Sketchbook: Cutting Patterns Accurately

Author:
Updated:
Original:
A. Because the interior dimensions on a boat are rarely straight, whenever you are thinking about adding a small locker or bulkhead you must measure, cut and trim the panels very carefully. Make sure the boat is horizontal so you can use a spirit level, along with an integrated laser, to project datums across the boat. Once you establish a fixed datum point, transfer as many measurements as possible to a pattern made of cardboard or hardboard. After cutting the pattern, put it in place and make sure it fits correctly before you start to cut the actual pieces of wood or plywood.

A. Because the interior dimensions on a boat are rarely straight, whenever you are thinking about adding a small locker or bulkhead you must measure, cut and trim the panels very carefully.Make sure the boat is horizontal so you can use a spirit level, along with an integrated laser, to project datums across the boat. Once you establish a fixed datum point, transfer as many measurements as possible to a pattern made of cardboard or hardboard. After cutting the pattern, put it in place and make sure it fits correctly before you start to cut the actual pieces of wood or plywood.

B. It’s easier to take internal measurements with two sticks held in your hand, or take a piece of plastic conduit with a snap-on top that slides with a stiff action that holds it in place.

B. It’s easier to take internal measurements with two sticks held in your hand, or take a piece of plastic conduit with a snap-on top that slides with a stiff action that holds it in place.

C. Transfer awkward shapes either with a profile gauge (which is like a comb with movable teeth) or by scribing around the shape with a compass held at a fixed angle.

C. Transfer awkward shapes either with a profile gauge (which is like a comb with movable teeth) or by scribing around the shape with a compass held at a fixed angle.

clamped a board in position, run the block over the relevant lumps and bumps and mark the corner positions as you go. Remove the board and use the spiling block to transfer the marks to a pattern. Having a long and short edge on the block makes life easier—but number the corners so you don’t forget which edge is which! E. When cutting a panel, measure the widest point to allow for any tapering; make a vertical cutout shape if you are going to have to slide the panel in vertically.

D. A spiling block can do a similar job. After you have clamped a board in position, run the block over the relevant lumps and bumps and mark the corner positions as you go. Remove the board and use the spiling block to transfer the marks to a pattern. Having a long and short edge on the block makes life easier—but number the corners so you don’t forget which edge is which! E. When cutting a panel, measure the widest point to allow for any tapering; make a vertical cutout shape if you are going to have to slide the panel in vertically. E. When cutting a panel, measure the widest point to allow for any tapering; make a vertical cutout shape if you are going to have to slide the panel in vertically.

F. A spokeshave is ideal for inside curves and shaping bumps and tapers, but it must be razor sharp to deal with all the end grain in plywood. G. For measuring bigger areas use a pointed stick with notches in it. Mark the notched positions on a board and use the stick again to transfer the shape on to a pattern board. A pattern board will also show whether you can get the full-sized panel in through the hatch!

F. A spokeshave is ideal for inside curves and shaping bumps and tapers, but it must be razor sharp to deal with all the end grain in plywood.G. For measuring bigger areas use a pointed stick with notches in it. Mark the notched positions on a board and use the stick again to transfer the shape on to a pattern board. A pattern board will also show whether you can get the full-sized panel in through the hatch!

Dick Everitt has been an illustrator, journalist and engineer for over 40 years. He has sailed many thousands of miles on all sorts of craft in various parts of the world

Related

AdobeStock_180386204

BVI Sets Date for Re-Opening

The BVI Tourist Board has set December 1st as the date visitors will be allowed to return to their territory, just in time for the winter charter season to kick off. Several charter companies including Horizon Yacht Charters, Dream Yacht Charter, TMM, CYOA and Conch Charters ...read more

DSC_5337-2

Boat Review: X-Yachts X4⁶

The Danish builder X-Yachts does not simply stick taller or shorter rigs and keels on the same hulls to create boats for both cruisers and racers, as some mass-production builders do. Nor is it content to build two distinct lines of cruisers and racers. Instead, the company has ...read more

Screen Shot 2020-09-18 at 1.18.36 PM

Harken Changes Hands, Stays in the Family

. In a video posted yesterday, Peter Harken cheerfully announced that his company, Harken Inc., the trusted hardware brand bearing his last name, which was formerly owned by founders and their families has changed hands. The owners have sold their shares to employees—"passing ...read more

OceanRace

Newport Hosts The Ocean Race Summit on Ocean Health

Hundreds of participants from around the world tuned in yesterday for the latest installment of The Ocean Race's (formerly the Volvo Ocean Race) Summit Series, which aims to bring the best of ocean racing—leadership, resilience, tenacity, collaboration—to solving the ocean’s ...read more

sp360_fs5-024crop (1)

Highfield SPORT 360

The new 2021 SPORT 360 is the next generation of Highfield boats. Highfield is celebrating its 10th year in the market this year and in this relatively short period of time has now delivered over 30,000 boats to happy customers in 38 countries. Highfield is already the ...read more

sp560_drone-028crop

Highfield SPORT 560

The new 2021 SPORT 560 is the next generation of Highfield boats. Highfield is celebrating its 10th year in the market this year and in this relatively short period of time has now delivered over 30,000 boats to happy customers in 38 countries. Highfield is already the ...read more

Three Props 1772x1181

EWOL Propellers

Ewol propellers make maneuvering easier, increase sailing speed and increase cruising speed under power. EWOL adjustable pitch propellers are made of stainless steel alloys that represent the highest technology in terms of marine corrosion and galvanic corrosion resistance, ...read more