Guitar One - Newbie getting feet wet

Discussion in 'Guitar Building' started by TheCaffeinatedOne, Apr 3, 2016.

  1. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    I've been studying this stuff for many years, but always came up with an excuse not to actually build anything. I did make some mountain dulcimers 40 years ago, so I've figured out a fair amount about the wrong way to install frets. :scratch:

    At any rate, I'm plunging ahead with an acoustic build; the body is based on a Gibson LG 2. My design has a boatload of differences, but I expect there will be a strong family resemblance. I'm not rushing anything.

    So far I've built a few jigs, a shooting board and a steaming box for heating up sides. I tried the shooting board out on some very old sitka spruce and it worked quite well; I got a great glue seam. I've jointed and glued the back plates and this afternoon will be doing some more puttering around, thinning the back and sides to building thickness.

    Here are a few pics of the project so far. Feels good to make some shavings.
     

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  2. poro78

    poro78 Well-Known Member

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    Always nice to see acoustic builds. Planning to do one in the distant future, we'll see if that ever happens.
    Enjoy the journey. :yesway:
     
  3. Murkar

    Murkar Well-Known Member

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    nice! Agreed, always nice to seeacoustic builds. looking forward to seeing how this comes together
     
  4. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    Yesterday I got the side bending form together. It's a little rough but should be functional. I used 3/4" ply and sunk 3/8" aluminum rods to form the surface for the wood. I don't plan to use this as a heating source, although I could change that down the line. Instead, I'm going to experiment with a steam box to heat the sides and use the form to capture and hold the cooling plates.

    I've finished that as well; it's a simple box about four feet long , six inches wide and four inches high. I'll install some aluminum rod to act as a shelf. There's a 2" hole in the underside and a vent. The plan is to sit this thing on top of a stock pot full of boiling water and let it cook for a half hour. The side then comes out and goes down quickly on the form and is clamped with cauls. I'll get some pics up in a bit. We'll see how it works.

    In the meantime, the sides still need another sanding to get down to proper thickness. Maritime rosewood is tough, knarly stuff to thickness down. When resawing (many years ago, before it seasoned in a forgotten corner) it dulled the bandsaw blade. I had to resort to lots and lots . . . and lots of sanding.

    Planning next to split a billet of Adirondack spruce and make up some top braces. I haven't decided on back bracing material yet - Should I go with the Adirondack spruce or mahogany?
     
  5. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    Here are a few pics of the progress to date. There's a steam box, which is an alternative to bending sides over a hot pipe. Basically the side is heated by steam and when pliable enough, placed on the side bending form and clamped in place with cauls until it cools in place. I've never tried this, so it will be interesting to say the least. The second is the side bending form - looks rough but measures out correctly and is good and solid. I promise the next one will be prettier. Last is a shot of the sides destined to be tortured. I need to finish sanding these down to proper thickness - about 0.08". Whooee!
     

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  6. Marty M.

    Marty M. New Member

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    I've built about a dozen acoustics over the years. I like spruce braces with spruce tops and mahogany braces on my backs. I did make a steam box once but didn't have a lot of luck in bending the sides with it. I ended up making a fox bender with light bulbs ( old school). Your halfway there with your form....LOL....

    I have used that bender on all my successful guitars. My last 3 were walnut parlor guitars and I like walnut a lot. I have one that I'm trying to get the enthusiasm to finish up. The sides and neck are done. I started one top and then a second. We had a weird winter with the heat on and off a lot, so I may end up doing the rest next year.
     
  7. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    I have a big 2" thick plank of African walnut, 8 inches wide and 6 feet long. Lots of striping and flash. There's enough for a half dozen sides, backs and some neck material. There's also an area of pretty crazy grain that would be interesting to work with. Needs resawing, though. My bucket list includes a few parlor guitars. . .
     
  8. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    I was thinning the sides in preparation for bending - sand, sand, sand, scrape, scrape. . . when on an impulse I swabbed one of the sides with a bit of denatured alcohol and snapped a picture. This gives a hint of what it may look like when finished. I like this stuff.
    :dude:

    [​IMG]
     
  9. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    Slow but steady

    Life intervened a little with my guitar building schedule, and that pesky thing called "work". Anyway, I've gotten the cauls done and on the side bender form. These will work well as long as the wood is hot; otherwise not so much. So the plan will be to heat the side up in the steam box to the max of 212 deg. F (which is all I'll be able to get out of it without pressurizing the thing) and get it on the form as fast as I can. The side will be wrapped in aluminum foil which should hold the heat in long enough to do a bend. If the waist doesn't want to bend easily I may have to bend it on a hot pipe or use silicone heat blankets; both are at the ready.

