A Seil in California

[The Jeff]

Re: A Seil in California

As I worked along the building jig, finding everything perfect to the millimeter, I must have internalized the idea that these were platonically ideal parts. I got to the end and found that the whole thing was 10 mm longer than expected and felt sincerely stumped. On reflection, 10 mm over 5,400 mm is an error of 0.1 % -obviously better than good enough, and far smaller than likely changes from heat and humidity expansion, to say nothing of my questionable joinery.

Man, that brings back memories of me bugging Ross about why some of the sub dimensions in his plans didn't add up to the overall dimension. It turns out he designs in metric and converts to imperial to the nearest 16th of an inch. I couldn't see the forest for the trees that .0625" in a stitch and glue boat is nothing.

I'm enjoying watching your progress and especially like your memorial boat house!

[pez_leon]

Re: A Seil in California

Thanks, Chris, for the notes on the boat and for the charming video. I'm glad to hear you are happy with her! I am indeed currently constructing the case. I hear you loud and clear about the vulnerability and inaccessibility of this part. Today saw the wet out and filling of 10 oz fiberglass glass along the plywood sides. It was warm enough here to kick one used foam roller into an exothermic reaction, which I haven't seen before.



I hope to have this thing glued together tomorrow so that I can start mounting transoms, bulkheads, forms, and the centerboard case on the strong back. I like your idea of taking the transom bevels directly by using the sole as a batten. I did notice that one of the mylar patterns includes bevels, and I'm half tempted to them on the bench to those plans. I bet either way works.

In between filling the CB caseI glued doublers to the top of the bulkheads.



Here is (I think) another testament to the accuracy of the parts: some of those small plywood doublers don't sit exactly flush with the outside edges of the bulkheads but are instead proud or shy by a few mm. It's always the outside bulkhead, and always the offset you need to carry the bevel across this wider part of the bulkhead. So unless I'm mistaken these tiny parts are intentionally made a few mm larger or smaller than the piece they double to allow for a perfect bevel. I bet that would satisfy even the most precise metalworkers among us!

Hey Jeff - how's that transom mounted bassinet coming along? Gotta start 'em sailing young!

- James

[pez_leon]

Re: A Seil in California

Transoms, bulkheads, and forms are (mostly) attached to the strong back:






I have some advice for future builders: Don't establish the section (bulkhead) locations by measuring, as I did.
I lost at least an hour today to moving bulkheads around and trying to persuade the molds to fit the measured bulkhead location. I persuaded emphatically, so forcefully that I persuaded one of the fore-and-aft molds to break in half!



All this accomplished was to persuade me of my own foolishness. Oh well, lesson learned. At least it's not a lasting part of the boat. I think that some part of the problem was a very, very tight fit in the longest slot connecting two MDF pieces, and a larger problem was my having already fixed the bulkheads.

Obviously, don't do this. Instead, use the fore-and-aft sole molds to position all your bulkheads, then attach the bulkheads to the strong back wherever they fall. Once I did this they met perfectly the middle leaving the exact length of the centerboard case, which I'll slot in there tomorrow.

There is one bulkhead that just won't quite fit onto the two bolt holes that position it on the strong back. I can't tell why. I also can't tell if I'm fitting the sole molds and the bulkhead supports together quite right. Where two MDF pieces slot together at 90 degrees, the bottoms of the slots are not square but instead u-shaped (because the corners are rounded to the radius of the cutting bit). This effectively creates a mushy interference stop. You can make the fit tighter by pushing harder or tapping with a mallet to deform those radiused corners. As I write this, I suspect that the designer intends an easy press fit, but when I'm out there working on the molds it always seems to me they need to be tapped down harder into position, so that they sit tight against the strong back. This is the kind of thing I can only seem to learn by trial and error.

But man it feels good to make progress!

James

[Lubber from Limeyland]

Re: A Seil in California

Hi James..

Yes, first mould, then bulkheads. Once I got it into my head that the jig, parts and instructions are very accurate, the solution to any issue always lay with what I had done. I did ask Francois for some clarity a couple of times...he always replied promptly...and he urged me to work things out for myself (in a polite way!) and not to worry about deviating from the detail which makes for a unique boat. I thought this phase the most satisfying as quick progress is made. The best is turning the hull over and sitting in the shell, although my friend broke his finger in the process.

