CONTINUOUSWAVE

My boat started life as a 19' SENTRY. When its aluminium top was removed so was some of the material on the gunwales in patches all the way around the hull.



How can damage to a Unibond hull at the gunwale be repaired?

Two more images showing very similar damage can be seen by visiting this URL:
https://www.amazon.co.uk/photos/share/f ... 5uiQoJiDMZ

The damage seen in Figure 1 appears to be limited to a separation between the relatively thin laminate outer layer of a Unibond hull and the foam interior, and possible mostly limited to the bond between the gel coat resin layer and the underlying laminate layers. Repair of damage of this type is explained in the Boston Whaler factory bulletin which is reproduced in the REFERENCE section of the website. Please visit

INSTRUCTIONS -- HULL PATCH KITS
https://continuouswave.com/whaler/refer ... tions.html

You can also see these methods applied to repair of a Unibond hull in a illustrative narrative of the repair process, also found in the REFERENCE section in this article:

Repairing Hull Damage the Whaler Way
https://continuouswave.com/whaler/refer ... epair.html

Your repair should follow the advice given and demonstrated in the above two articles.

As seen above in Figure 1, the damaged area does not appear to contain a molded-in pattern for non-skid. This will make the repair of this area much simpler, as only a smooth surface finish is needed.

Because these repairs will be highly visible, a good color match between the existing hull and the gel coat resin wil be essential. Because the boat to be repaired was a model from Boston Whaler Commercial and Government Products, the hull gel coat resin color was probably gray. It should be straightforward to tint white gel coat resin to a matching shade of gray by adding small amounts of black tint to the white resin. To facilitate this matching, I suggest you begin by mixing a small amount of black tint into a larger amount of white resin, then thoroughly mixing these two component to produce a medium gray shade. Then use this shade to tint more white resin to reduce it to match the hull color. In this way you can gradually darken the white resin with the medium gray resin, rather than trying to go for a match adding miniscule amounts of black tint to a large volume of white resin.

When attempting to tint the gel coat resin to match the hull, I offer this advice:

• thoroughly clean the existing hull
• remove any oxidation from the existing hull
• buff the existing hull to a reasonable lustre
• make the color comparisons under sunlight, not with lighting from random electric lamp sources
• make the comparison without using strong direct sunlight; a partly cloudy day is probably best.

Richard -

Are you planning to reinstall the aluminum gunwale caps or leave as is?

It would help if you might outline your plans for the repairs. Quick and easy or back to factory?

As I suspect you are in the UK, many of the quick suggestions for repair I would offer are not possible as the products are not available to you.

I would do a bit of a search for a marine two part epoxy. This can be used to inject into the screw holes and spread on the damaged areas. Covering the spread epoxy with clear packing tape gives a smooth finish.

Something similar to this: https://www.amazon.co.uk/JB-Weld-JB8272-Waterproof-Adhesives/dp/B000KKPFFA/ref=sr_1_3