SAMS Hull Inspection and Materials 3

Question 1

What condition is indicated when a ferrocement hull shows a network of fine surface cracks but no spalling or delamination?

Accepted Answer

Superficial crazing that may be cosmetic but warrants monitoring

Answer

Fine surface crazing in ferrocement is often cosmetic and caused by curing shrinkage, but the surveyor must probe further to confirm no deeper structural compromise.

Question 2

A surveyor finds that the garboard strake on a wooden boat shows soft wood when probed. What structural concern does this most directly raise?

Accepted Answer

Compromised connection between hull planking and keel

Answer

The garboard strake is the planking adjacent to the keel; soft wood there indicates rot that directly compromises the structural joint between the hull and keel.

Question 3

When examining a hull's underwater body for electrolytic corrosion on a bronze through-hull fitting, what visual sign suggests active corrosion?

Accepted Answer

Dezincification leaving a pink, spongy copper residue

Answer

Dezincification of brass fittings removes zinc, leaving a pinkish, weakened copper sponge that is a classic sign of electrolytic or galvanic corrosion.

Question 4

In ABYC and SAMS standards, what minimum gel coat thickness is generally considered acceptable for a production fiberglass hull?

Accepted Answer

18–20 mils (0.45–0.51 mm)

Answer

Gel coat is typically applied at 18–20 mils thickness; significantly thinner gel coat is prone to crazing, porosity, and early osmotic blister formation.

Question 5

Which test is used in the field to detect moisture content in a fiberglass hull laminate without drilling?

Accepted Answer

Capacitance-type moisture meter

Answer

A capacitance-type moisture meter measures the dielectric constant of the laminate, which changes with moisture content, providing non-destructive readings.

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

SAMS Hull Inspection and Materials 3