Largest shortcoming of penetrating stains, when you want to work with raw wood (plywood too) and achieve sharp transitions, is one of their important attributes, that being that they penetrate. As in following the grain as well as saturating (relatively) deeply into the wood fibers upon which they're being applied.

Paint's easy - if need be you can start with a clear undercoat along the taped lines, sealing the surface against creep.

Some masking tapes are better than others. I've heard (but have yet to use) a Gorilla brand that touts sharp edges.

Keep in mind also what's required of whatever product you choose as far as dry time before epoxy's used. Alcohol-based stains seem to be least problematic, oil-based the opposite.

I have some experience with sharp lines and stains.....and it can be a bit tricky but doable with some care and practice.

my process (and i have practiced/perfected it) includes a couple steps.  first, mask off the line or area i don't want to be stained and epoxy coat it (to fill the pores) and then remove the masking tape.  then when the epoxy is set, i mask the epoxy area and stain up to it with care such that when i am staining up towards the line my rag is not 'wet' but is sort of dry so that against the line in am just working the surface (vs soaking the wood)   i then put a coat of epoxy over the stain and then remove the masking tape.  any spill over onto the epoxy side can be relatively easily cleaned up.    

anyway, you can test and perfect on a scrap okoume.  it can be done but it is labor intensive and you need to be careful.  you are really focused on working the surface and not soaking the wood with stain.

h 

That's a very clever approach to what otherwise would be a frustrating exercise @hspira!

In essence you're dividing the surface you want to work with into discrete areas, not unlike a stained-glass window, then treating each section according to your design. Using epoxy as a 'resist' as when doing an etching, to keep the adjacent stain where you want it.

What's your preference for stain media? Available retail or you mix your own?

I ever get around to building another watercraft, knowing what I do now after nearly a year working on this Waterlust build, I might just opt for a 'bright' finish, showing off the wood grain, maybe an attempt at something using your technique. 

(Curious your first image, among the waterlillies, came up fine. But the second one's still just a 'broken link' icon? I envy you your success with posting images, dispite this latest snafu...)

on the stains, i just use behlens (now Mohawk). 

not sure what i did on the links,  i have just been trying the postimages.org after seeing another forum poster use it and it seems to work.

here is another boat, my petrel, on a recent lunch paddle and it has some pretty fine lines.  in addition to the sheer line, there is a waterline and very fine lines on the deck.

your description of the approach re stainglass is spot on.  i have also explained it to folks like doing tie dye and other forms of printing on fabric where wax is used as a resist.

h

That inspires an interesting thought, Howard - using batik technique to make a skin-on-frame kayak covering :-)

More seriously, I hadn't realized that those trim lines on your boats were masked stain jobs. I had always assumed that they were simply strips of contrasting wood glued into place. How to make a finicky labor-intensive job even more so :-) They sure look nice, though.

Laszlo

Sorry for the extremely late reply to this thread but I was having trouble getting images to post via Flickr until I just started manually editing the url.

I wanted to see if I could hold a precise line with the Mohawk stain and using whatever painters tape I had laying around. The blue is 3M and the green is Frog Tape. Since the bulkhead will be hidden I figuered it would serve as a good test subject and with the large surface area I could do four variations.

The epoxy here was left to dry for 24 hours then the tape surrounding it was pulled and fresh tape applied over the cured epoxy. The stain was applied and left to sit overnight.

Here you can see the bleed after the tape was pulled. Both tapes applied directly to the wood didn't fair so well. The tape over the epoxy came out better but surprisingly the Frog Tape lost out in both tests. The 3M worked wonderfully.

The cool thing about placing the tape on the epoxy is that even if the epoxy is a bit exposed the stain will come right off with the light scraping of utiliy blade.

Here's the deck. I thought it came out pretty well at least until assembly but that's another story. I could do a build thread with more images now that I know how to post if you all are interested.

Alam, 

you nailed it.  that's how i do it...blue tape and razor blades for cleanup....and it's also ok to shoot from a couple feet back.  thanks for the demonstration.

i am sorry to hear about the deck.   that would definitely be a piece that i would have advised you do after it was attached.  unlike the shearwater series, a chesapeake deck's 'fit' and final position is not known until it is attached to the hull.   its called a tortured deck for reason... but not the reason they give.  i think it tortures the builder!   but your deck (at least before you attached it) looks incredible:)

anyway, would love to see how it is coming and see the creativity you bring to the place.

below is a picture of a boat i built last season with paint on one side of the line and stain on the other.  it came out really slick.  keep up the positive vibe!