New Luthier Tips du Jour Video - Shellac & sawdust pore fill

[Robbie O'Brien]

Good Monday morning everyone.
Here is the latest Luthier Tips du Jour video - The topic is using shellac and sawdust as a pore fill
This video as well as all my other videos are available via my website, http://www.obrienguitars.com/videos , LMI's website or on youtube.
Enjoy!


youtu.be/

[Beau Hannam Guitars]

Great video Robbie- ive been using this method as im trying to get away from the CA glue pore fill and im sick of burning my eye balls...

[Allen]

I just tried this method on 2 Baritone ukes and I'm pleased with the results. It is a bit of work (lots of elbow grease) but I pore filled both instruments and got the first couple of coats of lacquer on in one day. Just not even remotely possible when using epoxy for the pore fill.

[Jeremy D]

I just tried this method on 2 Baritone ukes and I'm pleased with the results. It is a bit of work (lots of elbow grease) but I pore filled both instruments and got the first couple of coats of lacquer on in one day. Just not even remotely possible when using epoxy for the pore fill.

Hi Allen,

Just wondering what you think of the look compared to an epoxy fill?

[Allen]

I'd say it's fairly comparable on the Blackwood. It doesn't darken the mahogany instantly like epoxy does, though it will age to a deep brick red with time.

I also used it on the soundboards. One in Western Red Cedar and the other on Huon Pine. Mostly to fill any little voids around the rosette and bindings. But also it really helped to firm up and flatten the Western Red. The first coats of lacquer just flowed out and laid down smooth and flat, whereas it would normally soak right in, swell up the grain and look a bit fuzzy.

[Jeremy D]

Thanks Allen I am definitely going to give this a try myself. Seems like it would be particularly good on guitar necks under an oil finish. Really like the idea of pore filling and spraying the same day.

[Woodsy23]

Would anyone care to speculate how this pore filling method might work with East Indian Rosewood. My concern is that the shellac might pull the colour out of the rosewood and stain the maple binding (and top if I am not careful). I guess I could sand any staining off the maple binding after the pore filling is done.

[kiwigeo]

Would anyone care to speculate how this pore filling method might work with East Indian Rosewood. My concern is that the shellac might pull the colour out of the rosewood and stain the maple binding (and top if I am not careful). I guess I could sand any staining off the maple binding after the pore filling is done.

Ive used sawdust and shellac and egg white and sawdust pore filing on IRW without any issues. Seal the bindings by wiping on 1 to 1.5lb cut shellac with a a small square of cloth prior to doing the pore fill job.

[Allen]

I have Rosewood bindings on the two Baritones I'm building. It did pull a bit of color out and spread to the maple in the purflings, but it sanded right off with the P400 grit I was using to level out the pore filling. Just a tickle really. After a couple of sessions, there wasn't any more color leaching out.

[Woodsy23]

I tried this method of pore filling for the first time last night on my second acoustic guitar - EIR back and sides & Mahogany neck.

It worked very well for the neck as I copied everything Robbie did in his video. However, I found a way to stuff things up a little doing the back and sides. I used Ubeaut dewaxed shellac but I was not sure what ratio to mix it with metho to achieve the 1 pound cut that Robbie recommended. I have used it before as a sealer at 1:5 so I tried 1:3 on the neck thinking that, if too thin, the sawdust might wash out of the pores. That worked well. I applied three "coats" to the neck.

I then foolishly increased the concentration for the back and sides. It was OK when first applied but soon became gummy. I remember Robbie saying don't let it get too gummy (the technical term). The pores were filled OK but it required a lot of sanding to remove the residue on the surface. During sanding, the sandpaper (3M Freecut) clogged a bit and created a few "corns" (is that the correct term), presumably because I did not give it time to dry properly. Of course, creating corns meant deeper scratches, even though I tried to clean the sandpaper regularly. Deeper scratches meant more sanding. I did try to remove some of the build up by wiping with thinned shellac rather than sanding but was worried that the shellac would pull the sawdust out of the pores. It did work however and reduced the amount of sanding I needed to do. In the end I sanded back to bare wood all over the back.

After finishing the sanding, the pores seemed to be well filled so it worked in the end.

The lesson I learned - don't let it get gummy.