Darken WRC when Epoxied

  • Advertise with us

« back to Finishing forum

Forum topic by SpottedGum posted 04-10-2018 10:25 AM 553 views 0 times favorited 6 replies Add to Favorites Watch
View SpottedGum's profile


13 posts in 1390 days

04-10-2018 10:25 AM

I recently built a WRC cedar kayak. During construction every now and then I would wet the kayak timber down with a wet cloth to admire the colouring. But when I epoxied/fiberglass the kayak the timber colour darkened considerably.

As I want to build another kayak does anyone know how to prevent the darkening of the timber during the fiberglass stage – like a pre coat product or similar

6 replies so far

View Aj2's profile


2656 posts in 2409 days

#1 posted 04-10-2018 01:47 PM

To prevent darkening don’t put epoxy on it. :^)

-- Aj

View RobHannon's profile


330 posts in 1141 days

#2 posted 04-10-2018 02:20 PM

What epoxy did you use? If you are using West Systems, the 207 hardener is going to cure the clearest. Some sort of UV topcoat may be needed as well to protect the color. Around here the West Sytems distributors are very knowledgable. I would check with them in your area. I don’t know a lot about other marine grade epoxies other than they exist.

View CaptainSkully's profile


1612 posts in 4169 days

#3 posted 04-10-2018 04:10 PM

Wow, that’s weird. Usually the wood darkens with epoxy the same as with water. Was the epoxy noticeably dark, possibly due to age? Were there any additives? @RobHannon is spot on with 207 being the clearest epoxy you’ll be able to find.

One thing you might consider is some sort of sanding sealer on the cedar prior to epoxy, but I would definitely ask on a cedar strip forum to make sure that doesn’t interfere with the bonding of the epoxy. For me, I’d be more concerned about making it waterproof than a darker color. A lot of woods will get darker with age anyway.

-- You can't control the wind, but you can trim your sails

View jklingel's profile


110 posts in 1768 days

#4 posted 04-12-2018 05:40 AM

Mine darkened somewhat, but mostly the colors just just stood out loud and clear. We used MAS and West Systems epoxy; seemed the same clarity to us. I think more darkening happened with the spar varnish than the epoxy, but I have no test pieces to verify that.

View John Smith's profile

John Smith

2135 posts in 773 days

#5 posted 04-12-2018 11:40 AM

Spotted – can you post some photos of your sample boards
as well as what other products you are using ??
it is hard to envision your issues just from the descriptions.


-- I am a painter. That's what I do. I paint things --

View runswithscissors's profile


3081 posts in 2636 days

#6 posted 04-14-2018 05:13 AM

If you want the epoxy to adhere, I wouldn’t put any kind of sealer on it. AJ may have been facetious when he suggested not using epoxy, but then you can’t fiberglass it. And no, don’t even think about polyester resin. It has crappy adhesion to wood, and will soon delaminate.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics