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Ever Scrape Though a Side?
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Author:  sdsollod [ Tue Nov 01, 2016 3:04 pm ]
Post subject:  Ever Scrape Though a Side?

I noticed (after putting in the kerf binding) that the sides of my 12 fret L-00 build (ishpingo) have some longitudinal rippling in them in the lower bout. Not terrible but, I'm just wondering if anyone actually scraped through a side when leveling them out... I have built 12 steel string acoustics and never scraped through...

Author:  rlrhett [ Tue Nov 01, 2016 3:13 pm ]
Post subject:  Re: Ever Scrape Though a Side?

Yes.

I've tried all kind of tricks to save the rims. Nothing has ever worked, and I usually end up wasting time.

I hope someone here has a super awesome trick that works.


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Author:  meddlingfool [ Tue Nov 01, 2016 7:08 pm ]
Post subject:  Re: Ever Scrape Though a Side?

Kerf binding?

Do you mean kerfed linings? As in, the top and back aren't on?

You can try adding 1/4 x 1/4" side braces, clamped in with flat cauls, and that can often help.

Author:  James Orr [ Tue Nov 01, 2016 9:03 pm ]
Post subject:  Re: Ever Scrape Though a Side?

I got frighteningly close on my second acoustic guitar. I still play it regularly, and when I push against certain areas, I have a hard time believing they're any thicker than .040".

Author:  Ken Jones [ Tue Nov 01, 2016 9:35 pm ]
Post subject:  Re: Ever Scrape Though a Side?

I've seen many old Martin 18's with paper-thin sides. I figure they were sanded within an inch of their lives to eliminate some ripples.


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Author:  Pmaj7 [ Wed Nov 02, 2016 12:34 am ]
Post subject:  Re: Ever Scrape Though a Side?

Not scraped, but sanded. Oh....the dread. Not really any fix except paint.

Author:  Robert Lak [ Wed Nov 02, 2016 7:32 am ]
Post subject:  Re: Ever Scrape Though a Side?

Pics? Are you saying the longitudinal is being caused by too much thinning?

Author:  sdsollod [ Wed Nov 02, 2016 8:40 am ]
Post subject:  Re: Ever Scrape Though a Side?

It's worse than I thought... Any suggestions? Heat would probably help, but. I don't want to loosen the kerf "lining". As suggested, I could clamp and glue a brace, but I'm not sure how hefty a brace It would need. My typical side braces would likely be hefty enough...

Author:  Pmaj7 [ Wed Nov 02, 2016 9:36 am ]
Post subject:  Re: Ever Scrape Though a Side?

Oh, it's just a rim! So yes, I would use a 1/4" brace and cut throuhh yhe lining. I would mirror the positions on the other side as well to make it look a little more deliberate.

Author:  sdsollod [ Wed Nov 02, 2016 10:03 am ]
Post subject:  Re: Ever Scrape Though a Side?

This is the approach I'm thinking of taking. Not glued yet. The other side needs it too, so I'll mirror this on the other side. The rest of the sides look okay. It's just at the ends of the lower bout. Once I get them glued in I can shape them up. Look like a reasonable approach?

Author:  SteveSmith [ Wed Nov 02, 2016 10:22 am ]
Post subject:  Re: Ever Scrape Though a Side?

I would cut the linings and run them top to bottom just for the extra glue area.

Author:  Pmaj7 [ Wed Nov 02, 2016 10:25 am ]
Post subject:  Re: Ever Scrape Though a Side?

Depends how much stress there is. Did it take much clamping pressure to flatten it out? If so, I would feel much better about the brace going all the way to the top and bottom through the lining. Otherwise, there could possibly be an even higher stress right in between the two. The brace probably only needs to be half that width. Well, depending on how thick it is.

Author:  Dave m2 [ Wed Nov 02, 2016 6:02 pm ]
Post subject:  Re: Ever Scrape Though a Side?

Steve it is annoying isn't it. I have not just a curve but a ripple on the cutaway side on my current build. I took the side down to 1.8 mm to help with the sharp bends required for the cutaway which probably caused the problem.

Having sanded and scraped as much as I dared I've decided to leave it. It is a hand built guitar after all!

I have seen descriptions of heating with cauls across the side to straighten it out. I will probably try this in future. I don't think that forcing with fat side splints is a good solution. the stress is always going to be there.

Good luck with the build Dave

Author:  printer2 [ Wed Nov 02, 2016 6:28 pm ]
Post subject:  Re: Ever Scrape Though a Side?

Make an inside caul and then spritz water on the outside and iron out with a regular clothes iron. Had some waviness on the walnut sides of a current build. Ironed it into a flat curve.

Author:  rlrhett [ Thu Nov 03, 2016 10:31 am ]
Post subject:  Re: Ever Scrape Though a Side?

Or a new set of rims, for Pete's sake. I thought it was a closed up body. You are talking only a few hours of work to make new rims or forever have this issue in a new guitar that you spent 100+ hours on. Hang that on a wall in your shop as a reminder/warning. My shop is FULL of such warnings.

Author:  George L [ Fri Nov 04, 2016 9:15 am ]
Post subject:  Re: Ever Scrape Though a Side?

I see no reason to toss the rims without even trying a fix. I have all kinds of reminders/warnings in my shop, too, but I learn a great deal more trying to work through my mistakes than by simply hanging them on the wall.

Author:  douglas ingram [ Fri Nov 04, 2016 10:53 am ]
Post subject:  Re: Ever Scrape Though a Side?

Try and save them first, if this does not work, walk away and make new rims.

As mentioned, wet the wood and clamp some cauls to convince the wood that being flat is the preferred state of being. Leave the clamps on for as long as possible as wood takes awhile to convince, it can be stubborn. Then make the rim braces and glue them on.

Author:  Pmaj7 [ Fri Nov 04, 2016 11:44 am ]
Post subject:  Re: Ever Scrape Though a Side?

Yes, definitely try to save first. No harm in having some braces inside. Or you could just use it for your test mule guitar, birdhouse etc

Author:  sdsollod [ Fri Nov 04, 2016 4:56 pm ]
Post subject:  Re: Ever Scrape Though a Side?

Okay, for better or worse, this is what I ended up doing. I was covinced that having the barces go through the kerf lining was the best approach. As you can see, I was pretty far along with the build when I noticed the rippled sides. I am pretty confident that I can scrap out any remaining ripples and if necessary a little extra z-poxy should do the trick. Two things - 1) This will be a test case. 2) I will pay more attention earlier on to ensure ripples are dealt with, if they occur, right after bending.

Building is always an adventure...

Author:  SteveSmith [ Fri Nov 04, 2016 5:12 pm ]
Post subject:  Re: Ever Scrape Though a Side?

Looks good to me. [:Y:]

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