Alvin Clark

[Dave Stevens (Lumberyard)]

The cap rail is a large timber which sits on top of the bulkhead stanchions and runs along the entire length of the hull. If you look careful you can see the wooden peg in the cap rail that holds the rail to the stanchion, the blue arrows.. A shallow mortise is cut in the bottom of the rail where the top of the stanchion fits in.



To begin the cap rails a cardboard pattern is cut directly from the plans and placed on the model to check how close the model was built to the plans. Over all, the cap rail pattern fits pretty close to the top of the bulwarks but taking a closer look we can see the bulwark does stick out beyond the edge of the cap rail in some places.

 

[Dave Stevens (Lumberyard)]

you really do not see mistakes or problems in a build log but that is exactly what i am going to do.

In the photo looking down the length of the hull you can see a waviness to the bulwark. A problem occurs when the distortion is greater than the width of the cap rail. This is a common problem when building a model out of wood, the hull structure will tend to move. There are a few solutions to this problem.



A solution invented by master builder Harold Hahn is to build the hull in a jig, thus holding everything straight and in place until the planking is installed. Once the hull is stabilized you cut it away from the jig and continue with the cap rails. This method works very well and insures a distortion free structure.



Because the Alvin Clark was not built up side down in a jig and movement occurred in the delicate bulwarks we will take steps to beef up and straighten out the bulwarks before adding the cap rails.

To begin we want to add the rail clamp shown with the blue arrow. In this photo we are looking at the inside of the bulwark. When the Alvin Clark was raised the outside planking of the bulwarks were removed for some reason or another. The rail clamp on the inside and the planking on the outside of the bulwark provides a wider seat for the cap rail to sit on.



These rail clamps were installed on the model but they are not strong enough to pull the bulwarks into a smooth line. The bulwarks will tend to pull the clamp to conform to the shape of the bulwark.

 

[Dave Stevens (Lumberyard)]

The solution i came up with to the problem of bulwarks being out of line. The bulwark is not a straight line there is a curve from the bow to the stern. What i did was trace the shape of the bulwark from the drawing then using a piece of scrap wood the correct shape of the bulwark was cut and used as a pattern. Next a heavy piece of planking was used on the outside and the pattern on the inside of the bulwark. By clamping the bulwark between the pattern piece and the heavy plank the bulwark is pulled into the proper shape.



While the bulwark is clamped filler pieces were added between the stanchions. You cannot see the filler pieces in the finished model because they are between the outside planking and the rail clamp and covered by the cap rail. By adding the fillers the bulwark becomes a solid structure and the filler pieces will hold the correct shape of the bulwark.

 

[Dave Stevens (Lumberyard)]

with the bulwarks now set to the proper shape use a piece of cardboard and trace around the entire hull. On some plans you may find a pattern for the cap rail but the model as built may not be exactly like the plans. The cap rail has a very slight overlap of the outside planking so I has to fit the bulwark exactly. The only way to get an exact fit is to trace the bulwark. Cut out the cardboard pattern and use it as a guide to make the cap rail patterns.



By using clear plastic patterns you can see through it to the tops of the stanchions but cardboard will work just as well. The plastic is the stuff you find millions of products wrapped in. Starting at the bow the first pattern is made and the first cap rail section is cut out.

 

[Dave Stevens (Lumberyard)]

Clark there are a few fancy joints used, the first being a hook scarf used to join the separate ends of the cap rail sections. The second is a butterfly joint at the bow where it is covered by the monkey rail so getting a clear photo of it was not possible.



The inside edge of the butterfly can be seen being pointed to by the white arrow.



The butterfly is parcially covered by the monkey rail but there was enough showing to get its shape by following the edges.

 

[Dave Stevens (Lumberyard)]

. Apple wood tends to be a bit hard so you cannot cut the joinery with a knife, you will need to cut with a small table top scroll saw. Electrical tape gives you a sharp clean edge to cut to. First use the end of the bow piece and lay it on the black electrical tape. By using a new sharp blade cut along the edge of the joint.



i cut out the butterfly from the plastic pattern and traced around it with the knife to produce the shape in the electrical tape. If your skilled and working slow and steady you can scroll saw your piece right to the edge of the tape.



