OM21 partial refret

Even if it ain't broke you can still fix it.
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colin
Posts: 6
Joined: Fri Sep 21, 2012 5:26 pm

OM21 partial refret

Post by colin »

Owner says the frets on his 2005 OM21 are worn, producing this
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Interestingly, I notice the fretboard does not have through fret slots
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So I contacted John Hall, who very kindly asked me to call him at home that evening, and emailed some pics and serial number. When I called he'd contacted Martin Guitars, who said the fretboard was not what should be on the guitar, and from the pics it looked to be bound. It was 2008 they started doing pocket slots I believe, so after confirming with the owner it had never been worked on before, it appears to be an oddball.
So me and John had a Transatlantic chat about the repair (I was a bit nervous) and he went over what to do, and said I'd be fine!
So, to work. Strings off - I like to keep the pins in order
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John suggested tapping the nut loose gently, then removing it sideways
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Last edited by colin on Fri Nov 06, 2015 5:25 pm, edited 3 times in total.
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: OM21 refret

Post by tippie53 »

looks good to me
nice work
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
colin
Posts: 6
Joined: Fri Sep 21, 2012 5:26 pm

Re: OM21 refret

Post by colin »

Tapped back on the nut gently with a small hammer and a wooden block
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Took a bit of time, but it came loose after 14/15 taps, then it slid out sideways - this one was well glued in, as evidenced by the wood that came away with it.
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John recommended dampening the fretboard before removing the frets, so I wiped a wet paint brush along each side of the frets concerned, 1 - 7, and wrapped that part of the neck in clingfilm for 15 minutes to let the water wick under the frets and get into the rosewood.
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Last edited by colin on Fri Nov 06, 2015 5:24 pm, edited 1 time in total.
colin
Posts: 6
Joined: Fri Sep 21, 2012 5:26 pm

Re: OM21 refret

Post by colin »

So, clingfilm (sorry, Saranwrap) off, wipe off excess water, go to it with a 30 watt soldering iron with a concave grove in the tip and fret pullers.
Had to lift the end of the fret first with the edge of the puller, even with a very thin fret protector (10 thou stainless spring steel) it was difficult to get a grip under the fret.
When lifting the fret, I just followed the iron across it, levered it by pulling towards me, parallel with the fret.
Not up and down the FB.
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I could see the steam coming off as the fret was heated and the FB oils bubbling, so I could see when it was ready to lift, went really quite quick, so I think 30 watts is enough power.
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Last edited by colin on Fri Nov 06, 2015 5:26 pm, edited 1 time in total.
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: OM21 refret

Post by tippie53 »

textbook fret work
nice job
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
colin
Posts: 6
Joined: Fri Sep 21, 2012 5:26 pm

Re: OM21 refret

Post by colin »

Frets came out pretty cleanly,
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No chipouts apart from one tiny piece on no 7, used a 0.020" Teflon fret slot "dam" and put a tiny drop of thin superglue to fill using a needle with the eye end just ground off (like a fountain pen nib) as it might just have shown from under the fret.
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Cleaned out the slots with a chisel edged "pick" made from a hacksaw blade ground to 0.020" wide, sanded the fret board with a 16" radius block and 400 grit paper, then vacuumed out the slots with my extractor.
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colin
Posts: 6
Joined: Fri Sep 21, 2012 5:26 pm

Re: OM21 refret

Post by colin »

So, checked the fret slot depths and width with a piece of the wire with the barbs filed off, cut fretwire to length then undercut & filed the tangs to width. Tried to get the barbs on the opposite side of the slots to the original frets.
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Hammered the frets in, paying special attention to the ends, then finally pressed them home.
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Ran some CA glue under the fret ends, trimmed and bevelled the ends to match the others.
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And just continued normal fret leveling, crowning and set-up.
Turned out the original saddle was not only flat in the middle (i.e.incorrectly radiused, should more or less match the FB radius) but also too high on the bass side, about 14.2 mm IIRC.
Nut slots filed to just a "ping", relief set at quite a bit less than when it arrived, and action set up to 2.4/1.4 mm at the 12th. Tried it - it not only played better, it sounded much better too. The high saddle had been choking the bass strings.
So, owner came the other day to pick it up, and couldn't stop beaming as he played it.
Felt good!
And many thanks to Mr Hall for his help and advice!
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