Advice on Touching Up a 50's Flaking Finish

[Michael Baresi]

I'm working on what I believe is a late 50's Kay model K-18
Laminate back and sides.
Finish flakes off due to age and leaves a light maple veneer.
Obviously the wood has not been dyed or stained and all the color comes off when it flakes.
I assume it is lacquer?
The pic explains it and I'm sure many of you have seen this before.
The sides are worse than the back
So with that said what would be the best way to touch up these areas?
I'm not looking for showroom finish on this.
I don't have spray equipment but can purchase cans
Also I'm handy with a brush and matching color is no problem with oils
thanks

[Barry Daniels]

Instead of spray, it would probably be easier to touch up the areas with an artists brush. Mix some dye with the lacquer to a light tint and build up the bare areas with several coats. This will allow you to sneak up on the proper shade. When the areas are dark enough switch to clear lacquer. The color of the sunburst looks similar to the Tobacco Brown ColorTone Liquid Stain that Stew-Mac sells.

[Michael Baresi]

Thanks Barry thats just what I wanted to hear and a brush is my favorite tool.

[Barry Daniels]

I approach jobs like this with artist tools, including a palette and tiny brushes. Put a squirt of lacquer and stains/dyes into separate blobs then use your brush to pull a little bit of color into the lacquer till you get the right shade. Just keep in mind that it is easier to make an area darker but you can't make it lighter without taking it down to bare wood. So go slowly and always stay several shades lighter than you think. Let each coat dry for several hours before applying the next. You want the repaired area built up a bit thicker than the existing finish because it will shrink down over a period of several weeks. After it is fully cured then scrape or sand it down and hit it with some polish compound. A single edge razor blade with a turned hook and scotch tape protective strips on the sides (ala: Frank Ford) is the tool to use for scraping the finish flush.

One other option to consider is that you could use shellac for the repair instead of lacquer. It probably won't blend in and look quite as good as lacquer but it would be more forgiving and less toxic.

[Michael Baresi]

Yes very good advice !
As a fine art painter I have lots of brushes and colors.
I'm wondering if I can use artists oil paints to color the brushing lacquer that I have?
With oils I can match the color easily.
Building the thickness has been a problem for me but I guess I just need to be more patient
thanks again

[Barry Daniels]

Oil colors are opaque whereas the tint on your guitar was achieved with dyes that are semi-transparent. However, if you are careful and only use a bit of oil color you might get away with it. Try it on some scrap maple and see what you get. Probably should put down a base coat of clear first to keep the color from soaking into the grain and getting splotchy.

Your fine art skills should come in very handy with this repair.

[Michael Baresi]

I appreciate all the advice.
I do have to make one small correction.
SOME oil paints are opaque while others are transparent. Depends on the color.

[David King]

I wouldn't be surprised if the original shading was opaque paint. Kay wasn't trying to impress anyone with their finishes back in the day. What they did got the job done.

[Chuck Tweedy]

I would know how to fill in the missing finish/color, but...
Question: Is there anything that Michael, or any of us, could do to stabilize the old finish? I've not dealt with this type of damage on an instrument, but I've seen it on old furniture and other wood - the crumbling lacquer. If that is what we have here. (Closeup pic would be great!). Seems to me the repair could stay, and the old finish could continue to erode around it.
I fully expect to see this type of thing some day and would like to know what's best to do.

[Michael Baresi]

Dave - finish is transparent on this one
Chuck - good question. Maybe someone else will know. As for me I'm torn between just leaving it and enjoying the history or attempting to make it look better. The only reason I consider touching it up is the side at the endpin is quite bad.

[Barry Daniels]

I saw a tutorial somewhere that restored crumbling lacquer by spraying an "amalgam" over it which remelted the finish and in effect put plasticizers back into the finish. I will see if I can find it.

[Barry Daniels]

Here it is. Frank Ford of course.

http://www.frets.com/FretsPages/Luthier ... ator1.html

[Michael Baresi]

Here it is. Frank Ford of course.

http://www.frets.com/FretsPages/Luthier ... ator1.html

Wow ! What talent.

[Chuck Tweedy]

Thanks Barry!! Good 'ol Frank!

[Clay Schaeffer]

The first time I read about that technique was in a little book called "The Furniture Doctor" by George Grotz. It covered "rebrushing" as well as a lot of other techniques for repairing finishes. It combined simple user friendly remedies with humorous anecdotes. A good book for anyone who does repairs on wood finishes.
If you don't want to invest in spray equipment a preval sprayer might not be a bad way to go. If the finish is really loose a brush can drag pieces of it off. If you are an artist with good brushes and technique you might be fine using a brush.

[Brian Evans]

I have a 1960's Kay that is shedding finish like a dog in springtime. The amalgamator technique is a slow acting solvent that redissolves old but still existing finish. If the finish is missing it won't work. I will probably scrape off old and replace on mine. In my case it's a layer of black that is no longer adhering to clear underneath it, but the clear is still good. I'll scrape, level and respray black. I also have to replace the outer layer of binding, so it might not happen for a while. Always remember you can wet-sand brushed finish to level.