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  1. #76
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    I think I have a plan for dealing with the peel ply, but would welcome input from anyone who has worked with the stuff. My main concern is to break the potential for disaster down into manageable chunks.

    The thing is that the area to be covered is roughly 19 feet by 2' 3" (figure out the French yourself) and I'll be doing the job singlehanded. This means I have to get all the glass over that area wetted out, and neatly tucked around stem and sternpost. Then I have to apply the peel ply without disturbing the glass, and get that rolled down tightly before the resin starts to gel.

    Having thought about the process, and how a long piece of peel ply will want to naturally fall around a boat-shaped object that is sticky as hell when it is being rolled out by one bloke, I think the best way to tackle it will be to slit the peel ply along the chine, so I can roll out the bottom and sides seperately. This means each panel is more or less flat, and smaller, which should make getting the peel ply on neatly a lot easier.

    It will mean the potential for some roughness or ridging along the chine, but that's a small area which is easy to fair, and where the glass will naturally want to sit tight against the timber anyway (ie: naturally good compaction of the layup there). Doing it this way also means that if the resin does start to kick off at some inconvenient point, I can just leave the rest of the boat to sort itself out. That'll mean more filling and sanding later, but wont create a huge mess.

    If anyone has some good ideas, let's hear 'em.

    PS: Oh and obviously I'll be pre-cutting and fitting the glass, and taping it in place around the upper edges.
    You know you're making progress when there's sawdust in your coffee.

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  3. #77
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    Usually when doing a project shaped like that, I don't bother with peel ply or anything else. I just wet out the fabric and concentrate on getting it down tight against the substrate. Peel ply is nice for multiple layers of fabric, because it keeps blush off the surface and another layer of fabric can be applied and wetted out directly over it. The other advantage of peel ply is you can improve the fiber/resin ratio by really rolling it down good, with excess resin bleeding through. Actually, when I use peel ply, I don't roll it, but use a squeegee or plastic applicator.

    One technique I've tried is to wet out the fabric directly on a piece of Mylar (on a bench). Once fully wetted out, I let it get just past the "green" stage and place it on the work (it's no longer tacky), then I trim it to fit and remove it from the surface. Next, I wet out the substrate and place the pre-cut, flexible, semi cured fabric and Mylar combination on the wet substrate. This get rolled down good and left to cure. Once cured, peel the Mylar (release fabric) and the surface is dead bang smooth.

    You can buy perferated release fabrics, which sort of acts like both a Mylar sheet and peel ply, but it doesn't bleed as much resin as real peel ply.

    As you'd suspect, these techniques are more advanced than most back yard builders are accustomed. With some practice and finding the right materials, you can save some effort, though you'll ruin a few pieces, before you get a feel for it.

  4. #78
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    The other advantage of peel ply is you can improve the fiber/resin ratio by really rolling it down good, with excess resin bleeding through.
    This is one thing I'm after on this boat, as I'd like to maximise the strength/weight. Also, the minimising of sanding when using peel ply is a big advantage IMO. I like the idea of just laying the thing up, peeling the peel ply off, and having the boat ready for painting almost straight away. Sanding glass and resin is not my idea of a good time, so anything that reduces it is a bonus.


    With some practice and finding the right materials, you can save some effort, though you'll ruin a few pieces, before you get a feel for it.
    At this stage I'm not into that rigmarole. I just want this sucker finished.
    You know you're making progress when there's sawdust in your coffee.

  5. #79
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    Peel ply doesn't leave a finish that's suitable for paint. When you peel it off, the fabric weave is clearly visible and needs to be filled or sanded smooth. It is a uniform finish and the texture is a good guide, letting you know when to stop sanding.

  6. #80
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    As long as it's uniform, not too rough, and doesn't require sanding into the glass itself, that's all good. The example I saw at Boatcraft Pacific was a pretty good surface. Certainly far better than the same cloth without peel ply. It wouldn't have needed much to get it ready for primer.
    You know you're making progress when there's sawdust in your coffee.

  7. #81
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    Have got the starboard garboard on the boat now. I would have done the port one yesterday as well (it's already cut) but I ran out of clamps and wedges (dammit). I have already made more wedges, and will knock up a few more clamps before fitting the broadstrakes. I'd like to have enough clamps to be able to do planks in pairs.

    TBH, it's not exactly perfect everywhere, so it's not a bad thing that I didn't get to do the port one yesterday. The imperfections are tolerable and I can sort them out by the time it's all finished, but I'll be revising my approach slightly before fitting the port plank.

    This is what you get when you decide to get a bit cheeky with construction (it's really getting down to the minimum weight consistent with a degree of practicality), and you only build a boat every so often, and have been off the tools for a while. OTOH, it'd be boring if there was no challenge in it.

