How to know when to shim bolt on necks?

[BlackhawkRise]

Every guitar with a bolt on neck that I've taken apart has had a shim. I will be marrying a random strat neck I have with a random strat body I bought on line. How will I know if, when, and how much to shim it?

[ICTGoober]

If you can't get the action at a comfortable height using the adjustments available on your bridge.

[Mr. B]

Yeah, it is usually when you have the saddles bottomed out on your bridge (ie. as low as they will go), but the strings are still too high off the fretboard. Occasionally, there can be paint overspray buildup in the neck pocket that can be keeping the neck from settling all the way down in the neck slot. If so, removing that paint buildup may put the neck back where it should be without shimming.

[PFDarkside]

I seem to be one of the only fans of the Fender MicroTilt as implemented on the 90’s/00’s Deluxes. I got my Deluxe Plus just dialed in with it. Of course it had the locking Floyd Rose saddles so they weren’t individually adjustable, just the two post heights, so if they were slammed there was no additional adjustment available.

[Mincer]

I seem to be one of the only fans of the Fender MicroTilt as implemented on the 90’s/00’s Deluxes. I got my Deluxe Plus just dialed in with it. Of course it had the locking Floyd Rose saddles so they weren’t individually adjustable, just the two post heights, so if they were slammed there was no additional adjustment available.

I liked those micro-tilts, too. Much better than the 70s versions,

[ICTGoober]

During the 80's and 90's I did a lot of conversion jobs from the old 3 bolters to 4 bolters. Imagine my surprise when recently kids started bringing me 4 bolters to convert to 3 bolters (I refused).

[Mincer]

During the 80's and 90's I did a lot of conversion jobs from the old 3 bolters to 4 bolters. Imagine my surprise when recently kids started bringing me 4 bolters to convert to 3 bolters (I refused).

I didn't realize that was a thing. I suppose there would be a market for a bolt that looked like a 3 bolt with a hidden screw, I don't know. It was a terrible idea.

[baritone]

I always start by lowering the bridge or saddles as much as I can. If the strings still are too high off of the upper frets, then it needs a shim. I've always disliked neck shims, and I've removed them from every used guitar I bought. The setups were always exceptionally better without the shims. Except for a Squier 51 I bought & sold this year - I lowered the saddles until the tiny screws were poking my right hand, but the action was still too high. So I shimmed it.