Liquid Life Calk for small gelcoat cracks?

[AlpineSailor]

Has anyone used Liquid Life Calk to fill in small gelcoat cracks?

Here is what their website says about it, not much, hence the question to everybody.

Has the same outstanding properties as Lifecalk Sealant. Non-shrinking, flexible, sandable compound. Low viscosity, free-flowing polysulfide sealant for use on fine cracks and seams.

[sailingfool]

Is there a reason that you don't want touse gelcoat to patch gelcoat cracks? If you get a kit and practice your mixing, you may be able to get a repair that is hard to notice.

Also try to figure out and deal with the source of the cracking, or you'll be doing it again.

[camaraderie]

Do you want to FIX it ...or temporarily insure that it does not get further degraded? Gelcoat crack repair kit is the only FIX.

[AlpineSailor]

It's for gelcoat cracks in a small 1981 trailer sailor, an S2 6.7

Perfect looks are not what I'm going for, just want to keep moisture out of the core.

[Catalina274me]

I have seen Marine-Tex used for this with great results.

[chucklesR]

I'd go with Marine-tex instead then, it's easier, sandable and far more permanent. Caulk will yellow, peel and fall out eventually.

[sailingdog]

Especially a polysulfide sealant...

[brak]

Marinetex turns yellow about as fast as caulk. I learned the hard way. It is also difficult to work with (absolutely impossible to measure correct amounts since it is not liquid, unless you have tiny scales), and as any epoxy based material, it will have different expansion characteristics from gelcoat - i.e. eventually the fix will separate from the surrounding area and let the water in.

When I first began doing these things, I tried Marinetex because it is very often suggested. Results were pretty darn bad.

Using gelcoat is actually pretty easy, it is fairly tolerant of improper mixing ratio (i.e. a little more or less catalyst - it will usually still cure properly). So I would advise doing that. If you color match even approximately - results will be pretty good.

[sailingdog]

Brak-

Marinetex is an epoxy, and as such needs to be protected from UV via paint or gelcoat. IF you don't protect it...it will yellow.

Personally, I think patching it with a gelcoat repair kit is probably the simplest and easiest...but as pointed out previously, if the cause of the cracks is not remedied, the repair will be short-lived.

[Catalina274me]

Originally Posted by brak

Marinetex turns yellow about as fast as caulk. I learned the hard way. It is also difficult to work with (absolutely impossible to measure correct amounts since it is not liquid, unless you have tiny scales), and as any epoxy based material, it will have different expansion characteristics from gelcoat - i.e. eventually the fix will separate from the surrounding area and let the water in.

When I first began doing these things, I tried Marinetex because it is very often suggested. Results were pretty darn bad.

Using gelcoat is actually pretty easy, it is fairly tolerant of improper mixing ratio (i.e. a little more or less catalyst - it will usually still cure properly). So I would advise doing that. If you color match even approximately - results will be pretty good.

Actually using Marine-tex is easier IMHO than gelcoating.

I have seen first hand some small holes (old traveler mounting location) filled in my boat 5 years ago with NO yellowing. It matched with paint so well I forgot to touch-up the paint.

Easy to measure with your eye. Guesstimate is fine with this stuff. Says so on the instructions.

Stronger than gelcoat, I've seen guys use it below water line on aluminum fishing boats, differant expansion than aluminum? Not 100% positive but suspect they're differant expansion characteristics. They are still not leaking after getting hammered on the Columbia River.

It depends on the cracks. Marine-tex is structural fixing.
Gelcoat is more visual than structural.