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Hi all,

Looking for a judgment and advice here on my first self-made (not store bought) rosette install. As you can see in the picture attached, there are some gaps along the inner purfling ring from the 5-7 o clock positions, and the outer purfling rings from 7-9.

I think my wooden rosette was the problem, as when I was cutting the rosette with a hand tool circle cutter (old LMII), I was cutting from opposite sides of the blank, and believe I may have cut the rosette slightly out of parallel.

I used a dewalt trim router with Downcut bit in a circle cutting jig for the soundboard channel, and as you can see, got it to fit seamlessly in many areas, so I don’t think that part of my process introduced the error (but I’m happy to hear if you think otherwise)

Given the size of the gaps here, I’m looking for a judgment on what you would do for this guitar to fix it. Note that this is for me, I’m still a newer guitar builder, but I also am happy to learn fixing methods for the inevitable errors that come along the way.

If it were you, what would be your preferred method that balances success (great looking rosette) with effort:
A) rout out the purfling lines only, and re inlay thicker purfs to take up the gaps?
B) rout out the entire thing, inlay a slightly larger rosette/purfs
C) seal with shellac, try black CA
D) fill with black shellac stick
E) something else?

Thanks in advance, and looking forward to the responses and suggestions!

It’s hard to tell from the picture just how big they are. Maybe it looks worse in person? Well, the last thing I would do is route anything out and start over. I’ve learned that it can make things worse. I would try a little surgical sanding on the brown wood and see if the brown dust would fill the gaps and what it would look like filled with brown.

If it was mine, I’d cut the purflings back out, cutting enough material from the guitar top and the rosette to provide a truly parallel channel for a new purfling scheme. It also looks like the purfling aren’t one continuous length. Diameter x 3.14 will give you a rough length for the inner and outer purflings.

Next time cut the rosette infill a few thou smaller than the rosette pocket, glue in, then cut your purfling channels. I usually allow an additional 3-4 thou over the purfling thickness.

It’ll look like it grew that way -

Cheers, M

Like Michael, I'd rout out the purfs and replace with something a bit wider. Pretty easy operation.

Problem with being a builder and taking pride in your work is once you see a flaw you will always be looking for it. Best to just fix it, give yourself less to worry about, and move on.

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Brian R, Wood Mechanic
N8ZED

Definitely A.

On the rare occasions I do a rosette like that, I will first install the brown part into a snug but not necessarily perfect pocket. Then with a bit with a smaller diameter than the purflings I want to install, I will cut a clean edge on the brown part just licking the edge of it in a clockwise climb cut til the edge is perfect, and then I will widen the channel til it fits the purflings perfectly by cutting the spruce in a counterclockwise climb cut. That’s for the outer ring. For the inner ring, I cut the brown with a counterclockwise climb cut and a clockwise climb cut into the spruce…

I usually revert to my dremel with a 1/16” downshear for that task…

This is a good place to use a hand cutter for the grove. Get a thin piece of soft wood veneer about 1/2" wide. Drill a 1/4" hole in it near one end and use a pivot in the hole in the top. Stick the point of an X-Acto blade or equivalent through the stick, perpendicular to it, at the correct point to hit just outside of the outer ring. The blade should lean forward, so that it's cutting down into the top. With the cutter tip protruding just a bit less than the height of the purfling line you'll use [u]lightly score[u/] all around the outside. Then deepen the cut carefully, Do the same with all the other cuts, and then ground out the channel. If the cutter is really sharp you can go against the grain safely with a light cut. It can be tricky to reverse the cutter so that you're always cutting down hill at the same radius, but it's better, so try it on some scrap.

I'm filling gaps almost exclusively with epoxy + West Systems 406 silica . I mix the silica with epoxy or with finish. The silica is bulking agent, fills gaps in one, sometimes two drop fills. Its invisible- give it a try off the guitar on scrap. Literature says it dries an off-white, but its invisible in small quantities in gaps. You can add sanding dust if you like....

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Measure Twice,

Karl Borum