Can we varnish toe rail and rub rail before installation?

[bobp]

We're leaning towards using a traditional varnish (spar?) with 10 coats. Can this be done before installation, or would the bending damage the varnish somehow (e.g. crack)? If varnishing before is not recommended, how about the combings (the don't bend nearly as much)?

Also, how many coats (if any) should be applied to the hidden surfaces? This is really two cases. First the surfaces that will be in contact between the rails, and second the other hidden surfaces (e.g. the bottom of the rub rail).

[Duncan]

We're leaning towards using a traditional varnish (spar?) with 10 coats. Can this be done before installation, or would the bending damage the varnish somehow (e.g. crack)? If varnishing before is not recommended, how about the combings (the don't bend nearly as much)?

Also, how many coats (if any) should be applied to the hidden surfaces? This is really two cases. First the surfaces that will be in contact between the rails, and second the other hidden surfaces (e.g. the bottom of the rub rail).

Good questions, which I am facing, too.

I believe (hope) that traditional varnish is flexible enough to withstand the bending. I am installing teak eyebrows on the cabin trunk, and part of them will require steaming to fit, so I am crossing my fingers that the varnish will stand up to the steaming and bending. To hedge my bets, and to allow for varnishing over the bungs, I am only doing the hidden coats before installing, with the rest to follow once they are attached.

With respect to hidden surfaces, yes, I believe that they need varnish, otherwise water will get in and lift the rest of the varnish on the visible surfaces. That happened within a year on a previous toerail job that I did without varnishing underneath. They looked great with six coats the year I did them, but they came off in sheets (to bare wood) before the next season came around. Caulking might help. but I think two-three (thinned) coats underneath is good insurance.

[Hirilondë]

Not only can you, but I highly recommend it. I did 3 coats, getting all but the top each coat. The goal was to get not just the hidden areas, but to have a continuous coat from them to the sides such as to avoid a mechanical seam in the varnish near where the caulking would end. This way the varnish is over-lapped by the caulking thus removing any inlet for water at the deck. It is a good practice to treat any wood trim that is bedded to a boat this way. You can varnish the entire piece (toerail, handrail, whatever) if you like, but the key is the continuous coats from the hidden/bedded surfaces to the exposed surfaces. I didn't bother with the tops as I was fastening through the top and bunging the screws. Hard sanding was going to take place and much of it would be removed anyway.

In regards to steaming I do NOT recommend varnishing before steaming. The whole point of steaming is to heat and infuse the wood with moisture to relax the fibers. Varnish will hinder this process considerably. The ideal way to do it is to make a mold of the shape you are bending around that is a slightly smaller radius than the real application. Steam the piece, clamp it to the mold and let it cool and dry in place. Then remove it and drill holes, pre-varnish and then install.

[Duncan]

Great points, Dave, thanks very much.