How To Build Alaska

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How To Build Alaska

Building a boat is never an easy task, especially if it is a first time effort. However, it is a straight forward operation and is thoroughly documented in the many excellent books on boatbuilding available today. The trick is to simply break the job down into its component parts and proceed in a natural order. This brief construction sequence lays out the steps for building Alaska using the epoxy/strip-plank building method described in the book "The Gougeon Brothers on Boat Construction: Wood and West System Materials", published by Gougeon Brothers Inc., Bay City Michigan.

"Boatbuilding", by Howard I. Chapelle is also highly recommended as a supplementary text, because of its emphasis on traditional boats and boat building techniques. Chapelle and the Gougeon Brothers both provide clear explanations of all aspects of lofting and construction.

1. Begin by drawing the section lines of the hull full size. Use the computer generated offsets provided to draw the moulds, frames, transom, and all other components directly onto a scrieve board or sheet of Mylar drafting film. See fig. 1 & 2 of the sections drawing.

2. Transfer these lines from the scrieve board or Mylar film directly to the moulds and set up the construction form as shown in drawing #203. Make sure everything is well braced, level and true. Passage ways can be cut out of the moulds to allow for access to the underside of the hull for cleaning up glue, etc.

3. Make up the inner and outer keels taking the measurements from the section drawings and offsets. Clearly mark the centre line, the station lines and the frame positions on the top of the inner keel for future reference.

4. Build the daggerboard (or centreboard) case and fit it to the inner and outer keels. Cut the slot to an accurate fit and align all the pieces together with temporary holding screws for gluing up later on. The hole for the bilge drain-plug can also be drilled at this time. It is easiest to do as much work on the bench as possible before gluing everything permanently in place.

5. Laminate the inner and outer stems and the sternpost knee. Make up the other backbone components and pre-finish as required. Glue the inner keel, the inner stem, the keel batten, the sternpost and the sternpost knee together and fix them in place over the moulds and construction form, as shown in drawing #203. Do not fit the transom or the other components just yet.

6. Make up a rough temporary transom from 3/4" press board. Measure and cut notches into it like the station moulds, so that the laminations for the gunwales and risers can run out past it without the need for tedious fitting. Use wax paper, or cellophane packing tape, to keep the laminations from sticking to the moulds or any other part of the structure, including the stem. Once fitted, glued and dried, the laminations can be marked and trimmed flush to the inside face of the temporary transom.

Remove the temporary transom and glue and fasten the permanent transom to the sternpost. Temporarily screw the gunwales and risers to the transom, but do not bond them in place just yet, because they will need to be released to allow the hull to be lifted off the moulds. Make sure all temporary holding screws at the stem and transom will be accessible once the hull is planked.

7. Plane and fair the whole structure in preparation for planking. Cover the moulds, gunwales, risers and knees (especially the joints) with wax paper or plastic sheeting so the hull can be lifted off later without sticking to any of these components.

8. Begin planking from the gunwale up, leaving a slight overlap for fairing the sheer flush with the top of the laminated sheer clamp later on. Each strip should be pre-fitted to the moulds, carefully aligned and drilled for fastenings or dowels before gluing up. (1/8" diameter hardwood dowels make excellent edge fastenings and should be driven into 1/8" diameter pre-drilled holes about 1-1/2 times the depth of the planking.) Four or five strips per side can be pre-fitted at a time. The overall fit should be a little on the loose side to allow for glue thickness. It is not necessary to bevel the edges of the strips, except at the tuck near the transom where the curve is extreme. A stealer or two may also be needed there to straighten out the run of the planking. A heat gun can be used to help bend the planks wherever the twist is severe, but this should be done when dry-fitting, prior to gluing up.

The glue for planking should only be thick enough to keep it from running out of the seams. If it is too thick it may cause the strips to bulge upwards between the moulds throwing them out of alignment. While not terribly serious, this can be annoying. Use a length pipe cleaner to lightly wet out the dowel holes with glue and drive the dowels flush, or set them slightly below the surface of the strip. All dowels should be of equal length and the holes drilled slightly longer to avoid over-driving and splitting the planking. Remove excess glue from off of the planking with a putty knife before it hardens and swab off what's left with paper towels soaked with methyl-hydrate (a cheap and effective solvent that is not overly toxic - wear protective gloves and a proper respirator). This will save hours of hard planing and sanding later on.

Temporary holding screws can be replaced by permanent bronze fastenings where required later on. Steel round head, wood screws make good temporary fastenings, because they do not tend to break off when being removed. Heat applied with an electric soldering iron will loosen any hard-bonded fastenings.

Please note that it is a good idea to wear a proper respirator with the appropriate filters and to provide good ventilation when working with epoxy and solvents. A powerful fan blowing fresh air across the work area helps eliminate harmful fumes or dust and will keep the builder cool on hot days.

9. Do not fair or finish the exterior of the planked up hull at this point. Trace the station lines from around the edges of the moulds on to the inside of the hull with a pencil for future reference when fitting frames and floors, see #12 below. Remove all temporary holding screws and carefully lift the hull off the moulds and construction form, leaving the gunwales and risers behind. Set it upright on a padded surface for interior finishing.

