Varnish inside before or after canvasing


'42 Yankee OTC
Is there any reason why I can't vanish the inside after I canvas? I'm thinking I could do it while the filler is curing.

(I did decide to go ahead and sand the inside and get it ready before canvasing to prevent any trash from getting between the canvas and planking. I'm thinking I should go ahead and apply linseed oil to both inside and outside before canvasing as well. )
I'm new to this site and restoring but I read somewhere it is recommended to varnish first to prevent bleed thru into the canvas. I am sure there are much more qualified members that can enlighten us both!

FWIW - I would have canvased first had I not read this. It seems to make sense. I think when I get to that point I will varnish first, but that is just me.

Two schools of thought:

1) varnish before canvas, so the canvas is not stuck to the hull by varnish seeping through the seams;

2) varnish after canvas, so that the varnish seeps through, and helps to seal the canvas against water absorbing during use.

Take your pick...

You can do both too. Do your sealing and build coats before canvas and then do a final finish coat after canvas. More often than not things get scratched and dinged along the way.

I used to think there was not much use in oiling a hull, but there may be some merit. I am currently rehabbing one of my first projects. It is my tripping canoe and it got kinda beat up the last few seasons. I originally oiled the hull exterior with thinned linseed oil in 2004 before canvas. I am now replacing some ribs and some planking. The oiled western red cedar planks are still somewhat oily (based on looking at the fibers during tack removal) and somewhat less brittle that I would have expected. I was genuinely surprised. I used leaded filler at the time and there was no evidence of mildew or critters living on linseed oil near the canvas either. If it wasn't for the damaged ribs and planking that I don't want to become an issue on the next trip, I wouldn't be changing the canvas. It looked very good. I do store the canoe indoors, but the canoe has gotten soaked to the skin on quite a few trips.
I've been varnishing after, but my next canoe, I'll varnish first.

It's a filler thing, I've been using a latex based filler. Took me till last spring to figure out that the thinned out varnish was creating the paint bubbles up along the stems that have been annoying me.
Varnishing after the canvas is on will often cause a blotchy effect in time to the exterior finish where the canvas and planking are stuck together.
I have always varnished after the canoe is canvassed and filled. I mix my own filler, and have never had an issue with paint bubbles or poor paint adhesion. I am of the school that believes it seals the planking gaps from sand and whatnot. I also oil my hulls prior to canvassing.