Personally I cut close to the tape, although in the photo it looks like I am a mile away from the edge of the tape, actually, I am only a few file strokes away from the finished edge.

 

[Dave Stevens (Lumberyard)]

Before fitting the cap rail along the hull i did the cap rail at the stern. The stern has a curve in two directions, looking down there is a slight curve to the stern. builders try to edge bend a plank and that just does not work out very well.



Looking from the back there is an arch to the cap rail.So now we have a piece that has to bend in two directions. It is possible to bend the cap rail in both directions but it’s really not practical. A solution to the matter is to carve the cap rail.

 

[Dave Stevens (Lumberyard)]

Start with an over size piece cut to the curve of the stern. Starting with an over sized piece allows you to creep up on the final size and shape rather than trying to make the piece an exact fit right from the start.




In the next photo the actual size and shape of the stern cap rail is marked out. At this stage only the curve of the stern is cut out, the piece of wood is still flat. The over size piece looks quite large in comparison to the final piece. Consider the actual piece is small to begin with so you are not actually starting with a very large piece of wood.



First sand the piece on the bottom to fit the top of the stern timbers,



i trace the arc at the top of the stern timbers and using a Dremen drum sander sanded the arc.



then sand the top to the final thickness of the cap rail. This may seem like a difficult task to get an even thickness but actually the piece is small and sanding goes quickly. You can judge the thickness by eye and get it really close.

 

[Dave Stevens (Lumberyard)]

The finished cap rail is now glued to the top of the stern timbers. There is no pressure to bend the cap rail it is cut to fit. Running a stick of wood through the framing then using two rubber bands from the stick up and over the cap rail will hold it down. The rubber bands will tend to pull the cap rail sideways so a clamp is needed to hold it secure. Tops of the stern timbers are a small area so there is very little holding the cap rail in place, any slight bumping of the cap rail will break it loose so care is needed until it can be secured to the cap rails on the sides

 

[Dave Stevens (Lumberyard)]

In the photo the lower knee joins the cap rail at the side to the cap rail over the stern timbers. The upper knee joins the monkey rail and davit.



ok then i need to go back and install the cap rails

 

[Dave Stevens (Lumberyard)]

The joinery along the cap rail is hook scarfs. You can either make these hook scarfs on the model or simplify the joint to a straight scarf.
The cap rail is fitted in sections by first making a cardboard pattern. The pattern begins over size to allow for any adjustments along the way. First cut the scarf to match the scarf on the last section. Then by tracing along the outer edge of the bulwark form the general shape of the cap rail.



the idea is to make an oversize pattern, the focus is getting a nice fit on the joinery first, Once all the joinery is done then i went back and shaped the cap rail



Taking a close look at the joinery between the various sections of the cap rail it is clear the widths of the component parts will vary. The extra room at this stage gives the builder enough room to adjust the seams between the parts without running out of material.
If you are trying to make tight joinery with a cap rail that is cut to the final width any slight movement at the joint will cause the cap rail at the far end to shift off center to the top timbers. Making the cap rail wider gives you room to fit and shift the parts to fit and still have enough width for finishing.

 

[Dave Stevens (Lumberyard)]

Final placement and gluing down of the cap rails are done with rubber bands.



Just using the rubber bands will pull the cap rails inward and off the bulwarks. A trick for holding the cap rails in place from side to side is to use clothespins. Take the pins apart and use each side. A clothespin has a taper so you can adjust the clamp and control the lap of the cap rail over the bulwark.



The cap rail begins wider with an extra overlapping of the bulwark. This is done to insure there is enough material to give the cap rail its final shape.



Using a sanding block, go around the outside of the cap rail and give the cap rail its final outer edge with an overlap of the bulwark. Attention is directed to getting a smooth outer edge to the cap rail without any sudden dips or waviness. Any imperfections of the bulwark will show up as an unevenness of the lap of the cap rail. The variance of the lap is so slight it will go unnoticed as apposed to an unevenness of the cap rail.

 

[Dave Stevens (Lumberyard)]

When the outer edge of the cap rail is finished, measure the finished width of the cap rail and sand the inner edge.



