A skiff

cracked_ribs

Well-Known Member
Screenshot 2020-10-25 at 21.45.58.png


I mess around with boat design a bit. My first boat was of my own design, a sailboat I had almost twenty years ago. I’m not particular about using my own designs, though; the last boat I built was someone else’s design. But sometimes I want some particular thing and I figure I can do it well enough that there’s no point in trying to adapt someone else’s design to my needs.

I have been wanting a simple skiff for a while, maybe to keep at the cabin, but maybe to use around the islands and keep at home. Something lighter and simpler than the big I/O Double Eagle, which is a tank but not really ideal to fish from: small dance floor, big doghouse. I loved it for crossing the strait but now that I’m mostly just inshore fishing in protected waters, it’s a bit cumbersome.

At first I was going to do a really oddball design; now that I have a kid I don’t spend money as freely so I was going to build a skiff that would plane off with my kicker, which I’d have to re-prop but it would work. That’s how I got it in my head that I’d need to do my own design for this one; not too many boats designed to plane with a 9.9 XL shaft motor. So I worked on that design for a while; it would have to be pretty narrow, or else dead flat. It was kind of an interesting exercise but then one day my dad emailed me to see if I wanted his friend’s ’79 Johnson 20hp. He’d bought it new and maintained it well and it didn’t have a ton of hours, but he hadn’t run it in 20 years and was going to scrap it.

Sure, I’ll take that. 20hp off a two stroke? Way easier to make a good basic skiff that’ll run well with that power. What kind of shape is it in? Well, not many hours on it, but it's 40 years old. The owner maintained it well, I think; I picked it up and looked it over. Grease on all the relevant points. Clean under the cowling. Unbelievably light weight compared to what we're used to now. I remember it being on a 14' aluminum Mirrorcraft we fished out of Bamfield when I was about eight years old.


So I shelved my 10hp designs which, while kind of interesting, would have been pretty tender to fish from. Now I have an easy task: a skiff without a crazy amount of deadrise, but no need to flatten it completely. As long as it’s stable and light, it should be fine. And then…there’s my complete inability to leave well enough alone to contend with. So why not complicate things by paying homage to the lines of classic BC commercial salmon trollers? I love the way those double-enders look, with their almost tugboat-like proportions. Naturally this can’t be a double ender if I want it to be fast, but still, I could incorporate those workboat lines.

And if I’m doing that, why not run a fairly plumb bow? I could carry the keel forward a long way, extending the waterline length and increasing the theoretical hull speed, like a Chesapeake deadrise boat. They’re a bit sensitive to following seas but I’ll work around it. Get that wave-piercing axe-bit of a forefoot to soak up some chop, should smooth out the ride on an otherwise very shallow-V boat.

Okay, here we go.


Step one: get the motor running. Otherwise, the project isn’t that viable. 2020-10-05 18.01.56.jpg
 

cracked_ribs

Well-Known Member
Well you know I would, but we're up to four rabbits and a kid now, and I think they'd all end up glued to each other in a tasmanian-devil-whirlwind kind of ball of energy and chaos and fur and I just don't think I'm quite up to dealing with that these days.

No, half the reason I left Vancouver was that I couldn't stand apartment living anymore. Now I have a house! With a basement, a yard, and a garage. I'm living the dream and damn it, I'm going to indulge myself.
 

Gong Show

Well-Known Member
You are going to need a test pilot for this skiff.
I understand the risks and offer my services despite them.
As you point out, there may be a tendancy for this to bow steer with the keel running so far forward.
Depending on weight, the proposed 20hp main should not make it too scary.
 

cracked_ribs

Well-Known Member
All right, well, you'll have plenty of time to find an excuse not to; I expect that this will take a couple of years to complete.

It will for sure be a bit prone to bow steering but I'm not super concerned just because the worst places I'll take it would probably be Thrasher Rock or the outside of Porlier. If I have to run from following seas I'll just slow down a little so I'm not overtaking waves, or stand at the stern and float the bow a bit.

