Anyway thanks for all the input everyone.
The aerosol nitro sanding sealer seemed to do the trick, I applied 3 coats the first one super light, gave it a light sand.
I just brushed a coat of the water based topcoat and there was almost no colour in the brush when I finished 
The nitro is pretty smelly and expensive so will give the non water soluble dyes a try next time.
Oh good. Glad you have got a good result.
I tried some alcohol soluble blue dye crystals and even though the oil finish had a different solvent it still lifted quite a lot of stain.
Spraying a seal coat would have solved the problem.
The takeaway from all of this, is that the stain and the finish are a unit. The stain and the finish need to work together. So, testing needs to include both products together.
I tried some water based finishes three years ago and the British products were awful. In the states they were using far advanced water based poly but it was largely unavailable or eye wateringly expensive. Afterwards, I read a blog from a British paint industry consultant who said that the British products were way behind the products in the states. The water based varnish I tried would not flatten and I used the recommended brush filament, plus others. It also left bubbles regardless of the brush type or the care in application. It also went milky and looked exactly like plastic. I ruined my project so I stripped it and refinished.
Put me off water based finish.
I imagine that we have caught up since then and there must be good products on offer due to environmental concerns. Low voc content etc.
Your finish surprised me, it looks smooth and exactly like a regular varnish.
The Bright Tone finish is american and pretty expensive 
I had to be pretty patient with applying it though, the coats have to be thin to avoid brush marks. This took a bit of practice, as the thinner you apply it the quicker it drys and turns gummy.
After about 20 coats I then had to level sand it to get out all of the remaining brush marks.
This guy did a pretty good build video of finishing with water based poly:
Crystal Lac do a range of pigments and a ‘stain’ binder as well, I couldnt find any available in the uk for this project.
I was looking around for alternatives for water based poly I found this from North West Guitars, they generally do pretty good products:
They also do a water based stain which might work better than the crimson stuff in terms of dissolving into the top coat.
Also this from Nitor Lac, they look like a pretty serious finish company they do nitro finishes and 2k oil based poly, but Ive never tried their products:
https://nitorlack.com/en/barniz/top-coats/waterbased-en/nitoraqua-lacquer-black-matt/
I may get some to try out, they may be rubbish.
Like I said previously Ive found finishing to be by far the most difficult aspect of building guitars to get good results.
Like you say Ive just got to develop a recipe of products and techniques that work!
I finally finished this guitar project!
I finished the ‘finishing’ of the body, it was a bit of a rigmarole as discussed above but I brushed on about 20 super thin coats of the Crystal Lac Britetone water based poly then level sanded it all and buffed up to a shine.
I still need to work on getting the figuring of the maple to really pop but Im pleased with the results.
There were a couple of other jobs, I carved a nut:
Wired the electronics:
Cut some scratch plates on the CNC machines, that came out really well, they fit all of the hardware like the bridge and the pickups super tightly, they just needed a bit of sanding and polishing to get them looking good.
Then there was just some final fret leveling and finishing.
And final assembly!
Im really pleased with the results! It plays and sounds great!
Thanks to everyone in the space whos helped, advised, inducted me to get to this point.
Im already planning my next build, its going to be a fender jazz bass style of instrument but fully carved on the CNC!
Looks amazing
That is fantastic. Thanks for sharing the process.
Looks like a really nice job. I’ve made a few guitars myself and that finish is lovely.
Did you make the neck? It looks like the truss rod adjustment hole has been filled.
Philip
I do have quite a few guitar tools like fret slot files (bass) , fret dressing files, set up tools etc if you think you might need to borrow them. Phil
Hey Phil, thanks! I did make the neck, the truss rod adjustment is at the heal, the wallnut tear drop on the headstock is just a 'flourish’
Thanks for the offer of the tools, Ive got a bunch myself ill be in touch if I’m in need!
What guitars did you make? I noticed Howard was making some sort of bass type of instrument today😁
So, you are a southpaw?
Hey Mark, yes! Its actually one of the reasons I made my first guitar, I wanted a six string bass of a particular style and, without getting something custom made, there was nothing available in a left handed version. So I built it myself
Hi Francis,
Mainly, I’ve made cigar box guitars of various shapes and sizes. Licence plate guitar, double neck, resonator, straight cbg, short scale bass and a dragon shaped full scale, solid body bass. Currently in the process of making a flying V, acoustic cbg. On hold at the moment as I have a badly broken shoulder from a bike crash.
Here’s a photo of the dragon bass.
Wow! That is a seriously cool bass, love the idea, Im trying to imagine what type of band you would be playing in with that I love flying vs as well.
Hope your shoulder gets better soon
Thanks Francis,
Here’s a couple of the fling V in construction. I’d love to meet up some time at the space and talk future bass projects.
Nice!
Yes always for time to talk bass, would be great to compare notes sometime.
Hi Francis,
We are starting to look at our content inclusion for the Dulwich festival Maker fair we have a “Don’t be Shy! submit your Make” event happening on Friday. Would this be of any interest to you maybe and/or do you know anyone else I can reach out too?
Cheers
Dorine
Awesome thank you! I saw you had a bunch of other stuff, apart for the Guitar anything else you’d be happy to share?
A lot of the stuff I made were present so I don’t have them anymore, I have the brass guitar bridge I made it’s unfinished but somewhat photogenic, I can bring that down too.