    The third pic shows a slight misalignment in the scarf joint. This is mildly annoying, since I know I can do them absolutely perfect if clamping them flat on a bench. It's not so bad though as I can fair it out without significant loss of strength, and this section will be painted anyway.

    The reason I scarfed the plank in situ rather than on the bench is because 19 foot long planks of 3mm plywood are very floppy, and hard to handle by yourself. I'll just take more care with aligning and clamping the next ones.

    The last pic shows a slight bulge about halfway across the plank at the stem. Again, I can fair this out easily enough (the gap is around 0.5mm) but I'll still be more careful with the next one. I find that if I aim for perfect, things usually come out good enough. Aiming for good enough is a bad plan.


    PS: The 3mm planking is already quite stiff across its width, even without any glass sheathing. In terms of basic strength and stiffness for hydrostatic/dynamic loads it would be adequate as it is, but I'll be adding the sheathing for extra resistance to impact and abrasion.
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    You know you're making progress when there's sawdust in your coffee.

  8. #82
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    Might as well put up pix of other imperfections, just as warnings.

    First one shows slight distortion of the planking due to a screw at one of the permanent frames. The screw may not be strictly necessary, but it's handy for positioning the planks. I also thought it was worthwhile just for added insurance, given that there are only three frames and they will end up taking quite a bit of load. It's long enough to go well into the frame, and the hole was wetted with epoxy before driving the screw home. There are matching screws through the bottom, just to the inside of the limber holes.

    The distortion isn't really a big deal. The angle across the chines there is about 1:4, so a slight dip looks much worse than it really is.

    Second pic shows some gappiness at the chine. This has occurred in a couple of spots. I'll be throwing more glue at the port one.

    Third pic shows the same area on the inside. The squeeze out there is adequate, and the ply is not at all drummy, so given that the width of the gluing face there is around 55mm, I think there is still heaps of bonding available. I'll fill the gaps with squidged epoxy soon (should still be fresh enough to get some bonding to the existing pox) and of course there will be the sheathing on top.

    I'm not actually worried about the strength or durability of these sections, but that's no reason to not make the next plank better.


    Speaking of sheathing, with originally got me to do 3mm ply with 6oz/200gsm sheathing was a video I found on YouTube. I have a 6 metre roll of 200gsm glass that has been sitting around for literally years, and was wondering if it would go well over 3mm ply, so I googled "3mm ply 6oz glass" and this video came up. After looking at it, I decided the combination was adequate for what I wanted.

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    You know you're making progress when there's sawdust in your coffee.

  9. #83
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    Port garboard is now on. I went a bit more enthusiastic with the glue and clamps this time.

    Clamps are spaced as close as I could get them and still put the wedges in, plus the central half of the boat has an external clamping batten on both chine and stringer. Why only the central half? Because it was a lot easier than trying to deal with a batten at the ends, where the twist is severe. The planking tends to sit tightly in the ends anyway.

    Anyway, getting the battens in while scarfing in situ and having glue all over the place was fun, but it seems to work. The scarf joints look well aligned at the edges, and I've gone belt and braces with clamping up at the stem. Hopefully, it'll all look slick when I take it apart tomorrow.
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    You know you're making progress when there's sawdust in your coffee.

  10. #84
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    Ok, that worked.

    Pulled the clamps off this morning and it's all looking good. Came out a bit fairer than the starboard one too. Seems that stringers/battens inside and outside is the way to go with planking this light. Also means there should be fewer clamps required.
    You know you're making progress when there's sawdust in your coffee.

  11. #85
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    Made a little more progress on this beastie.

    I've removed all the temporary props that were all over the place, since I don't think they're necessary any more. There's enough planking for the bottom to hold its shape now. All the laps from now on are above the waterline, and just need to look fair.

    This means it's now possible to get underneath and inside the boat and do a bit of cleaning up. There's some cured glue squeeze out around the place, which it just wasn't practical to clean up before it cured. Trying to do that would have made a bigger mess (including of me). Cleaning it up now is a bit tedious, but not difficult (now that I can get under there).

    I've found that one of those wheeled garden seats is great for working under the boat. It's nice and light, easy to scoot around on, and it's plastic too so pox wont stick to it.

    GR85_1-b.jpg

    The height I happened to choose for the strongback has just worked out perfectly for someone my height sitting on the garden seat, so from now on cleaning up the inside of the boat should be quite easy and (relatively) pleasant work.

    I have also ordered some rowlocks. Having rowlocks without a finished boat is better than having an otherwise finished boat without rowlocks.

    After looking around I've chosen to use Gaco rowlocks. They're cheap, light, quiet and durable, and when used with flat-backed oars they offer excellent control of blade pitch. IMO this is a pretty much unbeatable combination, so I see no advantage in using anything else.

