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I was doing some practice FP this weekend. My primary purpose was to see what color shellac I wanted to use. I prefer to add some color to the Zebra Wood, to tone it down a little. Trying various shellacs, I settled on the Brown for that part of the guitar. For the top, I wanted to know what the various prep steps are before adding the spit coats prior to starting the actual FP process. I know egg whites are considered a good sizing for the top. Does this not raise the grain a good bit. If so, what do you do then? Scrape it flat? FP it with the ridges intact and have that corduroy look? Inquiring minds really want to know. The one test piece I tried is not real smooth. Is that normal? Remember, this is a classical guitar.

One other thing. What do you do to fill the rosette prior to FP? Do you work it with pumice, like the back and sides?

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Waddy

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Waddy I have sized my tops with egg whites but to be honest I seldom do any more than a good scraping then just spit coat them and proceed from there I never get a corduroy appearance because I am constantly leveling the film as I body via spiriting off between every body session. I have had a set of BC Sitka that I had to spit coat then scrape again before I was happy enough to proceed.

On pore filling hardwood rosettes on Spruce tops I first coat the spruce about an inch around the hardwood and the spruce inside the rosette with shellac to keep the spruce clean of Zpoxy, fill with Zpoxy then scrape back to the wood leaving the Zpoxy in the pores of the hardwood. Then seal the top and hardwood rosette with a spitcoat of shellac and proceed to FRP from there.

Thanks, Michael. When you did size with egg white, did you then scrape back before spit coating?

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Waddy

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Waddy, I always size with egg white, leave two days then lightly scrape back.

Colin

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Thanks Colin. That's what I did yesterday. Well, I didn't wait 2 days, as I was experimenting, but primed with egg white - 2 coats - then scraped back. Still had a bit of the corduroy feel to it, but it was a 1 day rush job to establish color. The brown is a bit dark for the top, I think. May go to amber or medium blond.

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Waddy

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Waddy, I usually work up the back and sides to near complete and leave just a seal coat on the top which is done last. The more control you develop the darker the shellac you can use and still produce an even color...........so far your choices sound good for a first go at it.
I'm using the microbead filler from LMI and just carefully fill the rosette with that. It sands off clean so once that is done I seal with the egg white and proceed. I usually wet the top prior to sealing with just a moist cloth and then sand back to minimize the grain raise and subsequent need for smoothing after the egg white application.

Thanks, Dave. Do you then just buff back the egg white roughness with a fine mesh pad or something? I have some of the steel wool substitute pads in the fine and extra fine range (Gray and white). Another thing I might throw in here. Do you FP the bridge or just polish it up? with micromesh?

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Waddy

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I typically do 3 linseed oil treatments over a course of a week. Allow to set up for another week or till just before I need to attach the bridge then buff with med fine, fine then extra fine Menzerna prior to glueing down the bridge.

Hi Waddy.

After final sanding I size with egg white, using quite a bit of it (the soundboard appears wet). Then I let it sit overnight and lightly sand with 400 grit before french polishing.

It does seem to raise the grain some, so if you are using any tint to your shellac it will give a bit more of a "vintage" look as the early growth takes less shellac than the late growth. Thats a good restoration technique, too.

Sometimes if I am going for a very clear and white look I just use straight shellac. But really, I like the egg white method.

Hope that helps.

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Thanks, Joshua. Sounds like the way to go. The piece of spruce I put the brown shellac on looks very old now, with that slight corduroy feel and look to it. It is very interesting, but I think a bit dark for the top. I'm going to experiment a little more with medium blond and amber and see what I get. The Zebra definitely needs the brown for some depth of color.

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Waddy

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I have not heard the term "sizing" before.

Could someone tell me what that is and why you do it? Why egg whites?

It sort of adds some hardness to the outer layer of fibers in the spruce. Apparently from the protein in the egg whites combining with the wood cells. It must be magic, it's not just math!

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Waddy

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Ask any woman over 40 what sizing is in referance to ironing. pretty much the same thing.

I am not discussing size with any woman I know!

