Archive for the ‘Boatbuilding’ Category

Eva Too – Coaming and Backrest

Monday, May 31st, 2010

Some time ago, I showed some “small stuff” that was done while waiting for epoxy to cure.

two photos of fabricating the coamingphoto of gray splotches on the coamingThat work was creating and dry fitting the coaming parts. I needed to turn the boat over again to finish painting the bottom, so held of on installing those parts. Back to them now. It seems an simple job: epoxy them in place, clean up the excess, and move on. So simple …

Unless of course, you botch it. My mistake was cleaning up with some contaminated white vinegar. I had degunked a cabinet rasp in the jug of white vinegar. That discolored the vinegar mildly, but not enough to set off warning alarms the next time I picked up the jug.  The contamination settled out as gray stains on the freshly installed coaming. Of course, it wasn’t immediately visible. The next day brought out the dreaded sandpaper and (with tedium) the stain was removed. You can still find remnants if you know where to look.

photo of backrest and a bit of coamingWork with the backrest went much better. The rest itself was assembled some time ago. Now with the actual width defined by the completed coaming, the job was to make the blocks, trim the crossbar to fit, reshape some for pleasing appearance and dry fit  it in place. Then, of course, remove it so the coaming, and the deck can receive a few coats of Marine Cetol as the finish that provides UV protection for the epoxy.

That last finishing is underway now. Pictures later.

FWIW, Sikkens advises re-coating Cetol after 24 hours, and NO sanding between coats. They do that (1) because the stuff isn’t cured enough for sanding after 24 hours (or 48, or 72 (dahik)), and (2) they want to be sure you apply a full 3 coats, not 3 diminished coats, to get the protection they guarantee.

Eva Too – Wordless Wednesday

Wednesday, May 12th, 2010

photo of sawing using a bevel gauge as a guide photo of hull with primer paint mostly sanded off photo of hull with first coat of paint

Eva Too – On Sanding…

Thursday, May 6th, 2010

photo of trash can full of worn sandpaperThree thoughts:

  • A wise man (maybe a wiseguy?) once said “Use sandpaper like someone else is paying for it.”
  • Hey Doc, is my shoulder supposed to make a clicking sound?
  • The provocative young thing, in her incredibly short skirt, about to fall off her incredibly high heels said, “For 100 bucks, I’ll do anything you can describe in 3 words.” As I reached for my money I said, “Sand my boat.”

Eva Too – Long Day’s Journey…

Wednesday, May 5th, 2010

photo of respirator, gloves, and a sanding blockNoisy sanding machines are forbidden in my shop. I have a hearing loss1, and don’t want any more. So, I hand sand. Yes, it takes a lot longer, but it also takes longer to make a mistake. And then there’s the fuel source; Milky Way bars are more easily justified.

Some people remarked that the glassed deck looks great. It does, but as they say in the commercials for cheap gadgets on TV, “Wait! There’s More!” Very simply, epoxy has no UV protection. It needs to be protected with either paint or varnish. (Ah, you thought we were done, didn’t you? Oh-No.) And of course, before it can be painted, it needs more surface prep. You see, epoxy has a lot higher viscosity than paint. It does not flow much (good; fewer runs), nor does it level nicely (uh-oh). When rolled on thin in several coats, it actually builds upon the weave of the fiberglass fabric, creating a surface that is textured or “printed through.” That surface needs to be smoothed prior to painting or varnishing.

photo of surface showing "print through"My concern, having never done this, was about accidentally sanding through the fabric and weakening the stuff that holds the boat together. A fellow calling himself “Laszlo” answered my question with words that helped me know what to expect. Here, I’ll supplement the words with pictures. Trying to avoid excess weight, I was careful in filling the weave and rolling on 3 thin coats of epoxy. That left a “printed through” surface where one can see either things that look like bubbles at the tops of fabric intersections, or pin holes at the openings of the fabric weave. I was confident that there was actually enough epoxy applied, as depicted by the third part of this CLC diagram.

photo showing partial sandingOK. Let’s take it down. The builder’s manual suggests starting with 80 grit. I thought that awfully harsh, but I can assure you it is not. Cured epoxy is very hard stuff. A milky Way bar gets one to the stage where the tops of the pattern are coming off, but there’s still a regular pattern of shiny spots remaining.

photo showing smooth surfaceKeep going. I continue working 80 grit until 95% of the shiny spots are gone. Then, I step down to 100 to start removing the 80 grit scratches and the remaining shiny spots. Then to finer grits. The goal is an evenly dulled surface, like that of wax paper. It will go clear again if / when varnish is applied over it.

photo showing faint pattern of the fabricIn an area that I knew could be easily repaired, I kept going to find the condition Laszlo described. He said that just before you start to sand into the fabric, you’ll see the fabric weave appear as whiter spots. Wetting the surface will make the spots disappear, but they’ll appear again when dry. At this point, you’re not into the fabric yet, but just above it. Stop sanding!  [I didn't need any repairs. :) ]

Now that I know what to look for, I am no longer concerned. Knowledge is power and it’s good that we have forums to share the knowledge. Thanks Laszlo!

OK. What about areas where there is fabric overlap? Now that we know what to look for, that’s easy. Sand through the top layer of the overlap and stop before getting into the lower layer.

