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| solid wood rosette glue-up question http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=11259 |
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| Author: | Eric Mathre [ Tue Mar 13, 2007 3:23 am ] |
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I hope this query is clearly worded enough to be comprehensible... I plan to install a solid wood rosette on my current build (#2, from the OLF SJ plans). I own the LMI drill press rosette cutter. I also purchased a pre-made Walnut ring from LMI and some of their "Wood Strips for Purfling & Trim". My desire is to directly bracket the ring (i.e., no gaps) with three veneer strips (black, white, black) both inside and outside. Can someone recommend a sequence of steps to do this neatly? I'm thinking I need to find a way to attach the strips to the ring prior to inlaying the ring the into the soundboard rather than trying to wrestle with six sticky, rapidly swelling veneer strips during the rosette installation to the soundboard. Would it work to route out an identical groove in piece of softwood scrap and line it with beeswax or shellac or something else that the glue wouldn't adhere to so I can do the veneer strip gluing and then still be able to easily extract the assembly from the scrap? What type of glue would you use? Thanks, Eric |
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| Author: | Pwoolson [ Tue Mar 13, 2007 3:35 am ] |
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If I were you, here's how I'd do it. Measure the total width of the the rosette plus all purfling strips. Set your cutter to cut that amount plus about .005". Drop in the wood ring and wrestle in all the purfling strips (dry). Once satisfied with the fit, drop in thin CA over the joints. Let that set up then go back in with thick CA and flood over the top. Don't use accelerator, just let it set up flat overnight. |
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| Author: | burbank [ Tue Mar 13, 2007 3:52 am ] |
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This might work. Bear in mind I've not tried this, so test it on scrap first. Rout for the walnut ring. Inlay it and glue it. After the glue dries, rout for the BWB on the inside and outside borders of the walnut ring. Then inlay each BWB border. More steps, but seems safe. This way you'd only be dealing with one element at a time: the walnut ring, the inner border, and the outer border. |
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| Author: | martinedwards [ Tue Mar 13, 2007 4:14 am ] |
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well I have done it a few times now and the neatest way is EXACTLY as described above!!! you can easily cut your own "donut" using the same cutter. these pics are a bit big........ 
IMG]http://i42.photobucket.com/albums/e328/gowanedwards/4060 0023-1.jpg[/IMG] 
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| Author: | LanceK [ Tue Mar 13, 2007 4:18 am ] |
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Ive done this both Paul's way and also the way Pat suggested. Both work great. Two things come to mind, if you wick with CA, coat your channel with shellac first to prevent the CA from wicking into the end grain, second, if you do as Pat suggests, you will need a router bit that is perfectly match to your purfling, or darn close 
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| Author: | gozierdt [ Tue Mar 13, 2007 5:10 am ] |
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I done two using the way Paul described, except I use Titebond for the glue. I dry fit all the parts, brush titebond into the channel, refit the parts, cover with waxed paper and a flat caul, weight, and let dry. I haven't had any trouble with the titebond wicking into the end grain. |
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| Author: | Terry Stowell [ Tue Mar 13, 2007 6:16 am ] |
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Whatever you do make sure you SEAL the top before introducing CA glue to it. On my first guitar many years ago, the end grain wicked up the ca and left a permanent stain 
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| Author: | Eric Mathre [ Tue Mar 13, 2007 7:02 am ] |
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Hesh, I had noticed that LMI sells a preglued .060 inch BWB purfling strip, but I was concerned about its willingness to bend to a 2.5-3 inch radius without recourse to a hot pipe. Eric Palo Alto, CA |
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| Author: | David R White [ Tue Mar 13, 2007 10:22 am ] |
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"I had noticed that LMI sells a preglued .060 inch BWB purfling strip, but I was concerned about its willingness to bend to a 2.5-3 inch radius without recourse to a hot pipe." That stuff bends easily for normal soundhole sizes, but I've never gone below 4". Did you really mean 2.5-3"? I bet it would bend fine, but I would buy an extra strip or two in case you break one. |
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| Author: | old man [ Tue Mar 13, 2007 2:00 pm ] |
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[QUOTE=Hesh1956] I just bent a sample of .060 black/white/black around a bottle that is 2.5" in diameter. It bent easily by hand - no problem! Eric with a 2.5-3 inch radius you have me curious since this is not a standard sized sound hole - what gives?[/QUOTE] Hesh, is that fiber or wood? The outer ring could easily be 3", if your inner one is, say, 1/8-1/4 from the edge and your rosette is 1/2" or wider, on a 4" sound hole. Unless I don't understand. 
Ron |
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| Author: | old man [ Tue Mar 13, 2007 2:11 pm ] |
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He's talking radius, not diameter. Ron |
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| Author: | CarltonM [ Wed Mar 14, 2007 6:25 am ] |
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[QUOTE=old man] He's talking radius, not diameter. Ron[/QUOTE] All this higher math is giving me a headache. I just can't work under these conditions! 
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| Author: | Todd Rose [ Wed Mar 14, 2007 12:15 pm ] |
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Another variation of Paul's method: Rout the proper sized channel for the walnut ring and purfs to fit very snugly in. Seal the channel, esp the sides of the channel, with shellac. From the underside of the soundboard, drill small holes every 3/4" or so all the way around the channel, centered in the width of the channel. Fit the walnut ring and the purfs in the channel dry. (The rosette will, of course, be proud of the soundboard surface at this point.) Wick in watered down PVA glue (Titebond or whatever brand) from the top. The advantage of using this glue over wicking in CA is that it will swell the wood and the purfs, so they will fit really tightly and look absolutely perfect when you're done. Wait for this glue to dry (overnight at least). Now wick in CA from the underside, through the holes. This assures the rosette will be well glued down in case the PVA didn't flow out everywhere. Scrape and/or sand it down and you're done. Admire your perfect rosette. I laminate a second piece of spruce in the area of the soundhole before cutting the soundhole, so the little glue-wicking holes will be hidden. (Hiding the holes is not the reason I laminate this area, but it's an added benefit.) |
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| Author: | Todd Rose [ Thu Mar 15, 2007 2:03 am ] |
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[QUOTE=Todd Rose] From the underside of the soundboard, drill small holes every 3/4" or so all the way around the channel, centered in the width of the channel. I laminate a second piece of spruce in the area of the soundhole before cutting the soundhole, so the little glue-wicking holes will be hidden. (Hiding the holes is not the reason I laminate this area, but it's an added benefit.) [/QUOTE] I just want to clarify that when I said "From the underside of the soundboard" I just meant that the holes go right through the soundboard, not that I actually drill in that direction. Drill from the the top side, in the channel, with a backer board beneath, so you won't have tear-out. Secondly, I'm not sure if my explanation of the lamination in the area of the soundboard was clear. What I'm doing, which many builders do, is stiffening the perimeter of the soundhole by making the soundboard double-thick in this area. The extra layer of spruce is laminated on the underside of the soundboard (obviously), after doing the rosette and before the soundhole is cut, and it extends out to the upper arms of the X braces and down to the intersection of the X (it is glued on before any of the braces). How far up and out into the upper bout area this lamination extends depends on the design of a given guitar's bracing. |
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| Author: | Cecil [ Thu Mar 15, 2007 5:21 am ] |
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Eric, Brock posted an exellent tutorial in the OLF build thread. I don't remember if it was 1 or 2. It will be in the archives. I have used it and was very pleased witht the results. Cecil |
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| Author: | Rod True [ Thu Mar 15, 2007 12:35 pm ] |
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I've done three the same as Paul's method and Like Lance and Terry mention, seal the channel with thinned lacquer or shellac before using CA. Also, since we are showing our rosette's I'll do the same. It really helps to have a micro adjust circle cutter to do this. You can really dial in the diameters better. 
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| Author: | mark [ Thu Mar 15, 2007 4:22 pm ] |
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I glue mine to the rosette first. 
Mark. |
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| Author: | rlabbe [ Fri Mar 16, 2007 5:29 am ] |
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Just to share, I do mine differently. I find it very finicky to get everything to fit if you rout once. So, I make my inner ring. It's just slightly larger than the final size I want. Rout the top to accept the ring, but no more. Glue the ring. Now I go back with a small bit - I have a bit that exactly matches the thickness of 3 purfling strips. I set it so it is cutting both the rosette ring and the top, and rout out a channel. It ends up so tight that I have to lightly tap the purling in with a hammer occasionally. Hit it with CA and I'm done. I'm not saying my way is better, just that it works for me. The advantage is that I can set my circle router jig by eye. Just put the jig on the board, and adjust the router position until the cutter is over both the rosette and soundboard at the same time. Oh, one tip that you may actually find useful. Before I rout the top, I put a diluted mixture of rabbit glue on the top. It's about a 10:1 ratio of water to rabbit granules. Why? Well, rabbit glue is a traditional sizing, and I find it does better at preventing fuzzies and blow out on the cut edge than shellac does. I also sometimes use rabbit glue as a sizing on my tops before french polishing them. You get a real nice look, and the build is very fast. But, that is a different topic. Definitely try the rabbit glue to seal the top - it colors the top less than shellac (requiring less sanding to get back to an even color after), and it seems stronger to me. |
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| Author: | Rod True [ Fri Mar 16, 2007 8:06 am ] |
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Thanks Hesh, yours is great looking too, I like the matching bound fb. Roger, rabbit granules......now that sounds interesting. Glad you didn't say pellets
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| Author: | mark [ Fri Mar 16, 2007 6:36 pm ] |
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Thanks Hesh but look at the back//////// 
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| Author: | nickton [ Fri Mar 16, 2007 7:09 pm ] |
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Thanks for the interesting thread. I wonder if anyone ever has trouble with having a soundhole ring in so tight it buckles or whatever after wood movement? |
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