DIY Precision Fretless Epoxy Coating

[Lucien]

So a few months back I decided I'd start my own DIY Fretless Project. At first I wanted to do it on a Jazz, but I've always been more inclined toward Precision basses, so I got myself a kit and defretted it.
Now that I have a bit more time to work on it I plan on finishing it this month, I'm aiming for it to look very similar to this:
[url="http://postimage.org/"][/url]

[url="http://postimage.org/"]Very simple natural unfinished body, mint pickguard and sometime in the near future the pickups are going to be Passive Bartolini Ps.

So this is what I've done to the neck so far after defretting:[/url]
[url="http://postimg.org/image/mfad9dlif/full/"][/url]
[url="http://postimage.org/"]free picture hosting[/url]
[url="http://postimg.org/image/lea4k94iv/full/"][/url]


I'll be updating the post as I progress.
Feel free to ask anything, as I am also doing this with the intent of it being a tutorial.
In the same way, if you have hints please give them!

Edited September 14, 2014 by Lucien

[Lucien]

So, this morning i've done a little bit more, the thin underlayer solidified overnight for 17 hours, and I just applied the second coat which is more than twice as thick as the first. I should point out that I am doing this in the same fashion as boat builders do, as I took advice from one before trying to apply the epoxy, and what they do is to always use a thin undercoat as some sort of a primer, then applying what they call the "brute/rough" coat, the one I just did, that will serve as the bulk of the coating as it will need some repairing over the years due to wear, and the final coating will be something in between the thickness of the first two, this last one will be shaped into the right radius and then buffed to a shine.

Another thing I should point out to everyone attempting this process is that bubbles will eventually pop out, so, first you should search for a top quality epoxy, as its better to spend a couple more quids than to having to strip this thing of your basses' neck, with a quality epoxy and an even layering you should get fewer bubbles than otherwise. The main thing really, is to focus on not getting solid bubbles in between the layers, as it will undermine the integrity of the whole coating, and also look horrible in the end result, but you shouldn't worry as normally, bubbles appear due to two key factors, the first being the wood releasing some oxygen and other gases and also the chemical reactions that occur during the process of applying and then drying the first layer, but those usually disappear mostly on their own, it's when applying the second layer that you must take an extra care, as it's a thicker layer, bubbles could be trapped between the top and the bottom of the coat if it is drying too fast, so if you let it dry naturally, you should be able to avoid this, and, even after drying if you have some issues with more prominent bubbles on the top, it can be easily corrected by polishing up a bit and then the void can be filled when applying the third coat.

This explanation is a bit messy, I'm sorry, but when I'm done and have a little more time, I'll be doing a topic list of things to follow.

New pictures will be uploaded some time this afternoon!

Edited September 15, 2014 by Lucien

[HowieBass]

Out of interest and for others intending to try this:

1. What have you filled the fret slots with?
2. Did you get the fingerboard as straight as possible through truss rod adjustment before applying the epoxy?
3. Have you got the neck supported such that the fingerboard is completely level?
4. What are you using to apply the epoxy?

[Bradwell]

Working on one at the moment and have done a couple of others in the past.

Usually I would fill the slots with shavings from a block of maple & glue them in, but the current one is epoxy mixed with white paint, both are a bit fiddly but work well.

I'd recommend slackening the truss rod off and going over the fingerboard with a radiusing block to even it out before epoxying.

Apply the epoxy using something like an old credit card or plastic spatula. I don't think the 2nd layer of epoxy needs to be particularly thick though as it forms a very hard surface.

My current fretless project is a bit different as it's an old p-bass neck and the truss rod was broken (couldn't grip the hexagonal keyway to tighten it). I sanded the old fingerboard off, used and angle grinder to take out the truss rod and replaced it with some 2x12mm carbon fibre battens - when it's finished they should keep it poker straight but no adjustment. Will keep you posted on how it develops.

[Lucien]

Thanks for pointing out those questions HowieBass!

1- I had pre cut purple-heart fillers, but after talking with the boat builder, he told me that sometimes they made small indentations/slots on the wood so the coating could "grab" onto it and become more stable than just the regular bonding to a plain plank, so, in this case the epoxy filled them, but you could do it either way. Also, I wanted to keep those fillers for my next fretless P that will have a maple neck.

2- With the epoxy I chose the bending of the neck either during the applying process or afterwards becomes irrelevant, as the end result will be a very hard but very flexible and temperature change resistant. But yes, I loosened the truss rod and the neck got almost completely straight, even though I made this so it wouldn't become twisted for not having the correct string tension.

3- For now the neck has been flat on my working table without any clamps, as these first two layers don't need to be ruler correct, on the third layer, however, it will be clamped down and as horizontal as possible, for it will make the radius shaping process much easier and less prone to imperfections on the final buffing.

4- Right now I am applying the epoxy using a very fine wide brush, but on the third layer I will be enclosing the fretboard with cardboard then pour in the epoxy and remove the excess with a wide spatula. After that will come the final radius sanding and shine buffing. I can't wait to see the end result, but it's a process that requires patience to get to perfection.

[Lucien]

Bradwell, that's actually a very good idea regarding the carbon battens, I have the same problem on one of my favourite precision basses, just can't get the action low enough, and I'm not the kind of guy who uses super low action, but the strings are just too bowed in the middle.

[Bradwell]

It's still a bit of an experiment but the theory is that 2-off 2x12mm battens epoxied into the truss rod channel should be so strong that there's very little deflection when the string tension is put on. They're so stiff that putting a truss rod in the neck would just add weight and adjusting the tension wouldn't make any appreciable difference.

Problem is that any relief may have to be sanded onto the fingerboard.

I prefer roundwounds so epoxy would save a rosewood fingerboard from getting chewed to bits. Using an ebonol fingerboard as the replacement on this neck so I'm not yet sure if an epoxy coating is necessary due to the hardness of the base material.

[Lucien]

If it's Ebonol I think you're fine, the stuff will be around and mostly intact when you and I are pushing daisies for a long time... heck it might even be around after the whole bass has rotten and rusted to nothing... Archaeologists of the future will be pulling hairs to figure out why the hell are all these black slotted slabs... hmmm...



And Ebonol can be polished up, when I bought my five string, the Squier Jazz Deluxe, some of the frets were kind of damp looking, so I used just a bit of polishing paste, and was ready to go.