Gluing planks with epoxy two ways - Glued Lapstrake Planking - Pt.5 - Building Gannet - Episode 14

Howdy folks, I'm Mark Rutten and welcome to No Mad Boatbuilding. Now we've been working on a project called Gannet, a glued lap strike plywood sailing dinghy, and I've been using this project to try and share with you some fundamental wooden boat building techniques. You can use these techniques for just about any boat building project. Now we've been doing a little deep dive into the glued lap strike plywood planking process. We've covered beveling the laps, cutting the gains, spiling for the planks, we've covered fitting the planks, and now we're going to install the planks. We're going to use epoxy adhesive to install these planks and I'm going to show you how to do it in two different ways. I just want to give a shout out to two manufacturers who both donated products that went into this episode, Total Boat and West System. They're both excellent manufacturers and produce a great lineup of products. Okay let's get a plank on. So I like using these little dixie cups for doing my mixing in because I don't need a big huge cup. These are good enough for getting, oh, two to three shots in. I'll use the slow hardener just because my fast hardener is empty. My slow hardener has plenty of that. I'll use it because it gives me a bit of working time. Now I know I'm going to need at least two shots for each seam on this boat, so I'll just start with that. I always pump my resin first and then my hardener. 1-1-1-1 always because it's easy to lose count. You'd be surprised. Okay, I'm going to put a mixing wand on my drill here. You wouldn't want to do this for doing a wet out of fiberglass cloth where you want it to be clear, but this is great for doing anything that is just structural. This speeds up the mixing time a lot. So here, a good 30 seconds with the drill and that gets mixed up pretty fast. We're going to need an acid brush. All right, let's go do our wet out. These acid brushes have a bad habit of losing hair, so it's always a good idea to give them a pinch with some pliers to lock them down. I want to apply unthickened epoxy to whatever surface is most porous first. I'll be the first to admit, I could probably refine these next few steps a little bit and save a little bit of time. Doing a wet out on the lap here where we've beveled it, I think is really important because there's so much end grain. It's really a very porous surface. On the plank though, we just have face grain. I could probably omit this by doing a wetter thickened coat of epoxy and I could just roll that right on here. But I take this step because I like to apply that epoxy to the plank edge that's on the boat and not the plank that I'm about to hang because it's just much messier to apply it to this plank and then try and handle it. Okay, now I'm going to take the rest of this and thicken it up. I've mixed this with some wood flour to what they call sort of a jam consistency. That means it just barely holds peaks and slumps back down. So that's a great consistency for bonding. And for reference, for every shot of epoxy, by shot I mean one pump of resin, one pump of hardener, I add about one heaping teaspoon of wood flour to get this sort of consistency. Wood flour is just sifted sawdust but West System makes a wide range of different fillers. I would choose their 403 microfibers, their 405 filleting blend, or their 406 colloidal silica for this. You can mix and match those to get just the right consistency as well. Their product guide can help you choose the right one for your application. So we're just going to paint on a generous coat of this. Now especially here at the stem, I know I got a little bit of a void at the back edge here, just didn't quite get the bevel right, so we want to make sure we fill that. So be a little more generous there. So you need to put more on now and clean out the excess than it is to try and squeeze in more later on, if that makes any sense. So I found there's a technique I've come up with for putting it along the lap. Make sure we get some up underneath there, and that is we take the brush and I kind of do this like rolling motion, and that sort of does a pretty good job of delivering the volume that I want. I think I might have to mix up an extra shot of epoxy here before this is done, that's fine. I'd rather mix up too little and have to mix up one more shot than having too much, because too much just shortens your working time. Still I'm going to be doing the other side as well, so if I have to mix up another shot and I only need a little bit of it, I'll use the unthickened to wet out the other plank so that it's ready to go. And the wet out coat, I've got tons of time to worry about that. It's only with thickened coats that you need to worry about working fast, because they're going to kick quickly because there's more volume. Just a wet out coat, you can let it sit around for 20 minutes, 30 minutes even. So I want to make sure there's enough on here that when I put these two planks together are going to get some squeeze out. Now to get the plank on here without making a mess out of this. I'm attempting to add a temporary outrigger here of sorts, in order to carry one floppy end of the plank that's going to twist into place. I'm not sure if this is going to work, I just decided I would try this. I'll just have a rag, some alcohol on hand to clean up any bits and pieces that landed in the wrong spot. I put this little leg over here because I know I'm playing around with this plank that if I try and drop it in place right away it's going to smear all over the place. So I've got a mark on it. Angle's not good. Okay that's not working. Try something different. Okay maybe that, that should work. Now you