Repair of Immense Spider Cracking on c.1979 Hull

[malcHILL]

[Moderator's note: separated from another thread which contained too many topics for useful discussion.]

Q1: how can extensive amounts of spider cracking in the gel coat layer of a c.1979 neglected MONTAUK 17 hull be repaired?

[jimh]

Q1: how can extensive amounts of spider cracking in the gel coat layer of a c.1979 neglected MONTAUK 17 hull be repaired?

When the number and distribution of spider cracks is large and wide spread, there is really no effective way to repair each instance of them individual while preserving the gel coat layer of the boat. The only workable approach is to abandon any notion of preserving the uncracked areas, and plan on applying an entirely new top coat layer, after repairing all of the spider cracks and any other damaged areas and extensively fairing and sanding the hull.

This repair procedure is demonstrated in a very well produced presentation by TotalBoat, whose products are used in making the repair. The presentation is available on youTube at

Boston Whaler Crazing Repair
https://youtu.be/4tZDBOYqdfA

[malcHILL]

My boat has the factory-gripped surface on almost all areas where one would stand, unlike (I believe) the 13-footer [seen]in the [youTube presentation linked above].

Q2: how would [a factory gripped surface be] preserved?

Q3: is it possible to completely re-make those gripped surfaces?

[jimh]

My boat has the factory-gripped surface on almost all areas where one would stand, unlike (I believe) the 13-footer [seen]in the [youTube presentation linked above].

At 0:42 into the youTube presentation the cockpit non-skid surface is clearly seen and has the typical crosshatched non-skid mini-pyramid pattern seen for many years on Boston Whaler boats. The notion that the Boston Whaler boat seen in the presentation lacks a non-skid deck is incorrect, however the non-skid pattern may be and likely will be reduced in its effectiveness after sanding, fairing, primer paint, and top coat paint, as is demonstrated in the youTube presentation.

[jimh]

Q2: how would [a “factory gripped” surface be] preserved?

If the extensive spider-cracking of the gel coat layer extends throughout the deck areas with non-skid surfaces, the only way to preserve the non-skid would be to attempt to repair each crack individually. A mold impression taken from an area of intact non-skid surface would be used to cast the pattern into the new gel coat resin before it cures at each individual crack repair—a tedious and lengthy process if the spider cracking is extensive.