Having damage to the bow stem around the towing eye is rather common. It should be repaired properly. This area needs to be returned to a solid, high-strength part of the hull.
tdenoff wrote:Q1: should the repair be rounded to match the rest of the keel profile at the bow, or should I shape a flat rectangular area that mimics the shape of the bow eye?
I do not recommend creating a rounded bow stem in the area where the bow eye is to be reinstalled. You should create a flat area so the bow eye rests firmly in place against the flat area.
tdenoff wrote:Q2: do I need to include two small indentations in my repair to match the dimples on the bow eye, or are they meant to indent into the finished surface with the pressure of tightening?
I would make the repair without the indentations. Then fit the bow eye onto the hull, pressing it into the laminate to mark where the dimples will be indenting. Then I would slightly relieve that area with a suitably matched drill to a suitable depth so that when the bow eye is tightened against the hull it will not be trying to crack into the laminate.
In addition to the obvious and visible damage to the hull laminate seen in Figure 1, the hole for the threaded rod that traverses through the foam interior of the Unibond hull and exits above the hull liner is probably enlarged. You will need to repair that hole. At the bow stem end, use epoxy resin to seal the foam in the hole and at the same time reduce the hole diameter slightly. Then you will re-drill the hole, working from the cockpit end, enlarging it back to the minimum diameter needed for the threaded rod to make a tight fit.
When you repair the hull damage at the bow stem, you will need to add fiberglass cloth or at the least some cloth fibers to impart strength to the repair.
I recommend you use epoxy resin for this repair. Most of the repair will not be visible once the bow towing eye is re-installed, so you do NOT need to have a perfect cosmetic and invisible repair.
For advice on making repairs see the FAQ at
Q5: how is damage to a Unibond hull repaired?https://continuouswave.com/whaler/reference/FAQ/#Q5A good article linked there is from Boston Whaler themselves. In that article you will be using Method 4 Structural Repairs or Method 5 Large Structural Repairs as the repair process. You really cannot repair this damage properly just by filling it with resin, at least, that is the impression I get from the view in Figure 1.
My preference for using epoxy resin is based on these factors:
- epoxy is a much better adhesive than polyester resin and will make a stronger bond to the cured material of the original lamination,
- epoxy resin is waterproof
- epoxy resin is available is small "repair kits" from WEST Systems at very modest cost, and
- epoxy resin when mixed in the proper ratio with its hardener will be a sure-fire cure, whereas polyester resins will not cure to a hard surface without some means of excluding air.
When working with epoxy resin be careful to avoid creating a large pool of resin. When epoxy resin cures the chemical reaction is exothermic, and as the curing epoxy warms from curing, the curing rate increases, causing it to warm even more. This can result in a very hot lump of epoxy and possible melting of the surrounding foam in the hull interior.
When sanding old laminate and gel coat, be careful. Old gel coat resin is often very soft and it can be abraded away VERY quickly.