Realigning Button Rings

[GeorgeH]

Occasionally I find bows with a metal ring out of alignment with the ebony core. Usually, it is only the outer button, which I always assume was carelessly re-glued after falling off.

However, in the one shown, both are out of alignment with the ebony. I wonder how this could have happened or if this was an original manufacturing defect. Regardless, I'd like to get it realigned.

What techniques are used to loosen and realign rings on buttons?

[Brad Dorsey]

This button was certainly not made with the rings misaligned.  In the making process, a button is first made round, and then the facets are filed or milled, automatically aligning the rings and the core.  If there was a manufacturing defect, it was making the rings too loose or nor gluing or pinning them, allowing them to rotate out of alignment.

Over time, the core can shrink, loosening the rings.  If they are not pinned, they can fall off, and if they are round on the inside, they can also rotate out of alignment and become stuck in that position.  (Some rings are octagonal on the inside.  These cannot rotate, but they can fall off if they are not pinned.)

If the rings are loose on the core, it is easy to re-align them and glue them in position.  You could also add pins to prevent them from rotating or falling off in the future.  If the rings are tight -- perhaps glued -- re-aligning them can be harder.  The problem is getting them loose.  I clamp the button gently in the padded jaws of a vise with one ring sticking out, gently grab that ring with padded-jaw pliers and gently try to rotate the ring and remove it.  If the ring won't move, I try heating it over a flame to expand the metal and break the adhesion holding it on.  If I get the ring off, I clean up the ring seat and glue the ring back on.

Normally, I clamp the core and an aligned ring in the vise, but your button presents the added challenge of having both rings misaligned.  This means that it would be harder to get a good grip with the vise.  Because your inner ring is closer to being aligned than the outer one, I would start with the inner ring and the core in the vise.

Sometimes I cannot get a ring loose.  There is not much to grab onto, and there is a limit to how hard you can clamp with the vise or grip with the pliers without crushing the core or a ring.  And there is a limit to how hot you can heat a ring without burning the core.  If I cannot get a ring loose, I leave it as it is.

[GeorgeH]

Thank you very much, Brad. I did not know that buttons were made that way. I thought that the rings were made separately and then fitted to the ebony by cutting or filling only the ebony. Good to know.

A few questions:

Pinned or not, aren't the rings always glued to the core?

How do they rotate out of alignment without simply falling off?

If you have to heat the button over flame to remove the rings, does that damage the mother-of-pearl at the end?

[Brad Dorsey]

17 minutes ago, GeorgeH said:

...Pinned or not, aren't the rings always glued to the core?...

It seems like they should be.  But, not knowing the working methods of everyone who has ever made a button, I don't know if they always are/were.  And even if they were glued, the glue might degrade or soften with time or under certain conditions, allow them to rotate or fall off.

 

17 minutes ago, GeorgeH said:

...How do they rotate out of alignment without simply falling off?...

Loose enough to rotate, but not so loose that they fall off.

 

17 minutes ago, GeorgeH said:

...If you have to heat the button over flame to remove the rings, does that damage the mother-of-pearl at the end?

I don't think so.  I think the wood would burn first.  Perhaps I should test a piece of mother-of-pearl in a flame to see what happens.

[Guido]

I find rings come lose and tighten again with the seasons as the wood core expands and contracts.

Sometimes I just wait for the weather to dry/warm up before I attempt to realign or take off and refit a misaligned ring.

I have had good success baking the adjuster for a couple of hours on very low heat in the oven if I don’t want to wait for summer.

[Brad Dorsey]

I think that’s a good idea, and I will have to try it.  I have a button with a misaligned ring in my workshop now that I was unable to to fix using my above-described methods.  I’m thinking that leaving a button in close proximity to a light bulb for an hour or two might do it.  The heat would shrink the core, expand the ring and degrade any glue bond.  I will report back.

[GeorgeH]

4 hours ago, Guido said:

I have had good success baking the adjuster for a couple of hours on very low heat in the oven

What temperature is "very low heat"? Thanks.

[Blank face]

7 hours ago, Guido said:

I have had good success baking the adjuster for a couple of hours on very low heat in the oven if I don’t want to wait for summer.

By the actual prices for gas and electric energy it would be cheaper to buy another bow.

[Brad Dorsey]

Reporting back:  The light bulb trick did not work.  But I think it’s still worth trying on other buttons.

[rudall]

8 hours ago, Brad Dorsey said:

The heat would shrink the core, expand the ring…

Wouldn’t the rings then just squeeze up tighter against the ebony?
 

[Brad Dorsey]

Shrinking the core would certainly make the ring looser.

Heating the ring might not be so straightforward.  If a metal plate with a hole through it is heated, does that make the hole bigger or smaller?  My recollection from physics and engineering classes is that the general rule is that the hole size does what a solid piece of metal the same size as the hole would do.  So the hole would get bigger

Of course, we’re not considering a hole in a sliver plate here; we are dealing with a ring.  I think a good analogy would be the iron tires on wooden wagon wheels.  The old-time wheelwrights would heat a tire to fit in on the wheel, then quench it in water.  As the tire cooled, it would shrink to a tight fit on the wheel.

