Stitch and Glue Video How-To

Stitch and glue is a simple boat building method which uses plywood, epoxy glue, and “stitches” and eliminates the need for stems and chines. [1] Plywood panels are cut to detailed profiles and stitched together to form an accurate hull shape, without the need for forms or special tools. This technique is also called “tack and tape”, and “stitch and tape”.

Shows the steps in making a composite joint of Okoume plywood, epoxy, fiberglass.

Wikipedia Says:

Technique

Stitch and glue joint crossection.

The technique consists of stitching together plywood panels with some sort of wire or other suitable device, such as cable ties or duct tape. Copper wire is popular because the wires can be twisted tighter or looser to precisely adjust fit, and because it is easy to sand after gluing, and it is suitable in a marine environment if left in place. To join, the cut panels are drilled with small holes along the joining edges and stitched. Once together, the join is glued, usually with thickened epoxy and fiberglass on the inside of the hull.

On the outside of the hull, the wire is snipped and the joints filled and sanded over. The outside of the joint, or entire hull, may be fiberglassed and glued as well, providing additional strength. The combination of fiberglass tape and epoxy glue results in a composite material providing an extremely strong joint.

An alternative is to use dabs of thickened epoxy in between the “stitching” to join the panels, and after it has cured, completely remove the copper wires instead of just snipping them off on the outside. With the wires removed, you can go back and apply a fillet of thickened epoxy over the entire length of the join. Yet another technique is to use heat to remove the wires after the epoxy is cured.

True stitch and glue designs generally have few bulkheads, relying instead on the geometry of the panels to provide shape, and forming amonocoque or semi-monocoque structure.

Spread of the technique

Stitch and glue has become one of the dominant techniques in amateur boatbuilding. While the use of relatively few plywood panels (which minimizes the joints and makes the construction easier and faster) limits the shapes possible, the simplicity and low cost of the stitch and glue technique makes it the method of choice among most amateur boatbuilders. Simple software CAD packages are available for designing stitch and glue boats, and there are many Internet bulletin boardsnewsgroups, and mailing lists dedicated to the subject of stitch and glue boats and various popular stitch and glue designs. Stitch and glue is not inherently limited to small designs though, as demonstrated by the boats made by Sam Devlin, who has applied the technique to making boats as long as 45 feet.[2]

The one sheet boat

The one sheet boat, or OSB, is an outgrowth of the stitch and glue technique. The OSB is a boat that can be built using a single sheet of 4 foot by 8 foot plywood (1.22 m × 2.44 m). Some additional wood is often used, for supports, chines, or as a transom, though some can be built entirely with the sheet of plywood. OSBs tend to be very small, since the displacement is limited to a theoretical maximum of about 1500 lb (680 kg), based on the largest hemispherical shape that could be formed with the same surface area as the sheet of plywood. Though forming a hemisphere is possible (see geodesic dome), it is not practical, and most designs have maximum displacements of under 1000 lb (450 kg), and practical displacements only large enough for a single person.

External links

Originally posted 2016-01-31 10:18:43.

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