when i did my stained night heron, had the same concern.

i matched the stain by colouring my wood flour  with the same stain that i used to colour my hull.

i got a yogurt container and put in about a cup of wood flour and then added a couple cap fulls of the berhens stain of the same colour i was using for the hull.  stirred/mixed.  added a bit of denatured alcohol to help get it mixed well....and then let it dry out.  basically, i now had coloured wood flour that i could use and it pretty much worked perfectly.

the important thing....let it dry out.  you don't want to mix with the epoxy while still wet.

try a small batch to perfect your technique.  but it worked pretty much perfectly.  worked just fine too with coloidal silica added.  so i never did a pure epoxy silica....but would always use my coloured wood flour as well to get the colour match right.  doesn't take much wood flour to basically colour the epoxy.

h

   Ahhh, hadn't thought of that. Love it - thanks.

PNWer - can I ask what stain you used (brand, etc) and how did the pre-stained wood-flour/epoxy mix work for you?  I'm in the same predicament now - trying to decide how best to fill a few gaps with a stainable or color-matching fill... and what stain to use (I'd like to go black also).  Any insight would be very much appreciated!

If you have not already, make sure that you read this article.  http://www.clcboats.com/shoptips/finishing-tips/staining-your-kayak.html

I followed those instructions with Behlin stain on two boats (Petrel Play and Shearwater Double) and really like the results.  In both cases, I stained the wood and covered with one coat epoxy prior to any assembly.  The epoxy evens out the color and protects it a bit during assembly.  After assembly but prior to glass, I repaired the color where needed with a little stain on a Q-Tip.    The S&G Petrel, like the Petrel Play is the latest generation kit from CLC.  It comes with the panels already beveled so if you are careful during the stitch up, you will have not have any external seems to fill.  The plywood panels fit precisely together and you should not have any "racing stripes."  One lesson that I learned the hard way is that dryed stain not coated with epoxy will wick a little when you wet glass out over it.  Not a big deal if the area is in the middle of a stained panel, but it will make the line between stained and unstained panels look fuzzy.  Lastly, after a couple of years in use, I notice that surface scratches in varnish/epoxy are much more visible on dark stained sections than they are on unstained okoume.

Here is a link to the photo log of my PP build.  You may find it useful because the S&G Petrel and PP share a common construction manual.  You will be following the exact sequence that I did but your parts will look a little different.  https://plus.google.com/photos/108197909267609876091/albums/6016182752308555809

Shearwater Double with hull stained with Behlin Cherry to contrast the okoume shear and sapelle deck.

Petrel Play with Red Belin Stain

Black stain? How about painting it instead? Can't beat the UV protection.

Good luck,

Patrick

RyanPett, Like Mark N, I used Behrens and am fairly pleased with the results. As noted in my OP, I appled a black stain, and basically followed the process in the video Mark referenced.

Thanks to life stuff, this project was sitting idle until a week ago, but I should have the hull seams welded tonight and will then run a small bead of stained epoxy into them. I want to use this to dam the seams, thereby avoiding the need to stain the large volume of epoxy applied in the glassing step while ensuring that unstained epoxy doesn't seep through and contrast against the hull's black finish.

I'll let you know how it all goes!

Wesley 

Just a follow up - I stained wood flour per hspira's suggestion and it worked very well. To date, I've stained ~two cups of wood flour. In total I added four caps of stain. I began with two, but that didn't get the mix to full black. I added denatured alcohol at a ratio of 2 stain to 1 alcohol. Once mixed, I dumped the wood flour onto a sheet of wax paper and spread it out to faciliate drying. Once dry, it  took very little flour to get the epoxy to the right color, so the task was really getting the consistency right (as per usual).

Wesley