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Let me just say

I started with my Western Red Cedar top thicknessed to .125 prior to installing the rosette scheme.

Scheme:
outside ring = B/B/B fiber (.6 mm each)
next ring = B/W/B fiber (.6 mm each)
next ring = 2.464 Herringbone (black and white fiber)
next ring = B/W/B fiber (.6 mm each)
next ring = 7.57 mm Spalted Maple
next ring = 3.43 mm Wheat (.6 mm black .3mm white)
next ring = 7.57 mm Spalted Maple**
next ring = B/W/B fiber (.6 mm each)
next ring = 2.464 Herringbone (black and white fiber)
next ring = B/W/B fiber (.6 mm each)
inside ring = B/B/B fiber (.6 mm each)

** actually used a 11mm spalted maple and inset the wheat in the middle.

Problem:
* cut the fiber to about .09"
* routing (using a home-made circle cutter and laminate trimmer) to .055"
* using Super Glue to glue the fiber to the soundboard.
* planning then scraping then ROS (150 grit) to level each ring prior to installing the next ring.
* after about 4 rings, I did a sanity check and realized that not only had the top around the outside ring thinned to about .07" - .08", but the inside WRC was thinned to about .03” where my next route had actually gone all the way through the top

Solution:
* Build the entire rosette separately to about .085
* Route out the old rosette rings as carefully as I could (left a ledge about .02 - .03” to where the cut had gone through the entire top
* Fit the new rosette into the hole in the WRC top
* routed out too much – needed 3 more .6 mm black (last one thinned) to get a tight fit between the rosette and the soundboard.
* Cut a patch to fit “INSIDE” the rosette and glued it in using Super glue (fit was good) so I can route out the sound hole and have some WRC on the inside of the rosette
* Turn the new sound board over and looked at the mess ARG
* made a slurry of WRC saw dust and liquid hide glue and smeared it all over the exposed areas, and missing WRC backing where the rosette is exposed
* Sand the inside clean
* wonder why the hell I didn’t just start over!!!

First off, leveling fiber that has been super glued together to the soundboard is a nightmare. The stuff becomes as hard as a rock, and with my fibromyalgia, not going to be able to use my arms for a week.


How do you that make complex rosette patterns handle the above situation without leveling through your top? Keep it thicker to start with? Use wood instead of fiber that doesn’t require such aggressive leveling? Use a better (more accurate) circle cutting jig? I’ve seen video’s of people using the first approach and never seem to have a problem, so I chalk it up to user error.

It is a passable fix and doesn’t look bad, but it’s not perfect. I’ll have to brace a little heavy around the rosette.

User Error? Teach me oh great masters!
Steve

First thing I do is to draw the rosette out in CAD or use something that can give you accurate layout, even a ruler with 64th's should get your very very close.

Once I've layed it out on paper, I start to think about how I'll do it on wood. If it's one big rosette (which can be done) then I think about insetting the entire thing onto the top, MINUS the outer and inner most rings.

One thing you'll want are some smaller router bits, like 1/32" if you can. This will help sneak up on the channel sizes.

Then, I take a scrap top (you can now use your to thin cedar around the lower bout) and route the channels I need. And I inset the rosette into the ring, again minus the outer and inner most rings. I'll run that through the thickness sander to get it level, leaving a thin veneer backing of about 0.010" Then I'll cut the rosette out with the circle cutter, ID first, then OD. Then I cut the ring just at the top where the fretboard covers it, this will help open or close the rosette slightly to get it to fit the channel on the real top.

Then I go to the real top and rout the channel to just fit the rosette I've just made. Test the fit before you glue it in, sneak up on the OD or ID of the channel so you don't route it to big. Also, leave the working top thicker by 0.020-0.030" so you can level the rosette again. Another thing you want to make sure of is to route the channel deep enough so you don't loose any of the rosette when you level it. When you're happy with the fit, glue it in with tightbond and clamp a thick block overtop of it. The go bar deck works good for this, also make sure you have wax paper between the clamping caul and the rosette .

When this is cured, level the rosette to the board or visa versa. Cedar is really really soft so the best thing I can suggest is to use a large sanding block, about 4"x8", thick too at least 3/4" plywood which is flat (Baltic birch is good for this). Now sand it with 100 grit, accross the grain or diagonal to the grain will be better as the hard grain lines will support the leveling to some degree and you won't thin the cedar more than the rosette. Don't bear down hard when sanding, but just let the paper do the work. Or if you're keen, just use a good sharp scraper but be carful again of the cedar.

When you're done this, route the inner and outer rosette rings and inset them. This will true up the larger rosette ring and it will be easier to get a good clean edge.

Level it all when your finished then do a final level on the inside of the plate so you don't loose rosette thickness.

Hope this helps.

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I would have done it this way ... working from the centre outwards .... inlay the centre 3 pieces first - cut the channel for, then inlay, the spalt wheat spalt. Lightly level .... then cut the channels, both inner and outer, so that the remaing layers all fit in - no reason why they wont. Sneak up them with the circle cutter - my design does this beautifully, I can easily add another 3-5 thou to a channel ... before dropping anything in, seal with shellac, then drop the rings in, then flood with CA.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I knew I could count on the masters to show me the error of my ways.

After the disaster, building the entire rosette separately - should have thought of leaving off the ID/OD black fibers - was actually much easier. I'll do it this way in the future.

Now, about using the black/white fiber vs. dye'd veneers. What is everyone using? I find the fiber absolutely miserable to level. I've never used wood. Tony, I like the idea of a "leveling sanding block". Makes much more sense. Saves me from a lot of frustration of the scraper/plane grabbing an edge and ripping out a piece of my wheat or herringbone (which I"m currently fitting a new piece in).

Also, the back. What about my method of filling the mess? I thought the liquid hide-glue cedar dust slurry to be quite imaginative, but it will take a while to dry.

I just couldn't start over on a new top. The cost of all the fiber for the wheat and herringbone was just to expensive to waste, and the top THANK YOU SHANE is the most beautiful stiff Colorful WRC I've seen. Silk all the way through. I'm going to do everything I can to make it work - stiff bracing under the thin areas, etc.

This is guitar is for me, so I'll live with the learning experience and look forward to using some of Shane's Lutz for my next with some nice colored veneers for the rosette - I'm bored of Black and White rosettes.

Thanks guys.
Steve

BTW .. I also do all my rosettes like this .. leave the top thick, like 150 or so. Install the rosette, and level as you go with the install as required - only take it down to the existing top thickness - dont worry if it isnt perfectly clean yet. I use my thickness sander for that ... Then you can clean up the whole rosette after after its in, and still have plenty of top thickness to work with. Your rosette is then clean and level, and the top will be thicknessed from the back side.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

So, if you remember, I broke through the sound-board with the Rosette and did some "down and dirty" filler in the back with liquid hide glue and Ceder Dust slurry.

After coming back from a customer site for a week, my sound board is now a potato chip - maybe a 4mm center rise from the ends along the center seam. Question - Iron flat with an Iron?

I still want to use the top because there is just too much for me to learn to waste a top that I may still make a hundred mistakes on.

I suppose I could just brace it and "go for it"

Thoughts?
Steve

Sounds to me like you have RH control issues in your shop. If you don't get that under control, you'll have a hard life building guitars, though I know there are a few builders who, somehow, manage.

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