Mine have a slight crack in each of them, and I want to know if anyone has tried this before and if it worked for them. And if it worked, how did it look?
I'm looking for a "quick fix" until I have the time to actually replace them.
I tried searching for it, but I'm not a guru with the search function lol.

I havent seen anyone do sails, but it may not hide the crack. I have it on some truck wheels, it disguised the delaminating coating on the aluminum wheels but you can still see the edge if you look close.

It wont hide the cracks. It is basically like paint that you can peel off. The cracks will show just like if it was regular paint. I have done my rims, and roof and sails and fronth mouth lol. You cant see the sails cus its kind of far but here is my car.

Same here. I did my sails to see if the dip would hide the crack. It does not. Like he said its basically a thick paint you can peel off.

Thank you guys for the replies, I was hoping it'd hide it but I guess I'll just replace it sooner then

If you are not worried about harming the sails, you can use some type of body filler, putty, glue, epoxy ect. Just lay down small bead in along the crack, work it in, then hit it with some sandpaper when it's dry. Then, when you Plasti Dip it, they will look nice and smooth.

It would make a nice treatment for the frame but there are better solutions for the "glass" part.
I have a set of 84 sail panels that I have been hanging on to, they have actual glass and not plastic.

http://www.fierosails.com has replacement sail panels

If you just want to make what you have now look better then John is correct you can use some body filler in the crack.
Used parts are getting harder to find and we are all having to think out of the box to keep our cars on the road.