Going around the bow requires a slightly different approach. First measure the width and make tick marks around the bow. Use a narrow strip of masking tape and follow the tick marks making a smooth curve around the inside of the cap rail. A drum sander is now used to sand the cap rail to the edge of the tape.



when i use a drum sander i will get close to my final edge. What happens is when you start and stop it leaves a slight dent. The final sanding to the edge is done by hand

 

[Dave Stevens (Lumberyard)]

one last piece to fit so back to the stern.

The issues with the cap rails are making sure all the joinery fits snug before all the parts are glued down. I used my pattern for the last section of the cap rail and fit it to the stern with the knee.



Before cutting out the shape of the knee first make sure the joinery between the knee and the cap rails are a nice fit. first between the stern cap rail and the side cap rail is an inset then the knee does not just rest against the inside edge there is another inset. Once again cardboard is uses as a pattern.




joinery first then shape the knee



and the cap rail is done from bow to stern.



There is no bending involved with cap rails and they are the finish piece so i personally like using a nice wood that will take a natural finish. I have used different rosewoods, fruit woods or some exotic wood.

 

[Dave Stevens (Lumberyard)]

By the time i got to the Alvin Clark the skylight was in pieces




at least i could see the joinery and how it went together




but with a little research i did find pictures of it still in one piece

 

[Dave Stevens (Lumberyard)]

Building of the skylight begins with the coaming. Like a hatch coaming it raises the skylight above the deck to prevent water from running into the opening, it also serves as the foundation or base which the skylight will sit on. Start with 4 pieces longer than the finished size of the coaming. Before assembling the coaming the lip along the inner edge has to be made. One way to make the lip is to glue a small strip of wood along the edge and another way is to cut it, we are going to cut in the lip. If you have a small table saw set the height of the blade and the distance to the fence, use one length of wood and cut the grove. For those who do not have a micro table saw lets cut the grove by hand.

 

[Dave Stevens (Lumberyard)]

The pieces we are going to cut are quite small, so setting them up in a simple jig will work the best. Start by using a piece of wood longer and wider than the coaming piece. Using two sided tape and stick the coaming piece along one edge of the carrier piece of wood. In the photo a steel rule is clamped to the carrier piece and against the edge of the coaming. The thickness of the steel rule just so happens to be the thickness of the lip. If you do not have a steel rule the right thickness just add layers of masking tape to the rule to raise it up. In the next photo the piece is tilted so you can see how everything is held in place and how the steel rule will form the thickness of the lip.



the piece is tilted so you can see how everything is held in place and how the steel rule will form the thickness of the lip. The coaming is held in place with two sided tape on the carrier piece of wood so it will not move. Then a clamp will hold the steel rule.

 

[Dave Stevens (Lumberyard)]

Now for the actual cut, turn the piece so the rule is standing up and make a light cut to score the surface of the wood. You want to make a shallow score so the knife follows the rule and not the grain of the wood. Once you make the first score cut then you can use a little pressure and deepen the cut. Note the lip is under the steel rule, this is to protect the lip from the knife running off and slicing into the lip your trying to make.



Once the rule is removed you can see the clean straight cut If you are doing your model work with power tools such as a small table saw or mill then the hardness of the wood does not matter. If your doing your model work with hand tools then your choice of wood will make a difference. Cutting hard wood with a knife is much harder to do the knife dulls quickly and the fine tip will break off the Exacto blades. Woods such as Hard Maple, Boxwood and most exotics like rosewoods are difficult to cut with hand tools. The best woods to use if you using hand tools is Cherry, Applewood and Pearwood and Basswood.



We are using the same idea to make the second cut as we did for the first cut. Secure the piece the same way it was done for the first cut or in the photo the coaming is set against the edge of a piece of plate glass I use on my work table. The first cut is face down on the table and a steel rule is used to cut along.



By cutting along a steel rule you get a clean, straight cut. Alternate between the two cuts deepening them until they meet at the inside corner.



Now you can gently lift away the excess wood.



you really do not need a table saw or a mill all you need is a knife.

 

[rwiederrich]

Very nice work and progress.

Rob

 

[Dave Stevens (Lumberyard)]

With the coamings finished it is time to build the roof. I made all the roof rafters and notched the ends also made the notches along the headers.



After building the roof i checked the size of the roof to the location of the cabin beams and the blocks between the beams. the roof sets inside the notch along the coamings which have to sit half way on the beams to leave a landing for the planking.




After building the roof