always want to have a registration mark somewhere. I've got one right in the middle, that's usually the best place for it. Put that on there, and the tail end of my plank notches into the transom. Good. Swing my little keepers into place, and we'll pop a few clamps on. Just tack this until I get it fitted up forward. Those can only reach so far. One of the viewers made these Brenner clamps for me. These work quite nicely. I want to give a shout out to Steve Lewis who gifted me these Brenner clamps I'm using. He makes and sells these over on Etsy. I'll leave a link in the description. A little different than my cam clamps but they they work pretty good. Okay so now I don't really want to clamp it any... Actually I think I can even take this one off because when I bend the front end in it's going to play around with this positioning a little tiny bit. So get it bent in first and then we'll come back and clamp the middle. Keep your hands clean. Okay now up here it's tricky to keep everything from going kablooey on you so you need to have some clamp pads. Making some little v-block pads is probably advisable. So we'll get some of those on. This one I think we need to nestle up high. I think I'm going to hold off on mechanical fastenings until... That's exactly what I was worried about. Until after it's all cured except for there's going to be one temporary mechanical fastening down here at the tip of the stem. I'll just put these right in the lap where you won't see them later on. Because there's so much tension up here I think I'll use another temporary screw. Yeah we'll do a temporary screw for now and we'll just fill that and then nail it later on. Hopefully the nail will hide the screw but this is all be painted so it really doesn't matter either way. Actually maybe I'll put one in really high where I'm pretty positive it'll get trimmed off. Let's do that. Now I'm worried about this. I can always add one of my little toe clamps right on there to make sure that stays down. Looks like I need a little shim under that. That's all we need right there. Now I'm going to just make sure this is clamped nicely, fastened, and then we'll go about the business of cleaning up. So any place that doesn't need heavy clamping I'm using these polymer nails. Now these aren't very long. They're only five-eighths long but they allow me to do a better cleanup without the clamps in the way. So this is a little hack that I like to use for doing glued lap strike planking. Now using these products costs a little bit more but it does save some time. So what I've got here is I've got a low viscosity adhesive. It's epoxy. You can see it dribbling out. That's how low viscosity it is. So I'm going to be using this to wet out my planking, wet out the joint, and then we've got a thickened epoxy for doing the bonding portion of the joint. So this is just to make sure that the open grain is filled and that the surface of the planking is well saturated. I'm quite confident I could probably just use the thickened epoxy for this operation but this product exists. I am confident this is probably making for a better joint by doing a wet out with this low viscosity epoxy. And so between the two I'm getting what I would consider a really good mechanical bond that I'm very confident in. So part of the hack here is low viscosity is because it dribbles out. I've come up with a neat way to use a brush to help spread it so that you can apply it more quickly. So one thing I find is I need to shorten up the hair on the brush a little bit. So just using a little metal acid brush. Knock about, I don't know, a quarter inch off the end. So once that's pushed down that's about the width of my joint roughly. It just moves a bit easier if we've shortened those up. And then I put the nozzle on, find the attitude that I want to work in. So I like holding my guns usually to the side for some reason. I don't like using them vertically. I like them to be off to one side. And so I'm going to want to apply the brush on this orientation. So what I do is I bend the brush down a little bit so that the end of the nozzle just touches the bristles. And then we use some masking tape here to tape this brush on and it makes for a great little spreader. So this definitely speeds things up. Now the only difference between doing this and doing the other way is the other way I would mix up some epoxy. So it saves me that mixing time and then I spend a bunch of time brushing it on and then thickening that epoxy and then putting thickened epoxy on. So you see how this really goes quite a bit faster. I'm not sure how much time I save but between the two planks I'm sure I save half an hour. Okay so this one's ready to go. This tube is almost empty so I'm gonna have to get another tube. This one is about halfway done. This has done two planks between the tube and two planks so far. So we'll see how far I get with this one. I might have to switch out tubes. I always do the bevel first on the planking where the open end grain is and that just gives the epoxy more time to soak in. It also takes a bit to get the epoxy running down these mixing tubes. There we go. So I'll try and make sure I get the end grain wetted out. Once you get the pressure going in these tubes it tends to dribble for a bit so you've got to keep going. Be wary of the fact that this epoxy is not going to stop coming out even though you stopped pulling the plunger on your gun. This is a self-releasing gun but it still fights me a little bit. So I usually just do this. I work my way down and every now and then I just do a little backstroke to make sure I'm spread nicely. There's a little bit of epoxy that's kind of splattered around here as I've been waving the gun around trying to move cameras so it shows you how quickly