Line up the strut with the keel temporarily mounted to the boat
Well, it’s time to start putting holes in the boat. Now this is a subject any boatbuilder approaches with at least some degree of respect, if not downright fear and trepidation. After all, you’re doing all this work to create something that floats, right? But boats have to have holes in them to function. You have to get water to the engine somehow. The propeller shaft has to get from the engine inside the boat to the propeller outside the boat. You have to vent the fuel tank. You have to have a way to pump bilge water out. The list goes on.
In this case, we need to mount the strut, which supports the propeller shaft, onto the keel. We’ll then use the strut as a guide to bore a bigger hole–the one for the propeller shaft. To make sure we get this right, a lot of attention gets paid to lining things up. I install a new cutlass bearing in the strut and pass the old shaft through it.
Line up with the centerline and the string over the centerline
Then line this up with the center-line on the keel, and with the center-line string suspended over the boat. Clamp it in place, and drill.
It’s not time to install them yet–that won’t come until after the inner layer of 1/8″ marine plywood is already fitted and installed. But we need to bend the outer planks to the shape of the hull while we can still get to the frames to use them to clamp the planks to. So now’s the time. Boatbuilding, as with many other endeavors, is often not done in a straight line. You do things when you can, when you have the extra help, when you need to.
The first step is to sort through the milled lumber and pick the nicest grain for parts that will show. We allocated the pretty stuff to topsides planks, transom planks and ceiling. That leaves the not-so-pretty stuff for the bottom, which will be covered with paint.
We’ll start with the garboard (that’s the plank that lies next to the keel, and incidentally, where a lot of leaky bottoms start) and work out way up toward the chine.
Having allocated our lumber, the next step is to cut out what I call the “blanks”. I used the old planks (never throw anything away until the project is finished) as patterns to get the general shape of the new planks and cut them out big on with a jigsaw.
Now that last sentence could be a whole blog topic in itself. I realize as I write this that there’s a lot of “how-to” that gets skipped over. How big? Bigger on one edge than another? Is there one brand of jigsaw that’s better than another? After all, the right tool really does make all the difference. What about grain orientation? Is there a problem with avoiding sapwood like when you’re cutting white oak?
I know there’s a lot that I gloss over here. If you’re interested, you can always comment or ask a question. I promise to answer. And I promise to tell you if I don’t know.
Using old planks as a pattern to cut the new “plank blanks”
Back to the main topic, I cut them out two at a time–one for each side of the boat, tracing around the old plank, leaving it 1/2″ big on the bottom and leaving about 3 to 6 inches on the aft end. This way, if I make a mistake when fitting (which comes much later), I can slide the plank forward and re-do.
New Plank Blanks in the soaking box.
Then I presoak these mahogany planks for at least 24 hours before steaming them. Mahogany, being less dense than white oak, needs less presoaking time. I would soak white oak for a week or two before steaming. Then it’s time to steam it. In this case, since the planks are 1/2 inch thick, they’ll be steamed for at least 30 minutes.
All clamped up
Finally, pull them out of the steamer and quickly clamp them to the frames of the boat. I only steam the forward planks. The aft ones are pretty straight, and won’t be stressed by attaching them to the boat without steaming. Having the forward ones curved to the shape of the hull greatly eases the task of fitting them, which is a topic for another day.
We’ve already discussed cutting the rabbet on the stem and gripe here. You can imagine that cutting this groove along the length of both sides of the keel with a hammer and chisel is a daunting task indeed. Especially in a tough wood like white oak. The procedure is complicated by the fact that the bevel changes along the length of the boat. Just look at the way the bottom comes into the keel.
Steam bend pine planks to serve as a router track.
But thanks to Don Danenberg, there’s a better way. He devised a method of setting up a router track along the length of the keel and using the frames of the boat to get the right bevel. It’s really clever, and saves a good bit of shop time, but requires that the frames all be fair before you start routing.
First, you steam bend a pine plank to lay alongside the keel.
Then screw it to the frames, and screw a 3/4″ x 3/4″ guide to the pine plank that your router will ride against. The router sits on the plank and the keel, and cuts your rabbet. It takes several passes because white oak is tough wood. But it gets the job done accurately and in much less time than it would take to do it with a hammer and chisel.
Ready to route!
I had some help from expert boatbuilder Mark Neely setting up this operation. Thanks, Mark!
All this hard work getting the frames and other structural pieces into shape is finally paying off. We can use this structural framework as a form when making and bending new pieces to fit the boat. A good example is the Intermediate Frames.
View from the stern
Intermediate frames are the sticks that go between the main and auxiliary frames to provide another fastening point for the bottom planks. We made these out of 5/8″ x 1″ pieces of white oak. We steamed them for about an hour–probably could have gone a bit longer–they were hard to bend! Then, as you can see, we just bent them under a batten clamped down the center of the frames to give them the curve they’ll need in the area of the boat they’ll be used. Keep in mind that you’re seeing parts for both the port and starboard sides of the bottom here, clamped on place on the starboard side only. But since the bottom is symmetrical, we can use one side for both.