[pez_leon]

Re: A Seil in California

Thanks, Chris. The mystery of bulkhead 8 will have to wait for a few days until I return to the boat. I’m sure you’re right that any errors are mine and not the jig’s. It has been quite accurate.
I had been thinking of mentioning my success with pocket hole screws (not in pocket holes) for temporary alignment and clamping of parts for glue up. I inherited a bunch of these and while I’ve never used them for their intended use they’ve proven strong, and the flat heads limit marring. But no! I broke two on removal from the CB case before wising up and applying heat. Both broken screws came out with the homemade screw extractor:



As hoped the CB case slots right in.



Once I placed it got to wondering if I should glue it to the adjoining bulkheads (called out with the yellow arrow in that photo). The manual is mute on the subject, which tells me it’s probably a bad idea (Screws are to be added to the joint after turn over). If it is to be glued, it must be glued now before the sole goes down. Any advice from the crowd?

[Lubber from Limeyland]

Re: A Seil in California

Hi James,

I thought I had posted a few days ago, but...smart phone, dumb owner.

Anyhoo, I didn't glue at this point because I wanted to have some flexibility when I lined up the CB slot in the sole as I thought it critical that the joint was absolutely spot on. I did apply epoxy fillets afterwards however and no issues so far...

[pez_leon]

Re: A Seil in California

Thanks Chris! I am not going to glue that joint and will trust in screws and fillets.

Meanwhile:

Beveling bulkheads. The sole mold makes this easy:


Sole pieces joined, glassed, and ready for fairing. This was my first time using peel ply and I'm not totally sold on it for my use. At present I have the luxury of full days to devote to the project, and I think I can probably get a better result with less sanding by laying down successive thin coats. Look close and you'll see the puzzle joint:



The sole is laid down with plenty of screws, but not yet glued. I beveled one side now to confirm that I can do it on the boat (and not back on the bench). No problems so far.

[pez_leon]

Re: A Seil in California

Everyone in the house got COVID, and that slowed progress a bit. We're all fine - have been all along, really - but between the isolation-necessitated total lack of outside childcare and fatigue and aches not much got done this week!

The sole is glued down, and the first garboard is ready to glue:



When the kids and I were most symptomatic, glassing two small puzzle joints to join the three pieces of a garboard was about as much work as I could squeeze in to any one day. This is the bench work done on a strake after the puzzle joints have been glued and leveled. First thing in the morning I'd apply 10 oz cloth, which I'd recoat every two hours or so until it filled. I beveled the edges of the patch with fairing compound to facilitate later sanding. This is only about a half hour of work total, but it occupies my full workbench all day. Which makes it a good fit for a day at home with sick kids!
On that subject of occupied bench space, I wonder how people manage multi-step epoxy operations without sanding "green" epoxy and creating toxic dust. I keep reading to wait a week before sanding. That challenges my patience when my entire workbench is occupied with pieces glued together yesterday that could be covered in fiberglass today (if only they could first be leveled). So far my solutions have been to be patient anyway and to try to scrape rather than sand. This old garage sale scraper does pretty well:


Long time readers will recall that I originally bought the templates to cut these pieces out myself before opting for the CNC kit. I'm glad I went with the CNC kit, and I also have to say I don't regret buying the templates. I rolled them out recently to both confirm I was assembling the garboards correctly and measure and mark their bevels. It wasn't strictly necessary - the bevel marking for each plank is given as 20 mm in the plans, and that's exactly what the template ended up showing me - but it was reassuring.


It's exciting to see the boat starting to come together!

