Cutting tips for semi-rigid enclosures

Published On: January 1, 2010Categories: Features, How-To Articles

0110_f1_1Semi-rigid enclosures have become a growing market over the past 10 years. The majority of these enclosures are bonded panels that are fabricated by EZ2CY and Rainier Industries. These enclosures are usually sold to the upper tier of boat owners and are generally out of reach, price wise, for the average customer.

In recent years, a sewable version of polycarbonate glass has grown in popularity and made it possible to offer semi-rigid enclosures to a larger segment of boat owners. Polycarbonate glass is in use everywhere. Eyewear, aircraft windows and bank teller windows are examples. Early versions, made in the early 1990s, were too thin and lacking in UV and abrasion resistance.

In 2005, I was introduced to the second generation of polycarbonate. It is 60 mil thick and has an abrasion-resistant coating on both sides. While 80 mil is too thick to sew, 60 mil can be sewn on your average canvas shop machine.

We use Makrolon AR made by Sheffield Plastics. Makrolon shares the same clarity as acrylic glass but has 30 times the impact strength and is shatter proof. The AR coating gives the polycarbonate excellent UV resistance (98-percent blockage) and is resistant to yellowing. Tight radius corners are possible without distortion.

There are a variety of ways to cut this glass. Sheet metal shears, jig saws and razor blades are common cutting tools. After a lot of trial and error, we have perfected our fabrication technique. We found that notching and “breaking” the cut line is the most accurate way to get a straight, smooth line. The tools we use are: OLFA glass notching tool, OLFA razor knife, Fiskar rotary razor knife, heavy-duty shears, cutting guide with non-skid bottom and safety gloves.

Once you learn these techniques, you will be able to increase your profits and your status as a shop on the cutting edge.


Chris Sharp, MFC, is owner of Sharp’s Custom Canvas Inc. in Georgetown, S.C., and a member of the Marine Fabricators Association.