Bridge pin size and angle

[Paul Levens]

Hi all.  I am new here!

Bridge pins have been loose since I bought the guitar, but now one is slipping. Can't measure the hole angle accurately, but 3 degrees is standard on a Taylor.  Hole at the top is 0.217", but pins only 0.200".  I doubt this is hole wear as all are smooth and consistent (modified perhaps?).  Can't find 3 degree "oversize" pins anywhere (even at Stewmac), but 5 degrees up to 0.220" are available..

Anyone dealt with this issue before?  I am not interested in plugging or re-drilling and reaming the holes - too invasive and/or costly.  Any feedback welcome - thanks.

[Roger Häggström]

I have solved oversized holes using 0.6 mm thick rosewood veneer as "wallpaper" lining the inside of the holes. The bridge was also rosewood. I put slices of veneer into hot water and used one plastic (preferably unslotted) bridge pin to roll the veneer around and cutting to length with a scissor. A bit fiddly, but not that hard to do. I then used HHG to glue the veneer in the holes using bridge pins to press the veneer tight to the walls of the hole. I also used thin household plastic film to wrap the pin. When done I used a reamer to give the hole the right size.

You can also use thick superglue to make the hole smaller or the bridge pin thicker. Put it on a and let dry overnight, you will get a thin plastic film that may be enough to get the pin snug in the hole.

Both of these methods will be almost invisible with the string pins in place.

[Paul Levens]

Roger, you have some good ideas there.  I don't have a 3 degree reamer, but I can buy one.  Based on your suggestion, I could also use the right thickness of shim stock as "wallpaper" and glue it in using standard pins to hold it. I think brass or plastic might work.  Thanks.  I think you have nudged me in the right direction.

[Russell Vance]

Before we go anywhere here,  The bridge pins are there to stop the ball ends releasing which are what couples the strings to the top(along with the saddle etc).  Primarily, the pins don't hold the strings in, the ball end and bridgeplate manages that - so, the pins don't need to be overly tight to do their job.  I use finger press tight but others may disagree.  A deadblow fretting hammer is the preferred snugging device North of the border here.

Wet a "Q" tip and plug the bore with it for half an hour which will snug up your pin as a get you home measure. Get a set of oversized .220,   5 degree pins and shave and rotary sand the thick end down to fit snug. The geometry works OK (ish) and the ball end will snug up the pointy end, and hopefully, that's that.    Don't go  too far down the rabbit hole here, this is not a difficult fix and paying 75 bucks for a proper reamer to fix a $5 problem and then wrestling  around with stuffing .050 (both sides) veneer rolled around a bridge pin is fine if someone else is paying for the time.    Brown shiny packing tape also works better than cling wrap as a release agent, can't see Saron wrap surviving being pushed into an irregular wooden taper bore - along with managing a pot of dead animal glue which will wick everywhere.

You may also wish to refresh the slight countersink around the top of the bore a tadge as that will give a little more depth and bite to the existing pins (along with expanding the bores a bit with the wet Q tip stuff).   

Come to think of it, and NOTE:  I have not done this as it just came to mind but next one of these I'm up for a wet cloth and a thin soldering iron tip into the top of the bridge bore to refresh the wood fiber (classic dent steam out stuff)  - this is not heart attack stuff, it doesn't take long to raise/refresh  the grain and it isn't going to detach the bridge glue.  The wood is generally still there, its just compressed a bit. 

Regards,

Rusty.  

 

[Roger Häggström]

"managing a pot of dead animal glue which will wick everywhere". Yeah, you really don't like HHG! Well. One of the MAJOR benefits with HHG is you can allow the glue to "wick everywhere" if you want it to because it only takes a damp cloth to clean it off. Try that with epoxy...

Using cling wrap instead of plastic tape is better in my opinion. The cling wrap is weak and will not get stuck by suction/vakuum like plastic tape, it will break. Especially good when using big flat cauls.

Using water and heat to swell the wood is a good one that needs to be tested!

[Russell Vance]

Its just applying the K.I.S.S. principle Roger, I have no way of knowing whether the OP is a qualified luthier or not so I advise accordingly.  The OP said he wanted to do the job in a manner that was not too invasive or costly so I also advised accordingly.     I have some experience with using release agents and have no idea what suction or vacuum occurs when you wrap a bridge pin in tape.  Which is what we were talking about.  I also didn't mention using epoxy or or big flat cauls or red herring glue.

  Hide Glue is a fine glue made from boiled down animals (dead as) and I'm fully across the technology (as opposed to those who do not feel the need to study and understand the technology behind the things they use).   Unfortunately, trad luthiers direct a lot of passion towards stuff that is fairly well ordinary - luthiers and woodworkers have been using hide glue and milk/fish glue to make fancy boxes for ions and we can pretty much say that we now know all we are going to know about its uses and qualities.   

Martin have got the voodoo glue gig worked out and charge an extra $1650 (at last look) to build an instrument with HHG.   It will sound better because it has to sound better, right, doesn't it?  Martin surely must have a video out there demonstrating the tone increase and extra benefits you get from using a 100 ml of HHG...maybe not.  So I feel sorry for all the other 99% of Martin users who are stuck with inferior Aliphatic glue in their Martins - Taylor uses Titebond for 95% of their guitar construction along with superglues, uv cured glues and some unidentified protein glue (for brace work on some models) so they also are using an inferior glue.  Seriously?    

Regards, 

Rusty. 

