OUYANG MATILDA 20 Owner's Manual page 14

Page Twelve
The mahogany used are finished with a satin varnish, and are used
in the berth and joint trims.
Interior bulkheads are formica applied. They do not require
exterior treatment. one should however maintain proper housecleaning.
F. GELCOAT AND FIBREGLASS:
A periodic maintenance programme a good cleaning and waxing of
the fiberglass surfaces will save expensive maintenance costs at a
later date.
Good hosing of fresh, warm water and chamois will do the cleaning
Job. Dull or faded spots should be waxed. Wax liberally at waterline and
at least 10 (ten) inches above.
In due course, you might experience 'streaks' on the gelcoat, or
what is termed as 'hairline cracks' which cannot be covered, filled
or repaired successfully. They are usually found in curves and
sharp corners, and are the results of the boat working in. These
are harmless in that it is only superficial and is not extended
beyond the gelcoat into the fiberglass.