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Waddy

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bak bak bak bak bak

Waddy as Joshua mentions, I use a little 400 grit paper (gold, coated) to knock down any raised grain before starting.......though, because I sand between bodying sessions I'm not so concerned about it....
My bridges get the full French polish treatment and go on after the top is completely finished.

Too late for that. I'll just do the best I can with it on the top. I'm not too worried about it.

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Waddy

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Waddy, I'm doing the same with the guitar I built in Siguenza,
Putting the bridge on before finishing was not my preference, but when in Rome (or Spain)............besides which, I felt that I wanted the feedback in terms of sound as part of the overall learning experience.
Best of Luck with it!

On my latest I did the final sanding with 360 I think, and no wet raising afterwards. I also did not do any sealing, just to see if it works directly. It takes a while to get a continuous film of shellac, and then it's bumpy, with ridges, no matter how much stiffing you do. So I had to sand it back with 1200 grit a couple times. On my next I'll definitely use a finer paper and try to raise grain with egg white before adding any shellac.

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Waddy, I lilke to put on a fairly heavy spit coat/initial coat of shellac and I use a small artist brush on the bindings, rosette, head, tough areas like the heel joint etc.. I let it dry for a few days then begin the pumice fill on the back, sides, neck, head, bridge (which is not on the guitar). I don't fill on the rosette at all or use any egg white, I don't have a reason for not I just never have. I also fp before I put the bridge on, some do some don't. I find obstructions like the fingerboard on the top and the heel at the sides to be the most problematic areas. If I gave any advice about fp I would say take your time on the pumice fill stage, I spend one week filling.

Great thread Waddy!

I'm always trying to improve my technique and was pleased to see many of our FP experts chime in on the thread. I had a few questions based on some techniques and terms I heard used here and was hoping to get some clarification. They are:

1) Sizing with egg whites...just plain old eggwhites whipped to a froth? I have historically prep sanded to 320 and then begin the bodying sessions.
2) Spit shine...never heard before in the FP context. I may already be doing this under a different term.
3) Linseed Oil polishing treatments...Michael!...you've been holding out on this one. When, how and for what purpose do you do this?

TIA

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JJ
Napa, CA
http://www.DonohueGuitars.com

Sizing is a term that comes from the textile and paper industries where it is used to increase surface adhesion and reduce surface porosity. If paper were not sized before using it the ink would just flow through the paper due to capillary action.
One type of sizing material is a gelatin type glue. In other words, hide glue. Starch can also be added to the mix. Think starching a shirt when ironing.
How does this apply to guitar building and why use it? Well, I mainly use it as an antiquing technique. You can use hide glue or egg whites, like others have mentioned. It will give your guitar top an instant antique look. Both hide glue and egg whites will do this. However, egg whites on cedar really pops the dark grain lines. It doesn't have this effect on spruce.
If using colored shellac you would want to pre treat the wood in order to have even distribution of the colored shellac. You can use the glue and egg whites or just use a spit coat of shellac as Michael says.
In summary, I usually only use the sizing techniques mentioned for antiqueing and not necessarily for surface prep.

JJ, one way I read for obtaining the egg white liquid for sizing involves whipping the egg white to a hard whipped state, then leaving it at room temperature for 16 to 24 hours. When you do this, a liquid settles out of the egg whites in the bottom of the bowl. This is the liquid to use for sizing. the thread I read says to put it on with your fingers, working quickly, both with and across the grain, but finishing across the grain.

I only know what I have read, and do not pretend to be an authority on this subject. There are probably other methods. Some even add brown sugar and molasses to the mix, probably while whipping the eggs. There are probably other methods, maybe even including just painting on a separated egg white, no whipping involved.

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Waddy

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Its really very easy. Just crack an egg and pour the white (but not the yolk) into some sort of container. I use a margarita glass for it. Then brush the egg white onto the soundboard.

As Robbie O'Brien mentioned, if you are using color this really helps to keep the color consistent. If I'm using anything other than pale shellac I use egg white for all the light colored woods.

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Then I adopt the Joshua French method. It is much more straight forward. It is actually what I did when playing around Sunday afternoon. I just read the other method in a post from a couple of years ago. It is the only place I had seen a description.

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Waddy

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