Building an Archtop Guitar

[wwwilkie]

Thought I would post photos as I build this custom guitar for Steve Rowe of Ashland, Oregon. This will be a 16" cutaway, the design of which is roughly inspired by my Northern Flyer mandolin. The first photos are cutting the sides from a slab of curly big leaf maple, then thickness sanding them to .090". I hope to post at least once a week.

[billkath]

Great stuff!! This will be really interesting.

[SamBooka]

I look forward to your posts. I never actually thought of how luthiers cut the sides. I assumed it was done at a mill and were then sold off.

Thanks!!

[wwwilkie]

Sure have nothing against buying sides pre-cut, but whenever I can I'll do it myself. Glad there's some interest here, will try to post as often as possible. Here's a shot of the body template with mould hanging above it. The next photo is the same template with custom sound-holes.

[wwwilkie]

Next the sides are bent using my home-made bending press. The flexible heater is sandwiched between two thin sheets of stainless steel, underneath that is the dampened wood, followed by one more sheet of stainless. Once the heater is turned on it quickly reaches a temperature of 325 degrees F. The presses are then cranked down slowly one at a time. This is done for each half. The cutaway side can be done by taking out the insert and installing heavy springs to support the wood as it is bent. Before building this contraption I would bend the wood over a pipe heated with a torch.
Neck and tail blocks are then cut from mahogany and glued up with the sides in the mould. Yes, this is my friday night.

[SamBooka]

Very nice.. how does the neck and tail blocks affect the tone? I have a Epiphone Emperor that has a remarkably cheap neck block (low grade plywood sandwich). It is quite solid but I dont know how the materials affect tone.

[amusiathread]

VERY cool, please continue to keep us posted, I'll wager that quite a few of us on the forum will be interested in keeping up on your progress.

[wwwilkie]

Difficult to say. Intuitively I will use spruce, mahogany or poplar for neck and tail blocks although there are many options that would work. I think weight is a big factor here i.e. lighter woods for a lighter, more resonant instrument. I think plywood would do a good job but I wouldn't use it just in case someone were to peek inside and see it.
Thanks for your interest, really appreciate the comments.

[SamBooka]

All thanks go to you. This is a great thread you have started!

[wwwilkie]

So the sides have been bent and clamped into the mould. Next the linings are glued in to provide a decent gluing surface for top and back, and side braces are installed for strength.
After this the wood for top and back is selected. In this case I'm using quarter-sawn big leaf maple for the back, trying to get a good match for the rest of the guitar since it will be a natural finish, no colour being added. The top is Engelmann spruce and is also quarter-sawn. These billets are resawn and joined. For 10 years I did this by hand, only recently buying a jointer, so now what used to take over an hour takes about 30 seconds. A long overdue purchase. They are then planed to 7/8", the outline is traced onto both and they are cut out slightly oversized.
Now there is some carving to be done.

[SamBooka]

Forgive me but I am miliking this thread (for the greater good of course
Do you make your own kerfing or is cheaper/easier to buy it?
EDIT: I just noticed the gaps every 5 or so inches in the kerfing. Why?

Side question. What do you use for glue?

I always wondered what jointers do but I can google that.

Keep it up!

[wwwilkie]

Hey good eye. I leave the gaps for the side braces which I make from straight, tight grained sitka spruce. I buy the kerfed linings for guitars, make my own solid linings for mandolins. Here is an updated photo of the guitar.
I use aliphatic resin glue for just about everything (wood glue). I've heard great things about hide glue but haven't felt the need for anything else.
A jointer (a good one) will make a clean, perfect joint in a few passes for joining tops and backs. Picture an electric planer mounted downside up on an adjustable table. It also doubles as a meat grinder so you have to be fairly confident with power tools to use one.
Thanks for the questions, I know I'm skipping over quite a bit so feel free to grill me about anything.

[Jazzaluk]

Hi wwwilkie

Great thread. I lived in Comox for 6 years. Fantastic place to live. Did you learn your craft in the area? I know there is a great luthier school in Qualicum.
My son used to hangout with a student who now works at Fbass in Hamilton.

