CONTINUOUSWAVE

Give me advice on repairing spider cracks and other repairs on a Unibond hull.

BACKGROUND
I plan to restore a 1972 TASHMOO [unspecified length model but probably a 16] which I have owned for several years. The "cap" [the third laminated structure attached atop the Unibond hull that adds the decks to the TASHMOO] has all-over spider cracking and other laminate damage.

Q1: what approach should be taken to make a full-refurbishment of a TASHMOO?

GENERAL PLAN
I plan, as much as possible, to remove hardware like the bow rail, the center console, the windscreen, the aft seat, and the pilot seat from the boat and try to work around the supports for the cap itself.

My concern is for the screw fasteners and rub rail holding the cap to the Unibond hull.

Q2: will it be possible to work around [the screw fasteners and rub rail holding the cap to the Unibond hull] them without removing them?

Q3: Is it possible to remove [the screw fasteners and rub rail holding the cap to the Unibond hull] piecemeal, and to essentially restore the boat a few feet at a time?

With a hull as old as this I am hesitant to start removing bits of it in fear of not being able to put them back as they were before.

For clarity, I plan on fairing and painting the deck to fill in all the spider cracks and any other repairs needed and then returning the hardware or replacing with new stuff.

BACKSTORY
My [1972] TASHMO [16] is a great boat for my needs, and overall is in great working condition.

A general approach to repair of a spider crack is :

• fashion a V-shaped tool point of suitable width for enlarging the width and depth of the spider crack;
• use the tool to widen and deepen the spider crack; alternatively, a DREMEL tool with a properly shaped pointer grinding tip can be used to grind out the crack
• carefully remove all loose debris in the crack;
• clean the crack with acetone or lacquer thinner and allow to completely dry;
• fill the crack with a color-matched gel coat resin with a wax additive (often in a paste consistency), or use regular color-matched gel coat resin and then cover the gel coat resin with a layer of poly-vinyl alcohol (PVA) which can be sprayed on from a spray bottle; this is necessary to allow the polyester gel coat resin to cure to full hardness, as it cannot be in contact with air.
• after full curing has occurred, wet sand to desired finish, using progressively finer grades of sandpaper, ending with buffing compound and polish to restore lustre.

This procedure works well for individual and isolated spider cracks. When faced with extensive spider cracking, repair of individual cracks will be tedious. The general preference is to apply a completely new surface to the entire area.

For repair of extensive spider cracking see

Repair of Extensive Spider Cracks
https://continuouswave.com/forum/viewto ... =6&t=10055


For damage that is more extensive than a spider crack see

Advice on Repair of Unibond Hulls
https://continuouswave.com/forum/viewto ... f=6&t=9254

For repair of loose screw fasteners that hold railings, see

Repair of Loose Screw Fasteners
https://continuouswave.com/forum/viewto ... f=6&t=3224