Should removable bottom boards on a wide board and batten canoe be varnished/oiled both sides?

[alick burt]

Hello Folks.
I have been asked to glue up some split bottom boards from an old wide board and batten canoe. When I looked at them initially I didnt turn them over so didn't notice that one side is bare unfinished wood.
Anyway what I am wondering is would they normally be varnished on both sides as they currently appear to have varnish on one side only? I am not sure if they are original to the boat and think they are made of white cedar.
I have had to clean off a bit of the dirt where the splits are not level so will probably sand and stain the unfinished surface incidently the varnished side has been stained mahogany colour.
so do I finish both sides or leave one open to the elements?

Many Thanks

Alick

 

[Michael Grace]

I say yes, absolutely. I don't know what the norm was among Canadian builders but I have seen some old floorboards that seemed like they may not have been finished on the backside. But I don't know if that was actually original, and if it was, whether it may or may not have been common practice. Builders of course cut some corners sometimes, but as we aren't mass producing, we have the luxury of being able to address more of the details. Leaving one side unfinished invites moisture intrusion. That intrusion will be asymmetric too, which could lead to the floorboards cupping.

Michael

 

[Andre Cloutier]

Often they were made of basswood, but of course replacements could be any type of wood. I always put tung oil and at least a coat of varnish on the underside, just to repel the water. No real need to finish to a high standard. Factory finishes were notoriously lighter than we apply; no factory would do 7 coats sanding in between!

 

[alick burt]

Sounds like both of you agree with me better to put a finish on both sides. I was thinking its a bit odd and yes they have cupped a lot!
Thank you Michael and Andre for your replies.
I have a Tung oil and varnish order on its way