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Hello,

I received some end mills from BQ Tool, thanks for the recommendation from John H! I followed the process I outlined previously:

1) Cut the outer ring on the wood that I plan to use for the rosette ring.
2) Move the Dremel to the soundboard and cut out the outer ring. No adjustment to the circle jig.
3) Cut out the inner ring on the wood that I plan to use for the rosette ring.
4) Move the Dremel to the soundboard and cut out the inner ring. No adjustment to the circle jig.
5) Place the wood ring into the soundboard and test fit that 1/16 purfling is snug around the rosette ring.
6) Glue it up with titebond.

Here is what I ended up with:


Question - It was really tight to squeeze the purfling into the channel. I'm worried that titebond will swell things up and I won't be able to actually refit it after the glue is in there. What would you folks recommend to use for glueup? Should I just CA instead?

I thought about trying to glue the wood ring down by itself in the right location first, but I don't think I would get it located correctly to allow the purfling to fit. I guess that is why some folks have recommended gluing the wood ring in first and then route the channels for the purfling.

Thoughts?

Thanks for all the help!

Brad

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Yes, if it's super tight already, I would ca it. Seal it with shellac first. Because that is a wide wooden ring, I might be tempted to put a very small amount of TB under it (not the purf). Small enough that you don't get any squeeze out.

I'm having memories though of the time a fellow lutherie student tried to put a "very small" bit of caulking under his truss rod. Well....it got everywhere!

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Pat

I've used thin CA into a seal channel but I have also used Duco cement when I make rosettes with this same process. It is not water based so no swelling.

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Will the Duco cement require the shellac as well to prevent distorting the top?

Thanks for the help!

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That's a great method for cutting the channel and rosette isn't it. Quick and simple. At this point I would shellac and use CA. In the future, if you want to use Titebond, make the channel a hair bigger and the Titebond will swell the ring and purfs for a nice tight fit.

Looking good Brad. Nice looking top.

Is your purfling really 1/16th? Of so, where did you buy it? I've only seen .060 purfling. Or are you using .060 purfling and even that feels too tight?


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I would not use a water base glue for that rosette -- pre-sealing (I always use lacquer) is a must if you decide on CA which I think is a good choice. Duco skims over dries very fast, with the CA method there is no rush. I also recommend beveling the edges as shown in the tutor below. That makes it a little easier to install with less chance of chipping the channel.

http://kennethmichaelguitars.com/rosette.html

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Ken Cierp

http://www.kennethmichaelguitars.com/

You've got your answers but I'll double down. Shellac, then CA. That's how I do all mine.

That's a clever way of cutting the rosette!

When I have a similar type of glue-up (gluing the main ring and purfling simultaneously), I seal with shellac, press everything in, and flood with thin CA.

What size end mill did you use?

That is a pretty clever way to tackle cutting out the channel.

Some operations in guitar building just seem perfectly designed for using CA. IMHO the rosette is one of those.

I'm using three of the .022 strips from LMI. I'll write up the whole procedure once I have it glued and scraped.

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I used this one: http://www.bqtool.com/square-end-mills.html

Part number 2F062.

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OK, so I went through this process again this evening to make the "real" rosette. I'm building a Zebrawood Guitar for my nephew. It will be my first build. I've built a few Stew-Mac Uke kits to get the idea and mechanics of instrument building into my head. Full disclosure though - I'm a beginner so please keep that in mind if you continue reading. I don't know if any of the steps below are ridiculous or not. The product seems to be OK, so I'm going with it.

Also, note that the steps below are not my ideas. I pulled a lot of information from this great community site and from youtube. So kudos to those that posted their ideas in previous threads.

Products in use:
Stew-Mac Precision Router Base - http://www.stewmac.com/Luthier_Tools/To ... _Base.html
Stew-Mac Circle jig - http://www.stewmac.com/Luthier_Tools/Ty ... g_Jig.html
Dremel 4200 - http://www.amazon.com/gp/product/B008N9 ... ols&sr=1-1
1/16 End mill from bqtool.com model 2F062 - http://www.bqtool.com/square-end-mills.html
1/8 End mill from bqtool.com model 2F125 - http://www.bqtool.com/square-end-mills.html
LMI Ebony wood purfling strips (.022 x .100) PF3A - http://www.lmii.com/products/mostly-woo ... fling-trim
LMI Maple wood purfling strips (.022 x .100) PF2A - http://www.lmii.com/products/mostly-woo ... fling-trim
Titebond thin CA glue - http://www.amazon.com/gp/product/B002FO ... 1_1&sr=8-1
A piece of zebrawood - You know what to do

The steps I followed are below and pics for most of them. I'm sorry for the bad quality of the pics, my phone sucks.

