Dykem blue for guide coat?

[piperdown]

Any of you heard of using this before? Putting dykem (?) blue in acetone or denatured alcohol and spreading across a surface to be faired and sanded. Acetone or denatured alcohol evaporate and you're left with a blue color that you sand. Like using a paint guide coat or graphite powder.
It talked about at 16:04 in this video https://www.youtube.com/watch?v=M46BkAtXlmo

[Jaysen]

Aceton and alcohol that is used to remove uncured epoxy? I would think you would want to wait for full cure times before you get near a hull with that stuff. Not the simple "it's hard" but the full cure time.

[cape_fisherman]

A fried of mine, and someone that I consider one of the best custom boat builders alive (builder of custom North Carolina sportfishing boats), uses regular food coloring mixed into denatured alcohol. Soak a rag & wipe it over the hull. It dries VERY fast. I'm not sure of the cost of Dykem, but food coloring is almost assuredly less expensive.

[Jaysen]

Is he using ester resins or epoxy? Only asking because I like cheap solutions and if he’s using epoxy I’m all in on this idea.

[bklake]

In a quick search on amazon, Dykem is $15 for 4oz and food coloring in $8 for 16oz. I'm sure the Dykem will definitely coat the epoxy and not sure if food coloring will get it done. I've never sniffed my bottle of Dykem but it must have something strong in it because it never fails to coat metal which usually has a little oil on it from machining. How will paint stick to the residual Dykem? It's not really designed for that.