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smccormick

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Everything posted by smccormick

  1. Thanks guys, Lenm, The boards are sepele, they're part of the sub structure of the deck, a slight deviation from the plans and will be covered over. . For whatever reason, my planking had pulled the shear clamp out about .125" between the frames in the cockpit so I glued some 2 x 3 stock against the clamp to straighten it. I didn't want the 2 x 3's to remain in the finished boat so I needed to transfer that load to the covering board and wasn't confident that the .375" ply would be up for the job. Any epoxy fairing filler can go directly onto properly prepared/ground glass work. The grinding part is why I like to trowel on filler while the glass is still green stage. I use a combination of prepared fillers and shop made fillers. With a cost around one third, a majority of work uses shop made. This project uses all alexseal products. All the white surfaces and brownish spots you see in the preprimed photos above are fillers. The darker areas of the white fields is the glass showing through the filler, so it's a skim coat in many areas. But my goal is to achieve a fair surface without sanding any long fibers of the glass.
  2. The long and tedious task of fairing the interior edges and corners is nearly complete. A few coats of 302 high build added to create the illusion of progress.
  3. That is or will be a beautiful little skiff, I'm glad you're taking the time to save it. I would love to get my hands on a decent one myself.
  4. You can use most of the two part paints below the waterline, they just can't soak for extended periods. I think two week is the limit of the paint I use.
  5. I wish I lived closer to you Chick, I would be over there picking them up already. I have two flawless tanks for those 50's vintage engines. May let them go for less than an arm and a leg.
  6. Ken, how's the recovery going? Are you able to make progress on the boat?
  7. A disclaimer to everyone; I am in no way suggesting there is any issue with the laminate designs from B&B for this or any of their models. They know far more than I do about all of this. I am merely suggesting that if you run in debris laden waters or tend to interact with the bottom of the waterway more than most and feel more comfortable with a bit more glass on the bottom that this may be one solution. Lenm, The drawing below is the most efficient way I have found to accomplish the laminating if you want two layers of glass on the bottom. It eliminates all the steps in the glass except for the one on the topsides above the chine. Fairing compound and a bit of sanding and that goes away. On the smaller hulls there may be no need for laminate 6 and 7 depending on the skin girth at maximum beam and the width of the textile that you have chosen. Even if the strip is needed, it's not the full length of the hull and can be tapered out to minimize fairing. Glass scarfs should be at least 12 to 1, so .037 for 1208 or .444". I am not comfortable with that and find it quite easy to extend the taper to 1.25 or more. The biggest problem I have seen with glassing the bottom is how do you transition the glass strip from the straight keel to the forefoot. As it (the textile) bends down the forefoot you begin to gather a lot of extra material at the edges. In most cases people will solve it with darts, I suggest against this. With any of the biax products that you'll be choosing for your build, you can work them down and flat with a little poking and squeegeeing. Perhaps not with 30" of tail hanging over, but with a properly tailored piece, it's very doable. Estimating the bottom size of the OK20 at 16' (water line length) x 3.5' , subtracting 6" overlap on keel and chine and ignoring the taper at the forefoot yields a 16x2.5 area of the bottom (half) that would have added glass. This is 4.44 yards at 20 oz per (1208) or 5.55 lbs of glass. Add resin at a 60/40 ratio is 8.33 for a total of 13.88 lbs per side weight penalty for this change. This is a conservative number because of the tapering bottom size forward that I ignored and hopefully you can squeegee your way to a better resin to glass ratio. A lot of folks "in the know" will say that the biggest mistake a builder can make is second guessing the architect and beefing things up, so you'll need to evaluate the benefits of this modification for your own operating conditions. Here's a visual. The shape and size of the drawing is not in any way to scale.
  8. Interesting research on failure modes for the cores. Just saw your message above about the diagram, I'll get it together in the next couple days.
