Wood Cavity Covers

[Duff Beer Man]

How are the wood cavitys done to where all the grain still matches up? Its kinda hard to explain so here is a pic of wardd's Gotm entry.

[thegarehanman]

I do it by slicing about 1/4" off of the stock i'll be using for the body(or rather getting someone with a big enough bandsaw to do it for me ), then I cut out the cover with a coping saw, slide a piece of veneer in the kerf going from the outside of the resawed piece to the new hole where the cover was just cut out from(this peice of veneer will be less visable if the cut goes parrallel to the grain), and glue the resawed piece back onto the stock it was originally cut from. Obviously it's a little more involved, but that's more or less it. This method allows you to avoid the brackets you'd need to add in if you cut out a chunk in the shape of the control cavity from your solid blank and put a top on it.

[Mattia]

On the one I did, I used a dremel with a small bit to simply route it out, and added binding around it to fill the gap it left.

[Setch]

On my latest guitars, before thicknessing the blanks with my router jig, I routed around the cavity cover outline on the back, and left this area untouched when thicknessing.

Once the piece has been thicknessed with the router, I used a small kerf saw to slice the pieces off the back of the blank:

These bits were then thinned down, and used for the covers. I left some space round the edges of the cover shape (by using the cover template and a guide bush) which means you can adjust exactly where on the blank you cut the cover from. This allows you some extra wiggle room to get the grain aligned - on a flatsawn blank the grain will shift sideways quite a bit.

Here's the result.

I do it by slicing about 1/4" off of the stock i'll be using for the body(or rather getting someone with a big enough bandsaw to do it for me ), then I cut out the cover with a coping saw, slide a piece of veneer in the kerf going from the outside of the resawed piece to the new hole where the cover was just cut out from(this peice of veneer will be less visable if the cut goes parrallel to the grain), and glue the resawed piece back onto the stock it was originally cut from. Obviously it's a little more involved, but that's more or less it. This method allows you to avoid the brackets you'd need to add in if you cut out a chunk in the shape of the control cavity from your solid blank and put a top on it.

Why do you need to glue in the veneer? Can't you drill a small starter hole and string the coping saw in the hole. This removes the need for an entry cut, so there's no need to dissappear it later.

Just FYI, I do a similar thing for templates. I got tired of drilling, jigsawing etc the waste out of templates whilst leaving the edges solid, Now I cut out the waste on the bandsaw, then glue veneer in to patch the entry cut.

Edit: The board seems to have picked up some cool new features - I added the question to Russ as an afterthought, in a separate post. The board appended it to my previous post - neato!

[Mattia]

On my latest guitars, before thicknessing the blanks with my router jig, I routed around the cavity cover outline on the back, and left this area untouched when thicknessing.

Once the piece has been thicknessed with the router, I used a small kerf saw to slice the pieces off the back of the blank:

See, now that's elegant, and would work great for the few flat-backed designs I make (I tend to carve top and back on my carved tops; I just like the way it flows). Neat!

Tip: get ye a japanese handsaw. Sooooo much nicer than western-style blades.

[Setch]

I have a small flush-cutting pullsaw (Shark brand), but I prefer this one for this application. Because you're ripping with the grain, the flexible blade of a pullsaw gets drawn off target. The added stiffness of this blade lets you minimise 'wandering'. It's also a very nice saw, and toothed like the little saws you get on a swiss army knife - very aggressive cut, and very little set to the teeth. I've used it to resaw a 7" x 24" maple block for bookmatched tops, not fun, but it worked a charm.

I do agree that pullsaws are much nicer for most applications, and very low effort, but unless they're back saws, your ability to 'steer' the cut is limited - once that blade starts going astray it's a bear to stop it going where it wants to.

[erikbojerik]

I do what Russ does, but make a starter hole with an Exacto knife and use a scroll saw to cut out the plates. I use the thinnest-kerf blades I can find.

I like the idea of filling the gap with veneer, that's a nice tip!

[thegarehanman]

I tried the starter hole method, but all of my coping saws have blades that have these pins used to attach them to the handle. It's not like a jeweler's saw where you just clamp it in. I even tried modifying th blades by cutting off the pins, drilling a hole, sliding the blade through the work, and sliding a finishing nail into the blade to serve as the pin. The nail couldn't take the stress though. I ended up using the method i described, and it worked well. I ended up binding the cover, but it would have looked fine without it too.

peace,

russ