Pore Filling Rosettes - Luthier Tips du Jour Mailbag
In this episode, luthier Robbie O’Brien demonstrates using CA glue to fill and level rosettes before applying a finish.
Video Transcription
[on-screen text reads: Luthier Tips du Jour Mailbag]
Mailbag question: Should I pore fill a rosette made of end grain?
Robert O'Brien: Today's Tips du Jour Mailbag question comes to us from Washington. "Robert, I pore fill my guitar before finishing. However, I have noticed that the rosette is made of end grain and therefore very porous. I'm having trouble getting satisfactory finish results in that area. Should I pore fill it? Can you offer any suggestions? Scott in Washington."
Scott, this is often an overlooked area when people do pore filling on the guitar. Like you've mentioned, you pore fill the entire guitar to get a great level finish. But why don't we also do that to the rosette? A lot of people don't and they count on the finish leveling and filling the pores in that area. And like you said, they get less than satisfactory results. Let's go over to the bench and I'll show you an easy way to pore fill that area.
How to pore fill the rosette
So Scott, here's my guitar. Obviously I'm not ready to go to the spray booth yet, but I'm getting close. I need to start my pore filling, and this rosette is made out of Brazilian rosewood and there's a lot of big pores in there that need to be filled so I can get a satisfactory finish, nice and level, and when I go to buff it, I'll have a nice high-gloss level finish. So what I'm going to use is CA glue to do that. Now, not all CA glues are created equal, especially this one. This was a UFO version. In other words, a user-friendly odorless version. And if you've ever pore filled a guitar with CA glue, boy, you really want to use this version, because it doesn't irritate the eyes or the nose as you work with it. That is a huge plus when doing pore filling. You also want to seal the area very well before applying the CA glue. If not, you could get some staining of the spruce, or if you're using a cedar top, obviously you get staining of that area.
Also, sometimes you get some yellowing under the finish depending on what type of finish you use. Therefore, I've put a nice wash coat of shellac on the rosette and around the rosette area. So now I've got my UFO CA glue in my pipette. I just come in and put some on there [Robert slowly works the pipette around the rosette, squeezing out a little bit of glue as he goes]. Now, I've noticed that the UFO thin version is not quite as thin as the regular version of thin viscosity. The regular thin viscosity CA glue from Satellite City, which I get from LMI, is very, very thin. It's like water. So it really wicks into things. I need a little bit of a solids content in this glue. That's why I like this UFO version as well. It's still thin and it's going to do the capillary effect and get in and seal everything off. It's got enough of a solids content to it that it comes in and really fills the pores well.
Now, if you were doing the CA method for pore filling on the back, you would probably want to work in small areas, and what people do is come in and sand the area, create a little slurry, and that fills the pores. Since I have spruce and also colored purfling lines around this rosette, I'm not going to sand. I'm just going to rely on the CA glue to do the pore filling. And be careful you don't glue yourself to your guitar or to your bench. It does happen, folks. In fact, it happened to a friend of mine one time, but that's another story.
Now, when you get done, you don't want to use accelerator, you just want to let it cure it all by itself, and it cures very quickly. Then you can scrape or sand it, and then you're ready for the spray booth. If you think you got happy with the glue, you can also come in and just wipe off the excess. Now of course, all of this as well as the rest of the top is going to get sanded back as I prep for the spray booth. So the majority of this is going to come off and the CA glue is just going to stay in the pores and works as a leveling agent.
So Scott in Georgia, thank you very much for your question. If you use this technique, I think you'll find you'll have better finishing results on the top around the rosette. So happy finishing.
[on-screen text reads: More Luthier Tips and online courses available at www.obrienguitars.com. Private and small group guitar building and finishing instruction available.]
