Thursday, April 11, 2002

Mandolin #1: Staining

It was sad to unstring her but had to be done to give her some color.



Final Prep for Staining
Before the final sanding, I used some Ash wood colored wood filler to patch some of the lingering gaps between the wood and the binding and to repair the torn point tips.

Touching up the points Touching up the scroll

Most of the final sanding was done with my random orbital sander. As I found while shaping the top and back, the 5 inch rotating disc fit perfectly in the recurve and removed scratches left by hand sanding. Careful hand sanding was required in the scroll area and on the neck. I did my best with plastic sanding strips to get inside the scroll but it's pretty hard to know what it looks like in there. I went up to 220 grit everywhere.

Final sanding 1 Final sanding 2 

Masking
Before staining, the fingerboard and headstock needed to be masked. I based my masking procedure on the Benedetto archtop video. He starts by covering the actual fingerboard with long strips of masking tape leaving only the ends of the frets and the nut exposed. He then separately masks the fingerboard binding, fret ends, nut, and headstock. With this two step approach, it's easy to remove the second layer of masking after staining to allow the fingerboard binding and nut to be lacquered. Actually Benedetto not only masks the fingerboard and headstock but also all the binding. The larger binding on an archtop guitar and more gradual curves may be a little easier to mask. I made some attempts to mask at least some of the binding but gave up quickly. I did mask the point protectors as I had learned from Kathy Matsushita's mandolin building pages that the porous bone can absorb stain too deeply to be scraped off.

Benedetto stuffs his f-holes with newspaper which seemed messy and could still allow some stain and laquer to seep in. The Dude pictures show Lynn blowing up a balloon through the f-hole and slipping a piece of cardboard between the balloon and the underside of the top. I started along this route and then found that I could just blow the balloon up enough to completely block the f-hole.

Masked and ready F-hole finishing prep 

Going Yellow
It's a big commitment, but in order to build the sunburst, the first step is to go completely yellow. I worked with a concetrated liquid stain from Stew Mac mixed with denatured alcohol and applied with cheesecloth. I didn't have any fancy spray equipment so I decided I would hand rub the color for the sunburst and use Stew Mac's aerosol spray laquer as a clear coat. I started out with pure lemon yellow applied to the entire body. You can see that I used a mangled hanger clamped to my work table hooked through a tuner hole to hang the "lemon"-dolin to dry.

In the yellow 3 In the yellow 1

Well, Mostly Yellow
Remember the chaos I tried to describe while working with rubber bands and wet binding cement? Well, inevitably, binding cement gets on the wood. Of course, sanding should mostly remove the errant glue but it's not easy to see... until you go yellow. Well, you sure could see it then. It wasn't as bad as it looks in the second picture but there were several spots that did not absorb stain at all. Thus, I had to go back over those spots with sand paper before applying more stain.

Leftover glue 1 Leftover glue 3 

I Use Tobacco
Instead of going with more pure lemon, I decided to cover the newly glue-free spots and start to build the burst with a lemon/tobacco combination (I hope Philip Morris isn't reading this). I believe I had read somewhere that some people wet the wood before staining because the endgrain absorbs more water and will then absorb more stain. I don't know the specifics but it sure seemed that the second application of the browner yellow went right to the endgrain and thus accentuated the flame.

Tobacco 1 Tobacco 3

Ready for Sanding Sealer, Right?
Okay, there was a logic to it. I was just following the process in the Benedetto video. I just missed a critical detail. In the video, he rubs on the yellow stain, sprays a sanding sealer (he actually just uses a thin coat of laquer), then proceeds to spray his colored laquer coats. So, I was ready for the sanding sealer, right? Well, not if I understood what a sanding sealer was. More to come...

So I set up my mangled hanger from the roof of my carport (don't worry, I live in a completely dust free neighborhood - well, anyway, it was the best I could do) and sprayed the smokey lemon with Stew Mac's aerosol sanding sealer. When it dried, the sealer raised the grain of the wood so the next sanding "buzzed" off the standing wood grain leaving an amazingly smooth finish. The sealer also locked in the color (anyone figure out the problem yet?).

Ready for sanding sealer (not) 2 Sanding after sealer 

I'm About to Burst
I mixed up the colors I thought I would need to create my sunburst. I mixed up a few variations of tobacco, medium brown, and red mahogany stains in some Snapple bottles. Of course, every time I decided to try another mixture, I'd have to drink another Snapple to get an empty bottle. It was during this couple minutes that labeling was critically important (see picture).

The importance of labelling

I started the burst around the recurve of the top and tried to blend in towards the belly. It was easy (too easy?) to wipe away any excess stain from areas like the belly that I wanted to keep light. The burst convention seems to be to leave light spots in the centers of the belly and back, the "bouts" (waists), between the front point and the neck, the bulge on the side of the scroll, the middle of the neck, and the sides of the headstock. It was easy to keep these areas light. What seemed to be more difficult was getting the dark areas dark enough. It just seemed like the stain wouldn't absorb. Like somehow the wood had been... oh I don't know... what's the word I'm looking for here... hmmm... well, almost like it had been... sealed.

Burst belly Burst back  

Yup, thanks for playing along at home. You see, there was a critical difference between my process and Professor Benedetto's. After applying the sealer coat, he sprays colored lacquer which layers happily over the smooth shell left by the sanded lacquer. I, on the other hand, working without the benefit of spray equipment, was adding color coats of stain rubbed by hand on top of the lacquer which is kinda like that prank where someone covers the toilet bowl with plastic wrap. Well, it's sorta like that. Nevermind. The point is that it was difficult to get the darker stain to really soak and leave a completely opaque color. I did my best by applying a second treatment of even darker brown around the edges of the top and back and on the surface of the scrolls. I also added a little more red mahogany to give the burst a little more of a rich feel.

Things got a little frantic as I was realizing all this (just as would be the case if you were the victim of the toilet bowl plastic wrap prank - nevermind). You may notice in one of the pictures that I did a little "burst" on the wall behind my table when I neglected to open my hand before reaching for a Snapple Red Mahogany and basically punched it into the wall. The wall and carpet was one thing but it almost got on my J-Lo mando picture!

 Burst 2 back Burst 2 front 2 The warroom jennifer

Scraping the Binding
There seems like there would be a better way, but other than masking all the binding ala Benedetto, scraping the stain off the binding is how many people do it. I actually thought it would be harder than it was, but other than stress of intensely focusing on such a small area for an extended period of time, scraping the binding ended up being a nice way to really get a close look at the entire instrument. Working with an xacto blade and the mando braced between my knees, I slowly worked around the edges scraping away a thin layer of stain and binding and hopefully leaving a clean line between the wood and the binding.

This much attention to the binding left me feeling worse about the black center of the binding that had become exposed in a few areas where I'd sanded through the outside white layer. I shopped around a bit for solutions to cover up the exposed black sections and eventually settled on some almond color appliance touch up paint. The results were somewhat mixed. I was able to cover up the black though the match with the binding color was not perfect. I basically ended up sanding the touch up paint coat as thin as possible and at least managed to make the black a little less noticeable.

Scraping binding 1 Scraping binding 2 Scraped front Scraped back

Index of Project

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