Re: Cracks on bow sprit
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MORE THAN YOU EVER WANTD TO KNOW ABOUT AMEL GEL COAT CRACKS.
The reason that the gel coat cracks at the bow and other places is purely cosmetic and is simply caused by the gel coat being too thick. Gel coat is essentially just polyester resin with pigment to add color and perhaps some ultra violet inhibitors. It has very little strength on its own and is extremely brittle if a thickness of more than about 20 mils is exceeded. For my metric based friends out there, a ‘mil’ is one thousandth of an inch. Amel thickened up the gel coat in several places to level or seal a seam/joint instead of using polyester fairing compound with the proper gel coat thickness on top of that. The gel coat is also way too thick at the aft end of the ‘rub rail’ on the Fango, Santorin, Super Maramu and Amel 54. Also, up until the production of the Amel 55, the gel coat used on all Amel boats to simulate the raised grain of weathered teak is also too thick. Go look at 51’ Mango or 48’ Maramu and unless the boat has been very well cared for or never ventured much below 45 degrees latitude, you will find hairline cracks and worse as the gel coat loses esters and dries out from sun exposure and other factors . 303 spray on sun protection and Polytrol both do a good job at delaying the onslaught of gel coat degradation. With Polytrol, go easy. Enough is good. More than enough is not better.
How do I know this? Jacques Carteau, who at the time was not only the technical manager at Amel but the Chairman as well, was giving me some routine technical training when I asked him about the gel coat failures I was beginning to see more often on older boats. He gave me pretty much the explanation above. When I asked him why they didn’t fair with fairing compound and use 20 mils of gel coat as the top coat I got the look I often received when I had exceeded either my question quota for the day or his patience, That time I think it was both…
To properly repair the cracks you need to sand the gel coat that has the crack until you see that the crack is gone and the surrounding gel coat is almost all gone in order to get rid of the too thick gel coat. Use a compatible polyester or better yet epoxy filing/fairing compound to level or to allow shaping of the repair area then apply the proper 20 mil thickness of new gel coat. Hint, use gel coat with wax mixed in to avoid having to use pvc or similar to form an atmospheric barrier that will allow the gel coat to cure properly.
Have fun with your Amel, Joel
JOEL F. POTTER-CRUISING YACHT SPECIALIST~L.L.C.
THE EXPERIENCED AMEL GUY
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Office 954-462-5869 Cell 954-812-2485
From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of James Alton via Groups.Io
Sent: Saturday, November 9, 2019 8:41 AM
Subject: Re: [AmelYachtOwners] Cracks on bow sprit
Fiberglass that is fractured does not break along nice straight lines per your photo. Those look like joints to me. Oliver could probably tell you for sure but I suspect that the parts forming the outer rail portions of the anchor platform were fabricated and installed as separate parts and the “cracks” you see are the mating/bonding lines.