Bench form for smaller pieces
For these small forward pieces it was easier to just make a simple form on the bench.
The Stem and Gripe together make the Forefoot of the boat. This is the curved part of the bottom that provides the transition from the stem to the keel. It needs to be a formidable piece of the boat because it is the piece that parts the water as the boat makes its way. It takes considerable pounding, and in an older boat, almost always has some rot in it. That means it’s going to have to be replaced.
Since we have the plans, we could loft the boat and then take off the curves to make a new stem/gripe. But we have a pretty good pattern (albeit with a little rot here and there) in the old one. Using a sheet of glass and some clear plastic from the art store, we can draw out a pattern and transfer that to properly dimensioned white oak to make a new one that’s better than the old–better because it’s made of rot-resistant white oak.
Using the old stem/gripe to make a pattern
So the first step is to lay a piece of 1/4″ glass over the old part and trace its lines onto a piece of clear mylar. Of course you want to get as much information as you can on this tracing, including bolt locations, bootstripe, etc. And make sure you are looking straight down on the part when tracing to avoid any parallax error.
Avoiding the lighter colored sapwood when laying out the new pieces.
Then take your new pattern and transfer the lines to your new wood. You do this by tracing over the new mylar pattern with a “pounce wheel”, which you also get at your friendly art supply store. You can see in our example that we made sure to avoid any sapwood in the new pieces. Sapwood is much lighter in color and contains dried sap and sugars. Including sapwood in your boat is like a flashing neon sign for rot spore–bad news if you want to keep your boat rot free.
Once the pieces were cut on the bandsaw, it took a little time to fit the joint between the stem and the gripe. You need a good, solid joint here that, once slathered with bedding compound, will not allow ingress of any water.
Clamped stem and gripe. Checking the overall curve of the piece and fitting to the breasthook.
Once we got that joint in good shape, the stem and gripe blanks were bolted together and fit to the breasthook. Then it was time to look at the curve of the whole assembly and make sure it would be fair with the keel joint. As you can see, we had to glue in a shim or two, but there’s no shame in that.
Grab your chisel, follow the lines from your pattern, and have at it!
Finally it was time to carve the rabbet. That’s the groove that runs lengthwise along the piece for the bottom planks to rest in. That’s really a topic all in itself, but we’ll show it here. To make a long story short, you use the lines you’ve traced on to your blank from the old stem/gripe assembly. Using those lines, you have at it with your chisel and carve out the rabbet. It helps to have a test stick, called a “fid”, that is the same thickness your planking will be to test how it fits in the groove as you carve it. With a tough wood like white oak, you have to pause a few times to sharpen the chisel. You can definitely tell the difference a sharp tool makes here.
Finished rabbet (on this side, at least).
Then clean it up with a plane, sander, Fein multimaster, whatever works. You’re done!
I used a piece of pvc pipe as my steambox for the lower transom bow since it was a short piece.
A lot of preparation is required for steam bending wood. You need a fair amount of specialized equipment. I covered that a couple of weeks ago here in Getting Ready for Steam Bending Wood. Now it’s time to put that equipment into action.
The first piece I bent was the lower transom bow. I chose it because it was short, and I figured it would be easy to handle without the help of another person. You have to get the piece out of the steamer and onto the form quickly, before it cools. So if it’s long or cumbersome, it helps to have more than one person.
8 ft. radius form for bending transom pieces
This boat has a curved transom with an 8 ft. radius to the curve. There aren’t enough pieces in the actual transom framing to support a smooth, even clamping surface, so I had to build a form. For everything else, we can use the boat framework as our form (i.e. keel, chines, planks).
Lower transom bow that was steamed and clamped to the form.
Here’s the lower transom bow clamped to the form. I tried 3 times to bend a piece I could use. But alas, because the oak was about 1-1/2 inches thick, and because the bend was so severe, I got too much springback. The bent piece could be clamped to the boat framing, and forced to the proper shape, but this isn’t really what you want. Particularly with the transom, you want the bow to describe the curve and hold that curve. Forcing a piece to a tighter curve here runs the risk of having the bow stress some of the joints and pull them apart. I guess that’s why the original transom bow was sawed on a curve.
I didn’t like the idea of sawing this piece on a curve. It gives you too much short grain at the ends of the curve, which can split. Of course, it worked for 60 years. We have the original transom bow to prove it. But there’s a better way. I finally chose to laminate oak strips to the correct curve, using the form I’ve already built. I’ll post some pictures of the laminated transom bow later.
Dave and James holding Sadie the Wonderdog. Lisa (standing) and Annie (down in front).
For now, it was time to move ahead and bend in the keel and chines. I was able to use the framework of the boat for my form for these pieces. They’re much longer (they run the whole length of the boat), and you need two people to get them out of the steamer and onto the boat quickly. So I enlisted the help of some good friends. This picture is of the crew that helped with the starboard chine.
Finally, after the chine was bent onto the boat frame, it was wrapped in wet towels to let it cool and dry slowly–over several days. Here’s a picture of it without all the people in the way. Not much to see really. But it’s there under the rags.