  9. Lenm, a couple of things I have learned along the way: Glassing will take far longer to complete than you will ever think reasonable. Do one strip of glass at a time, bow to stern. Wait for it to kick and grind a nice bevel to accept the next strip with 36 grit, except for the keel overlap.. Don't grind into the wood. If there is a slight step off, smooth with thicken epoxy while laminating the next strip rather than divot the planking. Grind the second piece overlap flat with the surface. Essentially a scarf. This will pay dividends galore when fairing. Secondary bonding is fine for our work, as long as the overlap is prepared correctly. It's done all the time with satisfactory results. Get the slowest hardener you can for the resin system you're using. Even if you wait until the fall to do the work, you'll appreciate the long working time and easy pace. I went with a 7-8 hour working time hardener, laminating was a casual event rather than a fire drill. Biax without csm can be pulled out of shape easily when positioning. If you have a tacky surface, applying and smoothing 1700 will be frustrating. Even 1708 will be a pain. Applying prewetted biax is an order of magnitude more frustrating. The design calls for a single layer of 1208 on your model I think. If you have a very slow cure, position the glass on the surface dry, fasten the top edge if you have to. Roll up the glass length wise about 3/4 of the way. Saturate the substrate, roll the glass down, then roll the top edge down and do the same, then finish wetting out and squeegee. This will be a disaster with a short pot life. With a short pot life, either wet the planking, let cure and grind, then apply or just wet through the glass. Don't mess around with brushing, much too slow. Dump a bucket of resin on the surface while squeegeeing it around. Easier said than done on some surfaces but you'll get the hang of it. For the bottom and large relatively horizontal surfaces get a squeegee with a long handle, so you can stand up and reach to the keel. I doubled the glass on the bottom of my build for the extra impact resistance, It was around a 54 lb penalty and worth it to me. If you look at the keel and chine overlap and the small distance between them, it really is a small area to fill to get double coverage. I can draw a laminate diagram if you are interested. Order of events is important to minimize work and fairing. Doing 2 layers of lighter glass rather than one will double your work and introduce another bond line. Getting a really slow hardener or waiting for it to cool would save a lot of work. Any surface where the next step is fairing, I would suggest applying fairing compound onto the green resin rather than peel ply. It's cheaper, lighter and saves a couple steps.
  10. When I first looked at the profile model I thought "wow, he should send a commission to Graham", but the closer I looked the more differences I could see. Of course that doesn't discount the obvious bracket theft.
  11. Thanks for the update. Hulls looking good. Some nice ocean conditions, glad you could enjoy.
  12. Looking very nice, keep it up. Sorry to hear about the MI, hope you fully recover. Pretty scary I assume. Bypass?
  13. I wouldn't worry about it from a hydrodynamic standpoint, it will probably be fine. It's really up to the builder; Blunt will be less susceptible to damage. The nice part about building this way is that you can easily glue some lumber back on and make it any shape you want. I would probably add material and reshape to a finer edge but that's just me.
  14. Making good progress. Like to see what's going on with others' projects.
  15. The only time I'm called a genius is with a condescending tone and the words "you're a real" before it.
  16. Hope you don't mind one more opinion on fairing. Regardless of how perfect you fair the hull before glassing, you'll be fairing it again after glassing, so I would suggest not going crazy. Run around the hull with a grinder or DA to get any large humps of resin flattened, then with a relatively long (30 - 36") medium stiff fairing board with 60 grit or coarser paper before making any decisions on filling. A quick pass will let you know what you have for lows, then check for highs with a batten where you may have gotten a booger behind a plank. Knock off the high, and only fill where there is a step off between planks that the glass won't follow. Use cabosil thickened resin. Grind smooth not fair. If the planking creates a gentle sine wave pattern leave it. Glass it. There will be plenty of sanding, filling, fairing to do now and it will all count. If you are still considering using fairing compound under your glass, do a peel test.
  17. I glassed to the edge of the rough cut ply and will dress that area when I have the deck on and start the rub rail build up. I other words, I didn't do anything to it at the stage you're at. OH, and congratulations on the whiskey plank.
  18. Thanks for posting stats. I think your build turned out fantastic.
  19. Congratulations, looks like some excellent craftsmanship.
  20. Don't tell her it's a new boat, just say you had to fix a couple of things on the current one and took it back apart. Paint them both the same color and scheme, she'll never know the difference. Otherwise you'll have to hear in the background, "how many boats does he need" like I do.
  21. Beautiful work and finished in four months!
  22. I may stream it live on youtube. Stay tuned for the link.
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