Sorry I have been away with work.
Mixing the solution is your choice, water and kero both have pros & cons.
I learnt from an ex-commercial keeper so I tend to be biased to there ways. but I am always open to new learnings also.
I paint inside and out, and leave out in the weather for another 2 weeks, paint fumes also upset the bees.
Copper mixed either way is toxic to you and the bees. But copper will prolong the life of a super from months to 30+ years.
-Stores well (can use any airtight container)
- Doesn't not stain skin as bad when spilt.
-asorbs slower (can take up to 72hrs for full penitration)
-water can cause warping
- Can take 8 weeks to fully dry out
- Asorbs well & fast (8-12hrs is enough to get 100%)
-Less prone to warping
-has been proven to last 30+ years
-termites tend to leave it alone also
-Storage can be hazarous