metalic gold flake finish

'had a request for a yellow or gold finish on an electric uke but when I was playing with it the colours just seamed to plain. I won't cover up the natural grains and figure of a wood no matter what but then I got to thinking about metallic finishes and whether one could apply it and still see the wood figure below. I haven't tested with a sprayed version yet but after dying the wood a yellow darkening out to gold on the edges I mixed some embossing powder pigment (gold fleck) into nitro and brushed it on. this is a vid of a uke in progress showing just one coat. (Huge brush stroke still present) I think I like it- what do you all think? BTW- the colour availability of embossing pigments is impressive. I bought a pack which had 16 different colours.

I have mixed powders into clears for metallic finishes, Graphite, and aluminum 'gold'. Personally, I like how they look sprayed better than brushed. The best gold finish I have seen is One Shot sign painters paint. It is thick out of the can, but thins and sprays very well. This is way better than any of the rattle cans I found. Good stuff.

I mix my own with bronze powders and clear two part urethane. You can put in as much or as little of the "gold" powder as you like.

Oh, better clean the spray gun really well and have no other work around when dealing with this stuff. Or better yet, devote a gun just to metallic work. Gibson used to even have a separate spray booth for doing gold top Les Pauls, etc. One spec of the powder in a clear coat, and you'll start tearing your hair out, and the stuff gets everywhere if you're not really careful.

Rick Turner said:

I mix my own with bronze powders and clear two part urethane. You can put in as much or as little of the "gold" powder as you like.

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Het Chris and Rick, Does it clog up hplv guns at all?

no problem with clogging, but Rick is absolutely correct about dedicated guns for your clearcoats. Things don't like to cut loose inside the fluid passages until the worst possible time.

Oh, one other thing, the only way to use the one shot would be to spray it thin, then seal with shellac. What Rick mentioned about laying powder into a 2 part urethane is far better. Nitro is friendly about carrying powders too. I would get the metallic portion done, (powder in the clearcoat of choice) then top coat with clear and no powder, at least a couple coats on top. The 'color coats' can be thinned beyond what you want for the actual finish clear coats.

Actually, sometimes I will mix wood dust in with nitro as a filler, it is like the lacquer wood filler, except you choose the exact color.

That answer was a little quick..

No clogging because, of course the mixed finish is strained carefully, just like everything that goes into the spray gun, and, with metallics, the gun is kept agitated constantly to keep the powder in suspension. It will settle out starting immediately when the fluid goes still. Too vigorous agitating, especially with an almost empty cup can bring air into the fluid passages, causing erratic spray behavior. The gun needs to be cleaned when finished. With 2 part urethanes, the gun needs to be cleaned well immediately after spraying. Nitro is very forgiving about lax cleaning habits. Always, the air cap needs to be checked for buildup, it is amazing how little buildup it takes to disrupt the spray fan.

Was also just thinking about tinting the clear 'vehicle' to deepen the effect of the gold. I have not done this, but have added tints to clears for many other reasons. I have not done any adhesion testing of Urethanes sprayed directly over CA glue, or epoxy grain fill, it probably adheres just fine. I like shellac as a seal coat because it sticks to just about anything, and just about anything will stick to shellac. Shellac helps cure issues with surface contaminants too. The dust from a shellac seal coat needs to be carefully cleaned up prior to the finish coats,

Having a plan to not end up with too thick of an overall finish is also a consideration, not a problem with a straight clear finish, but with different materials, different effects, the layers add up quickly.

sorry, i'll shut up now...

Chris_H said:

That answer was a little quick.....
sorry, i'll shut up now...

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Please feel free keep going, I am learning a lot

Chris really knows this stuff...and not many do. You may think that you can just blow and go with colors, metallics, etc., but it's a dark art.

For the gold, I'm just using an old DeVilbiss suction feed touchup gun. It works fine. The clear urethane I'm using as a vehicle is designed as a sealer/isolator/adhesion promoter. It's made by Simtec. I can also add MEK soluble metal acid dyes to it to make my own colors for sunbursts, etc. That's much more economical than buying the colors pre-made.

BTW, for all my catalyzed finishes, I'm extending the life in the can (pre mix...) by squirting in a layer of argon to keep oxygen away from the liquid. If I don't do this, first the catalyst of the urethan will kick off and absorb oxygen and gel in the can, then the urethane. Ditto with the polyester; since I get it already cobalted, it will start sucking in oxygen and gelling up even without adding MEKP.

