Official Luthiers Forum!

Very cool Brian. I have a tutorial I did on the OLF about this using the top dome with sand paper on it to shape the bridge bottom.

These days though we have moved on from this method and find a simple solution using a single edged razor blade to scrape the bridge bottom into the dome shape of the top much faster and easier. It's scrape, scrape, scrape and then trial fit and repeat until only light finger pressure is needed to have the bridge down everywhere including the wings.

Additionally there is the issue of increased "joint energy" at the molecular level where a recently scraped surface, less than 15 minute delay is said to glue better than a sanded surface that has sanding debris at the molecular level. Or, we always scrape bridge bottoms anyway just prior to gluing so scraping to shape has two benefits.

Al Carruth IIRC is who turned us all onto the idea of scraping a joint just prior to gluing years ago and we put it in practice in the commercial repair world. Thanks again Al.

Agree Hesh, I fit the bridge on the convex sander sometimes days or weeks ahead of the glue-up.

But I give the bottom of the bridge and the bare area of the top a light scrape just ahead of glue to clean and freshen up wood.

There was an article on surface prep for glue maybe in Fine Woodworking years ago. It suggested planed or scraped over sanded and possibly freshly done too.

On critical joints I always give a fresh scrape. I think that's a fairly common and not sure when I started or where I picked up the practice. I appreciate all of Alan's posts also, usually more in depth than I'd usually go so always something to learn.

_________________
Brian R, Wood Mechanic
N8ZED

restoring a Froggy Bottom from 1978 a most interesting neck joint design. Douple tapered pin across the tenon. Doesn't let a lot of room to work.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

another pic

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

That's the Gurian neck joint outlined in the Cumpiano/Natelson book. I actually used that neck attachment method on my very first build, using the Cumpiano/Natelson book as my guide! I quickly moved on to better methods.

Works great!

_________________
Measure Twice,

Karl Borum

John, how did you get those out?

_________________
Measure Twice,

Karl Borum

Yay - looks great Karl nice work.

These work well for unserviceable neck joints. Swearing also helps.

when I looked in there I saw what I was up against. The first one went easy as the pin was below the surface of the side of the block. I cut about a 1/4 long piece off a 18 penny nail. I had to use my small adjustable wrench to tap on it , as a hammer wouldn't fit. In about 10 min it was out , so the 2nd one was one heck of a challenge. This took hours , as the pin was about 1/8 proud and I thought easy street. Well the dang thing flattened out flush to the block.
I tried about everything you can name. The holes are so far down and toward the side that you don't have a lot of working room. As an old toolmaker it was hard to get a good hand on measuring the pin hole center do I had to experiment a lot. With things so tite I had to be aware of swing area to tap and not hit anything. I even tried making a small C press but there was no room to tighted the screw. In the end. I just made a block that I could drill a hole to fit a 10 penny finish nail. I ground that to a point.This let me locate the nail on top of the I found lexan made the best holder as I could see the side of the block. I used double sided foam tape . This held the plastic , which held the nail so I could tap it out. The figuring out the holding fixture was the challange. I will convert this to a bolt on for sure

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

In the Cumpiano/Natelson book, they describe how to make special long handle pliers that allow one to both drive the pins and push them back out. It would definitely be a hassle to remove the pins without the pliers. I think I still have mine somewhere, but I haven't needed them since I finished that guitar in 1996 (or thereabouts).

Sawing and sanding

















Brad


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Beautiful AND clean too work Brad very nice to see.

Agree with Hesh - that is some outstanding work. Well done.

_________________
"Act your age, not your shoe size" - Prince

Too funny not to post a Saturday morning pic Brad. Swear to god not doctored, just moved the tools to the top for the photo.

Always amazes me how often different folks come to such similar methods. Often it just makes sense, others times it's almost scary.

You are more refined and your pics are better too! Some day I'll have a clean shop too.

_________________
Brian R, Wood Mechanic
N8ZED

Love it!


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

I've been spending a significant portion of my time rubbing beetle excrement on a spruce and African Blackwood guitar the past week or so. Nearing the finish line soon.

Really nice Brian too!!! I have to tell you as a neat freak who has been called Felix Unger before, many times... it's nice to see others who are just as sick as I am

Wow Beautiful work Brian!!!

Great photo, Brian.

_________________
"Act your age, not your shoe size" - Prince

Sounds around the shop today.

https://youtu.be/4x4pNfYfwhM?si=NEVMf1G-xkVCBThL


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Very cool Brad!!

Did you guys notice the orientation of Brad's nippers when he nips a fret end off? More specifically how he holds the jaws horizontal and not vertical?

This was something, a very small thing that we taught in our classes and it made me grin like an idiot this morning to see Brad doing it.

For an OLF tub of lard who wants to be the first one to correctly guess why we nip with the nippers horizontal and not vertical?

** Offer null and void for people who took our classes, only one entry per participant, offer not valid in states where it's prohibited.

Hello Brad,
thanks for this video! Very good job, and I like the sounds so much ! There is only one sound I love more: the "singing" of a very sharp plane
Juergen

Great video Brad, but I couldn't figure out what was happening at 7-10 seconds. Is that a fret doctor to file back barbs on the tang? If so, what is your theory there.

Hesh, I'll bite -- cause that's the way the Summit nippers work those are the nippers I use too. I always bind fingerboards so the tangs are nipped off at the ends ahead of fretting. As such, I always nipped with the old style nipper with the cutting edge perpendicular to the FB. Reasoning has been it is less likely to send a shock wave up the fret possibly unseating it IMO. Change my mind.

Thanks guys!

_________________
Brian R, Wood Mechanic
N8ZED

That’s correct, it’s the “Fret Barber” from StewMac. I was using that to take the tang down to .022” (slot is .024”) but only for frets 16-23, the ones over the body that are fretted through the sound hole. This was a tip from Dave Farmer. It just makes pressing them easier.

Brad


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars