StewMac tools

Weissenborn sound hole rings

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Weissenborn sound hole rings

Postby Bob Howell » Tue Aug 16, 2016 9:15 pm

I have my sapele top down to .09" and now see there is no reinforcement below the sound hole.

I have cut several strips of black veener 1/32x1/32" on my table saw. About half survived.

I'm looking at inlaying it into the top. I have a Proxxon, Drimmel type tool with a 1/32" cutter and a plunge base so I guess I can make the groove.
This black strip is mighty small. I will try to inlay it with hide glue. Doesn't seem possible.

I'm concerned about going through and messing up the top.

Ill be practicing on scraps for a day or two.

Is this the best way to make sound hole rings?
Bob Howell
 
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Re: Weissenborn sound hole rings

Postby Todd Stock » Wed Aug 17, 2016 7:27 am

There's no need for the plunge base...lock the depth where required, or using ...for a shallow cut like a rosette channel, there's no danger of the tool thing off...a standard circle-cutting base allows the bit to be started under the fretboard and continued around the hole. Rout to .040" -.050" depth. Another approach is to use the popsicle stick/Exacto blade method that Cumpiano covers in his book or as seen on YouTube. Even 1/32" may be a little stiff for bending around a sound hole...always an option to route an identical ring in a plastic cutting board, steam the wood, and prebend/allow to dry, then transfer. Cut the channel .0015 oversized in width for every shop-made glue joint made with hide or similar, as waterbased glues will swell veneer and fiber (e.g., single ring milled .003" oversized; three-ply ring with three separate laminations to be glued up in channel is milled .006 oversized due to the four separate glue lines; commercial three ply WBW milled .003" oversized because the interior joints are already glued...just the two exterior joints to handle).

Keep in mind that a Style 1 Weiss has multiple, multi-ply rings that may be built up with commercially purchased purflings or shop made...a razor bade scraper with two support blocks of the correct thickness allow purfling to be pulled through the gap between blade and surface for precision thicknessing. FWIW, the spacing between rings is not always even...Martin rosettes are a good example, where there is about .020" to .030" greater space left between the outer and center ring than inner and center ring.

How I do it? Wells/Karol routing jig and a Ridgid laminate trimmer with decimal downcut end mill...the jig is fairly easy to make, the current Ridgid trimmer is an excellent tool for all the stuff me use these trim router for doing in instrument building, and high quality decimal and fractional bits are fairly cheap at $5-$6 each if you look around. 1/8" shank decimal end mills are sharper and more durable than the Dremel-style bits for this work, and the bearings on Dremel and Proxxon tools - even with repacking - have more play and more potential for rough cuts) than trim routers.

Misc: Lightly shellacking the rosette area stiffens wood fibers and makes the cuts a little crisper in some woods like spruce or cedar (use dewaxed, blonde or super-blonde shellac - Zinssers's spray shellac works.
Todd Stock
 
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Re: Weissenborn sound hole rings

Postby Bob Howell » Wed Aug 17, 2016 11:51 am

I have now ripped a piece on ebony .07x.09".Should I bend it on the heat pipe or soak it in hot water.
Also more strips of black veneer cut this time. It bends easily.
'
Is hide glue better than thick super glue? I saw somewhere sealing the area with shellac to stop run out/staining with sg.
If done before the cut is made, will it stop wicking out?
Bob Howell
 
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Location: Atlanta, GA

Re: Weissenborn sound hole rings

Postby Greg Steil » Wed Aug 17, 2016 12:05 pm

I also build Weissenborns, among other things, and the way I do my rings is, first, I use a router to cut a disc of plywood(1/8 or 1/4) to the INSIDE diameter of the ring. I then mount it to a hunk of Balsa wood with a piece of waxed paper between. Use T pins to mount it for reasons you'll see later. Wax the outside of the disc. I then start wrapping my veneer strips(careful with the glue) around the circle using T pins to hold them and just continue till you have the desired width. Taper the ends of each strip so they blend. If your veneer is thin enough you can possibly do it all at once. After it is dry and the outside pins are removed, you can pull up the disc to facilitate removing the ring carefully. THEN you can rout your top to suit the diameter and width of the ring. Hope that helps.
Greg Steil
 
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Re: Weissenborn sound hole rings

Postby Greg Steil » Wed Aug 17, 2016 12:07 pm

Oh yes, I forgot, Inlay the ring and THEN cut the sound hole.
Greg Steil
 
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Re: Weissenborn sound hole rings

Postby Todd Stock » Wed Aug 17, 2016 12:54 pm

Does he need to worry about joining the rings under the fretboard if the fretboard will cover the joint? Seems like it's easier to a) measure the ring's thickness/width of layup, mill channels, and glue in with hide, TB, or (with shellac seal) thin CA...no issue with getting the diameter correct. Having built a Weiss or two, I don't recall the fretboard stopping short of the sound hole...have a 1929 Style 1 in right now and can get some shots if you'd like, but the drawings from GAL are pretty decent, and in combo with the SM drawings (not accurate for shape or bracing, but good for structural details), enough to build from.

Ready-made purfs and veneers are pretty cheap...anything on a Style 1 can be made up out of individual veneer or fiber strips and pre-made purfs from LMII or Stewmac...
Todd Stock
 
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Re: Weissenborn sound hole rings

Postby Bob Howell » Thu Aug 18, 2016 4:41 am

I had put off the sound hole till I had ordered the purfs but I have not decided on some other items and I hate multi orders in a row.
I was not even sure what I was getting into so I just jumped in with veneers on hand. The Proxxon and base cuts a nice groove and the strips went right in.

Groove seems to be 1/16 deep and I stuffed 3 strips into it. They bend without steam but I see the benefit of pre bending.