the stuff will come bleeding out. Okay so while that's going I will now apply some unthickened epoxy to the plank that's going to go on, hitting the stem area obviously. And then I'm going to run to the back to the other end where it's more effective for me to paint but the process is the same. I could probably omit this but I've done this on every boat that I've ever built and none of those have failed so I don't intend to stop now. If you're liking these videos you can support me by giving me a thumbs up, throwing me a couple of bucks or super thanks, subscribing to the channel, turning on notifications and of course you can join me over on Patreon. Find links in the corner or down in the description. Okay so now I'm applying thickened epoxy and I've tried to come up with applicators for this nozzle as well but I've just not come up with something that's quick and easy to make that works any good so we just smear a bead on and we're going to comb it out with a spreader. You could probably just slam the plank right on top of this bead and be okay but I try to be a little more even. Okay then you don't want to have somewhere to hang your guns while you're working because it'll keep dribbling for a little bit. Now just take a spreader. I like to use maybe about a medium comb. I might have to come back and get this in a couple more spots but that's fine. So I'm sure I got a little extra in the spots that I really need it. So now we just take this plank and I've got one nail that locates it in the center here and when we're re-hanging a plank especially when we're going to glue it we want to make sure that our plank is located in the exact same position that it was as we're doing our fitting and so for this reason I'm just using a single finishing nail tacked through these planks so that when I come in here with a glued up plank I can drop it down and just get that finishing nail locating us fore and aft and that takes care of everything we need in order to get this into its finished position. The hood ends at both ends are going to locate both ends of the plank to their finished position and so this just helps me to get in the right spot in the first place so that those all work out. Get that to drop in and my little buttons that one just fell off. Go forward and get the forward portion in. Stay on. Get it. Ah, come on. Get a clamp on here. Down here at the bow. Swing that in. Got a screw ready to go in. Swing our buttons into place. Now the buttons help to locate it. Let me just pop some clamps on. Okay now everything just sort of tacked into place with clamps and buttons. Nail it off. These are polymer nails I'm using. So they don't have a super strong hold. They kind of tack it in place. Check if I still got bullets. Yep. These are just, they're five-eighths of an inch long so they don't go all the way through the planking. Okay so now I can clean up that joint. I can even pull these clamps off and this will be done. I've got to put some nails in the stem. The transom doesn't really need it for now because there's not a lot of twist but up here I need to get a little more hold going directly into the surface of the stem. Okay so I just eyeball all of my other nail holes here. Coming back along the face of the stem. There. I know I'm going to have one nail down here in the lap so I don't worry about that. So I'm going to go up here. So let me nail there. This will be my lap. So I'm going to try and space them evenly. So one, one, two. There we go. And just to make sure it's holding give them a little set. Okay and that's it. Just take a knife. I'll clean up all the extra goo. Use it on the other plank. So I'm going to go start by wetting out the other plank and I'll come back and clean this up so I can use the goo on that side. So a general word of caution about epoxies. If they've been sitting around for a while, after a few months or a year, epoxy resin will sometimes start to gel up. It'll get kind of granular and chunky. Now it's not bad. All you need to do to fix that is you basically have to warm it up. So a very simple way to do that is if it's a can of epoxy resin you can just drop it into a bucket of water. Of course making sure water can't get into the epoxy itself. Or in the case of these tubes you can just put them in a bag and drop those in a bucket of hot water. It takes about 15 or 20 minutes for them to come back to life. Now it's especially important with these tubes because if this stuff is thickened up you're not going to get it through these little mixing wands. And the mixing wands are half of what makes this caulking tube epoxy worthwhile. Now I'm using Total Boat because Total Boat has supplied these to me for free. It's very nice of them. I appreciate that. West System also makes a similar product. West System does not make a low viscosity one in a tube that I know of. Maybe in their Pro Set product line they do but I'm not familiar with it. But they do make a thickened one called 610 which works just fine and for all intents and purposes seems to be exactly the same as the Total Boat Thickso. This is our third pair of planks going on with this tube. So this particular tube looks like it's just about played out. Hopefully it'll make the rest of this run. So a 14 foot boat, 14 times 12, like 144, 150 feet. I'm painting here three quarters of an inch wide for reference. So how much would you need for a boat? It's like you know two tubes of each. The thinned one being purely optional. I'd get a third one just to be safe. I feel this is just about done. Come on. Working the end of the toothpaste tube hard here. Squeezing for every last drop. Yep that's it. That's done and happily that's all we needed so that's great. Now another important tip. If you are starting up a fresh tube of