Thread: GIS Massachusetts/Maine build (a.k.a. the 'Perpetual July' project)

I'd sort of assumed that any sanding, if needed, would be on the edges of the panel (which, along with the bow, will likely get painted with 3" stripes). If there's too much sanding needed in the middle of the sides, then I may just paint the entire exterior (if restaining doesn't work out). Worst case, I'm out the $10 can of stain... I've seen other build threads (including one for the goat) where butt-joined panels were precoated with the three coats of epoxy, and have seen others recommend the same.

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mxP
GIS in Progress

Hi mxP!
So your idea is to have stain, epoxy and varnish on the outside of the boat? Paint on the bow and around the chines? The paint will make it possible to fair over the glass fibre tape, so that's probably a good idea. Drywall screws as clamps won't work (except top and bottom where it will be gunwales or paint to cover the holes) and I suppose it will be a bit tricky to get the scarf between the who side panels look good... You're not making it easy for yourself, but the end result might be worth it? Regarding sanding, you just have to be carful not sanding through the epoxy, I can't imagine how difficult it must be to re-stain when the wood is partially soaked in epoxy. But as you said, if it doesn't work out you can just paint it.

Pontus

Hi Pontus,

Yeah, my thought for the exterior is stain, tinted epoxy, paint stripes and then varnish. The semi-opaque tinted epoxy should hide some some of the issues I may encounter with the stain. I was planning on filling the screw holes with epoxied small dowel stock (with the end stained). I'm not worried... if necessary, I can just paint the whole thing. If it works out though, it'll likely be easier (and less expensive) than paint.


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mxP
GIS in Progress

While the epoxy coatings might help protect the stained surface, I think you might have better luck getting a good stained finish if you glue up first and then epoxy coat after assembly. This would give you a chance to touch up the stain, which you could blend to some extent with another coat if necessary. I think you might have a hard time not cutting through, dinging up, etc, the epoxy coated stain during construction. Tinting the wood flour filler or the epoxy itself to fill screw holes might be an option rather than staining end grain dowels and then having them absorb epoxy and varnish differently than the rest of the surface. You could also cut plugs with a plug cutter to match the grain and how the whole surface takes the stain and finish. A few tests might help.

I ended up applying fairing filler to the exterior around the butt joint and at the bulkhead points and at the stem if I recall. Fairing in the epoxy coating along the fiberglass chines also takes some sanding on the panels and bottom. If you are careful during assembly and use good size cushions to keep from denting the surface you might be able to bypass the fairing filler and go straight to epoxy coating and varnishing.

Originally Posted by Beaton2

While the epoxy coatings might help protect the stained surface, I think you might have better luck getting a good stained finish if you glue up first and then epoxy coat after assembly. This would give you a chance to touch up the stain, which you could blend to some extent with another coat if necessary.

Yeah, I began to lean toward the same conclusion last night... On a related note, the epoxy arrived via UPS this morning!

Very exciting! If you waited to coat, you could even sand off the stain to even it out before reapplying. If you decide to tint the epoxy, I think applying it untinted initially might be a good idea to prevent blotching as the epoxy soaks in on the first couple coats. It can be pretty tricky to get an even tone when applying color in a finish film over a stained surface. On surfaces as large as the boat, it would probably be easier if the color layers are sprayed on. You can also tint the varnish by mixing dye with acetone and then adding to the varnish. Thin, lightly tinted coats will be less frustrating than thicker and more opaque coats.

Sounds like this boat will have a one-of-a-kind look. I look forward to seeing how it turns out... in person at the 2015 North American North East Great Goat Gathering and Home Bake/Brew/Roast-a-palooza! Or better yet, on the lawn at Mystic.

I just experimented with stain under epoxy. I'm not a woodworker, so my learning curve is quite steep. What I learned is that deep sandpaper scratches (60 grit or rougher) will jump out and scream at you when the stain is wiped. At least that was true on the Fir pieces. I never touched the Okoume with coarser than 150 and it seemed to fare better. My work is not competition ready to say the least!

I would tend to advise against dowels in holes.

The proper way is to use timber plugs which have the grain the same way as the planking to prevent water ingress and keep any swelling in a compatible direction with the wood grain.

