Building the (Modified) Macomber 15

[AndrewT]

My kids (ages 7 and 9) and I recently started work on a Macomber 15. The M15 is a traditional Westport skiff and was recently featured in WoodenBoat's Small Boats issue. We've been working like mad in order to have it finished in time for a family reunion later this month.

The plans include three 24x36 sheets (lines drawing, building jig details, and construction notes) plus a well-written Builder's Guide and an extremely useful pictorial guide of the designer building the boat. There are about 40 pages total between the two guides.

We are building in my workshop, which is a 32' x 40' gambrel-roofed barn; please forgive the omnipresent clutter in the background (and sometimes the foreground) of every photo.

The first thing we did was loft the jig frames using the table of offsets included on the jig details page of the plans. This went pretty quickly, since all the jig frames use straight lines. Then we assembled the frames on the lofting table, using drywall screws.



Next thing we did was to set up the building jig. I used two 16' 2x6s for the base and screwed 2x4 spacers between them every so often to keep them parallel and stiff. I also screwed the whole thing to my assembly table. (I forgot to take pictures of this part, so you'll have to imagine it all by itself in the picture below.)



One thing we didn't do up-front that I would do next time is to install diagonal bracing from the uprights back to the jig base. I ended up going back and adding some later on.

Installing the frames was an easy task, conceptually speaking, although the actual installation was a little tricky. Mostly because of gravity and poor measuring skills. Eventually, though, everything was plumb, level, and at the correct distance off the baseline.



More to come...

[StevenBauer]

You sorted the pic posting! Nice!



Steven

[AndrewT]

So the first part of construction that was actually going to end up on the finished boat was the transom. Unfortunately, I took zero pictures of this part, so the pictures below are from a later point in the construction. Started off with a bunch of 5/4 African Mahogany (because the Honduran variety was way out of my budget). Planed everything down to 1", jointed the edges, cut some grooves in the mating edges, and used epoxy (West System, holla!) and splines to glue up the big panel. We let that dry for a day or two, then started sanding. We sanding for 28 years, and finally ended up with a relatively smooth, flat panel approximately 3/16" thick.

I'm kidding. But sanding WAS a b*tch. Started with R.O. sander - no dice. Graduated to belt sander with 80-grit; better, but still too slow. Upgraded to belt sander with 60-grit, then 40-grit. This is a good time to wonder aloud why, after planing all the boards together (i.e. I didn't adjust the planer at all between boards - ran all boards through at first setting, then lowered blade, then ran all boards through again, etc.) and cutting all the spline grooves together (run board on-edge through table saw, flip end-for-end and repeat to ensure groove is centered), why is my panel not flat and smooth? There are ridges at every single glue joint that have to be sanded down. Anyhow, the belt sander - as you can imagine - gouged the hell out of my nice transom. So, I got on the Woodnet forum and found a guy down the road from me with a wide-belt sander who was kind enough to let me run the transom through it eleventy-billion times until it was reasonably smooth. (You can see a bit of it in the photo below.)



Next, we laid out the transom profile and cut it to shape, leaving the decorative curves at the top well-oversized to be trimmed later. Mounting the transom to its uprights at the stern was tricky, because that sucker is heavy, and it has to be at the right height and the correct angle and plumb and level and all that jazz.

Next up was the stem. This was actually pretty straightforward, as the dimensions are given on the plans, including the angles at the top and bottom and the details for mounting the stem to the jig. (Once again, I was more into building than photographing, but you can see the stem head-on below.)



I used some offcuts from the transom and/or stem pieces to form the corner posts. These got epoxied and screwed to the transom. I left them long at the sheer to be trimmed later. (Wish I'd remembered not to epoxy the parts to be trimmed off, but that's a story best left for later.) After the epoxy set, we notched the corner post and transom for the chines.



A word about fasteners: I really wanted to use Silicone Bronze throughout the build, but frankly I just can't afford the stuff. I was looking at $700-800 just for fasteners. Instead, I used stainless steel for all of the screws, and galvanized later for carriage bolts (I'll probably replace the galvanized stuff at some point with either stainless or bronze).

