Blackrock 24 (Build)

Discussion in 'Wooden Boat Building and Restoration' started by LP, Mar 12, 2013.

  1. LP
    Joined: Jul 2005
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    LP Flying Boatman

    Transom and such.

    I let myself get low on fairing supplies so I've switched gears until I get more fairing materials. I thought I was going to have enough so I wasn't concerned and thought I could avoid purchasing more epoxy and such until after roll over. Such is the way of things. I was getting a little tired of the whole fairing process so the change of pace was welcome.

    I built the "step" for the transom. Some minor changes took place in the process. It was simply going to extend straight up from the extended hull planking, but I had a moment where I stopped, thought and went "Hmmmmm, I can cantilever a slight extension on the step and improve the geometry for boarding the boat!" The step got a 3" cantilevered extension, but then, I had a moment where I stopped, thought and went, "Hmmmmm, it's always nice to have a place to grab on the boat and this step extension is the perfect place to put a hand hold." So, I cut a slot in the extension and added a doubler to improve the grip. The final detail will be a small knee to replace some strength lost due to the slot. The last detail that I believe I need to add to the transom is a small pad just below the tiller cutout for the gudgeon (or is it the pintle? I forget the dumbest things).

    IMG_3379.JPG IMG_3381.JPG

    I also went back and started working the upper portion of the hull. I has stopped work here to wait for some thicker resin to run the scraper coats with. I have the resin now so I did a heavy sanding to take down the biggest portion of the stipple left by the roller coats. The thicker resin was/is much friendlier to work with on the vertical to overhanging sections of the hull while being applied with a scraper. I was so excited about it, I even ordered a gallon of my supplier's thickest resin just to have the experience of using it and to have a new "tool" at my disposal. It took a couple of coats, but I finally got into a groove with regard to getting good coverage and consistent results. I seem to recall with my first build (16') that I could run the scraper the entire length of the hull and worked the epoxy in a horizontal fashion. I have been completely unable to work this hull horizontally due to the way the epoxy is behaving and possibly due to it being a longer hull. I've had to reorient to a more vertical application. I feel like the epoxy is acting differently (West v RAKA), but that was also 15(+/-) years ago.

    I feel like the RAKA starts to go "tight" after a few minutes of being on the hull where it seemed like the West stayed loose during the entire wet out of a side of the hull. My current epoxy isn't going off because the time frame from mixing isn't long enough. Even going back over epoxy that's been laid down 5-7 minutes earlier feels draggy on the blade and no longer lays smoothly if disturbed.

    With those properties to deal with, I went to a vertical application to keep the strokes shorter. With the hull tipped up, I can lay out a bead of epoxy on the bottom of the boat and every time I come back up to the top, I can grab a little more epoxy for the down stroke. I've settled into an arc shaped stroke that let's me grab epoxy off of the bottom, pull it down through vertical at mid stroke and as I approach the rail, the stoke goes more horizontal again so I maintain control of the epoxy on the blade and can adjust the flow as necessary to get good coverage along the sheer. The edges are always the hardest to maintain good, consistent coverage. Control here is always good and a little extra attention to edge coverage is important to getting quality coats.

    I'll cover about a 3' length of the hull at a time and before the epoxy tightens on me I'll run some final strokes over the recently laid epoxy to catch as many runs, gobs and imperfections as possible while it's still user friendly. I've also made some modifications to my scraper to reduce imperfections. The corners of my blade had a tendency to leave edges on each stroke. I've increased the corner radius to my blade and also feathered the thickness in the corners to create a soft edged scraper. It seems to work and my most recent coats go on pretty smooth and uniform.

    IMG_3394.JPG IMG_3396.JPG

    I can never get enough of an expanse of epoxy covered wood.

    IMG_3391.JPG
     
  2. LP
    Joined: Jul 2005
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    LP Flying Boatman

    Nothing picture worthy. A lot of sanding has taken place. My order for thick resin has arrived and I've used with my last round of epoxy coating. It was glorious to work with while using the a scraper blade. I feel that the higher viscosity cushions the blade as it spreads the goo and it goes on like silk. It may be that my technique has improved, but I like that it goes on with fewer imperfections than the thinner resins. It's like the resin is pushing back on the scraper while the thin resin is fully compliant to the scraper and is more susceptible blade induced imperfections.