 

[Roger Häggström]

Personally I'm not disturbed by the fact that hide glue actually is made of animal hide, after all this is a waste product for the most part and most of us actually eat dead animals. It's a natural thing. The way you use the phrase "dead animal" is kind of derogatory. Most modern glues are made from byproducts from the oil industry and that's worse IMHO.

Factories commonly use stuff that's quick and cheap, not the stuff that would be the best choice. Martin don't even ream the bridge pin hole now, probably to win the few minutes needed to do it! The day someone invented slotted bridge pins was the day no factory took the time to do the better solution using unslotted pins. And the list goes on. What factories do is not always the best example.

[Russell Vance]

Hello Roger, 

I use the term "dead animal" product because it serves two purposes. 

Firstly, its a consumer awareness and choice issue.   You will note that Doc Martens make a vegan boot which has no animal hide or product in its composition. A goodly proportion of vegan and animal lovers don't have leather upholstery in their Autos.   There are 8 million American vegans and the figure of 5% of the world population is somewhere near right.  This group of people have the right to know that their instruments do not contain animal sourced products.  Which also includes the "cute" practice of calling animal origin glue "Protein" glue as a way to disguise its origin.  

Secondly, it annoys (us) old guys and encourages broader discussion outside of the small proportion of rusted on traditional puritans who have monopolized the conversations and forums with idle speculation and sometimes ill formed or supported opinion for way too long. There is balance and understanding in the modern luthiery and guitar making sphere  but it has a difficult time making its voice heard in an environment where old stuff is assumed and promoted as better  

Am I a vegan or a member of PETA?  Nope.  However, this does not negate  the responsibility to call out issues that are important to luthierie's progress in acknowledging technical change and diverse market/consumer requirements. 

Understanding the changing world around us is as important to the charter of this forum and to it's members who make their living repairing, making and selling instruments in a very competitive environment.  I believe discussions of this type, while uncomfortable, are nevertheless important in supporting the Forum and its aims.

Regards, 

Rusty.

[Roger Häggström]

You must be a really devoted vegan to refuse buying a guitar glued with animal glue. Can't be a big percent of all guitar buyers out there.

A bigger problem is the making of throw away instruments that can't be repaired without spending a lot of time and money doing it. Modern glues, plywood and plastic lacquer. That's not sustainable. In the old days with solid woods, animal glue and shellac based lacquers the guitars were made to last and to be easily repaired when it needed to. I love working with old parlor guitars from before 1940, any wreck can be transformed to a beautiful and good sounding guitar.

The use of endangered wood species is another big problem. The answer to that challenge is not new modern plastic based materials, but other common wood species that can sound and function as good as the old ones.

Love talking about it, but I wont do any more of it in this thread.

[Russell Vance]

Gees Roger, 

"Am I a vegan or a member of PETA?  Nope".   And there 8 million American Vegans.  I already said that.  You don't need to answer as you have expressed a desire not to, but at least go back and read what was offered.   

The consumer's  right to be informed about what they are buying and where it was sourced is an important part of modern business and marketing ethics and I have no difficulty accepting these responsibilities.   This also goes to such things as the use of elephant ivory etc.  These issues were unheard of and ignored in the 1940s however its now 2019 and change has happened.  

Disposable guitars or synthetic based instruments are a permanent part of the industry and enable beginners to get into guitar playing cheaply and then exercise the option to upgrade to a premium instrument should they wish to progress with their playing. Throw away instruments are not a problem - they are cheap and disposable and not designed to be fixed, they serve their purpose and then they are done.

This evolution is a good thing for mid level, premium makers and boutique makers alike as the cheap entry level guitar has led an increased number of consumers/players  through their doors as they seek to upgrade.

The fact that 50 bucks worth of Asian mystery wood ends up under a bed or in a dumpster is no real loss as wood is a renewable resource.   A renewable resource is by definition sustainable if the resource can be replaced at the same rate it is drawn down.  The use of common fast growing/abundant  timbers and plywood for the manufacture  of cheap guitars is not unsustainable nor is the use of petrochemical based glues or finishes.   

A relevant example  of sustainability with wood is that the Swedes make up to 925 million matchsticks a day from sustainably grown and harvested wood. Imagine how many guitar soundboards they could make if they were so inclined.

These are things for consideration.

Rusty.   

 

     

[Paul Levens]

Hi Rusty,

Ii makes sense that the oversized pins, sanded a little to fit should work, even though they are 5 degrees. And yes, I have observed that it's the ball end wedged in under string tension that provides the restraint, not the taper. The current pins are sloppy as hell and have held the strings okay up until recently.

Must admit, the countersink idea did not uccur to me.  I'll measure first and see how deep down I find .200".

Did not know the wood could be "refreshed".  Would that work in this dry prairie winter climate?

And no, I am not a trained luthier, just a guy who stubbornly insists on fixing everything himself!  Have always set up and tweaked my own instruments since day 1.  Happy to learn from you guys - Thanks

[Mark McLean]

Paul

I think Rusty is onto a good idea.  You might be surprised by how much some boiling water on a Q-tip will swell up the compressed timber in the hole.  It won't take much to make the pins feel snug again.  

[Paul Levens]

I may try that Mark.  Have been scratching my head as to why the pin holes have got so oversized.They do not look ragged or worn.   

After looking at the hardwood floor I laid 15 years ago (all  3" planks butted tight), I see huge gaps from shrinkage. 

Not hard to see how the holes could have opened up .020" or so.  This guitar has lived in Alberta (ultra-dry winters) for over 15 years too.

Such a fix may last for quite a while.  In the meantime I'll obtain oversized pins and /or suitable shimming.  Cheers!