Like most task it is easier than you anticipate.
Bob Howell
 
Posts: 162
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Location: Atlanta, GA

Re: Weissenborn sound hole rings

Postby Bob Howell » Thu Aug 18, 2016 4:47 am

Greg Steil wrote:I also build Weissenborns, among other things, and the way I do my rings is, first, I use a router to cut a disc of plywood(1/8 or 1/4) to the INSIDE diameter of the ring. I then mount it to a hunk of Balsa wood with a piece of waxed paper between. Use T pins to mount it for reasons you'll see later. Wax the outside of the disc. I then start wrapping my veneer strips(careful with the glue) around the circle using T pins to hold them and just continue till you have the desired width. Taper the ends of each strip so they blend. If your veneer is thin enough you can possibly do it all at once. After it is dry and the outside pins are removed, you can pull up the disc to facilitate removing the ring carefully. THEN you can rout your top to suit the diameter and width of the ring. Hope that helps.

After studying your method I see how the rings could work. Once laid up the bottom can be joined by drawing over a clamped plane. If the groove cut is off in size the ring can be cut with the joint placed under the finger board.
Bob Howell
 
Posts: 162
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Location: Atlanta, GA

Re: Weissenborn sound hole rings

Postby Bob Howell » Thu Aug 18, 2016 4:54 am

Todd Stock wrote:Does he need to worry about joining the rings under the fretboard if the fretboard will cover the joint? Seems like it's easier to a) measure the ring's thickness/width of layup, mill channels, and glue in with hide, TB, or (with shellac seal) thin CA...no issue with getting the diameter correct. Having built a Weiss or two, I don't recall the fretboard stopping short of the sound hole...have a 1929 Style 1 in right now and can get some shots if you'd like, but the drawings from GAL are pretty decent, and in combo with the SM drawings (not accurate for shape or bracing, but good for structural details), enough to build from.

Ready-made purfs and veneers are pretty cheap...anything on a Style 1 can be made up out of individual veneer or fiber strips and pre-made purfs from LMII or Stewmac...

I am working with the SM plans. I saw nothing at GAL. Never got around to ordering the plans offered here. Read that all sets had flaws and the design changed much over the years. A moving target.
Bob Howell
 
Posts: 162
Joined: Sun Jan 08, 2012 4:23 am
Location: Atlanta, GA

Re: Weissenborn sound hole rings

Postby Todd Stock » Thu Aug 18, 2016 7:30 am

Not Gal plans - MIMF...aging brain syndrome and up too late watch us get our butt kicked in beach by the Brazilians. Other than some missing details on the neck construction, the MIMF plans are pretty good for shape and trim details. Agree it's a moving target - and Weissenborn construction was never that robust, so worth making sure the upper arms of the X and the transverse brace above the sound hole are fairly robust...I cap all x-braces to avoid the issues with the usual stress risers.
Todd Stock
 
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Re: Weissenborn sound hole rings

Postby Alan Carruth » Thu Aug 18, 2016 12:45 pm

Strad & Co. used to make purfling lines with a plane. He used a narrow piece of poplar, and set the plane for a heavy cut. The main trick is to wet the wood just before you plane it. This makes it flexible enough so that the chip breaker on the plane won't fracture it; you get a nice solid piece that is usually flexible enough to bend easily. He would cook strips in vinegar and iron with some tannin to dye them black for the dark lines. He probably used logwood, but you can get tannin at a store that sells wine making or brewing supplies.
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Re: Weissenborn sound hole rings

Postby Bob Howell » Tue Aug 23, 2016 8:43 pm

Making progress; Working on several approaches to get experience.

Cut strips 2milx2mil from walnut maple ebony and paduc (?). Walnut bent well but not darkening in black dye. Put 5=6 drops of Transtint black in 1/4 cup water and after 2 days little effect. I thought that was strong but guess not. Maple same result but wood had grain in some areas some lot of breakage on hot pipe. Ebony worked fine. Paduce broke, lot of grain.

I cut a bunch of strips from black dyed pear. I need 3 to fill the 2mil channel. That is hard. See I should have cut 1mil but to late now.
Have not mastered gluing up on mold but soon.

Any dye better than Trainstint?
Thanks for suggestions.
Bob Howell
 
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Joined: Sun Jan 08, 2012 4:23 am
Location: Atlanta, GA

Re: Weissenborn sound hole rings

Postby Todd Stock » Wed Aug 24, 2016 7:08 pm

Todd Stock
 
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Re: Weissenborn sound hole rings

Postby Bob Howell » Wed Aug 24, 2016 8:50 pm

Todd Stock wrote:Chemicals and mordants...

http://www.woodfinishingenterprises.com/dyes.html

I have used some of these years ago. I had a book "Adventures in Finishing" By George Frank I think. Used it in the early 90's then lost it.

I switch to Al and double the strength.
Bob Howell
 
Posts: 162
Joined: Sun Jan 08, 2012 4:23 am
Location: Atlanta, GA

Re: Weissenborn sound hole rings

Postby Doug Shaker » Mon Aug 29, 2016 6:49 pm

Here is an article on ebonizing wood using iron and tannic acid.
http://www.popularwoodworking.com/techniques/ebonizing_wood
-Doug Shaker
Doug Shaker
 
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Re: Weissenborn sound hole rings

Postby Bob Howell » Thu Sep 01, 2016 8:04 pm

I'm on my third sh ring. The first two were messed up so I removed/routed out them. The hole is getting bigger. Now 5.1" or so.

I'm also getting lots of practice.

Found a bowl blank, 6x6x 3" thick of manzetta burl. I sliced off a 1/8" sheet. A ring this time cut from it.

I hope to border it with black and/or paduc veneer strips.
Once you start thinking, all sorts of design ideas come to mind.
Bob Howell
 
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Location: Atlanta, GA


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