From this, I conclude that heating a metal button ring will expand it.  If it expands, its fit on the core would be looser.  QED

I don’t see how the inner edge of the ring pressing against the ebony as it expanded would change any of this.

The other thing that heating the ring does is stress the glue bond holding it to the core.

[GeorgeH]

Heating the ring will make it expand. I think that uniformly heating it in an oven might work better than a lightbulb or even a flame, but could it also cause the ebony to crack?

[Guido]

9 hours ago, GeorgeH said:

What temperature is "very low heat"? Thanks.

I operate in Celsius… kept it under 100, maybe 80. Still had some thin gloves on handling it while warm. I suppose you can try hotter and shorter or cooler and longer.

The objective is just to “dry” the wood core and make it shrink a tiny bit.

[Guido]

2 hours ago, GeorgeH said:

Heating the ring will make it expand. I think that uniformly heating it in an oven might work better than a lightbulb or even a flame, but could it also cause the ebony to crack?

I don’t think you get a noticeable expansion in the metal, the wood is what you want to change. And it is not so much the heat (which expand everything incl wood), but the moisture content that is reduced in the wood to make it shrink.

[Guido]

4 hours ago, Brad Dorsey said:

 I think a good analogy would be the iron tires on wooden wagon wheels.  The old-time wheelwrights would heat a tire to fit in on the wheel, then quench it in water.  As the tire cooled, it would shrink to a tight fit on the wheel.

That is a really good analogy. I’m not familiar with this though, and would guess that the water swells the wood as an important part of the procedure? Also, did they heat (dry) the wooden wheel or just the iron tyre?

[Blank face]

To heat a small metal ring I would use a soldering iron. That's IMO more adequate to apply the heat precisely and controllable.

OTOH I never needed to do this. To realigne button rings I used the vise/padded pliers method; if this didn't work in the first place I removed the thread, which often spreads a cracked up ebony core and could move the rings after doing this.

[Brad Dorsey]

5 hours ago, Blank face said:

...I removed the thread...

I assume you meant that you removed the screw.  Good idea.

[Blank face]

53 minutes ago, Brad Dorsey said:

I assume you meant that you removed the screw.  Good idea.

Of course. The thread has to stay at the screw.

Btw, glueing a short piece of very thin cotton thread or string between ring and shrunk ebony helps to keep the ring in place.

[GeorgeH]

Are the rings usually originally glued in place, pinned or not?

[GeorgeH]

6 hours ago, Blank face said:

if this didn't work in the first place I removed the thread, which often spreads a cracked up ebony core and could move the rings after doing this.

Does the crack extend to the surface? If it does, do you just glue it closed?

[Blank face]

3 hours ago, GeorgeH said:

Does the crack extend to the surface? If it does, do you just glue it closed?

Yes, they do extend to the surface. No, I rather fill them with matching ebony splines (not dust and glue), because they are usually not to close by force, because the cracks are caused by shrinkage and swelling corroded screws.

Here we have typical cracked adjusters from my junk box, the left is only hold so close together by the ring.

[Brad Dorsey]

41 minutes ago, Blank face said:

..not dust and glue…

Why not?

[GoPractice]

20 hours ago, Brad Dorsey said:

Reporting back:  The light bulb trick did not work.  But I think it’s still worth trying on other buttons.

The traditional incandescent bulb was/ is a good tool. Inefficient. Can be time consuming. Available in various watts ( there for heat output. )

When I was a kid, there was a thing called an Easy Bake Oven. It was a "toy" that allowed kids to bake very shallow cakes in an aluminum? form. The heating element was a light bulb. When a friend's sister allowed us to watch the process, I was blown away.

Anyway, the bulb offers way more control than an oven. When it comes to humidity, one might have to try many experiments. There is the side of the bulb, the top of the bulb, below the bulb. Maestro Blankface's soldering tool proces is what I use. It can localize heat. But with an expensive button, start next to bulb, but not above it. If it's an issue of breaking a simple glue bond, the process takes time but is not so drastic.

Helps to use a fairly cheap IR tool. The better ones are more.

[GoPractice]

31 minutes ago, Brad Dorsey said:

Why not?

Much will depend on the customer. The grain orientation matters. I would think that the slippage is less likely to occur.

The work is small. I like the spline, but it takes more time. And it is not so much about the cost, fee. It's likely the more "organic" fix, though that might not be the best use of the word. Replace the screw.

I have used powder to fill. If the bow is brazilwood, the fix is cosmetic. Likely no pins, the work is simple. The fill will not be complete unless placed into vacuum bag ( and still not 100% ) but will likely not completely come apart as the bonding agent flows everywhere.

Dremels and Foredoms will work quickly, or I can spend a better part of a day with a jeweler's saw. Depends on the value of the button.

[Blank face]

35 minutes ago, Brad Dorsey said:

Why not?

Looks better.