Anyway I took today off work and need to get back to work on the old wood stove to keep that shop warm enough to kick epoxy!
 

cracked_ribs

Well-Known Member
Preliminary steps


I wired up the garage with a couple of outlets today; there was no power in it at all before. Now there's rudimentary power out there. Good enough for now and even if the motor is junk and the project gets scrapped, it’s still worth doing. As is getting that wood stove going.

2020-10-26 16.50.09.jpg


With the wiring in place, the infrared quartz heater is up and running. I then spent some time on the stove, taking it apart a bit and replacing a couple of those fiberglass rope gaskets. Now I have it back together, the gasket adhesive drying. Tomorrow I might have a little fire in it just to see if it's sealed up properly. I guess I'll have to get a section of 6" stovepipe just to test it out. I probably should have bought that today but I didn't know if I'd get this far. If it seems reasonable, I'll pump more furnace cement in all the seams and build some kind of simple chimney, and cut some flashing into the garage roof.

2020-10-26 16.49.15.jpg


The old Johnson is in pretty decent shape, all things considered. It turns over and there’s spark, so probably a carb refresh and an impeller will make it run. I fed in some seafoam to the throttle body just to get the thing lubed up a bit, and pulled her over a few times. Doesn’t feel bad. A spritz of seafoam, a pull, a spritz, a pull, repeat for a while. I gave it a hard yank after about 20 minutes and she fired up, running briefly on the naptha in the seafoam, I guess. Okay, pretty encouraging. But no love off the gas tank, so I think the carb rebuild is unavoidable. New kit, plus new water pump with all the bits, and a Johnson gas tank fitting so I don’t have to use the ancient metal tank it came with, all in for a little under a hundred bucks from Amazon. Should be here in a few days.

In the meantime, I’m rendering the skiff design, or at least the panels, in Delftship. The software is a bit glitchy but should be sufficient for this design. It’ll get built in glass-ply-glass composite sandwich, with epoxy resin. Should be very light and strong, although it’ll eat a lot of resin. The hull will be ¼” ply with 12oz biaxial fabric on either side. I’ll try to squeeze it into 10 sheets of ply, and will probably burn 10-12 gallons of epoxy glurping it together. That’d put the weight at about 300 pounds.

I think a 16’ skiff around 300lbs should motor along okay with a 20hp two stroke. Of course, I suspect the only difference between the 20, which was a down-regulated Canadian-only motor, and the 35, was the carb. Maybe the intake. And the same skiff with 35 hp will really move.


And so the project begins.
 

ab1752

Well-Known Member
There are some talented folks on this board, and rest assured I for one will he watching this build thread with great enthusiasm. Snyder set the bar pretty high with 80+ pages only to switch gears over to a campion with the end so close in sight. As long as you don't get stuck on the age old "command bridge / no command bridge" conundrum, I'm going with you get this done in 50 pages or less. Bam.
 

cracked_ribs

Well-Known Member
Today I kept grinding away on the wood stove, and started the strongback for mounting the stations or bulkheads on to wrap the hull around. The wood stove seems all right; with the new gaskets in I lit a small fire in it to see if it seemed like it was going to dump smoke out the seams. But I think it’s sealed up tight enough.

2020-10-27 14.36.38.jpg

Always have fires next to old gas cans just in case you need the fire to get bigger in a hurry and don't want to run somewhere to grab fuel.

The strongback I mentioned at the start of this post is a couple of 16 foot 2x8s, separated about 30 inches. Basically I’ll screw uprights to the beams at given intervals, then put bulkheads on the uprights. The bulkheads will define the shape of the hull panels, although not rigidly: this style of construction floats the hull panels around the bulkheads and allows the panels to self-align to a degree, obviously subject to the constraints of the bulkheads. Anyway the strongback is just a frame everything gets bolted to during assembly.