-James

[rgthom]

Re: A Seil in California

On that subject of occupied bench space, I wonder how people manage multi-step epoxy operations without sanding "green" epoxy and creating toxic dust. I keep reading to wait a week before sanding. That challenges my patience when my entire workbench is occupied with pieces glued together yesterday that could be covered in fiberglass today (if only they could first be leveled). So far my solutions have been to be patient anyway and to try to scrape rather than sand. This old garage sale scraper does pretty well:

-James

I am going to call advantage Fairfield for sanding. My building jig was on casters, for any sanding work I rolled the boat out of the garage into the usual howling wind and sanded from the upwind side. For green epoxy though I agree on scrapers. I first found an ancient steel one which worked but needed frequent sharpening, later bought a carbide blade type with replaceable blades which so far is still on the first blade.

And yes COVID is everywhere suddenly. Literally everyone at work except me had it over the last two weeks, and many friends also. I am somehow still negative, maybe had it and did not notice at some point.

-Rick

[WI-Tom]

Re: A Seil in California

A heat gun, judiciously applied with a scraper, is the only tool I consider for epoxy clean-up these days. Beats sanding or scraping or anything else I know.

Tom

[John Meachen]

Re: A Seil in California

A heat gun, judiciously applied with a scraper, is the only tool I consider for epoxy clean-up these days. Beats sanding or scraping or anything else I know.

Tom

True enough,but bear in mind that epoxy bonds normally degrade at 95 deg C or thereabouts-so be careful not to overdo it.

[pez_leon]

Re: A Seil in California

Thanks, all, for the thoughts on epoxy. I am making great progress hanging strakes:



When I see that picture I'm struck by the mess. Some time ago I developed a habit that keeps most my job sites tidy: as soon as I realize I'm missing a tool or don't know what to do, I drop everything and start cleaning. Invariably the tool or the needed insight appears just as the shop is returned to order, time is saved, and mistakes are avoided. A cluttered messy job site thus reflects confusion that needs to be resolved. But not this time! I realized yesterday that for the first time in this project, I have known exactly what to do for days on end, and needed only a very few tools to do it. The mess thus reflects progress. Or at least that's what I'll tell myself.

The end of planking is in sight. Then: fiberglassing the sole and garboards, hanging the skeg, and painting the exterior.
I would appreciate your insight on paint. Inspired by some old posts from the PNW Sail and Oar crew, I have been leaning toward using water-based house paint for the hull. I like the idea of reducing my solvent exposure, reducing environmental impact, and making later touch-up easier. I'm concerned that the water-based paint may not play nicely with my varnished transoms and gunwales, and generally apprehensive about using anything other than salty "marine" products. This is a day-sailed hull that will never be submerged for more than a few weeks at a time, rarely that much. I'm not presently planning to pre-coat the upper strakes with epoxy, though I could be convinced. Any advice?

Thanks!


- James

[rgthom]

Re: A Seil in California

For paint on mine I used System III water based LPU. You have to add a few drops of the crosslinker and mix it in, but water is the solvent and there are no fumes. In our low humidity it was hard to maintain a wet edge and the finish looked all blotchy at first, but it smoothed out and took an even gloss after a few days and still looks as good 12 years on. I have touched up a few scrapes from the same old cans, they look fine. Touchup on small spots could be done without adding the crosslinker but the film would not be as tough. No issues at the interface with varnish, but I was using their varnish (and epoxy).

-Rick

[The Jeff]

Re: A Seil in California

Nice progress! I haven't done anything lapstrake, but it looks like the CNC kit really speeds up planking.

Inspired by some old posts from the PNW Sail and Oar crew, I have been leaning toward using water-based house paint for the hull.

I was swayed by the siren song of easy touch ups and put some Behr exterior latex from Home Depot on my dinghy but I think it was a mistake. It certainly is easy to touch up, but it's also fairly easy to get scraped off. I don't know if the hull wasn't clean enough or there wasn't enough tooth or if that's just as good as latex paint is, but I wish I went with something closer to the top shelf. It's on my long list to strip it off and go for something better. I've had the boat in the water for a week a few times and it always seems like the paint is slightly gooey when I pull it out.

[nrs5000]

Re: A Seil in California

Great progress!

I feel like I've seem people post about using porch and floor paint to good effect on dry sailed small boats. I'm afraid I can't offer any personal recommendation for a low VOC option as I am guilty of priming my plywood planking with CPES and then using traditional marine enamel.