[AndrewT]

The chines started out as 16' lengths of 1"-thick mahogany, 2" wide. Fitting them into the stern notches was easy, but getting the stem notches right was a pain. Epoxy and sawdust filled a bunch of gaps here. Plus which, I didn't cut them quite deep enough and had to do a fair bit of sanding afterwards to fair everything up.



Cutting the chine notches in the frames was easy enough, but I never did really get the chines to actually seat into the notches.




I talked to the designer before proceeding, and he assured me it wasn't a problem. It might change the bottom profile just a hair, but as long as everything is fair, don't worry about it. So naturally I've worried about it ever since, but things turned out fine. Incidentally, none - not one piece - of the wood used to build the boat was wetted or steamed prior to bending - and not a single piece snapped. Anyhow, we got the chines cut, glued, and screwed in place...



...and after a bit of sanding, everything was smooth and fair up-front (but note the significant epoxy/sawdust glue joint line...grrrr).



The last thing we did before starting the planking was to install the inner keel. This was another 16' length of 1"-thick mahogany, this time 3-1/4" wide. I didn't get a good picture of it, but you can see it on the left in the photo below. I cut the frame notches oversized so we could adjust things if necessary, but the keel was epoxied and screwed at the transom (after cutting a notch) and the stem.



Up next: planking....

[TerryLL]

It's about time we saw some pics of this build. Looking good there Mr.T. Keep those pics coming.

[AndrewT]

The planking on this boat is 1x12 material; the designer calls out Eastern White Pine, but I didn't have access to that, so we used Cypress instead.



Let me just tell you: a 16'-long 1x12 plank is heavy, and hard to work with. Another handy pointer: when clamping one of these boards to the frames, forcing it into a curve, it's a good idea to keep your shoulder between the board and the side of your face while tightening the clamps. Ask me how I know this. These boards get VERY sproingy when clamped into a curve.

Clamping these big things was also kind of an adventure. As you can see from the photos, I ended up using a bunch of homebrewed lapstrake clamps about 16" long. Cost me about $10 in materials and about 2 hours to make a dozen of them. They worked pretty well, too - particularly once I figured out that I needed to install them from below instead of from above.

After temporarily mounting the first plank and scribing the chine to the inside, we removed it and cut the gains. No photo could possibly do justice to the Rube Goldberg-ian system I came up with to perform this task, but I didn't think to video-record it so you'll just have to bear with me.

The gains on this thing are 1-3/8" wide by 30" long, at both ends of each plank except the sheer plank (a total of eight). The first four went smoothly, because the garboard plank is straight-edged on the gain edge (i.e. along the top edge). I don't own a rabbet plane, and I didn't want to buy one, so I needed to figure out another way to do this. What you see above is what I came up with. The plank is clamped to two posts on the deck of my workshop, and supported under the working end with a roller stand (for no other reason than it's adjustable height).



Next, I clamped a thick piece of scrap to the face of the plank, opposite the side the gain was being cut on and flush with the edge of the plank. Then I clamped a long piece of steel plate to the boards, with the edge of the plate on the sloping line of the gain. The steel plate served as a straightedge for the bearing-guided router bit to follow.



I clamped a steel clamping square under the steel plate to support it. The end-on photo below shows the setup pretty well, I think.



Finally, I used a router, following the steel plate, to cut the gains. It took several passes and another Rube Goldberg solution (adding a second bearing to one of the bits to extend its reach), but I got it done.



The other end of this plank - and the second garboard plank - went fairly smoothly.

[AndrewT]

It's about time we saw some pics of this build. Looking good there Mr.T. Keep those pics coming.

We've been working under a tight self-imposed deadline, trying to have her ready in time for a family reunion at the end of the month, so I haven't had time to post my progress. I spend all of my time arguing about how to finish the bottom...

[AndrewT]

Next we prepped all the frames to receive the planking. This was not strictly necessary, since the frames never really touched the planks, but I didn't know that at the time and wasn't sure how messy the epoxy would be.



Speaking of epoxy: The plans did not call for gluing the planks together; they called for BoatLife caulk and copper rivets. I wanted to use screws instead of rivets, and epoxy just seemed like a better option for me. I did not consult the designer and do not hold him responsible for any adverse effect on the boat.

Anyhow. We clamped the planks back in place and pre-drilled screw holes every few inches, then removed the planks and countersunk for the screw heads. Then I coated the chine and the bottom of the garboard plank with unthickened epoxy.

