Jump to content

Finally Made Some Semihollow Sawdust


davee5

Recommended Posts

Well I finally started cutting wood on the guitar I've been planning forever. Here's what's gone down.

RoughTopHollowedBody.jpg

The Overview:

Mahogany body hollowed (Scott French style) and overall outline routed. Koa flat-top roughed and f-holes cut, filed to shape, and purfled. Built an electric pipe-style bending iron for the wood bindings. Generally made a huge mess in the garage and worked through 4 meals this weekend. Guitarbuilding will be great for my skill development and waist reduction at this rate!

What Went Wrong:

1. When I drilled out most of the wood for the hollowing I use the biggest twist bit I have, about 3,000 times, with tape as a depth reference. A few went a mote deep (internal, cosmetic annoyance, not threatening to punch through) and couple are off-axis (handdrill) and into the wood I want to keep (again, just annoying).

2. When I routed the internals I hadn't planned for the size of my router base and so there are a few areas where I was using only a few millimeters for support and I let it dive a bit in places, again cosmetics since it's not perfectly flat.

3. When routing the outline of the body I have serious tearout along both of the horns, quite luckily it was all on the second pass and all the tearout falls well withing the roundover space. Frightening but no damage.

4. When routing the outline I bobbled the router a bit and have a slight gouge on the outside. Again I got luck in that it's right where I should put the output jack, so I guess the cover plate will just cover the slight divot.

5. I can't bend bloodwood bindings for beans. Before I glue the top on and then rout it to match the sides I want to have the f-holes finished, including binding and purfline. I got all the f-holes purfled no problem (I cheated because there was no way I was going to rout a 0.030"x1/8" channel in those tiny things. Instead I just glued in 4 full layers of purfling and then scraped them down the the right surface. HA!) and even got some nice miters in there. The bloodwood I want to use for binding, though, is not going so well. The wood doesn't bend until it's scorched and scraping off the char leaves a remarkably uneven surface, then once it's the right shape (almost) it's splits. ARRGH! I'm going to soak a strip in water overnight and through the workday tomorrow, but I think bloodwood might not have been the best choice for my first woodbending project. I might try rosewood next, and then if I have no skills at all I'll just use tortise-shell plastic.

Notes to other novices:

- Cutting the rough outline of a 1-3/4" thick mahogany body with a coping saw works fine, but it takes for ever. Also if you're single you might not be getting any "action" for a while 'cause your forearms will be a bit sore.

- BWB style purfling is easy, it's basically paper and you can tie in knots, but wood bindings are friggin hard.

- F-holes are awesome and all but they are not easy to get right, you can't really rout 'em and if you dont' have the patience to file for a day or two to get them right, forget it.

- Plan your routing carefully ahead of time, including how much support your router base will have if you aren't using a router-table. Also take off as much wood as possible in your roughing-stage. The less wood the router needs to eat the better it will do. Sharp bits kick serious-butt. Lastly, I highly recommend constructing some kind of containment zone for your routing because the chips and dust will be FLYING. I made a little booth out of any old sheet tied a few stools I clamped to my workbench, helped a ton in cleanup an roomie relations.

That is all for now, more updates to come as this thing rolls along. Unfortunately it's almost at a standstill until I get the binding thing figured out. I guess I could do some neckwork when I'm freaking out about the latest broken piece of pretty red wood. Well, what do you all think so far?

-Dave

Link to comment
Share on other sites

Also if you're single you might not be getting any "action" for a while 'cause your forearms will be a bit sore.

Well, you won't get any if your'e in a relationship either. The time you spend doing (!) the guitar instead of treating your better half will suffer this. And your arms will still be sore, so there you go.. :D

I think it looks good so far. Bummer with the inside cavity, but it's not gonna show anyways, so not too bad...

Keep on it!

Link to comment
Share on other sites

Yeah, the goofups are on the inside but it still bums me out. However the drill marks at teh top are unfortunately placed JUST right for me to see them from a playing position through the f-hole.

I'm thinking about putting a Gibson-style label over the drill issues in the top hole. Maybe an ebony or other dark-colored veneer to also make the holes look darker in direct light.

-Dave

Link to comment
Share on other sites

Looks very nice so far, but there's two areas that I'd be a little iffy on. The "support block" for your bridge doesn't look very big/wide/thick. I'd be worried that once strings had some preassure on them that that little wood around the posts wouldn't be a good thing, ESPECIALLY if it's a wrap around and not just TOM.

Secondly you don't seem to have left much wood mass for glueing in support for you neck set either... so unless it's a bolt on that may be issue as well. In turn with this the edges in the upper horn seem pretty thin as well... but I guess there won't be much hitting in those areas so that's not HUGE.

