Spider cracks

[pillars]

Looking at a catamaran 12 years old. This particular one has lots of these gelcoat cracks. I've looked at other boats same year, make model and they didnt have them as much. Is this just a cosmetic issue? What causes these and is this repairable?

[SuW]

Originally Posted by pillars

Looking at a catamaran 12 years old. This particular one has lots of these gelcoat cracks. I've looked at other boats same year, make model and they didnt have them as much. Is this just a cosmetic issue? What causes these and is this repairable?

It looks like something hard/heavy was repeatedly dropped in that area.

Probably cosmetic. Just in the gelcoat (which is like a thick paint, basically). It's a bit more brittle than the underlying fibreglass.

If you can check behind the fibreglass and the laminate appears solid, that is, it doesn't push in/out with strong finger pressure, it's cosmetic. It's above the waterline and water is unlikely to leak inside the deck core, if any.

You can repair the gelcoat, grind out any loose material and fill with epoxy then re-coat with gelcoat, but matching the colour is a bit tricky, especially the pattern in the non-skid.

Or you can paint the deck and kiwigrip the non-skid areas. We did that but our boat is 42 years old. (We think it looks good though).

Or you can live with it.

[boatpoker]

Looks like voids to me ..... Take a small hammer (I prefer brass) and gently tap around the area. If you hear a hollow sound at the crack, you are likely encountering a void between the gel and the underlying laminate. Is so there's a good chance it's cosmetic but such cosmetic repairs are very expensive to do well. I almost always find a few voids even in brand new boats. Some more than others. The fractures over the voids may not manifest as fractures for years but can be found with percussive sounding.


Suggest you take a look at Marine Survey 101

and

Moisture Meter Mythology

[pillars]

I should mention that tapping around the area sounds solid the same as the rest of deck. Note this isn't the only spot. There are a few places around deck hatches with similar spider web cracks.

[SuW]

Originally Posted by pillars

I should mention that tapping around the area sounds solid the same as the rest of deck. Note this isn't the only spot. There are a few places around deck hatches with similar spider web cracks.

Sounds like the boat has been ridden hard and put away wet!
Only you can decide if it's worth a lowball offer because of condition. Perhaps it was in charter?

[jt11791]

Spider cracks like those are very common in gelcoat 10-15 years old or more. They are only cosmetic. They can be repaired, but it's a lot of effort and getting a perfect color and pattern match is a real art form, thus most owners just ignore them

[nightowle]

Originally Posted by pillars

I should mention that tapping around the area sounds solid the same as the rest of deck. Note this isn't the only spot. There are a few places around deck hatches with similar spider web cracks.

It's possible that the gel coat was too thick, which can cause this type of cracking. As mentioned, it is just cosmetic if that's the case. Hard to fix well, though.

[pillars]

Originally Posted by nightowle

It's possible that the gel coat was too thick, which can cause this type of cracking. As mentioned, it is just cosmetic if that's the case. Hard to fix well, though.

This is key I think. I don't have any experience with this but reading the forums gave me a feel for the difficulty in "fixing" this especially wrt to colour match. So when the broker says it's only a couple hundred bucks to fix this, I squint a bit. If that's the case why hasn't the previous owner fixed it because it's not helping the sale of the boat right now.

[rabbi]

Check out this video to get an idea how to fix. This YouTube channel has many more vids about gelcoat repairs

https://youtu.be/2eZLorXTNys

[boatpoker]

Originally Posted by pillars

This is key I think. I don't have any experience with this but reading the forums gave me a feel for the difficulty in "fixing" this especially wrt to colour match. So when the broker says it's only a couple hundred bucks to fix this, I squint a bit. If that's the case why hasn't the previous owner fixed it because it's not helping the sale of the boat right now.

These can be fixed. I have buddy who does this professionally and he is nothing less than an artist, however ...... even he will tell you that the chances of it staying fixed more than a year or two are pretty slim unless you fix the issue that caused it in the first place. The chances of that are even slimmer.