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Building an archtop of some sorts

Posted: Thu Nov 24, 2016 7:00 pm
by Jay
May as well post the occasional update in its own thread rather than putting things in "Just Saying".

After the feedback from BG and others I have bought a cylinder rotary rasp. It really takes the edge away in a hurry on a high speed drill :D

Borrowed a grinder as the Bunnings suggested one was sold out in my local shop. Couldn't be bothered to drive towards Remmers for the next Bunnings.

I'll buy the grinder flap thingy tomorrow for removing the flatter areas.

So I focused on one horn and looks like it is going to be quite an arch. Totally unlike a Gretsch, or at least the one that I have. May have to start with a thinner board next time... Sigh!

Anyone knows what the typical archtop board thickness is prior to starting carving?


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See that blimmin knot? What a pain to carve that.

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Re: Building an archtop of some sorts

Posted: Thu Nov 24, 2016 8:43 pm
by dayl
Nice. Keep the updates rolling

Re: Building an archtop of some sorts

Posted: Thu Nov 24, 2016 11:46 pm
by robnobcorncob
jvpp wrote:
Anyone knows what the typical archtop board thickness is prior to starting carving?
1 inch according Bob Benedetto's "Making an Archtop Guitar" book.

Re: Building an archtop of some sorts

Posted: Fri Nov 25, 2016 6:16 am
by Jay
robnobcorncob wrote:
jvpp wrote:
Anyone knows what the typical archtop board thickness is prior to starting carving?
1 inch according Bob Benedetto's "Making an Archtop Guitar" book.
Interesting, his tops look deceptively flat. I started with 20mm but have kept the pickup area flat all the way to the neck, hence the more pronounced horn arch.

Re: Building an archtop of some sorts

Posted: Fri Nov 25, 2016 7:13 am
by bender
jvpp wrote:
robnobcorncob wrote:
jvpp wrote:
Anyone knows what the typical archtop board thickness is prior to starting carving?
1 inch according Bob Benedetto's "Making an Archtop Guitar" book.
Interesting, his tops look deceptively flat. I started with 20mm but have kept the pickup area flat all the way to the neck, hence the more pronounced horn arch.
I thought the usual thing was to taper the top from about the bridge or bridge pickup area. Are you going to carve out the back of the top (so that it's a more uniform thickness overall)?

Re: Building an archtop of some sorts

Posted: Fri Nov 25, 2016 9:18 am
by Lostininverness
Yeah, from what I've read you get your "neck plane" done at the angle to suit your bridge height, then to do the "pick up plane" from the end of the fret board to the bridge.

Looking good tho JVPP!

Re: Building an archtop of some sorts

Posted: Fri Nov 25, 2016 9:48 am
by AiRdAd
would this be suitable as a bridge? Seems cheap enough

http://www.trademe.co.nz/music-instrume ... 414196.htm

Re: Building an archtop of some sorts

Posted: Fri Nov 25, 2016 10:37 am
by Jay
bender wrote:
jvpp wrote:
robnobcorncob wrote:
1 inch according Bob Benedetto's "Making an Archtop Guitar" book.
Interesting, his tops look deceptively flat. I started with 20mm but have kept the pickup area flat all the way to the neck, hence the more pronounced horn arch.
I thought the usual thing was to taper the top from about the bridge or bridge pickup area. Are you going to carve out the back of the top (so that it's a more uniform thickness overall)?
Yes, the back will be carved out. Someone gave me some handy tools for it :D
Post by AiRdAd » Fri Nov 25, 2016 9:48 am
would this be suitable as a bridge? Seems cheap enough
Parts all sorted, bought the ABM bridge and Bigsby early this year.

Post by Lostininverness » Fri Nov 25, 2016 9:18 am
Yeah, from what I've read you get your "neck plane" done at the angle to suit your bridge height, then to do the "pick up plane" from the end of the fret board to the bridge.
I did the neck plane and the pickup plane angle is 0 degrees :D Doesn't matter for this build as I am telling myself it is a rehearsal for when I build one from the Redwood.

Reason for not planing the 'pickup area' is that I will be gluing the neck in with a longish tenon and will not use a dove tail as in 'proper' archtops.

Re: Building an archtop of some sorts

Posted: Fri Nov 25, 2016 2:40 pm
by StrummersOfThunder
This is very exciting .

Re: Building an archtop of some sorts

Posted: Mon Nov 28, 2016 11:38 am
by Jay
I can confirm BG's 'Flap Disc Carving' is marvellous and certainly speeds things up. I hate working with a blimmin grinder though. Still gives me the sh..ts.

After the flap disc agressive wood removal back to chisel and sandpaper. Here the result so far with 150 grid. I have gone for an 'unconventional' carve in that the carving rise happens fairly close to the edge. No need for acoustic resonance in this build.

I am also contemplating cutting off the neck bit at the pencil line shown in the 3rd photo. This would allow for better high neck access. Any reason why I shouldn't?

Flap Disc Carving result on the lower bout:

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Chisel and Sandpaper 150 grid result:

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Proposed guillotine cut shown by pencil line on neck bit: Should I or not?

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Re: Building an archtop of some sorts

Posted: Mon Nov 28, 2016 12:27 pm
by jeremyb
Looking awesome man!

Re: Building an archtop of some sorts

Posted: Mon Nov 28, 2016 12:52 pm
by bender
Didn't want to use the thumb plane? That's exactly what they're for- and they allow for a much smoother transition from concave to convex. Also, a French curve cabinet scraper does a great job at achieving a lovely, uniform carve.

Re: Building an archtop of some sorts

Posted: Mon Nov 28, 2016 4:06 pm
by Jay
Yes, i have used both quite a bit on certain sections of the top... the scraper quickly removes the chisel dimples/uneveness and leaves a surface rady for sanding. Great tool!

The problem I have with the plane, even on the smallest blade protrusion, is that it cannot handle the sections on the top where the grain 'doesn't behave'. Great for sections where the grain is cooperating so to speak. Maybe it is because of the macrocarpa (it being a softwood) that makes using the thumb planer difficult. On this top I had much better control with a rasor sharp chisel which allowed my to take tiny cuts out in the grain induced difficult areas.

So to avoid having to carve for the next month or so, I decided to make the concave/convex transition narrow.

As the inside carving won't be that critical from a visual point of view, I intend to practice and use the planer a bit more as it is indeed a neat little tool.


Anyone any feedback on the neck question I asked?

Re: Building an archtop of some sorts

Posted: Mon Nov 28, 2016 4:15 pm
by GrantB
Cool stuff.

The neck pocket - how deep will it be? Or is that finished depth?

Re: Building an archtop of some sorts

Posted: Mon Nov 28, 2016 4:19 pm
by H671
This might be a bit late, but you can buy a special carving disc to fit angle grinders. I can't remember where they are sold though.