is there any reason to thin interlux varnish?
Have the same question, although I am using Kirby Varnish. One vendor suggested six coats. The first thinned 50/50, second 25/75, and all subsequent coats being 100%. Sand first time after 3rd coat. Would like verfication of this before I start.
I finished my spars bright following the advice of jf_poirier(thanks, Jean!) on this forum. I started from bare wood. First coat thinned 10/90, second 20/80, third 50/50, rest with just a little thinner to help the varnish flow. The early coats penetrated deep into the wood. After the 50/50 coat, the wood started to become shiny. After all the coats and a few weeks when I've been working on the hull paint, I notice that the spars are very shiny, and quite dry. See how well the finish stands up to use and keeps the water out one I get the beastie in the water...
I don't think this kind of schedule will give you any benefit if you're varnishing over epoxy, since there is no penetrating into the wood to be done at that point.
Not sure about Interlux varnish specifically but I thin Captains with a bit of penetrol and mineral spirits (Thanks Joey@CLC). This seems to help the varnish flow out better, helps prevents runs and brush "skittering".