10. Plug all unnecessary screw holes inside the hull with wooden bungs or thickened epoxy about 1/2 the depth of the planking. Once the epoxy is cured, fair and smooth the inside of the planking with a blockplane and spokeshave followed up with 80 grit sandpaper to remove the blade marks. Finish up with 120 or 150 grit paper for a smooth, clean surface.

11. Apply three coats of resin to the interior of the hull. Use a large flat tray and thin foam rollers about 3" to 4" long on a small applicator frame to roll out the resin. Mix only about 6 oz. of resin at a time so as not to rush the job. Smooth out any air bubbles that form on the surface by jamming the roller to keep it from rotating then dragging it back across the wetted surface. This will assure a smooth finish and minimum sanding later on.

After applying the first coat, go back over any dry spots, then let the resin dry thoroughly before lightly sanding it with 80 grit paper. At this point, stop and apply an epoxy fillet along the edges of the lower stem, keel batten and stern post. Build it up in successive layers to keep it from sagging out. Fair and sand when cured then apply the next two coats of resin, one over the other without sanding in between, allowing the first coat to become tacky before applying the second coat. Let the resin cure completely before lightly sanding with 80 grit paper and finishing up with 120 or 150 grit. Re-coat any spots that appear thin or oversanded.

12. Make up and fit the frames and thwart webs. Temporarily fasten them in place. In pencil, line off where the frames and webs lie across the hull and then remove them. Re-fasten the gunwales and risers and mark where the frame and thwart web pencil lines cut across them. Remove these once again and then notch the undersides of the gunwales to accept the frame heads and cut through the risers to accommodate the frames and thwart webs. Provide limber holes through the risers wherever they butt up against the frames, thwart webs, stem, sternpost and transom. Cut notches into the risers to form the tie downs as shown in drawing #203. A router may be useful here.

After final fitting, epoxy coating and finishing, permanently glue all framing and interior joinery components in place. All the finished parts of the hull can now be painted if desired, taking care not to cover areas yet to be glued or epoxy coated.

13. Turn the hull back over and begin finishing the exterior by removing all temporary fastenings and plugging the holes with 1/8" dowels and wooden bungs set in epoxy glue. Then trim and plane the edges of the planking flush with the inner keel, inner stem, transom and stern post. Fair and sand the hull smooth and apply 3 coats of resin as was done on the inside of the hull.

14. An optional layer or two of 6 oz. fibreglass cloth, Dynel, or other fabric can be applied to the hull if desired. This will help toughen the surface a bit, but is not necessary structurally and may result in a little more difficulty making repairs to the hull later on. It will also add some weight.

To apply sheathing, dry fit the fabric to the bare wood of the hull one side at a time. Staple it lightly in place along the top of the keel to keep it from sliding down and apply epoxy resin with a foam roller in the usual way. Wedge shaped darts will need to be cut out of the fabric where it bunches up, especially along the sheer, and is best done during the wetting out period.

Once the resin is set and almost tack free, any staples holding the cloth in place can be removed and one or two more coats of resin applied to fill the weave. Excess fabric can be trimmed away later after the resin has cured.

Note: Fabric should not overlap the keel, stemface, transom or edge of the planking in any way in order to avoid any possible cracking along these edges in future. Glass the surface of the planking only!

After the resin is well cured, the surface can be sanded smooth in preparation for the second layer of fabric or for painting. Any exposed weave should be re-coated and sanded to ensure a uniform finish.

15. To finish up, seal all end grain thoroughly with epoxy resin and then fit the outer keel, the outer stem and the outer stern post batten to cap the planking. Glue on the sacrificial hardwood shoe, making sure all edges are well rounded and well coated with epoxy resin. After bonding and fastening the external hardware in place, the hull can be painted and rolled upright to fit the gunwale caps, decking, rubrail, trim and remaining hardware.

16. Finishing the hull is mainly a matter of taste and experience with the different kinds of products available on the market today. It is basically the constructor’s choice, but here are a few suggestions that may be of some help to the first time builder.

* During construction, all parts of the hull and structure to be painted should be given a minimum of three coats of epoxy resin to seal out moisture and stabilize the wood, particularly end grain and faying surfaces. Most of this work can be done on the bench before final installation to make the job a lot easier.

* The interior should be painted with a good quality marine enamel. White or light grey looks good when contrasted with oiled or varnished wood and will help keep the hull and structure cool and stable. Surprisingly, glare is not a problem, because reflection off the water is far more overpowering than light-coloured paint. The exterior should also be painted, but colour is less critical here and even black paint is quite acceptable. The transom, on the other hand, can be finished bright for appearance.

* A varnish finish is not recommended for a craft that is expected to be used hard, oil is better and far easier to maintain, although it must be recoated much more frequently for best results.

* Oil or varnish looks best on bare teak without an epoxy undercoat. However, epoxy resin can be used under varnish if desired, but not under oil.

* Below the waterline, a good hard finish anti-fouling paint can be used for protection.

* Whatever the finish, it is still best to keep the boat on a trailer and stored in an open, breezy shelter away from the elements as much as possible. That way, the finish will be preserved and maintenance will be reduced considerably. As with any wooden boat, preserving the finish means preserving the structure. It's nothing to add a coat of paint or varnish regularly, compared to wooding down and refinishing a badly weathered hull.

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