Finally, I coated the plank with epoxy thickened with silica (I think - can't ever remember what that stuff is - comes in a big white tube, it's a white powder) and we clamped it back in place. I worked frantically, unsure of how long I'd have until the epoxy kicked in the heat and humidity of south Texas, but it turned out to be a pretty easy process. The screws went in quick and easy, and before long we had a pair of planks hung. (We just let them run long at the transom to be cut flush later.)



Hanging the next planks went much the same, except for cutting the gains. This pair of planks didn't have a straight edge to work from, so the gain was curved. I devised yet another router-based system to cut the gains relatively close to their final lines, and then cleaned them up with a chisel, plane, and sandpaper. We let these planks run long both fore and aft and cut them flush later.



Clamping these monster planks was sometimes an adventure.



And working when my helpers disappeared also necessitated more Rube Goldberg solutions. Note the bungee cord holding the aft end of the sheer plank in the photo below.



Of course, when they ARE there, they're very useful. I believe this one is labeling "good" and "bad" plane shavings. Note the green (for "good") and red (for "bad") markers. Clever girl.

[AndrewT]

Clamping the sheer planks was really a project. They just wanted to move all over the place.



About this point, I broke into a cold sweat when I saw the funky hump in the sheer plank, about four feet back from the stem.



I'm glad it was a hump and not a dip; it was easily fixed later. I still haven't figure out what went wrong there; I double-checked my measurements and they seemed to be correct, which makes me wonder if there's an error on the table of offsets for the jig frames (which have the sheer markings on them).

At various times during the installation of the remaining planks, I worked on flushing up the garboard plank with the chine. Helper #1 is manning the camera in the following shot; note helper #2 in the background, doing what she does. (That's me in the ugly shoes.)



This project (flushing the plank to the chine) caused me a great deal of unwarranted frustration. I tried to come up with all kinds of shortcuts to do this, but in the end, a handplane worked best. First time I've ever used one for any length of time. Here's the results of an early failed attempt to flush up the chines with a router before installing the plank (look at the aft end of the chine, for the last foot or so before it meets the transom).



Sometimes reinventing the wheel is not necessary.

[AndrewT]

Believe it or not, by this stage in the construction (which was 48 days after starting), I still hadn't learned to stop and take photos while I was working. Consequently, I only have photos of the completed bottom to show.



Other than milling the planks (which started out as 4/4 x 12" x 16' Cypress boards), the bottom was easy. The planks are square-edged, about 5" wide, and nailed to the chines and the inner keel with stainless steel ring-shank nails. There is a bead of BoatLife Caulk between each plank, and between the chines and the plank. I got several planks installed before I remembered that I was supposed to have beveled the bottom of the garboard plank a little to receive cotton caulking later. I had to go back and cut the bevel under the installed bottom planks by kerfing the joint with a handsaw, but I cut the rest of the bevels with a handplane rather quickly before proceeding.

These planks were installed about May 9th; as of today (June 6th) I can see daylight between a few of the planks near the bow (the shorter planks). After much discussion in another thread, I have decided to live with it, at least for the time-being. I may replace the bottom or add cotton or goo at some point in the future, but it ain't going to be now.



Next, I installed the outer keel and the strakes. I was originally going to use mahogany for these and finish them bright, because I thought it would look cool against the white-painted hull. Then it occurred to me that, unless something goes terribly wrong, nobody is ever going to see the bottom again after I flip this thing right-side-up. So, I used some pine 2x material I had laying around, ripped to width and planed to 1" thick.



There is an error (well, an omission) on the plans as regards the outer keel. The plans specify a bead of caulk under the strakes before installation, but not the outer keel. So I merrily drove screws through the outer keel and bottom planks into the inner keel without any kind of goo between the outer keel and the hull. When I installed the strakes, it dawned on me that there probably should've been some goo under the outer keel, too. Designer confirmed (and has hopefully added the info to the plans), but by then I was done. I went back and added a bead of 3M 4200 (I think - I was out of BoatLife and went by West Marine to pick up something else) along the edges of the outer keel. Hope it works. Did the same thing at both strakes.

