Fretless fingerboard coatings

[SurferJoe46]

I've searched here, and on the interwebs at large, looking for the definitive answers for the DIYer on this. This is what I've come up with (basically, a lot more questions than answers).

Application methods:

• Brush - Simple set up. Minimal cleanup. Coating build-up will follow radius of FB. Potential for brush-bristle FOD. Potential for brush-stroke marks (depending on how well material flows). Potential for air bubbles. Considerable post-cure sanding/polishing.
• Wipe On - similar to brush.
• Pour - Build a tape dam around FB and pour material. Simple set up. Minimal cleanup. Maximum post-cure sanding/polishing. Coating buildup will need to be re-radiused (hand sanding with radius block - since the point of these coatings is to provide a hard, abrasion resistant surface, hand sanding to remove a lot of material may prove quite dificult). Potential for air bubbles (but may be able to "torch" them out).
• Spray - More set up. Maximum cleanup. Minimal post-cure sanding/polishing.

Chemistry

• Cyanoacrylate (super glue) - Research suggests this is Carvin's Hard-As-Nails FB finish. This is what I used on boalg's neck (though that was fretted and no string wear on the finish is anticipated). Wipe on. Many many many coats. Lots of level sanding and re-coating. Looked great when I was done.
• Epoxy - What Would Jaco Do? Brush or pour application.
• Polyester - Same as Pedulla's Diamondkote. Brush or pour.
• Polyurethane - Automotive clear coat. Spray. Easy peasy. Is it tough enough for a FB coating?

Risks:

• Is the coating abrasion resistant enough to be long wearing under round wound stings?
• Is the coating tough enough to not crack or chip due to the wood moving?
• Does the coating form a good bond to the wood so it doesn't lift or separate (is there a clear primer that should be considered)?
• The coating will be on the FB only. The back of the neck with be oil and wax. How concerned do I need to be about the coating along the edge of the FB. Likely the weakest part of the system. How to minimize lifting/chipping here?

What haven't I considered?
Success stories?
Horror stories?
Thoughts, concerns, advice?

Polyurethane is not good for long, even the catalyzed kind. It just ain't hard enough.

C.C. is hard enuff, but like you say a lot of work. I agree and never used it myself.

I like polyester resin, clear or tinted. If you like Corvettes or surfboards, you'll love polyester.

It goes on great, you can "push" it around to fill the spots that don't want to cooperate with the coating and it smells good!

I build a dam along the board with masking tape (sticky side IN) to keep it inside the area I want it to stay in/on. Then after it ceases off-gassing, you can carve it down and shape it as you want.

I just mix and pour the resin from a 2 ounce plastic sample cup, and that eliminates brushes, sprayers and nasty clean up. OK... Ya might waste a stirring stick, but they're free at paint stores.

One thing.......a notice to others about polyester applications of fingerboards.

The resin is so strong that it will not yield like wood does, and you've gotta modify the frets on this type of instalation

"De-barb" the frets to anyone who wants to put frets on a glassed fingerboard. The barbs will force the glass to open up a lot and you can lift the glass off the fingerboard, letting air under it and it looks nasty.

Don't ask how I know.

 

[earlysecond]

I have used both sprayed polyurethane and epoxy. Sadly, both ended up with string marks from round wound strings. In both cases it is hardly noticeable and does not have any bearing on sound.

As far as hardeness- CA is likely the hardest but anything that requires that much work is not for me. Polyester, I can see how it would likely be the hardest and most durable but have not tired it.

SurferJoe- are they polyester resins you can buy off the shelf somewhere that do not have and amber tint? I searched years ago when I used to pour the stuff for various projects and never found one. Lowes carries Elmer's and I've used USG both are amber in color with is not acceptable for a full half of my applications.

I HAVE to be missing something. When I pour, there are no dams I place the fretboard on an elevated surface with lots of cardboard under it and let it roll off the edges. i have done this to just the fret board and to the fretboard and neck. In BOTH cases with the epoxy I chose, it covered enough to sand. If I would have sanded through, it would not have been an issue as I was spraying poly on the sides in any event. So I must ask. . . Am I doing something wrong? In a singe pour I was able to coat the top and sides, have enough to level sand on the tops and finish sand on the side.