    The only thing left for the form is to wrap a steel mesh around the curves to distribute the force evenly against the wood.
     

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  10. TheCaffeinatedOne

    TheCaffeinatedOne New Member

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    Well, that was an adventure. The rosewood has some serious short grain and, well, I blew up a side trying to bend it. I suppose I shouldn't be blaming the wood.

    Anyway, I learned a bunch of stuff and have decided to set aside the rosewood project for the time being, until I can get my side bending chops in better order. So, being a guitar packrat, I went to my stash and pulled out a nice set of Honduras Mahogany sides and back timbers that I picked up from a luthier supplier back in the 1970s. I've gotten the back seam jointed and glued, so the next thing will be to thickness the sides to about 0.08" and give it another try. Not going to go with steam this time. I have a set of silicon heat blankets a friend loaned me that will be the heat source. I'm making some changes to the side bender, beefing it up, and am firing up a hot pipe as well. This one won't split. Hear that, in there? (the shop door is right behind me).
     

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  11. HEADKNOCKER

    HEADKNOCKER Active Member

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    Looks Good..
    Someone get that man a latte stat..
     
  12. dewittm

    dewittm New Member

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    It looks great. It also looks like you are MORE than getting your feet wet. Good work to date. Keep posting, you need to watch-out or you are going to have a really nice guitar, if you don't.
     
  13. cmarr6

    cmarr6 New Member

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    Be careful with mohagany, it likes to split if it get too wet and if you try to bend too quickly. I have made about 10 guitars with mohagany B&S's and I love it. It is beautiful wood and sounds great too. I use a pipe bender I made out of 2" steel pipe from the hardware store. Used a base piece screwed to a wooden base then a 4" long piece screwed into that. Then a "T" with a 6" piece coming out one side of the "T". I made a bracket to hold a propane torch that shoots directly down the other end of the "T" into the middle of the pipe. You can adjust the flame of the torch for accurate temps. Just be careful, the air coming out of the end of the pipe can be pretty hot so try to stay away from the open end of the pipe. I use just a spray bottle to spray the wood as i go. Set the form by you and use the form as a guide bending to as close to the form shape as possible. Go slow so it doesn't split. If you watch the wood closely, you can see if it is wanting to start splitting. Move away to another spot and come back after the spot has cooled. It may take a couple of hours for me to do just one side, then I clamp it onto the form using large rubber bands that I get from a well known supplier and leave it sit overnight. Comes out perfect.
     
  14. CatonGuitars

    CatonGuitars Member

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    Just thought I'd give my 2cents. Put a notch or make a mark in the waist of your bending form. Transfer that mark over to the mold in the exact same position. When you bend decide where you want your sides to be in relation to that mark on the mold and mark it on the sides. You now have a registration point that you can use to fit the sides into the mold in the exact same spot every time, as long as you line the marks up when you bend.

    212 deg. F is too cold. I don't initiate a bend on any wood until 260. However that is with a heat blanket, the steam may make it more pliable. I then raise up to 300ish for around 5 -15 min depending on the wood. I also wouldn't use aluminum foil. Mahogany has a bit of elevated tannin levels that can react with the foil and stain the wood, especially if the wood is wet. Ive turned maple blue with foil before.

    I mist my sides with a spray bottle and the wrap them in white butcher paper. If you dont have a way to control the heat just plug the blanket in and slowly initiate the bend when you see steam rising from the form. Its best to bake it for a few minutes at just over 300 F but if you cant control the temp, let it heat up until touching the slats will hurt like hell. Unplug the blanket and let it set in the form over night. Softer woods like Mahogany oddly enough have really good memory and will tend to spring back if you dont get them hot enough and give them a nice short bake, but if you let it set at least over night youll be fine.

    From what I see youre doing everything right. It takes me about 20 minutes to bend a side ready for the mold in my bending form. If you use your friends blanket you should be good. Mahogany will bend at .090" no problem. Mahogany bends like hot plastic, so at .80" you'll be fine.

    Please keep posting on this build. You're obviously doing your research and taking the time to do things right. My guess is, this guitar is going to turn out great!
     
    Last edited: Jul 10, 2016

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