Speaking of strakes - they are screwed to the bottom from inside the hull. I don't have any pictures of it (naturally), but I had to brace them to the ceiling of the workshop while I laid underneath the hull and drove the screws. Getting all of that lined up and secure while the parts slide around in the caulk was a mess of a chore.

[AndrewT]

HOW NOT TO FLIP A HULL
So it's just about time to flip her over. I was having a hard time rounding up enough hands to help with the job, so I rigged up yet another Rube Goldberg contraption that would hopefully let my wife and I do it alone. This was a bad plan and I strongly recommend against any of you trying it out.

The plan was this: I would install a temporary brace across the transom, and then sink a screw-eye through the middle of it. Then I would hook the screw-eye to a come-along attached to the ceiling above the hull, thus providing a pivot point aft. Standing at the stem, I would lift the boat (by hand) and, with my wife standing amidships to keep the thing from spinning out of control, we would gently roll it in place and set it back down on the table. Easy squeezy lemoneezy, as my kids would say.







Big, fat, giant, honkin' mistake. First, I couldn't find the come-along, so I used a cargo tie-down strap instead. It works, but the problem with it is that you can't ratchet it back down - when you release it, it just lets whatever it was holding drop. Like a rock. Second, in order to spin the hull and clear the work table, we had to lift it like three feet - which put it at a very awkward working height, and put the center of gravity - the heavy, 1"-thick bottom - way, way, WAY up high. Third, the screw-eye, while technically centered on the support screwed to the transom, was not, in fact, centered on the hull. Fourth, the bow was much heavier than I anticipated. Fifth, my kids were running around like cockroaches when you flip the lights on.

All of which conspired to make the hull flip go down like this: We lift the aft end up way high. My wife stands amidships to steady the hull, and I lift up the stem. My kids pull the support structure out from under the hull, and as soon as there's no support under the stem, I realize I am f*cked because I can't hold this thing up. I'm screaming at the kids to bring me a sawhorse, and the now super-top-heavy hull decides it would be a good time to check into the laws of physics and gravity, and begins a slow but fairly persistent roll toward my wife. About this time, a kid finally brings me a sawhorse, but now I'm so worried about crushing my wife that I can't deal with it. She's trying like mad to keep the hull from rolling over and, as best we can tell, temporarily dislocates her thumb trying to hold it. She screams and lets go.

Now I am really up sh*t creek. I can't let go, can't get to a phone to call anybody, can't reach my wife, the kids are scrambling, and the way the hull is swaying is making me seasick. Eventually my wife's lightheadedness passes and she is able to assist me with the sawhorse, and we get the stem supported so I can let go and invent some new four-letter words. (Sorry kids.)



After a few "Hey, I tried to do this without your help and we dislocated Julie's thumb" phone calls to buddies who'd been too busy to help, I managed to get some guys over the following morning to do it the right way. In five minutes we had it picked up, moved out, rolled over, and put back on the work table.



I may have said once or twice before - sometimes there is no need to reinvent the wheel. Sometimes the hard way is really the easy way.

[AndrewT]

First thing to do after flipping her over was to shoehorn the inwales into place so I could deal with the funky sheer. (There are, of course, no photos of this; a later photo will have to do.)

What I did was this: I put the inwale - a 16' length of 1x2 (net) mahogany - just inside the sheer, butted against the transom, and clamped it loosely in place at the transom. Since the inwale hadn't been cut to length yet, it ran out past the stem, so I put it on the opposite side of the stem (i.e. I clamped the starboard inwale to the starboard side at the transom, but put it on the port side of the stem at the bow). Then, I worked my way from aft forward, installing clamps and pulling the inwale tight against the sheer plank. When I had it mostly complete, I marked it to length at the bow, unclamped it, and cut it. Then I clamped it back in place and adjusted it so it a) hit the sheer mark at the stem, 2) hit the sheer mark at the transom, and D) sprung a nice, fair curve.

Next, I used a jigsaw to cut the sheer plank to within 1/8" or so of the inwale, then used a big router with a big flush-trim bit to cut the plank flush with the inwale. This worked out perfectly except in two or three areas where the router bit ripped out part of the top of the plank. I'm planning to install Dutchmen here to cover the rough areas.