1) Drill a 3/16" centered hole in the zebrawood and double stick tape it to the working surface.
2) Set the depth of the Stew-Mac router base to a little less than the height of the purfling. I liked having the purfling a little proud to make it easier to get out of the channel between test fits. Also, just a note, it might make sense to keep around some scrap purfling or make a spacer ring or something because the purfling got beat up from being taken in and out of the channel so many times between test fits. The final purfling was a new set just before glue up.
3) Route the outside channel into the material for the wood ring (zebrawood in my case).

4) Drill a 3/16" hole centered on your soundhole location and clamp the soundboard to the working surface.
5) This step might be critical for a good fit. I put a mark on the knob of the Stew-Mac circle cutting jig. I use this mark to know how far I'm turning the knob. I was nervous about keeping the fit tight so I turned the knob 1/4 of a turn in, which made the outside ring slightly smaller than my outside diameter of the wood ring + 3 strips (BWB) of the purfling.

6) Route the outside channel into the soundboard. Between each use of the router I was cleaning the edges of the cut with a sanding block and a small edge sander like this one: http://www.woodcraft.com/product/123283 ... piece.aspx
7) Put the material for the wood ring back on to the working surface (if you had to move it to make room for the soundboard).
8) Route the inside channel into the material for the wood ring. Set aside the wood ring material for now and put the soundboard back onto the working surface.
9) The same as step 5, turn the knob but this time a 1/4 turn out so that the inside ring on the soundboard is slightly smaller than the inside diameter of the wood ring + 3 strips (BWB) of the purfling.

10) Hog out the remaining material in the soundboard between the two channels. I tried to make sure everything was level to make good contact between the wood ring and the soundboard. I switched to the 1/8" end mill for this step.
11) I have a drum sander, if you don't have a drum sander then maybe adjust step 3 & 8 and set the depth to go all the way through your wood ring material. What I did was flip over the wood ring material and run it through the drum sander until the ring fell out. This was a great tip from a user here.

12) Test fit the wood ring and the inside and outside purfling. If things are too snug use the router and take a very small amount out of the outer or inner ring, whichever needs adjusted (or both). Remember that it doubles as you go around so try to take a very small amount.

13) Once you are happy with the fit remove the wood ring and purfling and shellac the channel to protect it from the CA glue. I used spray shellac available just about anywhere: http://www.amazon.com/Rust-Oleum-Zinsse ... ay+shellac
14) Allow the shellac to dry for an hour (may not take that long, I was just following directions ).
15) Place the wood ring and purfling strips back into the channel and flood the channel with CA glue.

16) Scrape or sand the surface after ample drying time. I gave it 30 minutes. I doubt that is required but I was doing other stuff.
17) Hopefully enjoy your results!





Hopefully this helps another beginner along the way. If any of my steps are absurd or anyone has ideas on improvements let me know. I'm enjoying the process.

Thanks!
Brad

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Just to be contrary I'll recommend Titebond!

I've seen heaps of pics of rosettes on these page where CA has bled into the spruce giving the ubiquitous yellow look. And that's even when the makers have said they used shellac etc.

Here's one done with Titebond. Get everything to fit, (but no too tight) then work fast. The bloodwood strip is 0.8mm.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

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Wood glue for me. The rosette should fit snug, not too tight. You could run your trimmer around again taking a thou. or two
off one side of the channel.
Ken

I grew up using Original Titebond and I use it for most every thing. But like the important warning about sealing the wood if using CA --- the "work fast" warning using PVA adhesive for the rosette must not be taken lightly. The water in the glue can puff up the channels in an instant and frankly if you don't have the inlay in place before that happens you are screwed! Been there done it --- for me water base adhesives for this process is an unnecessary stress inducing potential problem and is simply out of the question. Duco solvent base wood glue is my first choice, and if there is a need to apply a lot of glue and fit is snug the CA method works for me and as you can see it worked well for the OP.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Put the glue on the stuff going into the channels as it goes in.

I frequently do rosettes off the guitar, just because I can do channels in multiple rosettes without resetting the router. Some of these have three or four lines laid in simultaneously, all done using Titebond.

Others have to be inlaid straight into the top, but still using Titebond, even with multiple pieces and mitres to align.

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Side bar -- The Taylor factory uses "Jet" thin CA and lacquer prepped channels

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Trevor those rosettes are beautiful in the image above, the first image, what is that one on the lower left? It looks like the top two as well but has a really cool fade effect.

