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Building my Osprey


Jan 21, 2006
Placitas, New Mexico, USA
At 81 I've decided I need a project, so I pulled out the boxes containing the Osprey kit I bought in 2005 and began. I was pleased to see that everything was packed so well and there was no damage!
I've set up on a covered patio and began when out daytime temps were in the high 80s. This morning the temp was 37 degrees! Work proceeded smoothly and I've finished gluing the outside seams; haven't yet turned the hull on its side to do the vertical end parts, I'll wait until the end of the week when warmth returns.
Here's my question: This kit was purchased in 2005 and the manual makes no mention of doing a "seal coat." I built two Terns: a 17 in 2003 and a 14 in 2011, and I remember doing seal coats on both of them with great results.
Have the instructions been revised as to doing seal coats? Of course I could call Pygmy, but I've enjoyed participating in this forum for so long I thought I'd start here. What's the current thinking about seal coats?
I await your recommendations....
2 S&G boats and others similar on the horizon:

I have and will always do seal coats on the ply wood sheets even before anything because I am a flawed and clumsy builder with coffee spills, beer spills, dirtstains, and rainstains. These have all actually happened during these and other builds because I build outside, usually stain the wood, and some time is taken during the process where lots of inadvertent happenstance can occur, sigh. So in your case with a kit, I'd seal right away - but that's me - obviously most people don't and great results are achieved: I don't really thing it matters.

Aside from the inadvertent spills and disasters in my case, the other aspect I worry about is differential UV wood staining over the long builds - for example on the drips and edges where a loooong drip crosses the unsealed wood and stays that way for an extended period of time. With a sealcoat, who cares?

With the extremely thin sealcoats that I use all that stuff doesn't matter a whit and yet there is still a lot of 'tooth' to the wood surface that allows killer subsequent epoxy bonding even when extreme bending is utilized during the build process after sealing.

So I think the answer is that it doesn't matter but a sealcoat will allow much more abusive handling during the process. But if you stain, sealing will be a necessity.

By the way, I loved building outside - especially at night for some reason, so have fun and good luck.
Mick's modus operandi makes sense. Greasy spills onto unprotected okume are a witch to deal with later. On protected stuff, alcohol or acetone, followed by a soapy water swipe and rinse with clear tap water eliminates problems.

One caveat: pinholes form more readily on ultrathinly coated plywood. Once they form, they are very tedious to remove. Oldpro is an experienced builder. I bet he knows about laying on resin at a temp slightly higher than the [overnight] curing temp to suck resin into the wood, eliminating pinholery.

Have fun, man.
Yes, all the above -- and
I feel that a seal coat makes it easier to wet out the glass because:
You have one less factor to control. (it takes time for the resin to go thru the glass and soak into the wood)
A seal coat makes it slightly harder for me to see the if I have fully wet out the glass.
"6 of one 1/2 dozen of the other"

If you do a lot of glassing and are skilled, then a seal coat could be just a waste of time.
I you haven't glassed for a time, then I would use a seal coat.

On the other hand,
If you glass the inside of the hull first with no seal coat, your skill level should be back up to 100% before you glass the outer surface.
If you achieved a good wet out without a seal on the inner hull ----- just keep going

Enjoy the build!
Good advice, Roy222. I agree that a seal coat, well sanded, helps in getting complete wetout of glass applied directly over it. On small boats like kayaks, maybe not as critical for multiple panel, larger plywood boats, where more fairing is often needed. Food for thought. Thanks.
Thanks, guys! Dave, you old O-Chem god, thanks for the reminder about falling temps being good during the curing phase of the operation. Once the sun goes behind the mountain the air temp starts to fall, so no problem with that.
We've got some really unsettled weather patterns swirling around us; so far the hull hasn't blown off the workbench. A bunch of neighbors and I are praying for some Indian Summer real soon so I can get more done. The kit came with fast hardener (for Pacific Northwest building) and I've bought some slow hardener so I can match almost any weather condition from here on out.
I'm leaning toward the seal coat; it just makes so much sense and gives me another opportunity to practice my rolling-out and then sanding skills.
Why didn't I get to this sooner; I'm really enjoying it!
First it was the weather gods: Hot, cold, windy, then hot and then cold again. I carved out a little work space in our "multi-purpose room" (garage) and got the hull coats done. Outside, I was drilling holes for the wire ties in the deck panels when I found that the gods overseeing kayak building really do have a sense of humor: I pulled the drill out of the hole I'd just drilled and watched in disbelief when my 1/16" drill bit fell out of the chuck, hit the patio floor, rolled downhill and disappeared into an expansion joint in the concrete!:( A screw-driving extension with a magnetic tip enabled me to retrieve the drill bit and continue working. I have a sealed bottle of hardener labelled "B" with NO indication of its curing speed. Apparently System Three changed its labelling sometime in the 13 years since I bought the kit. I contacted Sys3 and found they only guarantee their epoxy solutions for three years. I've done limited testing and it appears that the hardener is "Fast Cure for low temps" which is good for the current weather conditions. Time to do some cleanup on the sheerstrake and get on with the deck assembly. I wonder what the Fates have in store for me today....:)
Hi Brad!