With the sheer planks cut to nice, fair curves, it was time to work on the interior frames. I was really dreading this, since I could figure no easy way to do it, and I suck quite a lot at making tight-fitting joinery. Also, there is approximately zero information in the plans regarding the frames and how to make them. At one point, the builder's guide just says, "And now you can flip her over and complete the interior. The end." Or something very similar.



But, once again, it turned out not to be quite as hard as I imagined (although I did end up scrapping the first couple of frames I made). I was able to use scraps of Cypress for most of the pieces, and didn't have to buy much additional lumber. Fitting was pretty straightforward once I figured out how to do it (basically, cut a blank to the right length, then clamp it in place against the hull, then use a marking gauge to scribe the inside of the hull to the blank) it went quickly. I think we did all the port-side frames on day 1 and all the starboard frames on day 2. Instead of riveting them to the planks, I used long #12 stainless screws, and it really stiffened up the hull. The joints are quite as tight as I'd like, but I can live with them.



Cutting the notches at the tops of the frames took another day, and bolting them to the chines took a few hours. Then it was time to work on the false stem, the breasthook and the quarter knees.







These were kind of hard, since they involved multiple angles and bevels and different working plans and I suck at geometry (as evidenced by the awesome stem/false stem/breasthook joints in the picture above; still not sure how I'm going to fix that). But patterns helped, and I only had to go buy extra lumber once.

Next, I clamped the inwales back in place, marked them to length, and cut them to fit between the quarter-knees and the breastook. Then I removed them (again - there is an awful lot of "clamp, then remove, then re-clamp, then re-remove" that goes on in boatbuilding) and, along with the gunwales, I painted the backs of the pieces with epoxy to seal them. They are currently awaiting installation.

[AndrewT]

Whoops - need to back up a bit. Before I could install the quarter-knees, I needed to cut the transom top to its final shape. For this, I had a buddy with a working CNC machine (I have a big one in the workshop, but it's currently undergoing some reconstructive maintenance) cut me a pattern that I could trim to. I clamped the pattern in place, used the jigsaw to cut to within 1/8", and then used the router to flush-trim to the pattern. A nice, unexpected bonus was that the contrasting-color spline I used between the top two pieces was revealed and looked great.



THEN I installed the quarter-knees. After that, I installed the motor board inside the transom, and then I started varnishing.



I wanted to get as many coats of varnish on the planking end-grain as I possibly could before I start painting, so I tried to do things in the order that allowed me to start applying varnish as early as possible. I'm up to four coats so far on the transom and stem, and I'll keep applying them until I need to start painting.

Next came the seat framing. There are two little seats at the transom (on on either corner), a bench seat (thwart?) about amidships, and a good-size forward deck up front. All of the main supports are 1"-thick by 2" wide mahogany, with a little bead detail on the bottom.



Each main support is supported at the centerline by a 2"-square mahogany post with chamfered corners.



On the amidships bench, there are Cypress facings under the main supports, with good-sized limber holes at the centerline and the outboard ends. A quick glance at the plans got me started, but as I was looking at them again last night, it dawned on me that the designer's facings are a single, wide piece running from one side of the hull to the other. (Once again, I wasn't paying attention to the details.) But, as it turns out, I like mine better, because they don't cover up the mahogany posts supporting the center of the seat.



Obviously there is only one facing installed in the photo above. As it turned out, the distance between the main support and the bottom of the boat was 11-7/16", which turns out to be about a half-inch wider than a 1x12. Argh. So, I had to rip some material to 6" wide and glue up wider panels, which are currently curing in the background somewhere. (Didn't want to lower the supports, because the seat top is supposed to sit on the plank overlap at the hull insides.) Here's a closeup of the first facing, the support post, and the seat support:

[AndrewT]

Another shot of the center seat:



And one of the forward deck framing:



Varnished (x4) stem (I'm overlapping the varnish onto the planking for no good reason; just seems like overlapping finishes is better than butt-joining them):



Varnished (x4) transom:



And that's where I stand as of today. We should be finished in a couple of weeks. I'm planning on finishing up the seats and forward deck over the next 2 or 3 days, and will put a coat of varnish on before quitting for the day on each of those days. This weekend we'll start painting the outside of the hull; plan is to prime, sand, prime, sand, paint, sand, paint, sand, and paint. After painting, I'll finish the interior with boat soup (which I mixed a batch of last night: equal parts pine tar, turpentine, boiled linseed oil, and tung oil - all from American Rope & Tar. My workshop smells outstanding right now.). Then I'll install the inwales and gunwales, varnish the mahogany trim, install the hardware and the motor, and drop her in the water.