Here is and interesting factoid. Once I sprayed a fretted guitar and decided NOT to mask the frets. I prepped and pounded a good many coats on the top of the fretboard. NOW, this did not do much for the sound. . . .the bass is playable but has some fret buzz caused by some higher spots on the poly BUT the polyurethane is STILL there, it is has not been worn off. And think of something, fretting a string to the crown is a lot like cutting it (at least pinching it) and there are dents but they are not significant.

My current build calls for a 5 string fretless set up into which I will likely incorporate LED's again. My process is to cut and radius the fretboard then level sand it. Install my lights, marker dots of epoxy over top of the LED's, dye the fretboard and pour the epoxy. It seems to work out ok but there maybe a better workflow?

 

[SurferJoe46]

I create a 1 inch wide masking tape dam all the way around the fretboard with about 25% of the sticky side of the tape standing proud of the board.

Making sure that I have built a complete circuit around the board, I then level it as good as i can and pour on the kicked resin and watch for bubbles, fish eyes and generally areas like grain that don't seem to want to fill.

Tilt the eck to get a relatively consistent coat on the whole board, realizing that the edges will eventually get more when you put the neck down after 20 minutes of tilting it every which way and go in to eat or get a beer.

I use new round toothpicks to push the polyester into those areas and also "pull" any bubbles to the surface to allow them to expire naturally. Don't worry about the resin seeking oneness with your local gravity fields, as the edge is very easy to blend into the side of the beck where whatever finish you use on it, is applied.

I have at times slightly tinted whiter boards with a little yellow ochre or medium sienna to add a distinctive effect to the neck in that area.

Once I used orange. It was super kewl!

For product? Get thee to a decent auto supply house that also sells automotive paints. They'll have a polyester repair "-kit" with a picture of a Corvette on it, that has a quart of resin, a tube of catalyst and a package of 2oz fiberglass cloth. The cloth I have not used on a guitar ..... yet. But that day is coming.

Under decent conditions, this is the easiest way to buy a short amount, like we would use infrequently. In yon days, I used resin in 55 gallon drums.

FYI: should you buy surfboard resin or what is more commonly known as marine top build or layup coat resin, as there'll be paraffin wax in it that will rise to the surface.

This is not a problem and certainly is good.

It certainly aids sanding and makes shaping a lot easier. BUT YOU WILL CRY IF YOU DON'T USE AN AUTOMOTIVE WAX REMOVER BEFORE ANY FURTHER WORK ON THE NECK IS ATTEMPTED. Future coatings will fisheye like mad (if you can even get it to stay where you want it to stay) if or after it gets contaminated by leftover paraffin wax!

Toluene or MEK - the latter being rapidly used and allowed to istantly dry - will remove that paraffin perfectly well if you use pure cotton (tee shirt or old cotton diaper) material which is constantly turned and rotated and disposed of in the same arm throwing movement.

Wax has NO PLACE in a paintshop....NOR DOES SILICONE in any form, eg: last week's car waxing job or the last time you Armor-All'd your car interior in the same building or having residue in old dirty rags! Use throw away gloves when you are in doubt....better yet, use then all the time.

Silicon is the devil's product! You'll see!

Here's a tip: if you or whoever washes your laundry also uses a fabric softener...... just know that they contain animal fats that create that soft feeling in your undies. That softener is tough to wash out as it is designed to have tremendous staying power in your lingerie. It will create monster fisheye.... more than Lloyd Bridges ever saw.... in your finished product.

 

[earlysecond]

Underarm deodorant and hand creams/lotions with dimethacone can be added to the list. In 12 yrs of painting im luckynto have had a fisheye problem only once.

 

[SurferJoe46]

Underarm deodorant and hand creams/lotions with dimethacone can be added to the list. In 12 yrs of painting im luckynto have had a fisheye problem only once.

Yup. If you want kissable hands or want to smell good, you should be doing fashion modelling or DWTS.... not painting, resining, woodworking or generally doing anything creative. ;p

To those AR's who are offended, please note the little winky-eye at the end of the last sentence.