Here is a quote from you when I was building my SOF "Every day we spend in the boatshop is another opportunity for an exercise in problem solving. Some are big; some are small, but we're learning all the time." I think it is appropriate for you today!!

Nice to see you back here. Hope you post some pictures.

That was really sage advice, wasn't it? I kind of had that in the back of my mind while I was on my knees on the cold concrete trying to fish the drill bit out of the crack. I did say something like "Well, here's a mistake I don't have to make again; lesson learned!"
The weather gods have smiled upon me! Got the multi-coated hull out of the garage and back into cradles on the patio. Started wiring the deck panels together; with luck and good temps continuing I may be able to start gluing those panels together. I wish the manual had some advice about managing to be both inside and outside the boat at the same time to do the stitching....
inside and outside the boat . . . stitching
So this demonstrates what I did the first time:
make a sharp bend at the extreme end of the wire and push thru the top of the free panel. Bend the inserted end of the wire into a U shape, and with needle nose pliers reach between the panels and insert that free end back up thru the base panel and make another sharp bend at the end of that free end - now the wire will not pull out either end - and repeat for the whole seam keeping the panels completely separate as the wire allows. It's amazing how rapid or repeatable this becomes. Lighting helps as the extreme wire ends catch light.
Then pull panels together and tighten after alignment is to your satisfaction.


Oh yeah, don't clip the wires short for looks as they really grab the clothing - keep the ends long as they deflect much better while brushing past, heh heh - lots of scratches for me!

Anyway, that's one way. But maybe it's stupid, I don't know.
Sage advice from Mick, the "old bull" of stitch and glue. His wire trickery I call "the fish hook method."

Never stint on wire. Long ends are easier to manipulate.
Thanks; I appreciate input from all sources! I've only got to do 13 more stitches on the right side, and I'll be finished with the stitching phase. I ran out of light and it's started to get cold again. I've been going back as far as Rider's Tern 14 build to refresh my memory and mine for odd bits of advice. Amazing what I've forgotten, but thought were first-class ideas for construction aids and techniques. Can't wait to start tightening stitches to achieve perfect alignment and then just snap that ol' recessed panel into place behind the cockpit like it was meant to be there. I remember considerable "fiddling" with those panels on my two Terns. Ted Moores admitted he had problems with his on the Coho build....
Finally, almost the end of March and the ice floes are starting to melt on the Rio Grande! Temps in the 70s for a couple of days and I finished gluing the deck panels together and pulled all the stitching wires out after curing. Not my best work at getting the recessed panel to fit perfectly, but OK; it's firmly in place. This morning the outside patio temp was 35 degrees F. Maybe I was too anxious to get building again, but by mid next week there'll be another warming trend. More building/problem solving to come soon!
Well, she's finished! Loaded her on the Hullavator just to do required adjustments and re-familiarize myself with all the tiedown rigging (It's been 6 years since I've done this) and drove around to ensure everything was tight and secure. And to receive complements from neighbors. Too hot for any boating; weather ought to moderate as we get closer to September. As to building outdoors: I wouldn't do it again in this environment, I'd rent shop space. Wide temperature swings, high winds, dust, pollen from Arizona were pretty challenging. Started in September 2018; just finished in August 2019. Had to shut down in November when the nighttime temperature dropped. The kayak building gods were messing with me and caused the deck width to grow by an inch while the hull stayed as was. A couple of other challenges too: Old epoxy resin had to be replaced (13 years is really too old), and the boards had taken a set from being boxed for so long. Varnishing required starting at 0630 hrs before the sun rose over the mountain and the temperature shot up causing varnish to dry too quickly. Tricky to get the right proportion of brushing thinner to varnish. All is now well; can't wait for christening ceremony and getting her bottom wet!
Congratulations on your build! I’ve got to get around to building myself a Pygmy one of these years...
Yes , a proud moment to finish the build. I am 77 and wish I could start another build.
Anyway, all that you described is what makes building a kayak a huge achievement.
Now be safe on the water!