I'll keep you posted on the progress.

[AndrewT]

Okay, over the last few days we've managed to get quite a bit done. First, I finished the forward deck.



The helpers are covering a lot of it, but you get the gist. The planks are 3-1/4" planks of white oak I had leftover from another project. Since they were being painted, I didn't mind mixing them in with the Cypress and Mahogany. A also managed to get most of the middle bench completed.



This took way longer than it should have, because I'm stupid. Long story short, I ended up having to do it twice. The planks you see now are, except for the last (outboard) plank on either side, all mounted to a frame that lifts out of the bench to reveal a storage area beneath the seat. You can also see in the picture above that the first four sections in the bow of the boat have been coated with "boat soup light," a mixture of 50% varnish (Le Tonkinois) and 50% turpentine. Goes on easy, soaks in well, and preserves the natural colors of the wood. I may go back and add a second coat later.

While all of this was going on, I had helper #1 prepping the outside of the hull for paint.



He's tired of sanding, but he's excited about painting, so he keeps going. When he finished touching up all the epoxied screw holes, dings, and divots, we got the first coat of primer applied.



This was a giant hassle. I am using Marshall's Cove Marine Paint, and their primer is formulated to dry quickly. Real quickly. We went through two foam rollers and two foam brushes just getting these first four planks done. By the time we finished the fourth plank, we were ready to sand and re-coat.

[AndrewT]

After a light sanding at 220-grit, we applied a second coat of primer. This coat was much easier to apply and didn't cost us any extra rollers or brushes. I guess it was just painting it on the bare wood that caused it to really soak in. Anyhow, second coat went on quick and easy, and we waited one day and then lightly sanded the 2nd primer coat. Next came the first finish coat.



The marine enamel from Marshall's Cove had a much longer open time. We were easily able to get the first coat on, and it was still tacky an hour or more later (we're working in 95-degree heat in an unconditioned - but covered - workshop, in about 90% humidity). We waited overnight, then gave it a once-over with 220-grit and applied a second finish coat last night. I checked it out this morning before leaving for work, and it'll need a third coat this evening.

We've got a family function at the house on Sunday, and I'm planning on using the free labor to help me flip the hull upside-down (again) so I can do some more work on the bottom. When that's finished, I'll prime and paint the bottom of the boat and the garboard plank up to the first plank lap. Plan originally was to paint the sides red down to the chine and then paint the bottom white, but the more we look at it the way it is now, the more inclined we are to paint that bottom plank white, too. I think we'll do that, and if we don't like it we can always paint over it with the red.

[Bluegill]

It appears you do superior work. I love the design. Did you add flotation ??? If the transom was at a greater angle the boat would look better. What are the modifications ??? Your pictures are great. Do the plans show the dimensions of the strakes ???

[AndrewT]

Didn't add any flotation. I really didn't modify anything, except I did add fiberglass to the cross-planked bottom (against lots of advice here, but with the stamp of approval from the folks at West System). The plans were pretty simple; each strake starts out as a 1x12 piece of lumber, and each one only gets trimmed on one edge.

I found the hardest parts to be the interior frames (for which there weren't adequate drawings/dimensions, and there were no instructions in the text for how to make them), the breasthook (which still looks crappy to this day because I haven't figure out how to fix it), and the stem.

[Bluegill]

What are the length and width of the boards you used for permanent frames in the boat ??? It looks like about a 1 X 3.
How far apart are the frames ??? It looks like about 15 inch centers.

[AndrewT]

They all vary. I started with something like a 1x3x24" or so and scribed them to the inside of the planking at the layout lines. I pulled the layout line locations off the drawing (I had to scale them - there were no dimensions given) and sort of rounded up or down to get a round number. All of the centers are different - they might go 18", 15", 12", 12", 20", 18", etc. . Lots of eyeballing. As mentioned above, the frame layout and construction details were one of my complaints about the original plans.