don't go past that amount. Then I let it sit while I go through a procedure of relaxing the bends. First one is behind the bridge pin, since when I tap around the hitch pin and duplex, the slack given up there will allow that first bend to move, centering its apex on the distal bridge pin. I don't do this to the bass strings until later, since the barrels and hitch loops take some time to deform.

I am wary of rolling wheels, as it is possible to go past the point of elastic deformation without breaking the wire, thus leaving a very false sounding string. I do use a "Straight-mate" type of tool to press up in front of the agraffes and capo bars after the piano is tuned to 440. This is just a precursor to individual string leveling, and most of that is to compensate for poor agraffe alignment.
Regards,

Well I restrung this 5' Kimball about 3 months ago.

I brought it up to pitch three times and it keeps dropping.

When I tried stretching the strings I found that the highest two octaves would drop the most.

I've been using TuneLab And it easy to see A1 to C88

It takes two years for new strings to reach a stable point. When first installed tuning is a constant moving target. Hard blows will keep them dropping slightly for several minutes.

I do not like to over-tighten new strings by much more than A443. I do not use a string stretcher or a straight-mate. I lightly tap the sides of the wound string hitching loops to snug them around the hitch pin. I will pull up lightly with a string hook in front of the agraffe to help make that bend after the strings are at 440. But I don't want to overdo this because some increase in bend must be available to use for final hammner/unison string mating, (phasing).

I can't wait that long

I don't think you have a choice unless you get a different piano.

What I find works for me after chipping a piano up to pitch after a re-stringing job is to over pull by 15-20 cents then use a regular old heating pad and warm it up and lay it on top of the strings for 20 or 25 mins then move it to another section of strings. The heat causes the pitch to drop drastically and in my experience helps begin to stabilize the piano alot quicker. The heat is not hot enough to cause any damage but helps relax the steel and allows it to stretch easier. Each time I move it to a diff section I go back over the section that previously had the heat pad on it and yank it back up to pitch quickly.

Tighten all the coils and beckets, and make sure the loops are at the bottom of the hitch pins. Check that all the non-speaking portions of the string are straight, and remember that it will take some time for all the little deviations to straighten themselves out. If there are duplexes, check to see that none of those portions vary greatly from adjacent portions, which indicates that the tension has not equalized.

I Agree. Pianos is what they is, and wire is what it is. There are no legitimate short-cuts.

Yup. One of the fundamental requirements for working on pianos is patience.

I see no legitimate reason to apply heat. Actually I can see that being potentially more harmfully, especially when getting close to a bridge. One shouldn't need to do much more than properly deal with the non speaking front and back lengths, properly seat and tighten coils. After recently restringing my 7' Baldwin it seemed that at the 6th tuning things didn't wander much.

What little time roller-type string stretching tools might save (if any) isn't worth the possible harm to strings that might ensue by using these. And, of course, these tools cannot be used on bass strings, and so the use is limited anyway.

Two chips and five tunings should begin to experience stability. Two chips and one tuning the first week and then an A440 tuning every 14 days after. That is a total of 9 weeks which is close to 3 months.

Small instruments like that should be fairly stable within 6 months; fully stable within a year depending upon conditions.

As mentioned by Bob and others, string stretchers are not that effective, most likely because that is not the only part that is moving into semi-permanent position.

Good point, Dan. (If we knew then what we know now, how much $$ could have been saved by not purchasing tools the use of which is dubious at best.)

Hi Bob,

It is something that is often overlooked following stringing.

The sounding board and bridgework are being pushed around by the increasing tension of the wire; mostly forced back into their original at pitch positions. This is a lot of the reason that the pitch changes dramatically, especially with the smaller mass strings as the OP has noted.

As you mention Bob, no amount of string assistance is going to counteract that. Unfortunately lots of tools turn out to be an appendix in the end. The wire is brand new. To overstretch the molecules in new wire is flirting with the danger of deformation, and down the road this will lead to a short life span along with unfortunate tonal qualities.

This is the biggest reason I chip and tune a restrung instrument by octaves following the temperament sequence; all the C’s, all the A’s, all the F’s, and so on around the circle. Tension is increased for the entire plate and other structural components almost equally which creates improved stability more rapidly than from one end to the other. Following chips I come up to 440 and then let the wire do its own thing naturally. Takes a little longer but the end result is better.

I agree with everyone who says not to use a string stretcher. It will only damage the wire. All of the pitch raise tunings do not have to be that precise. Most technicians can do them in about 20 minutes. If you labor over a tuning at that phase, you will only be working too hard to accomplish nothing and you will be disappointed at how quickly the piano falls out of tune.