Naturally I got a quarter of the way into putting the strongbacks together when my drill began to die. I had thought I’d felt the gears skip a bit previously but now they’re starting to strip. That drill has had a lot of use but it’s an annoying development, regardless. So now I have to get a new cordless drill. I finished up the stuff I was doing with a plug wrench and a ⅜ robertson bit but I’m not doing that for another 48 screws, so I have to see if I can locate a drill that’ll fit my Hitachi batteries so they don’t just go to waste.

2020-10-26 16.52.41.jpg


Tomorrow parts should start arriving for the Johnson, so I can get back to that for a bit.
 

Dorman Point

Active Member
Great looking little stove! Beautiful. That and a bzzr fridge and you’ll never have to leave the shop. The boat will be built in record time.
 

Pineapple Express

Well-Known Member
In the meantime, I’m rendering the skiff design, or at least the panels, in Delftship. The software is a bit glitchy but should be sufficient for this design.

Tell us more about Delftship! I've been looking around a little bit for hull design software. I want to design/build my own 17-18ft alumimum skiff. Anyway...Delftship...I think it's free for use but you can't export cut files from the free version? And Windows only? How is it to use? I've gotta buy a decent Windows computer and try it out I guess.

Maybe we need a separate thread for this.
 

cracked_ribs

Well-Known Member
I would say Delftship is okay, not great. I know there are people who can get a ton out of it; certainly it's quite visual and compared to what you pay for some of the other options it's pretty good. I don't think it handles intersecting planes very well. I find I have to really watch out that I don't overload it with a lot of points that are connected to multiple vertices because it seems to glitch right out when it tries to unfold those panels. Even some flat panels it gets confused by - there's a control net that you subdivide and push and pull and it drags the actual faces around using a sort of automated fairing principle. It works for hulls but gets weird if you start doing too much complicated stuff. What I've been doing is running multiple models, one with just hull panels, one with just bulkheads, that kind of thing. It's fiddly. I actually preferred their old software, Freeship, which was simpler and less capable but less prone to getting you in trouble.

In fact I keep a version of Freeship on hand and I will probably input all the control points into it for the hull panels and bulkheads as well, just to make sure that it spits out the same panel shapes.

I've only ever run either one on Windows and it's usually been fine, but the most recent update has this quirk in which causes Windows 10 Pro, at least, to keep burying the control point coordinate window behind the main window, so I'm constantly having to drag the main window around to find the coordinate window which I use a lot. I have three screens here because I work from home and need a lot of desktop to do everything I do for work, so it's not TOO bad, but it's annoying.

I suspect I could do practically everything I actually do on Delftship in Sketchup if I thought it through and bought a few plugins, but having a boat-focused interface does make some stuff easier. You don't need to trick it into telling you information about displacement, say. It understands pounds-per-inch of immersion; I doubt Sketchup has that built in.

If I did this professionally I wouldn't use Delftship, I'll put it that way. But the only way I'll ever do this professionally is if I retire, get a good aluminum production welding setup (there was one in the Buy and Sell subforum a few weeks ago that I almost cried when I saw, I just can't justify the expense right now) and do boats one at a time with no promises about delivery dates. I don't think there's a market for wood-cored composite boats, wood just has too problematic a reputation to overcome, although there are some things about wood cored boats that are just about unbeatable.

So for an amateur I think as long as you discover the limitations of Delftship early on, it's pretty good. Even the "pro" version doesn't cost that much, around $200 CAD IIRC. It runs easily on my computer but then I have a fancy Zbook provided by my employers and it'll run anything.
 

cracked_ribs

Well-Known Member
Oh also, don't worry about starting different threads, this one is going to move slowly for two years, I think, and it'll always get dragged back on topic as I update it with build info. It's effectively un-hijackable. Do your worst.
 

Dorman Point

Active Member
You don't say! So wait, did you build that boat? I don't know the whole story here.
Taking you at your word you don’t mind a de-rail...