MIK

(crossposting from the blog...)

On Saturday, I began the bulkhead-framing process by pre-coating the surfaces to be glued (plywood and framing) with a single coat of epoxy (System 3 Silvertip) applied with a 2″ chip brush. Despite the 90-degree temperatures and the fact that I bought ‘fast’ hardener (expecting mild 70s), I was pleasantly surprised by how easily the epoxy went on. As I’d never used two-part epoxy on wood before, much less mixed it with cell-o-fill to create a glue, I chose to begin with the pieces that would be hidden once the boat is complete (bulkheads 1, 2 and 4).

For mixing, I measured by weight (using a small digital scale I bought from Amazon) as I figured that it would be more accurate and less messy than by volume. Rather than attempting to use a calculator while wearing rubber gloves potentially covered in epoxy, I created a cheat-sheet to maintain the 100:44 mix ratio for the resin and hardener at different weights.

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GIS-20140907-IMG_0215-1024x768.jpg	GIS-20140907-IMG_0216-1024x768.jpg	GIS-20140907-IMG_0217.jpg
GIS-20140907-IMG_0219-1024x768.jpg	GIS-20140907-IMG_0220-1024x768.jpg

With the epoxy cured enough to be handled, I began the framing on Sunday morning (the temperatures had dropped about 20 degrees!). After mixing up a batch of Cell-o-Fill-based glue to a honey/peanut butter consistency, I applied an even bed to the plywood using a popsicle stick, and clamped the frames into place using medium pressure (I’d previously marked the edges of their correct locations using a pencil). Using the slight excess glue, I practiced my filleting technique on the edges of the framing.

One thing I noticed is that the epoxy seems to inevitably end up on the rubber gloves and, eventually, somewhere on the wood where I didn’t intend. I think the solution may be to keep some paper towels (and possibly some rubbing alcohol) on hand to regularly wipe the gloves between steps.

With the frames curing, my wife and I decided to take advantage of the beautiful weather and headed off for an afternoon of apple (and flower…) picking in nearby Bolton. Later this week, I hope to finish the framing for the bulkheads and then tackle the transom.

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mxP
GIS in Progress

Each weekend, I’m finding at least a few hours to work on the goat. On Saturday, I began to tackle those pieces of framing that will be visible once the boat is complete: the bottoms and arms of bulkheads 2 & 3 . Learning from my previous experience with epoxy, I applied it more carefully this time, erasing pencil marks beforehand (lest I want to finish the wood bright instead of painting it). Using scraps of cardboard (actually, junkmail flyers) to remove excess glue made for a cleaner process. I’m pleased with the result: smooth edges and accurate placement! While I precoated the surfaces of the plywood and framing that were to be glued, I missed one detail: the cut (angled) ends of the bottom framing of BHD3 (which are now hidden by the arms) . When I finally coat the entire bulkhead in epoxy (likely months from now), I think I’ll be able to force some into the small gap. For now, I’ve made a note on the bottom to remind myself.

Next up: the transom and seat cleats.

IMG_0250.jpg Surface cleanup before epoxy	IMG_0251.jpg Bulkheads glued and clamped
IMG_0255-1024x768.jpg Bulkhead 3, now with arms.	IMG_0254-1024x768.jpg Bulkhead 2 has a bottom of its own

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mxP
GIS in Progress

MxP,

it is pretty interesting how varnish hides things better than paint does.

The wood grain acts like dazzle camouflage and it is difficult to see things unless you know about them in advance.

ONWARD!

Originally Posted by Boatmik

it is pretty interesting how varnish hides things better than paint does. The wood grain acts like dazzle camouflage and it is difficult to see things unless you know about them in advance.

But, but, that means I'll be forever bothered by those epoxy-preserved imperfections. Great, now I need to be even more careful.

Feel free to make your own joke about Jurassic Park's amber-ensconced mosquito.

With varnish you can have all the amber-ensconced mosquitoes you like. Go for it.

In retrospect, my greatest regret was working late into the night gluing parts together and waking up to hardened ooze. If a all possible, builders should glue parts least a couple of hours before going to bed so they can scrape off thickened goop before turning out the lights.


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