Chris

Link to comment
Share on other sites

Hmmm, well lemme clarify a bit and lemme know if you still forsee some issues:

It's a string through design, the curvy island block is the where the string holes will be drilled. The bridge (graphtech TOM) will be sunk into the Scott French tuning forks and should only see close-to-vertical loads, so I forsee no issue there. Additionally it will have a 1/4" thick piece of koa to fully surround it. All horizontal loads from the strings should be borne by the presumably thick-enough koa top, as distributed through the metal top-ferrules, so I figure the size of the block I have for taking up the vertical tension (through the body) string tension should be fine.

You can see the overall layout in the laser-cut template here: http://www.devansdesign.com/files/guitarbu...AndTemplate.jpg

Clearly these are all my own conjectures from weeks of staring at this wood to properly asses it's strength. So in all cases I say should be strong enough, but it's not like I did wood FEA.

Bolt on neck. Basically all the pocketing is designed for 3/8" clearance around all edges, and a little more around the bolt on neck pocket. The extra material at the top edge is to allow for a slightly deeper body cut.

-Dave

P.S. Anyone got tips on how to bend bloodwood?

Edited by davee5
Link to comment
Share on other sites

Hmmm, well lemme clarify a bit and lemme know if you still forsee some issues:

It's a string through design, the curvy island block is the where the string holes will be drilled. The bridge (graphtech TOM) will be sunk into the Scott French tuning forks and should only see close-to-vertical loads, so I forsee no issue there. Additionally it will have a 1/4" thick piece of koa to fully surround it. All horizontal loads from the strings should be borne by the presumably thick-enough koa top, as distributed through the metal top-ferrules, so I figure the size of the block I have for taking up the vertical tension (through the body) string tension should be fine.

Clearly these are all my own conjectures from weeks of staring at this wood to properly asses it's strength. So in all cases I say should be strong enough, but it's not like I did wood FEA.

Bolt on neck. Basically all the pocketing is designed for 3/8" clearance around all edges, and a little more around the bolt on neck pocket. The extra material at the top edge is to allow for a slightly deeper body cut.

-Dave

P.S. Anyone got tips on how to bend bloodwood?

Looks structurally cool to me. I referance an acoustic top and how it carries the bridge load with much lighter support. This one has many times the strength of an acoustics top. I think the work looks great! very clean and I think you are putting a lot of thought into the design(and it is paying off :D ).

As far as Bloodwood. It is brittle. Take it down thin maybe .04" and get up to temp before you bend it. Those tight curves are going to snap in a heartbeat if you do not have it properly heated and well supported as you bend. I would personally perf out a little fine line BWB to fill out the width a bit.

Peace,Rich

Link to comment
Share on other sites

Supported.... good call. I'd just been pushing on either side of the bend without supporting the bend point itself, I can see how that woiuld exacerbate a tendency to fracture. I've been wearing my welding gloves while I do this, so I'm handling the wood directly, not with sheeting or anything. I made my bending iron using a roll of thin aluminum sheet, which I bent into an egg shape for versatility, around a BBQ heating iron. I'll take some of the extra Al and make a bend supporting piece, should distribute the load better too.

-Dave

Link to comment
Share on other sites

Supported.... good call. I'd just been pushing on either side of the bend without supporting the bend point itself, I can see how that woiuld exacerbate a tendency to fracture. I've been wearing my welding gloves while I do this, so I'm handling the wood directly, not with sheeting or anything. I made my bending iron using a roll of thin aluminum sheet, which I bent into an egg shape for versatility, around a BBQ heating iron. I'll take some of the extra Al and make a bend supporting piece, should distribute the load better too.

-Dave

Dave, A little trick that can help with really touchy wood. Take a piece of tin foil and place the binding on it. Spritz it with water and wrap it up(no more than two wraps of foil) use some common masking tape to lightly seal the ends. This will help get a bit more even heat transfer. Getting the wood up to proper temp is the real trick with a bending iron(made tuffer in a tight corner).

Peace,Rich

Link to comment
Share on other sites

Mahogany neck, 25.5" scale, ebony fretboard w/ matching binding to the body (whatever works). I'll be taking extra koa cutoffs and making the headplate (the best flame is actually in the scrap. boo, but it couldn't be avoided). Dots will be black MOP, side dots might be paua for better visibility (I have sets of both, I just need to decide). As a mechanical engineer I'm thinking I might make the dots little gears as a personal touch, but those seem like they'd be hard to get just right, lopsided gears look really bad.

Had a nice flatsawn board that twisted on me, I ordered a new honduran mahogany neck from LMI and I'm not sure I like it as it's really light in color and density. I might pick up another. I don't have a jointer or tickness planer/sander so trying to save the other piece might be a bit hard with a jack plane.