    I'm thinking that one more coat on the upper hull will finish out the epoxy applications there and then it will be back to the lower hull and fairing with microballoons. I feel paint and varnish on the horizon and it is very exciting. I do actually have a photo to post. I've seen this photo over the years and have always admired the color scheme. It's from the John Redmond Elver website.

    Elver_DanG2_sm.jpg

    I was planning to do a simple white on wood scheme, but my wife would really like some green and the splash of green in this scheme really sets off the wood tones. Even the red anti-fouling paint contributes to the overall appearance of the boat. It will be a little more work, but I think the results will be quite satisfying. I may step away from the white and go with a cream to complement the green a little more.
     
  3. LP
    Joined: Jul 2005
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    LP Flying Boatman

    So here we go. It's been a bit of a dry spell in the boat shed. Finally able to spend some time out there. I'm back to fairing the bottom areas and I believe I have the last of the fairing compound applied. I spend a big part of yesterday sanding the previous application. If I sand tomorrow it should go quick as I only had scattered low spots that needed filling today. I've finalized the transom details and applied the cosmetic fillets that are exposed there. I have also been applying the filler coats to the taped seams inside the centerboard box.


    I have some questions as I'm building this boat differently that any others.

    1. Should fairing compound be sealed with coats of straight epoxy? I like the hard shell aspect of doing this, but is it required. The microballoons are in an epoxy matrix, so inherently water"proof"? . . . . . .

    2. Is painting the hull where anti-fouling is going to be a redundant operation? Prime, paint and anti-foul vs. prime and anti-foul.

    3. How much sweep would you suggest in my Waterline and Bootstripe? This is sort of directed to PAR, but I will listen to all input. I'm referencing back to an old post by Paul on another tread of mine. 2" in the front WL and 4" for the boot stripe? More? Less? I'm just looking for a starting point.

    http://www.boatdesign.net/forums/wo...ion/do-bottoms-really-need-painted-43834.html

     
  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I like to seal fairing compounds, but you have to me confidant about being able to apply a smooth straight epoxy topcoat. Some will go right to an epoxy primer and I've seen good success with this approach too.

    Use an epoxy primer under the antifouling, if over the epoxy coated hull, but no, it doesn't need regular paint.

    You should be able to get a pretty close idea of the boot stripe dimensions by scaling it off your drawings. L.F. Herreshoff (and others) have published a set of formulas for getting the right amount of "sweep" in the bottom and top of a boot stripe. I just do it by eye, which I'll bet is very close to the LFH dimensions, simply because I find them pleasing.

    [​IMG]

    This clearly shows the weep to the WL, though isn't really a boot stripe. A boot stripe has sweep on the bottom line, typically about 1/2 as much as the top.

    Where to place the boot stripe comes to play also. On your boat 2" - 3" above the actual LWL is where the low point, of the bottom of the boot stripe should live. The amount of sweep in the ends can also hinge on the "springiness" of the sheer, with a well sprung sheer liking more boot stripe sweep.

    Here's one by a master:

    [​IMG]
     
  5. LP
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    LP Flying Boatman

    Thanks, Paul. I will probably make more work for myself than necessary and do two coats of straight epoxy with a sand job in between. I feel learning curve coming on with your reference to epoxy primer. I started looking at primers and found multiple mentions of airless spraying. Argh. I won't be going down the spray route. Any single part primers you prefer? :eek:

    This also leads into anti-fouling choices. Any insights into a good plan for a trailered boat that will see dunkings of a few days to hopefully multiple weeks and see the remainder of the time resting on the trailer?
     
  6. whitepointer23

    whitepointer23 Previous Member

    Looking sensational lp. Looking forward to pics of it in the water.
     
  7. PAR
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    PAR Yacht Designer/Builder

    Go the epoxy primer route. I know way too many that haven't and wished they had, usually after a reaction and they're grinding off the first attempt. System Three is popular, but there's several that work fine.

    Don't spray it, just roll it on, trying to apply it as uniformly as you can. Apply two coats, the second as soon as you can to get the no sand chemical bond. Don't tip it off, just put it on, stipple and all. Let it dry, then long board with a modest grit, to find the lows and highs. Check the lows (a steel rule works) to see how low they are and decide if you need filler. If you've faired the hull well, you should be able to just used primer. The straight epoxy sealing coats should give you a clue as to how fair she really is anyway. A simple "down and back" cross hatch pattern is all you want. You're just identifying the lows, not trying to move material. Mark the lows and apply 2 more coats of primer in each low spot. Let this dry and long board the lows again to see if you need more.