[wwwilkie]

I've only lived here in Comox for a year. I apprenticed with guitar maker Bob Benedetto in Savannah, GA. Before that I built mandolins for many years mostly in Great Britain.
Comox really is a great place to live and we're glad to be here. Finally settling down and really getting into building.

[Jazzaluk]

Very nice!!!

Have you met Doug Cox, the force behind the local RootsFest and a big influence Canadian folk scene. He used to host a really cool open mic in Cumberland.

Anyway, I always wanted to build an acoustic or archtop guitar. The idea has always appealed to me as an engineer and as a guitar player. Unfortunately, I fear that I underestimated the craftsmanship, dedication and time required. Maybe when I retire I'll give it a try.

I am following your thread with great interest. Thanks for posting.

[wwwilkie]

Here is probably the most labour intensive part of building an archtop guitar. For this some will use a gouge with mallet, some use a pantograph carving machine, others use a CNC. Lately I've been getting some help from an angle grinder with a 40 grit flap-disc attached.
In the first photo I'm drawing a line approximately 1/4" up from the bottom, knowing that I can't carve below this line.
Next is roughing out the general shape (very general) with the angle grinder.
I will then rout down to that 1/4" line creating a flat area around the entire guitar. For this I use an overhead router but a safety plane could be used mounted on a drill press.
After this I'll go to the angle grinder again, or the big planes depending on my mood. This is getting close to the final shape and takes a lot of practice. I don't use templates for this, going only by eye and by feel.
Here the smaller planes come into action. It is time to get down to the final shape.
The outside arch is finished and ready to be smoothed out.

[wwwilkie]

Here we have the smoothed out maple back. Next I'll flip it over and roughly trace in where the blocks and linings will be, giving myself plenty of extra room.
On the drill press I'll set the drill bit above a rounded dowel to a measurement I have predetermined. This measurement isn't critical as long as it is not set too shallow as this will be the thickness of the arch I'll be working with.
Next I place the back over the dowel and drill holes all over the area between the lines I sketched in earlier. The number of holes doesn't matter, but the more holes drilled the less wood there will be to remove later.
After drilling I use the grinder again and grind down until the holes are just about gone.
Then it's back to the planes. I'll plane all of the drill holes away and work at blending the arch from the middle out toward the edges.
After this step there are no more measurements to be made, going by feel and flexibility.
The final thickness will be carved in after the guitar body is put together but in the next step I'll take it nearly to that point.

[kamlapati]

Great thread, thanks for sharing. You really are lucky to have rubbed shoulders with Bob Benedetto.

My big sister lives in Victoria, and my nieces and nephews are all over the island in Vancouver too. I'd love to drop in some time!

[Dookychase]

Kamlapati, while you're in that area, you could also check out Mike Kinal. He builds some nice guitars, he's also in Vancouver.

[wwwilkie]

Originally Posted by kamlapati

Great thread, thanks for sharing. You really are lucky to have rubbed shoulders with Bob Benedetto.

My big sister lives in Victoria, and my nieces and nephews are all over the island in Vancouver too. I'd love to drop in some time!

I was lucky to be able to learn from Bob Benedetto. I had been building mandolins for many years when I met him and jumped at the opportunity to work with him. I spent two years building his great guitars with him.

You should stop by the shop next time you're on the island.

[Meggy]

This is such an interesting thread, thank you! I wonder if you can explain the whole business of "tap tuning" at some point as I have always wondered how this is done and what you are aiming for with this. Cheers!

[wwwilkie]

Originally Posted by Meggy

This is such an interesting thread, thank you! I wonder if you can explain the whole business of "tap tuning" at some point as I have always wondered how this is done and what you are aiming for with this. Cheers!

That's a good idea. In the next post I'll try to explain my method and how it has developed.

[Meggy]

Originally Posted by wwwilkie

That's a good idea. In the next post I'll try to explain my method and how it has developed.

Thank you! I will wait with interest.

[lindydanny]

Wow. Awesome carving! I could never get my plane irons sharp enough for that time of curled shaving. Do you hand sharpen or use a grinder/jig?

~DB

[wwwilkie]

Originally Posted by lindydanny

Wow. Awesome carving! I could never get my plane irons sharp enough for that time of curled shaving. Do you hand sharpen or use a grinder/jig?