About the title of this post: what’s that all about? We live within walking distance of a commuter rail line that will carry us to New York City. We visit occasionally and really enjoy not driving or parking in the city. One of the most tedious things I can remember is Eugene O’Neill’s play “Long Day’s Journey Into Night.” It’s a terrible thing, tediously redundant, about a family that’s become completely dysfunctional due to drug and alcohol addictions. The play depicts one long day of this family’s life, full of anguish, accusations, attempts at resolutions, and more of the same over and over again. Did I say it was tediously redundant? Oh, the tedium of it all! The version we saw was in 1986 starring Jack Lemmon as James Tyrone, which he did superbly. An innovation in this revival was director Jonathan Miller’s decision to have some parts of the dialog be delivered by people talking over each other … which is very common in New York anyway. That actually shortened the play from 3 1/2 hours to only 3 hours. Despite this innovation, it lost little of the feeling of tedium.

This sanding process has a similar amount of tedious redundancy. At the moment I’m partly through the 80 grit and on my way to 100, 150, 220 for the hull, and further for the deck. See why I mentioned 438 Milky Way bars in a previous post?

1. About the hearing loss: It takes only about 10 minutes to change a tire on a KC-135 Stratotanker, less if you arrive to find its engines already running, idled down to minimums, and a crew eager to be on its way. (Killing the engines means another pre-flight and probably filing a new flight plan.) The crew chief jacked the bogie while I set about changing the tire. I had hearing protection, but not enough, plugs, no cans. I was changing the front starboard tire and wheel on the starboard bogie, with engine #3 about 5 feet directly behind me. Remove the safety wire from the hubcap screws – remove the screws and hubcap – remove the safety wire from the nuts of two bolts that lock the large wheel hub nut from turning – remove the lock bolts and their nuts – remove the hub nut – ensure the flight crew has the disc brakes locked – wiggle the wheel and outer bearing off the axle – pull off the inner bearing – push on a freshly cleaned and repacked inner bearing – wiggle the new (about 200 pound) wheel on, aligning brake keys with the notches in the brake rotors – push on a freshly cleaned and repacked outer bearing –  install and tighten the hub nut, aligning castellations with lock bolt holes – reinstall the locking bolts and their nuts – tie the nuts with safety wire so they don’t loosen – reinstall the hubcap and tighten its screws – tie down the hubcap screws with safety wire – drop the jack – gather up the tools, old wheel and other parts – get out of the way. 8 minutes 20 seconds! Forty some years later I benefit from the marvels of ultra miniature electronics which compensate for much of the hearing loss. Yet, I can assure you from my ever present tinitus that engine #3 was idling at 8520 rpm and engine #4 was idling at 8780. No more loud machines for me!

Eva Too – Small Stuff

Tuesday, May 4th, 2010

Or, maybe we could call this post “Waiting for epoxy to cure, episode 496.”

Let’s prep the rub rails while that last coat of epoxy is curing. They’re easy. These will go on the outside of the hull just below the edge of the deck, and are intended to take the abuse of banging into docks, other boats, and such. They’re skimpy little things 1/4 inch by 3/4 inch, ash, scarfed lengthwise to a bit longer than needed. … and still longer than my wonderfully long, but still too short, bench. Preparation of these parts includes three operations. three photos of fabricating the rub railsI taper the height of the rail for about 18 inches toward each end. Shortening the height by about 1/8 inch at the ends, shaved from the bottom edge, subtly accentuates the curve of the sheer.

Next, the edges are chamfered. One could use a dedicated chamfer plane for this, but I decided to use the money for 438 Milky Way bars instead. My method of chamfering these long pieces uses a collection of little 45 degree blocks, adhered with my favorite temporary adhesive, and propped up against a row of dogs. They laughed when I made a dog for every dog hole in my bench. A few block plane passes, flip the other way, and a few more block plane passes, and we’re done chamfering. Lastly, a 1/16 inch hole every 4 inches sets these up for nailing to the boat. I’ll set them aside now and attach them later.

two photos of fabricating the coamingNext day, that epoxy is cured enough to work around. So, let’s fit out the coaming. It is mostly 6mm plywood which gets attached to the carlins around the cockpit opening. The raw edges on the front are covered with a nose block. Mine is a bit different than the one pictured in the builder’s manual, and of course I like mine with its arrowhead base, better. This is really fussy work. Everything is either curved or angled. The block and arrowhead are built up from small bits of mahogany (Never throw anything away). Here again, this prep work gets done to a certain stage, pieces get marked with “p” or “s,” and then set aside.

Next … why one needs 438 Milky Way bars.

Eva Too – Deck Glassed

Tuesday, April 27th, 2010

Excuses for no “before” or “during” pictures:

  • The dog ate them. Ooops, we don’t have a dog.
  • You’ve seen this stuff before.
  • Didn’t want to get poxy all over the camera.
  • Forgot.
  • Too stressed by the messy challenge.

photo of scored and ripped fiberglassphoto of full deckGlassing the deck was simpler because it’s smaller than glassing the full hull. It was more difficult because it consists of two overlapping pieces. Other than that, it went quickly and with a little less mess than the big job.

Like many woodworking jobs, prep takes almost as long as doing the job. Prep in this case included much better sanding than the hull because the deck will be finished bright and every little scratch is visible through the glass: 120, 150, 220, 320, brush off, vacuum, wipe with tack cloth, wipe with alcohol.

Hint: wipe on a liberal wetting of alcohol. This briefly simulates a clear finish, highlighting any remaining scratches. It evaporates off quickly, leaving no stains.

Prep also included applying package tape where I don’t want new fiberglass sticking to the hull. The tape was applied with it’s top edge right at the line which will be the bottom of the rubrail, 3/4 inch below the rounded over deck edge.

After about 8 hours of cure, I scored the fiberglass that was hanging over the side with a sharp knife. That score line is about the middle of where the rubrail will be, about 3/8 inch below the deck. Then, I pulled the excess fiberglass upward, breaking off at the score line. Score and rip. Neat!