Hi Judith, I recently switched to Foster Fire and I love it! I have found that if I have mixed it too dry that I will get cracking during the wind on - so I use that as my cue to mix through a tiny amount of water - and without fail this has fixed that problem for me. (It also gets drier due to be open alot - not closed completely between dippings - Im flame drying it)
Ive heard people using it when it was very thin and very thick - so I cant tell you a hard and fast rule for what consistency to shoot for. For me its sort of like thick cream.
Another thing - if you are flame drying it - I find a cool flame (I just back off the oxy a smidge on the torch) and running the coated length back and forth thru the flame better than full strength flame and cooking it hard - but thats just me!
Once you find your groove with Fosterfire - you'll be hooked!
Cheers,
Lavender