After stripping the bottom planking off (see Remove the Bottom), it’s a good time to take another look at the soundness of the bottom framing. Now you can see it from it’s most vulnerable angle–the joint between the frame and the bottom planking. This is where water is most likely to collect (the bottom of the bilge) and be absorbed into any unsealed wood. Remember, any wood with over 20% moisture content is a great place for rot spore to grow. The factory may or may not have sealed this joint with paint, but that was 60 years ago.
After taking another look at the bottom framing, it’s in pretty good shape for being 60 years old, but still, it is 60 year old wood. It leaks around the transom joint, and is oil-soaked under the engine. We’re going to be putting a newly rebuilt engine in this boat and it is, after all a speedboat. You wouldn’t put a new engine in a 60 year old car without addressing the chassis. It would soon shake apart.
Aside from all that, the original bottom frames are made of Philippine Mahogany–a wood with little to no rot resistance. We’ll replace them with white oak which is a traditional boatbuilding wood because of it’s good fastener-holding and rot resistance properties.
New frames being fit in with old
We’ll use the old frames as patterns to cut out new ones. Then we’ll install each new frame, using the old keel and chines to get the lines right, along with battens, and bevel the new frame in place.
Fairing the keel landing forward
Finally, disassemble the whole thing, seal the new frames properly, and permanently install them. This gets the new frames sealed at the joint surfaces–a very important step that keeps them from soaking up moisture where you can’t see it.
The Chine is the piece that defines the “corner” between the topsides and the bottom of the boat.
So we’ve got the bottom off (see Remove the Bottom), what now? Well let’s take a moment to look at the chines (the longitudinal piece of lumber that creates the “corner” between the topsides and the bottom). While we’re at it, we’ll take a look at the keel as well. These pieces are made of white oak, so that’s good material. But they’re also 60 years old, and very perforated. The keel is oil-soaked under the engine, which weakens wood considerably. It also has a bad dip in it forward, with no good way to smooth that out. Once you’ve come this far, you’d be crazy not to replace these pieces. So off they come.
In order to get the chines off, you have to remove the first topsides strake (plank) next to the chines.
Tape off the area to be stripped and slap on the stripper.
The first step in removing the topsides strake is to strip the varnish off it to make removal of the bungs easier.
Stripping the old bottom paint reveals a low spot in the old plank faired out with compound.
We haven’t made a decision yet on whether to replace this plank, so to avoid splintering around the bung holes when removing bungs, we strip the finish which acts as a glue and can pull splinters of this delicate old wood.
Remove bungs by stabbing them with an ice pick.
Once the finish is stripped, the bungs can be removed by splitting them with an ice pick, and pulling the pieces out carefully. This exposes the screw heads which you can carefully back out, trying not to catch on the side of the bung holes and splintering the wood. You will inevitably break some screws and find some already broken. Mark them for later drilling and extraction.
Close up of bung being removed.
After you’ve got the planks removed on both sides of the chine, it’s a pretty simple matter to unfasten the chine and remove it. Broken fasteners holding the chine in shouldn’t present too much of a problem since we’re replacing the chines and the bottom frames.
I’ve briefly mentioned Sadie before in here. But I’ve been advised that I should devote a little more time and mention to this all-important member of the crew. Sadie is of the Mutt breed. We adopted her from the Charleston Animal Society a little over a year ago. She’s about a year and a half old now, is smarter than she let’s on most of the time, and is the social ambassador of Ashley River Boatworks. She’s great friends with all of the other folks in the building complex where the shop is located here in Charleston, SC, USA.
She especially enjoys visiting with the schoolchildren Isaiah and Malaysia who check in with her most mornings while waiting for their bus. She also loves running over to visit with the guys next door when they’re practicing their karate moves. And she supervises the loading and unloading of the trucks for a nearby landscaping business. In between, she consults with me on the best approach to take on repairs and projects in the shop. Usually we find that the best way is to do it right the first time and not cut corners. You only end up paying for “quick and cheap” over and over in the long run. Most of the time we agree on how to handle a particular problem, but when she doesn’t agree with something I’ve done, she just finds a way to chew it up when I’m not looking.
A poultice of kitty litter and lacquer thinner is used on the stringers to draw out oil.
A poultice is a moist, soft mass used to treat inflammation of a body part. It is often applied with heat. It can also be used to draw out stains and other contaminants from a porous material.
In our case, it is a way to draw out oil from oil-soaked wood. The stringers in this boat have, over time, absorbed engine oil that has been spilled in the bilge. They’re not damaged enough to warrant replacement, but I want to get the oil out of them to facilitate sealing of them, and paint adhesion. A good way to do that is by making a poultice of ground up non-scented kitty litter (dried clay) and lacquer thinner. The lacquer thinner is a solvent that soaks into the wood, dissolves the oil, and keeps it in solution long enough to leach out through osmosis to the kitty litter where the oil concentration is less. This may sound like snake-oil. But it really works. Try it.