~DB

Thanks. I just hold the iron and move it over a bench grinder, kind of swooping it across to follow it's curve. Then I remove the burr on a strop. I don't use any kind of jig for this. It is a quick and simple method that keeps the blades sharp for a long time without being so sharp that the edge becomes brittle. I can carve several tops and backs without sharpening. It's kind of a compromise, pretty sharp and pretty strong.
For awhile I was a sharpening junkie but found I was spending too much time on it. On the grinder I think the trick is to have the light at the right angle so you can see the burr form.
I know there is a whole sharpening sub-culture out there that would be horrified by this but it works really well for me and keeps me productive.

[wwwilkie]

In an effort to explain my approach to tap tuning I'll include a few photos.
In my opinion there is no right or wrong method for this, and I'm sure every builder achieves different results no matter how they might approach it. Aside from the design of the instrument, tap-tuning is the one area where the builder can add his/her own voice to the work. And this comes about through experience.
My own experience with tap-tuning began when I started making mandolins. Like many others when I started I used Gibson blueprints and followed the measurements listed very closely using calipers. But then why didn't they all sound the same? I then did some research and noticed a lot of mandolin builders were using a strobe tuner, tapping various parts of the top, back and tone bars trying to get certain pitches consistently, hopefully get consistent results. I did this for a few years without much success. After awhile (maybe too long) I gave this up, throwing away all the notes I had taken along the way, notations made after just about every plane stroke, every tap of the hammer. It seemed to all amount to nothing. The last thing I would want to do is discredit this approach as I'm well aware that many use it with great success. It just doesn't work for me.
It was around this time I landed an apprenticeship with archtop guitar builder Bob Benedetto. This changed everything for me almost overnight. For 2 years I got to learn from a master who had been building for 40 years (I had been doing it for a mere 8 or 9 at the time). It was around this time I learned to throw the calipers away and follow my instincts. I'll try to keep this short as I go over the photos.
In the first photo I'm checking the flexibility of the plate after the initial planing down just to see where I'm at. It is always very stiff at this point so there is more carving to be done.
I'll keep carving and checking until it starts feeling flexible, making sure I keep things even all over.
The 3rd photo is one way of holding it while checking for flexibility, I'll get into a routine, checking it while holding it in both hands as well as pushing down on it while it's clamped in the cradle.
The next photo is the classic tap-tuning pose. This is a way of getting familiar with the wood and tones produced. In the beginning it will sound very tight and unresponsive, but slowly the pitch will lower and become more defined. Once you become familiar with the tap tone, there will be certain sounds you will seek out and come to expect.
In the next photo it's back in the cradle for some more carving, getting it to open up some more.
When I'm satisfied with the feel, flexibility and tap-tone I'll take it to my sanding table and smooth it out with 40grit sandpaper, then finish it to 80grit or so.
This, a very abridged version tap-tuning, is a great way to eventually get consistent results carving top and back plates, as well as leaving lots of room for growth and improvement as an instrument builder.
Questions and comments are welcome if anyone has made it this far.

[SamBooka]

Originally Posted by wwwilkie

I know there is a whole sharpening sub-culture out there that would be horrified by this but it works really well for me and keeps me productive.

I read an interview with Paul Reed Smith where he went to Japan. He was amazed by how sharp the tools were. In Japan you "sharpen all morning and carve all afternoon" or something to that effect.

StewMac had a Tech Tip on how to sharpen chisels. I had never tried it and was shocked how easy they are to use when they are sharp.

Keep it up!

[lindydanny]

These are some great walk thrus! Thanks for the effort!

~DB

[wwwilkie]

[quote=SamBooka;95510]I read an interview with Paul Reed Smith where he went to Japan. He was amazed by how sharp the tools were. In Japan you "sharpen all morning and carve all afternoon" or something to that effect.

Yes, I've made a couple trips to Japan myself in recent years and there seems to be an ancient, truly magnificent woodworking culture they have. I picked up up a few tools while I was there and I use them often.
Never have I had my instruments scrutinized like I had over there either, really forces you to take things up a couple notches.

[jackmac]

YouTube - Hybrid archtop guitar

This builder has a series on his You Tube site showing the stages of building a guitar from start to finish.
Interesting process