Side profiling question

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Metalone72
Posts: 48
Joined: Wed Jan 18, 2012 3:36 pm

Side profiling question

Post by Metalone72 »

I'm in the midst of building my first scratch build and have a question about profiling the sides. The prices I've done this far was to:
1) trimmed the sides in the mold and profiled the top and back with the radius end dishes.
2) glued in the neck block and tail block. Trimmed them and radiused them to meet the profile.
3) Roughed in the angle on the top side from neck block to waist
4) Glued in the kerfing

Now I am ready to do my final profiling on the Top side. Watching the one bluescreek video it was said to flatten the profile, then radius and then set the angle again. It seems like it is extra work that is not needed to flatten the profile that was already established. Am I correct in this assumption or did I mis-interpret this? If you flatten the profile again and then re-establish the radius and then the angle, then you will continue to remove material, making the body narrower. It seems to me that at most you would reprofile the radius into the top side to bring the kerfing into alignment with the establish profile and then re-establish the angle. Thinking about it further, it seems logical to just profile the radius initially into the sides and blocks. Then once the kerfing Is glued in, profile that into alignment with the sides and then establish he neck angle from the neck block to the waist. Am I over thinking his or did I misinterpret the instructions in johns videos?

Thanks,
Scott
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: Side profiling question

Post by tippie53 »

The first time I do it pre kerfing is a roughing in so when I set the kerfing I have a target. Also it is easier to remove 1/16 in of wood than 5/16.
Then when you do the rim with the kerfing installed you won't have as much work. Take the time now to do the details as it will safe you a lot of work later.
Getting the neck angle set into the sides now , will make the final set up easier.

Like building a house. Set the foundation right and the work is easier. Other wise you are following a mistake through the whole construction
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Danl8
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Joined: Mon Jul 28, 2014 7:50 am
Location: Chadds Ford, PA

Re: Side profiling question

Post by Danl8 »

I can echo what John said having observed one being done and got hands on another. His process is well-thought out, efficient and fast. And like he said, provides an excellent foundation for later in the building process. This part of the build didn't take more than 5-10 minutes not counting kerfing gluing.
Metalone72
Posts: 48
Joined: Wed Jan 18, 2012 3:36 pm

Re: Side profiling question

Post by Metalone72 »

I am not questioning John's process at all. I think it makes great sense to do it starting with the just the sides. I guess I was a little confused. If you take the time to put the radius in the side and blocks prior to gluing the Kerfing on, then why would you want to sand it out (Flat) after the Kerfing is on and then re-establish it? Again I'm not questioning the process per se, but trying to understand it. Unless I have it wrong, which wouldn't be too far off :)
MaineGeezer
Posts: 1711
Joined: Wed Aug 13, 2014 12:14 pm

Re: Side profiling question

Post by MaineGeezer »

That doesn't sound right. Can you provide a link to the video in question?
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: Side profiling question

Post by tippie53 »

you don't have to do it again once the kerfing is on. If I did say that in the video what I should have stated is
do the radius on the top the middle part gets flattened.
If you remember I put chalk on the rim. That is the read. So it sounds like your questions were valid and correct
One the first is is flatten and radius
then radius and flatten it is just that center section that gets the flatten process to joint the kerfing for later gluing.

if you need to call me please feel free to do so
jh
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
MaineGeezer
Posts: 1711
Joined: Wed Aug 13, 2014 12:14 pm

Re: Side profiling question

Post by MaineGeezer »

I just watched this one: https://www.youtube.com/watch?v=LrgRKKsxL-M

John first sands a 28' radius into the top, then he flattens just the small area around the neck block, just enough to take out the radius in that section. It takes only a few strokes of sanding. You'll note that when he does it, his flat sanding plate is tilted so it contacts only that front area. This is, I imagine, to let the fingerboard extension lie flat on the top. The amount in question is tiny. In fact, I just drew it out to scale in a CAD program, and over 3" the difference between a 28' radius and flat is only 0.0033". I think this qualifies John for the title of "Perfectionist," but the details matter.

Is that what you are talking about?
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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