Dorman Point was built by a friend of mine, who is an old-school English boatbuilder. He was trained at a yard named Dixon’s of Exmouth, on the Exmouth estuary. He apprenticed building traditional wood fish boats. Dixon’s apparently started keeping records in the late 1600s.

Anyway, he has always built and repaired wooden boats and Dorman Point was his only fiberglass boat. She was to be a prototype. He was going to build them here and sell them in England (at the time, he had a means of getting them there cheaply). Small, heavy, full displacement boats like her are commonly fished commercially in the UK.

Long story short, she was the only one to come out of the molds. Pretty heart-breaking to watch, really. After he realized there wouldn’t be another, he tried to sell the molds. Then he tried to give them away, and still had no takers. There just is no market on this side of the pond for a slow day boat. He ended up cutting up the molds and throwing them in a skip. A real shame.

So, Dorman Point is the only one of her kind. Despite her 6knot speed, I’ve covered a lot of water in her Over the last 12 years or so. I fish all over Howe Sound and the Vancouver side of lower Georgia Strait. I have run her over to Gabriola a few times, but that really requires a multi-day trip as it’s basically a 3 hour trip for me. A few years back I jerry-rigged a trailer (not a very trailerable hull) and took her to Ucluelet where we fished out of a camp site on Gilbert Island for three days.

She’s a tough little boat. Fully beachable with a purpleheart full-length keel shoe and oak beaching keels. The lapstrake design makes the hull extremely strong and stiff, as at each “lap” the hull is over 1/2” thick. Down by the keel, where the garboards would be, she’s about 3/4” thick. In keeping with her commercial-fishing pedigree, my friend built the hydraulic pot-hauler she’s fitted with. Made the patterns and had the parts cast in aluminum, fabricated the aluminum boom. Runs off a little PTO. The hauler is rated to pull about 1 1/2 tons. If I hang up I never have to worry about getting the gear back.
 

walleyes

Crew Member
Taking you at your word you don’t mind a de-rail...

Dorman Point was built by a friend of mine, who is an old-school English boatbuilder. He was trained at a yard named Dixon’s of Exmouth, on the Exmouth estuary. He apprenticed building traditional wood fish boats. Dixon’s apparently started keeping records in the late 1600s.

Anyway, he has always built and repaired wooden boats and Dorman Point was his only fiberglass boat. She was to be a prototype. He was going to build them here and sell them in England (at the time, he had a means of getting them there cheaply). Small, heavy, full displacement boats like her are commonly fished commercially in the UK.

Long story short, she was the only one to come out of the molds. Pretty heart-breaking to watch, really. After he realized there wouldn’t be another, he tried to sell the molds. Then he tried to give them away, and still had no takers. There just is no market on this side of the pond for a slow day boat. He ended up cutting up the molds and throwing them in a skip. A real shame.

So, Dorman Point is the only one of her kind. Despite her 6knot speed, I’ve covered a lot of water in her Over the last 12 years or so. I fish all over Howe Sound and the Vancouver side of lower Georgia Strait. I have run her over to Gabriola a few times, but that really requires a multi-day trip as it’s basically a 3 hour trip for me. A few years back I jerry-rigged a trailer (not a very trailerable hull) and took her to Ucluelet where we fished out of a camp site on Gilbert Island for three days.

She’s a tough little boat. Fully beachable with a purpleheart full-length keel shoe and oak beaching keels. The lapstrake design makes the hull extremely strong and stiff, as at each “lap” the hull is over 1/2” thick. Down by the keel, where the garboards would be, she’s about 3/4” thick. In keeping with her commercial-fishing pedigree, my friend built the hydraulic pot-hauler she’s fitted with. Made the patterns and had the parts cast in aluminum, fabricated the aluminum boom. Runs off a little PTO. The hauler is rated to pull about 1 1/2 tons. If I hang up I never have to worry about getting the gear back.

Way too cool DP, thanks man.
 
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