I would suggest a couple of refinements on Brad's approach.
1. The pivot for the hole-cutting jig (which in the case of the Stew Mac is 3/16", not 3/8") should also go into a work board below, making sure the axis is perfectly perpendicular. Any tilt or wobble will cause issues in getting a clean, perfect circle.
2. Placing multiple pieces into a channel simultaneous can be tricky. On my last rosette, I was installing a segmented wood ring, 4 pieces of purfling (2 different sizes) and 2 shell strips, all of them different thicknesses. I cut the wood ring a tad oversize and hogged out a channel to receive it at the correct depth. I used epoxy to install the ring, as I don't think you can get a thin enough glue line for a good joint with a PVA and epoxy tolerate unevenness and gaps this well. Once the epoxy is cured, I go back to cutting channels, trimming a bit from the wood ring and adjusting the depth as I go to accommodate the various components. I adjust the hole jig on a scrap board to sneak up on the final cut, so that the fit is perfect. A generous spray with shellac, a final cleanup, then fit all the bits (I use a Teflon strip at this point, rather than fiddle with shell pieces). Flood with CA. Pull the Teflon strip(s) and install the shell, flooding again with CA. Doing the installation in steps removes the stress and requirement to rush, making it easier to get a perfect fit.


Edited for many typos.

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Thanks for that, Tim! Indeed, the hole is 3/16" (late night ) and I was putting the pin through the material and into the workboard but didn't call that out.

Excellent rosette in the pic! I hope to do something a little more complex on the next one, but wanted to get the process down a bit first. Like I used to tell my wife, who was a fine arts major, too many of her fellow students were in a hurry to cut their ear off. Meaning, give time to learn the craft, then you can do the art!

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You might be thinking.... "Hey, where did the purpleheart rosette from the first post go?" I know, it's on the top of everyone's mind.

Well, after the discussion here I decided to open the channel just a hair and try the Titebond approach just so I could see both scenarios. In short, it turned into a total trainwreck. Here is what I did:

1) Opened the channel up just a hair on both sides to give the purfling a little wiggle room (this is where my question comes in, see below).
2) I put just a small amount of Titebond Extend (not Titebond 3 or 2, but the Extended Time original Titebond) onto the bottom of the wood ring and got it close to where I thought it was supposed to sit in the channel.
3) I used a syringe to squirt a small amount of glue into the channel just ahead of where I was seating the purfling. In other words I didn't go all the way around with the glue, I squirted it in as I went.
4) The inner purfling went in OK, so far so good.
5) The outer purfling went in OK for the first 1/3 of the ring then got tighter and tighter until it I couldn't fit it any more.
6) Bail out time, I pulled it all off and cleaned up with a damp cloth (glad I used the extended time ).

I let everything dry up and then opened the channel just a bit more and went with 4 of the purfling strips in a BWWB configuration and used the CA method.




Question - How loose is too loose when planning on using Titebond? There were no visible gaps but I could rock the purfling back and forth and see a very small gap between the pieces of purfling as I rocked it. I'm guessing that this is just a feel scenario and you have to do this on test pieces a few times to get a feel for it?

Thanks!
Brad

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They're all palm from my neighbour's back yard. He took some trees down so he could fit a new garage in. All three rosettes are from the same block of wood, with sections taken out at different radial distances. The colours change from light to dark from centre to bark, also with different transition rates in different places around the circumference. I just cut wedges out long enough to get sufficient "tiles" of the same transition rate to go around the rosette.

Well, the trick, such as it is, is in the preparation. For example, if you're putting in a B/W/B purfling strips it needs prepping first. If usually comes with a burr on the edges due to the shearing cut when it is made, so that locally increases the dimension on the edge. If you leave that burr on, you run into what you described above. Further, it also pays to scrape a bevel each side of the entry edge of the purfling so you have a wedge lead-in as you push the purfling in.

I did a rosette on the same principle as yours yesterday, purfling ring, centre field, purfling ring. I bent the outer purfling ring pretty much exactly to shape and cut it exactly to size. Fitted to its channel, it forces itself to the outside because of the tight fit. There was a small bevel on the inside exposed top edge of the purfling. Then the centre field, with a slightly relieved lower outside edge can be pressed in, which locates the whole rosette in the channel. You're then left with the inside groove, which takes a purfling strip beveled on the bottom edges. Dry, it's still a small push to get everything in, so not much clearance, but not much of a bigger push with the glue on. To do the glue-up, a small fillet of glue is applied to the outer edge of the sound board channel and the outer purfling line goes in. Then a quick brush of glue to the bottom of the field piece and that gets pressed in. The inner purfling ring can have the glue applied to the purfling (pull the purfling through a brush or over a roller) or blobs of glue dropped in the channel just in front of the entry point. Applying glue just in front of the entry point of the purfling will actually lubricate its entry.

The prepping process takes just a few seconds if done before the purfling is bent and the total glue up/assembly time is probably only about a minute. Provided you don't smoother the field piece with glue, you can take a break after that point because the inner channel should still be dry. I usually just plough straight on. Using too much glue is a common mistake, I think. You end up having to force glue out of a channel for the purfling to go in, which is certainly a recipe for disaster. Remember, the old guys used to do all this using hot hide glue, usually with more intricate rosettes.

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http://www.goreguitars.com.au

A late answer, but no it does not wick into the spruce.

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