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Re: Skin-on-Frame: epoxy the plywood form edges or
By:Bill Hamm
Date: 3/23/2011, 9:20 pm
In Response To: Re: Skin-on-Frame: epoxy the plywood form edges or (ancient kayaker)

: Air temperature and pressure and wood dimensions change all the
: time. In unsealed wood that creates a constant exchange of air,
: moisture and whatever goes with them in the outer few mm of
: wood. If the surface is sealed but it is less than perfect the
: exchange continues, but at a lower rate, so whatever the builder
: was afraid of is not prevented.

: If you want to seal it helps if the wood is warmed before epoxy
: application; this will make the epoxy more runny and expel some
: of the air from the cells. As the wood cools the epoxy will be
: drawn further into the grain.

: If the objective is to prevent rot perhaps one should ask the
: question, how many kayaks and canoes have died from it? I have
: never seen a ply structure with rot. Outdoor wood structures
: that I have seen don't rot above ground. I have seen lots of ply
: panels that have delaminated, but that is not supposed to happen
: with marine ply. Sealing with epoxy is likely a waste of time
: and money for a dry-moored boat even if it is stored outside.

: My ply sailboat is left outside all year round - it's only in its
: third year so it may be too soon to tell - but so far it shows
: no effects even with only 3 coats of latex house paint.

Actually plywood doesn't change shape much with temperature and humidity changes, though it does increase/decrease in thickness slightly. I still oil them, more because it's prettier that way and does tend to repel some moisture. The oil adds very little to the weight, unlike epoxy which can easily add a couple pounds. I have troubles adding weight to a SOF, lightness is nice :)

Bill H.

Messages In This Thread

Skin-on-Frame: epoxy the plywood form edges or not?
Todd O -- 3/21/2011, 1:29 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Dave Gentry -- 3/21/2011, 1:50 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Foster -- 3/21/2011, 6:04 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Charlie -- 3/21/2011, 6:20 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Kudzu / Jeff Horton -- 3/22/2011, 8:24 am
Re: Skin-on-Frame: epoxy the plywood form edges or
Charlie -- 3/22/2011, 2:30 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Kudzu -- 3/22/2011, 2:45 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Charlie -- 3/22/2011, 3:40 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/23/2011, 1:50 am
Re: Skin-on-Frame: epoxy the plywood form edges or
ancient kayaker -- 3/23/2011, 9:13 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/23/2011, 9:20 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/23/2011, 1:45 am
Re: Skin-on-Frame: epoxy the plywood form edges or
Paul G. Jacobson -- 3/23/2011, 1:14 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/22/2011, 2:21 am
Re: Skin-on-Frame: epoxy the plywood form edges or *PIC*
Tom Yost -- 3/23/2011, 11:37 am
Re: Skin-on-Frame: epoxy the plywood form edges or
Todd O -- 3/23/2011, 12:26 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/23/2011, 1:59 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/23/2011, 2:01 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Todd O -- 3/23/2011, 3:12 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/23/2011, 4:04 pm
Re: Skin-on-Frame: epoxy the plywood form edges or
Foster -- 3/24/2011, 12:56 am
Re: Skin-on-Frame: epoxy the plywood form edges or
Bill Hamm -- 3/24/2011, 7:38 am