this stuff you need to waste at least an inch or two of mixed epoxy just to make sure that you have started the mixing process evenly. Because if one comes out, the resin or the hardener comes out faster than the other at first, you could end up with an uncatalyzed mix that happened to be once. It was a huge pain in the butt to try and clean out the joint and re-glue it in the section where it was not mixing properly. Very worrying. So it feels to me like the savings in time is relatively significant because I'm not spending time doing more mixing. Now I'm pretty fast at mixing but all the little elements combined, not having to mix, using the brush applicator, using the thickened epoxy in a tube, and then also throw in my polymer nail gun and I think I get this these planks hung pretty fast. Now not that you can really get more than one pair of planks hung in a day because once the plank's on you can't necessarily move on to the next because there's tension in the hood end that you can't unclamp until the epoxy is cured. So you're kind of stuck. Now if there's anywhere you're going to screw up your bevels, it's up here in this section right here. So make sure you are fairly generous with your epoxy there. The combination of a wind in the shape of the bevel plus the tension in the plank, that's the trouble spot. That's all there is to it. So those are all on. Here we go. I can't tell you how that one little nail, how helpful it is to get it in the right spot. Now the trick is to not wag it up and down and smear the epoxy all over the place, up forward especially. Get a few clamps on. I just want to make sure I got it sort of clamped in the middle before I finish laying it down near the ends. Now one of the reasons for using the clamps here is just to make sure that this epoxy joint is well seated because the nail gun I have doesn't have the power to really bring it in because the little plastic brads are fairly short and I'm keeping them that way because I don't want them going through the back of the planking where they kind of have a bit of a blowout and they make filling all those little holes a real pain. Now the polymer nailer is nice to have but it is not the only way to put these together. A lot of people will just put a screw in at each mold. Some people put a batten across the whole thing and screw the batten down in several spots. That works really well too. I've done all of those things but lately this has been working well for me. Now finding a drill bit that fits your your ring nail properly can be a bit challenging. It's easy to get ones that are undersized or oversized and more importantly when you drop the drill which you will do you're probably going to break the bit. So the best thing I suggest is you make a drill bit out of a finishing nail just sharpen it into like a three-sided awl. Works beautifully. Okay now to clean that side up. So there we have two different ways of hanging a plank using epoxy. Now we've used a what I would call the traditional method using the west system products the 105 205 resin and hardener along with a thickener and then a separate method using the Total Boat products in caulking tubes. I just want to point out that West System also makes a thickened epoxy in a caulking tube. It's called 610. However it only comes in a single cylinder tube just like the Thixo low viscosity epoxy. If you want a larger size tube a double tube like the other Thixo comes in West System does manufacture that in a different product line that they refer to as ProSat. It's intended for the professional boat building industry. I've never tried that specific product but I'm sure it's quite comparable to the Thixo. The point being is that both those caulking tube configurations are available from both manufacturers. The single tube for any old caulking gun or the double tube which does require a proprietary gun. Now I've got a couple of those guns from two different manufacturers they appear to be virtually identical so there's some standardization in that double gun. So if you have one from Total Boat it'll probably fit the ProSat and vice versa. If it were just me and I'm working as a hobbyist I wouldn't bother with the double tube I would just get singles. If you got to buy an extra caulking gun to be able to carry a low viscosity tube in one gun and the thickened in another that's not a big investment that's like 10 bucks. Anyhow I want to thank you for watching this little deep dive into the glued lap strike planking process. I hope it was useful to you. I've tried to provide some good in-depth information that you can apply to any boat building project. It's provided it's glued lap strike of course. Now I should say that a lot of the techniques I have presented related to glued lap strike planking are fully applicable to doing traditional lap strike planking. Virtually everything. The only difference being is that we need to be more careful with our fitting because we don't have the benefit of putting a thickened adhesive into our joints. That said there are a lot of people out there who do traditional lap strike planking and will use a thickened adhesive in there like a flexible polyurethane or something like that and there's some argument to be made that you could do that with epoxy too. I want to thank a lot of followers who support these videos over on Patreon and if you can support me there too I would really appreciate that. You can find links in the corner or down in the description and I want to thank everybody else here on YouTube for liking and subscribing and all that sort of stuff. So I hope you'll join me again on the next episode of Building Gannett where we're going to finish off that planking by hanging the whiskey plank. That'll be fun. I'll see you next time.