: Right on Bill!

: Also to be considered in the time required ...

: Time lost due to little R&D projects necessary to get something to work.

: Time lost chasing perfection.

: Time lost running around trying to find stuff.

: Time lost due to down time when you're so fed up with working on the thing
: that you don't go out into the shop for weeks on end ...

: Ken Blanton

I'd venture that's not really 'time lost'; ever hear 'it's the journey, not the destination'? I think that applies. Personally, I work on it when I feel like it, and let it languish when I don't. My current project 'simmered' nearly a year before I finally jumped in, built the strongback etc.; once I had the forms up, things started to move nicely (for me; I'm not nearly as 'productive' as most of the posters here). Take your time, enjoy - or try to beat Maurers record. Both are good.