I'm also winding my own buckers. Yeah, I know, I'm out of control, but I built a winder already and now I'll have built just about everything on the guitar, even have ebony cutoff I've jointed, glued up, and slated for pickup rings.

The design planning is in this thread, you can see the headstock/neck layout there:

http://projectguitar.ibforums.com/index.ph...hl=devansdesign

Thanks for all the nice notes, guys. Unfortunately I'm gonna have to bolt for Germany tomorrow on business, so it's on hold again for a bit.

-Dave

Edited by davee5
Link to comment
Share on other sites

Davee, for your router problems --take a fairly long piece of MDF that's as least as wide as your router base, and, say, twice as long, and cut a decent hole in it. (I use scrap from fake parquet flooring--nice and slippery). Then use double-sided tape to hold it onto the router base (you can also drill countersunk holes and bolt it to the base, if your base allows that).

That will take care of your worries about the router slipping off the edges of things.

For the outside, I save the scrap from the body blank after I cut out the body, because obviously the scrap is the exact same height as the body. Makes it easy to clamp it down to provide support for the router. You can add the scrap from the top to keep things at the same height too.

That MDF sled is also really helpful if you're trying to plane/thickness with the router. For larger pieces, though, I replace the MDF with a couple of long hollow square steel rails--they won't bend at all.

Link to comment
Share on other sites

This is looking really good, Dave...e :D Good to see you are planning out things in advance, something I didn't do as much as I probably should have, haha. Your pictorial is coming out really nice!

It's too bad about the little craters in the inside cavity, because when I first saw the clear template over the routed body, I thought that a clear plastic top over the chambered body would look awesome :D

Good luck!

Link to comment
Share on other sites

Yeah I'm thinking rosewood might be the way to go. I'm way out in the Black Forest (far far from the wood in my California garage) on business and can't stop thinking about the binding. I really would like the red border on this guitar, but if I can't do it then I'm hosed. In any case I actually need to get it rather done by March 1st (including it in a design portfolio I'm submitting somewhere) so I can't sit at home and bust binding stick after stick trying to get the horns right.

I figure even if I thin out the portions for the f-holes I still want the edges to be full thickness and the horns are as tight as my curvature gets. Maybe time to switch it up.

Can't wait to get home and get cranking back on this, I know what my all-too-short winter holiday is gonna look like... Avoid the family and play with the guitar project! (I love my family, but they don't sound nearly as good as I hope this will.)

-Dave

Link to comment
Share on other sites

  • 3 weeks later...

Well I got back from Germany in time for the holidays and a chance, between family obligations, to bend some rosewood bindings. Holy geez is rosewood easier to bind than bloodwood. At first I was afraid I just didn't have the touch for bending wood and I was doomed to plastic, but no sir, I just made a bad choice for my first attempts. even my first try was right on, and immediately glued in.

wet_top.jpg

So the f-holes were bound in rosewood, the top was glued up, routed to fit, scraped flush, and then a slight carve scraped into the top. Tonight I'll rout the body binding ledge. Then I'll need to rout pickup cavities, drill holes for bridge posts and string throughs (need a drill press first, not gonna do those by hand), and shape the back edge of the mahogany a bit. Then it's on to the neck.

In any case, here's a few update shots.

Also I'm exploring a possibe fretboard inlay/position marker arrangement in this thread, and I would love some feedback.

A few quick questions:

- I have purfling and plain bindings, but I would love to have purfling "under" the binding on teh body side too, not just around the top. Can I bend the finebwb purfling easily in the "wrong" direction to hold it in place, or should I buy the bindings with bwb accents pre-attached?

- Should I wait to route the pickup holes until after I've finished then neck and then routed the neck pocket?

More pics as progress rolls on!

-Dave

Edited by davee5
Link to comment
Share on other sites

Dave, I haven't read the whole thread, but based on your first post and the pics things are looking really nice! One thing I have to say is, I'm impressed by your evaluation of your work at every step. You're taking every opportunity to learn by seeing where your techniques could be improved. Sign of someone that will be making some great instruments :D

Edit: Yeah Bloodwood. I bought a couple boards to make tops from. I haven't cut it yet but it's amazingly dusty with fine red dust. I bet it'll be great fun putting this stuff through the plainer...

Edited by Son of Magni
Link to comment
Share on other sites

Hey I remember the design thread for this

Thats looking really fantastic!

Looking forward to seeing how this develops

Link to comment
Share on other sites

man, i'm loving this guitar.

i think it's one of the best builds i've seen on these pages for a while. (no offence to any one else!)

can't wait to see it finished.

cheers

darren

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...