    Antifouling is location specific. Any recommendations I have might not work for you, so ask the local fisherman, they'll know what works for the area.

    How many cases of Bud bottles are we up to? Just kidding, though as anal as you're work appears to be, your project will easily be the bell at the ball, keep it up.
     
  8. LP
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    LP Flying Boatman

    Ill take the anal part as a compliment. :D I'm afraid that my boat is more photogenic than I am and a great many transgressions are too subtle to show in my photos. Still, all compliments are readily accepted. :cool: Thanks to WP also. I believe that I have almost reached saturation with this phase of the build and I am pushing myself not to let quality slip (too much). I've pretty much decided that the hull is as fair as I'm willing to make it. I am pretty much just filling and smoothing at this point. I'm ready to get some paint and varnish on her so I can roll her over and play with her topsides. (Oh...did I really say that?) :eek:

    A few pics.

    My last round of fairing/filling. As you can see it was just a matter filling the low points (the little shinies).

    IMG_3443.JPG

    My stern handles. I finally decided to go with solid fillers, primarily for the cleanliness of the finished shape. I was considering knee type supports (light and strong), but a very complex shape for filleting, fairing and finishing. Also note the pads for the upper rudder fittings. Oversized no doubt, but better than the alternative.

    IMG_3444.JPG

    The first barrier coat over the fairing substrate.

    IMG_3447.JPG

    RE: anti-fouling. I'm wondering what thoughts are regarding ablative vs. non-ablative coatings on a trailered boat that will spend more if it's time out of the water than in it. I suppose most or my cruising will be up north during the summer (Northern Passage, Cape Code, Long Island Sound and the coast of Maine), but I plan to sail Florida waters and optimistically, take the leap over to the Bahamas. I anticipate a higher than normal amount of time on the go when compared to a vessel that moored of in a slip.
     
  9. SukiSolo
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    SukiSolo Senior Member

    Nice work LP. I'd second PAR on sealing the fairing layer and then 2k epoxy primer with a roller. Even a brush is not bad if you have a good 'feel' for even thickness. It is also my preferred way to deal with the internal buoyancy tank problem, wher I go with 'white' (well cream more like) to help see any dirt and 'stuff' that may get in there later so you can get at it or wash it away.

    She's coming on really well. The painting and fairing will soon generate a swan from the 'duckling'!.
     
  10. philSweet
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    philSweet Senior Member

    Re. paint

    I would try it with no bottom paint for a while. I finally broke down and bottom painted my skiff after 20 years. Spent five years in the Keys doing 9-days-in and 5-days-out trailering before finally caving in. That was mostly because the boat started to be left in longer so GF could fish and crab for dinner. The deck-grade epoxy finish would clean up with surprising ease. If you do antifowl it, the ONLY consideration is the wet-dry-wet-dry... issue. Few antifowl paints are worth anything under those conditions.
     
  11. LP
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    LP Flying Boatman

    I understand your point, Phil. I'm being optimistic that my boat will spend enough time in the water to NEED anti-fouling. I believe that wet and dry cycles kill the anti-fouling. I'm kind of leaning towards a biocide type anti-foul. I believe they might be a little more durable. I'm still researching. I have little knowledge in these areas. Based on what you've said, a week or two in the water is will not be a big problem with or without anti-foul. I'm thinking the one that goes on smoother and has the harder surface would be most suitable.
     
  12. PAR
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    PAR Yacht Designer/Builder

    On a trailer boat that occasionally spends an extended time afloat, the best thing is to just clean it after you do pull it out. Give it a good easy wash, then let it dry, after which a good scrub if necessary.
     
  13. LP
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    LP Flying Boatman

    Are you saying what Phil is saying? Skip the anti-foul all together?
     
  14. PAR
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    PAR Yacht Designer/Builder

    Yeah, pretty much, just use a good epoxy primer and topcoat, then keep it clean.
     

  15. LP
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    LP Flying Boatman

    Hmmmm..... It doesn't hurt my feelings to not do anti-fouling. Looked like the stuff that fit my wet to dry wet requirement was going to run close to $200 a gallon. A lot of bucks for something that wears away to nothing. Especially if it's not needed. A lesser product is still $140 a gallon.


    Does anyone have a favorite single-part topsides paint? I've been using Interlux Brightsides for years only because it is so readily available. I'm curious what others use.
     
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