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djobson101

Carving & cutting questions

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I am trying to make a punch list for my current project, and am having some deliberation on the order of operations for the top. Basically what I have is an old import LP copy that I have been tearing apart and dressing it with some better quality woods for improvement - I figure this is good practice before I start building one from scratch. 

I'm not sure what wood the neck and back are made of, maybe you guys will know if I can figure out getting some pictures on here. My old man suspected it was meranti? Anyway, the "top" just had to go, it was pretty much a piece of thin plywood that was bent/pressed over a little block that was adhered to the back for the bridge and tailpiece bushings to go into. I realize putting effort into this guitar is only really fruitful for sentimental attachment more than anything (a friend's dad found this thing in a dumpster when we were in high school :rolleyes:), but again I think it will be a fun way to sort of cut my teeth on guitar building.

I'm in the process of making templates to rout hollow chambers in the body, and then I'm planning on having a carved top with f-holes. This is sort of where I'm scratching my head as far as which thing to do first. Is it wiser to cut the f-holes before or after carving? I will get some pictures going here shortly.

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This thing is pretty horrendous. Since I took these photos I've been epoxying some hardwoods into some of these really... questionable areas, like the rout for the selector switch wiring that is over an inch wide for some reason. And the truss rod cavity as well I adhered a strip into, to re-rout in the future because it too was much too wide in what is already a real flimsy neck

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Photo Dec 18, 7 58 53 AM (1).jpg

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These are some oak wall panels that I obtained from my folk's house, they are about 1/2" thick. One additional question I have, is that I have a slight cup to this "top" - will this be acceptable to let the clamping take care of, or would it be good to address this before I start gluing things together?

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Photo Dec 28, 9 10 56 AM.jpg

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The cupping is an issue you should deal with before gluing the top on. It needs to be flat on the side that will get bonded to the body. Attach some full sandpaper sheets to a flat surface and sand it down level. I think ScottR has some pictures of this process in one of his build threads. Be prepared to use a lot of elbow grease using this method. Actually Scott can probably chime in here as he's done many of his tops around existing necks to cover his deep neck tenons.  

As far as the F-holes, You'll usually want to cut them after you've completed your carve but before you glue the top.

 

BTW Are you using the oak for sentimental reasons? 

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Not entirely, with the oak - it did happen to be in the right spot when the thought crossed my mind I suppose :) but I've been wondering for some time why I don't see or hear much about oak being used for guitars, I'm starting to think there's probably some good reasons not to?

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On 12/28/2015 at 4:51 PM, sdshirtman said:

The cupping is an issue you should deal with before gluing the top on. It needs to be flat on the side that will get bonded to the body. Attach some full sandpaper sheets to a flat surface and sand it down level. I think ScottR has some pictures of this process in one of his build threads. Be prepared to use a lot of elbow grease using this method. Actually Scott can probably chime in here as he's done many of his tops around existing necks to cover his deep neck tenons.  

As far as the F-holes, You'll usually want to cut them after you've completed your carve but before you glue the top.

 

BTW Are you using the oak for sentimental reasons? 

Agreed. You need to flatten the gluing surface before actually gluing it or it will spend the rest of its life trying to pull away from the body. Check out pretty much any of my builds for some pictures and instructions on doing what sdshirtman is describing. However, I would recommend gluing the top to the body before carving. I just trust clamping flat parts together more so than curved parts, which is what you'd have if carving first. That would call for cutting the F-holes first. I also prefer to route for the pups and what-all before carving because of the nice flat base you have to attach your template to. But that's just me--sdshirtman has demonstrated awesome results using the opposite work flow. Just be sure to think it through and note what you'll need to make each step successful.

SR

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Oak (at least, white Oaks) are silky woods and looks great when well finished. They are however somewhat hard to work and coarse. It's not a common guitar wood mostly because people are too hung up on the traditional established norm woods and partially because it isn't as easy to work as more commonly-used woods. It's also awfully heavy.

Personally I love Oak, especially when burnished up and given a little clear paste wax or beeswax. Or treated with ferric acetate (steel wood dissolved in vinegar) to turn it a deep black blue.

Very true about the cupping. Consider (and test) how much force it takes to drive it back to flat using clamps. That exact (well, a bit less since it'll be made smaller but the magnitude is good for demonstrative purposes) force will be the one the finished piece will live under. At worst it'll try and pull away like @ScottR mentioned; at best the body will cup to balance forces between the top and back.

It definitely needs consideration for flattening, however this is simply about informed choice; once you know the risks or downfalls, you can weight those against the work it takes to flatten it (if that is an option for you) or accept them if you don't.

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Thanks all for the insight on this guys. Hoping I'll be able to dedicate a few solid nights to making a plan & working it out now that the holiday/new year madness isn't pulling me away from the guitars. I was thinking what might be a good idea to try, since I will undoubtedly get good use out of it in the future, is to build myself the thicknessing jig from the other thread in this section (thank you @Prostheta)

The gluing surface of this top could probably lose about 1/16" - 1/8" to be in good shape to move forward, which is good because I forgot to mention too that there is still the remnants of the profile/coves/whatever it is that millwork guys call it on the back of these oak boards. I had run them through my old man's planer to get rid of them, but I was in somewhat of a rush that day, the blades on the planer were near the end of their life and I think the oak may have been the proverbial straw, if the blades were a camel :unsure: 

If nothing else, using the oak will push me to get some nicer tools. Somehow I don't think the $5 rasp set I currently have from Harbor Freight will hold up to working on this :happy:

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I won't lie. It's a lot of work; more than it would be to build one from scratch in many respects!

Oak is one of those woods that seems odd in instruments, but mostly from a lack of familiarity. Once it gets sanded up to about 400 grit it becomes silky and quite unique-feeling. I have a couple of Oak stools around the house that I made which just have a simple colourless wax finish on them....really tactile. Oak displays medullary ray flecks off the quarter too. Those are beautiful, but weird to work with since they like to catch and pop.

Can't say no to a good rasp. I've been hankering for a new short Liogier rasp to match my cabinet maker's rasp. I can't get over how transformative working with that was for me.

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