    Anyway, a couple of pix just for fun. One has the boat wrong side up but the world right side up. The other has the boat right side up but the sky at the bottom. This may confuse the birds, but is a good way to get an idea of the shape of the boat.
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    You know you're making progress when there's sawdust in your coffee.

  12. #86
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    I'm getting ready to put the next stringers on (or was before lunch ) which means getting frames, stem and transom bevelled correctly. Port side is done. Will do starboard side after lunch.

    I've found another handy use for my planking clamps. This works quite well, because I just eyeball the bevel and then slide the batten out of the way before paring the bevel with a sharp chisel, then slide the batten back over the frame to check it's ok. I have a pretty good eye and am quite handy with a chisel, so this works well.

    (A really sharp chisel of the appropriate size is an exceptionally versatile tool if used with care).
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    You know you're making progress when there's sawdust in your coffee.

  13. #87
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    Got the next stringer on.

    I've got this process down to a fine art now. Obviously I have to cut the bits to fit first, which is just a matter of being careful.

    Once it's cut to fit I set it up one of my planking clamps on the first permanent frame (approx. 1.9 metres from the bow). This is just a handy rest for most of the stringer while I'm getting glue and clamps sorted.

    2nd_stringer_2.jpg

    I flop the stringer over that, with the twisting clamps for the stem already on it.

    2nd_stringer_3.jpg

    Then I put on the clamping strip at the first temporary frame forward of the transom. This holds the stringer in the right position for the rest of the boat, and checking it against the transom is easy.

    2nd_stringer_1.jpg

    After that, all I have to do is start with the clamping strip at the transom and work my way forward to the stem.

    2nd_stringer_4.jpg

    It all goes very smoothly.
    You know you're making progress when there's sawdust in your coffee.

  14. #88
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    And it ends up looking like this.
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    You know you're making progress when there's sawdust in your coffee.

  15. #89
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    First lap is now bevelled for the broadstrake. There's a story here.

    As already mentioned, I'll be glassing the garboards and bottom with 6oz/200gsm cloth for a bit of extra protection. Given how thin the planking is, I don't want to simply stop the glass right at the lap, because that is potentially asking for trouble. So, what I'm going to do is run the glass about halfway across the first lap. The laps are 18mm, so halfway will allow for the laminate strength to run consistently over the stringer, without creating a possible break point where the glass stops on the face of the ply.

    Ok, so why not all the way across the lap? Because then it would be visible inside the boat, which I don't want. Halfway is adequate for strength, and I'll put a matching, very shallow, rebate halfway across the lap on the broadstrakes (which might sound tricksy but is really just a pass with a hand plane).

    All of those considerations are why I wanted the second stringer on, and the garboards bevelled using the stringer as a guide, before I did the glassing. That's the next big job, since I've already rounded over the chines, stem and sternpost to take the glass easily.

    I've also cut shallow rebates across the ends of the garboards so the glass can lap over itself in those places, without creating a fairing problem later on. I figure this way really is easier in the long run, and it wasn't at all hard to do. These rebates only run part way across the width of the stem and sternpost, so it's not as though the shallow cuts will weaken the planking.

    I've also added some small aluminium plates to the bottom of the stem and sternpost, to give a bit more protection against bangs and scrapes there. These are just offcuts from when I made the router table, and are bonded straight to the boat using the "smear 'em with pox and sand 'em wet" method recommended by the Gougeon book. After the pox sets up, I'll round these over to match the chines. The aluminium works easily enough, and by paring along the boat I can do most of the rounding over with a sharp chisel.

    Once that's done, these plates will just be glassed over as if they were any other part of the boat, although of course I will give their outer faces a bit of wet sanding with teh pox before putting the glass down permanently.

    I figured since these little plates were so easy to do, I might as well do them. I'm planning on treating this boat pretty carefuly, but a bit of added insurance for the cost of a few ounces is probably worthwile.
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    You know you're making progress when there's sawdust in your coffee.

  16. #90
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    And here they are finished.

    I started off with a 3 mm roundover router bit, just because it was already set up in the router, and the router was sitting around. It was attached to the lift-out plate for the router table, but not fixed into the table, so I had a brainwave. This base would be much more stable than the basic base of the router, which was a good thing given that I would be using it at the very pointy ends of the boat. It enabled me to stabilise the router very easily, even when it was hanging over the ends of the boat. Win.

    That got rid of most of the excess aluminium, and from there it was a combination of paring with a sharp chisel, a bit of filing, and some 120 grit to finish up. Didn't take that long, and they're all faired in now.

    These little bashplates are a bit of an experiment. I figure if they fall off in a few years it's easy enough to replace them with another solution (several spring to mind) but I thought they were worth a shot.
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    You know you're making progress when there's sawdust in your coffee.

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