Chandlery January 2018 Issue

‘Magic’ Fix for Hairline Cracks in Gelcoat

Spider cracks can indicate impact damage or serious structural problems that will need to be addressed to prevent spreading, but most often they result from relatively inflexible gelcoat that is too thick. Stress by thermal expansion or when bulkheads and liners were installed can cause minor flexing. Cracks from larger issues­—a winch, for example, that was inadequately mounted—will need to be fixed before cosmetic repairs begin.

Hairline cracks
Hairline cracks commonly develop around fasteners.

Our test boat has had a few spider cracks since a few months after she came out of the mold. They never got worse. A prior owner had “fixed” a few with Evercoat Gel Coat Scratch Patch gel coat repair, with ugly results. We tried West Marine Gel Coat Scratch Patch, and although very careful, the results weren’t really an improvement. Finally, we tried a very minimalist approach using Magic Ezy Hairline Fix. It’s not cheap—$25 for a 0.43-ounce tube­—but it’s hard to find a solution that’s much cheaper except in buying a large volume of gelcoat that would go to waste. It’s available in ten colors.

The instructions direct you to clean the cracks out with a fine needle and then to wash, rinse, and dry. Although slightly tedious, the needle step is very important. Do not attempt to widen the crack—the Fix will seep into very thin cracks. They then direct you to carefully fill, level, and wipe around the crack. This worked perfectly on flat sections, but it broke down for us on corner cracks or through non-skid, where leveling difficult. Where there is compound curvature, leveling is impossible. Instead, we often simply smeared the product over the cracked area, waited about 5-10 seconds (depending on temperature) and wiped it off firmly with a paper towel just before it set. Although this did not result in perfectly filled cracks, but they were now white and nearly invisible. Repeated treatments gave more improvement.

We like that we couldn’t make things worse and that it was a simple project, without the need to trim after curing, sand and polish. It took just a few minutes of easy work, and after six months was still good.

They also sell a 9-Second Chip Repair Kit. Similar to Marine Tex, it was easy to use and can be finished using the crack repair product. We used it to repair two 3/16-inch voids left by bubbles during layup. How long it will last remains to be seen, but it certainly made for an easy repair. Just fill the hole and level with tube end, allow to cure, and finish with the Hairline Crack Repair. Recommended for cosmetic repairs.

Comments (5)

Porcelain bathtub repair worked great on my old 21foot semi-self built Luger. Hard enamel touch up but the easiest way is to clean the area very well especially the cracks. Needles sounds good but the tiny cracks I had a needle would have been to big. Cleaned well and wipe down with acetone or rubbing alcohol then press hard while wiping product on. As the article says, backing plates are needed behind some stress areas. Must be an improvement.

Posted by: Donnymac | October 13, 2019 10:06 AM    Report this comment

Latex paint would be a bad choice as water and humidity would break it down, even weeks later. It would also discolour in sun. Find a spray enamel in the colour you want, spray a bit into the cap and apply with a needle or similar pointed tool. Should be much more durable.

Posted by: WeekendSailor | August 17, 2019 11:58 AM    Report this comment

Wondering if Practical Sailor has tried Captain Tolley's Creeping Crack Cure? A number of users report that it works well. My question would be whether it lasts, does it really adhere to gelcoat/fiberglass and permanently fix the hairline cracks?

Posted by: Sea Life | August 17, 2019 10:39 AM    Report this comment

here is a quick fix for superficial gelcoat hairline cracks. Apply a very thin coat of white latex paint with a soft cloth...Remove excess paint...wipe clean... Some of the white paint should remain in the cracks. Cracks are still there but less noticeable/ still there.



Posted by: dean paul | August 17, 2019 9:32 AM    Report this comment

I used magic ezy and had a problem with the color match.. the final product did not match what it looked like on the tube package.
i contacted the manufacturer and he sent me another tube with the same result. the color was too dark for the white.
now it looks worse than before.
not sure what the problem was

Posted by: badornato | December 31, 2017 12:05 PM    Report this comment

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