From the SM web site it looks like they intend for the filler to go on first, then finish. I think that is true of most fillers. The exception, in my experience (which is, admittedly, limited) is that only clear fillers, like AquaCoat Clear work over stain. ColorTone says it is stainable, as does Timbermate (which I have not used, but others here have).
It's worth testing since some filler/stain combos stain better than others. Also, it may depend on what you stain with, and how you do it. Some take stain like wood. Others block stain from penetrating.
The other thing to think about is that ColorTone is water based. If you wipe/brush a water based product over it, you may reactivate and "pull" the filler. This is less of an issue if your next cap is sprayed on or something other than Water-based.
Thanks Fender I am in the process of experimenting with different ways before I touch my build. So far filler first then water based stain seems to work ok. I will try some wipe on poly over that today - steady as she goes
It occurs to me that the back an this may have the same sort of basswood laminate back and sides the the ES kits have...and maybe the top too. If that's the case, they may not need filler...or at least not much. With one of my ES's I decided I liked the color fine, and just put clearcoat directly on it. Polished out nicely. Not sure if the resonators are the same?
Thanks fender, yes the back and sides are basswood the front laminate looks like a very fine grained oregon which it probably is not. It’s pretty good except in a couple of places where in the cutting out the edges have splintered a bit, a sharper cnc bit might help, but I think I have successfully filled these.
The sides have little parts where the wood is stressed by curving it to the body shape - small “hairy bits” sticking up which sanding doesn’t remove - hopefully after some top coats of poly the will get rigid enough to break off and will allow sanding to work. Lots of poly coats.
It’s all part of the fun
Cheers
graham