And as has been implied here...one of the real tricks is getting these trick finishes on thin. It's all in the surface prep and early sealer and build coats. You are simply NOT going to fix any surface issues once you start blowing on color. The surface has to be perfect, and I find it best to have the last sanding before color be at 320 grit. The colors will grip the surface...there's some texture there...but no swirls will show through as they can with 220. I'm talking random orbital sanding here...DynaOrbital sanders. I then shoot three coats of polyester ultra clear top coat onto the color. Or I may shoot clear urethane so I can do one more very light sanding and then shoot on Cardinal nitro satin.

good advice Rick; It is a dark art isn't it? I have never ventured away from nitro finishes except the first two ukes I did with true oil. I only get into colours when using figured maple. The nice thing I find about maple, even heavily figured is that it is an easy wood to get a smooth finish on. You are right in that you cannot correct imperfections with more finish. When I work with walnut and mahog I spend crap loads of time just getting its pores filled. Whenever I get an indoor area to spray in I will start spraying colours more. I always get my wood surface sanded to 360-400 grit. Right now I dye the wood before applying any finish. Using alcohol as the solvent keeps the grain from raising. Then when that's right I take it outside weather permitting for all the clear coats. This metallic adventure may expand my finish choices though. I would love to spray more colours but my setup is less than ideal right now.

I kind of like it...but its too subtle in the video. I didn't really see any metallic flakes until the end of the clip.

intersting... one of my friends is a pretty decent classical guitarist who knows and trusts my work. He just brought in a Ramirez guitar that he just purchased, for me to gently re-shape the neck. I can feel what it is that he does not like, and understand why he wants the work done. He is a professional musician, and well aware of what he wants. This is one of the places I am most comfortable in using colors, in finish repairs, and blending different colors. The neck is Spanish Cedar, and the color has taken a nice patina. This guitar will be a workhorse, and he says that he does not care that the finish will probably look repaired. I think it has a polyester finish, but not as heavy as some I have seen. I plan on sanding the neck to shape, filling with CA, scuff sanding the entire neck, probably to 600, masking the neck at the body, blending the color with tint in shellac, and then repairing the lacquer. It will be interesting to see what kind of witness lines are at the perimeter of where the old grain fill is cut through, and where the new stuff begins. I think the shallac will help prevent any problems with potential contaminents in the old finish. I can get the color matched OK. I think the final coats will be over the entire neck so the polish will look correct. Again, this guitar is a workhorse, he purchased it from one of his students because of the price, and because it has a pickup installed. He does not care what it looks like, only what it feels like. I want to do the best repair I can, I would not feel good if I left the instrument in worse shape than before I touched it.. He told me that this is not a sacriligious thing to do to this instrument. Any thoughts on how shellac will adhere to a scuffed polyester finish?

Another option is from ReRanch who offer a Les Paul gold top aerosol can.

http://reranchstore.stores.yahoo.net/goldtopgold.html

Chris_H said:

I plan on sanding the neck to shape, filling with CA, scuff sanding the entire neck, probably to 600, masking the neck at the body, blending the color with tint in shellac, and then repairing the lacquer. It will be interesting to see what kind of witness lines are at the perimeter of where the old grain fill is cut through, and where the new stuff begins. I think the shellac will help prevent any problems with potential contaminents in the old finish. I can get the color matched OK. ... Any thoughts on how shellac will adhere to a scuffed polyester finish?

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Chris- do you spray the shellac for this???- if so, what size needle is needed to spray it????

Yes, spray.
the actual color blend will require some hand work where the old finish starts to avoid/ minimize a dark halo where the old finish starts. That is the tricky part, and where it will likely be more or less visible. Spraying some color over the whole neck will help to ease the blend, and to help in how the color ages. I have done repairs like this in the past, it is difficult to get a good repair. Shellac is super friendly to spray, it will spray well with the same type of setup as lacquer. I have a gun that is dedicated for shellac. For spraying thin finishes, the fluid needle is tightened up to where it is comfortable. If need be, I have some smaller needles/ fluid tips. I think a thin coat of shellac over the whole neck is a good idea to avoid problems with lacquer top coats, and to ensure a decent bond. Brushing, or wiping shellac would not give the even coating, or would likely leave more irregularity than with spray. I will probably mask the heel tight, and pull the masking with each coat, while wet, to help reduce such a hard line that a finish drying to tape will leave.

I would love it if someone like Rick would come along and give these ideas a bit of a slap down, and tell how it really should be done...

Modern Ramirez guitars are finished in catalyzed polyurethane with a fair amount of toner to give that very orange look. I've got a 1988 Ramirez 1a done like that. They're not polyester.

Your plan is basically very good.

One of my tricks for doing touchup is to only mask pretty far away from the touchup area and then to spray through a hole in a piece of cardboard that I hold three to five inches out and away. That way you don't get a hard line of new to old finish. You will have to completely overspray the neck as shellac won't burn into the urethane, but you'll probably want to strip the entire back of the neck. They are huge...

Thank you Rick.

This one is not a 1a, I think it is a 4a. And yes, looking at it now, I do see color in the finish. I think that might make it easier to match the repair, as I can probably taper sand the color out, giving a wider area to make the blend. I will find out...


Yes, the neck is huge... super wide.

It is kind of sad really, a couple more minutes of attention given to this neck, and the uneven profile half way through it would not exist. He did say that for a 4a, this one is a good one.

sorry for the detour..