Removing Fiberglass
from a Plywood Hull
By Dan Roberts
EDITORIAL NOTE: “We get quite a few inquiries about removing paint and fiberglass from
wood. Dan Roberts was kind enough to send us this outline (with pictures) about a clean, quiet and efficient
way to remove either from a surface. We thank him!” –Dr. Rot
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Click to enlarge
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Dear Rot Doctor,
From Practical Sailor comes a quote: (See Link 1* at end of article.)
“There is no reason to remove fiberglass that is adhering to a plywood hull or deck. If the glass has
separated in small areas, grind the loose glass away down to the plywood, then reglass the exposed section.
The only practical way to remove fiberglass is by sanding or grinding with a disk sander, a tedious and
messy job. You must take care when grinding not to remove the surface layer of veneer from the plywood,
so this is a job which requires a certain amount of care.”
I have found a better way to remove fiberglass from a plywood hull.
I bought a rare boat. Designed by Howard I. Chapelle back in the 1930’s, it is a 30’ double ended
sharpie cruiser (built in 1971) whose lines can be seen in Chapelle’s book, Boatbuilding. I doubt if
many of this design have ever been built, so I figured if it was worth buying, it was worth restoring
to a high degree and I was determined to remove the polyester/fiberglass outer covering both to better
enable an assessment of what needed doing and to upgrade it to epoxy saturation later in the process.
Searching the internet for various methods of paint stripping, I stumbled across the Speedheater
infrared paint stripper made in Sweden and sold on the web by several dealers online for nearly $500.00.
(See Links 2* and 3*.) A high price? Maybe, but it has the advantage of being easy, relatively clean
and faster than you may think.
The instructions say to hold it in place for 20 - 30 seconds then scrape off the paint… and it works
like a charm. But it will also loosen/soften the polyester resin holding the layers of glass cloth to the
hull and after cutting around the 12” x 5” heat affected zone with a razor knife, a corner can be lifted,
grabbed with a pair of pliers and simply peeled off in one piece. All this in about 45 seconds or so.
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