Spider cracks in Gel-Coat

[Codger2]

Does anyone have a method of dealing with spider cracks other than grinding them out and re-gel coating? I've heard of guys just wiping a white calk on them with their finger but I've never tried that.

 

[psneeld]

Does anyone have a method of dealing with spider cracks other than grinding them out and re-gel coating? I've heard of guys just wiping a white calk on them with their finger but I've never tried that.

If truly just spider cracks, filling with anything white might be good enough. I would try a little matching gel at first...if really fine....a tiny opening with an old style can opener should work...then a touch up sand and buff.

If down into the first layer of resin (more stress crack), say in the corner of steps or around hardware.....grinding is the only solution with structure added somehow to prevent reoccurance.

 

[Larry M]

...other than grinding them out and re-gel coating?

It's really not all that hard. Your boat is not that old so good glass guy, with a Dremel tool, open up the cracks, a little filler, then spray on some gel-coat, then sand appropriately and then buff out/finish, it should match the factory. Short of anything else I don't think you'll be happy later.

 

[cappy208]

They usually indicate some other malfunction going on. As in core rot, flexing of bulkheads or decks, deck fittings or poor design of the underlying support structure.

It all depends on what is the reason that defines how 'much' the cure will be (both in terms of work and cost.) If it's just cosmetic, from a whack with a boat hook, or a dropped anchor then the topical 'fill in the crack' would be fine. If it's deeper, then I'd be worried about what lies underneath.

I have three areas on my boat that will need attention soon. All design flaws that are magnified by step up locations. Fun fun fun.

If it is small impact spiders, don't bother with caulk. Use colored epoxy. White as a base, then drops of resin dye: EVERCOAT Resin Coloring Agent | West Marine yellow or black or blue as appropriate to try to match. You'd be surprised how many times yellow is used to age the colors to match faded gelcoat.

 

[Gordon J]

Follow on question

I looked at a 2001 Ocean Alexander today that had hundreds of gelcoat cracks on The deck. I do not exaggerates the numbers. Is there a simple way to handle such a large number. This is purely a cosmetic issue, but I have never seen so many cracks on a boat.

Anyone have any ideas?

Thanks in advance
Gordon

 

[Northern Spy]

All my spider cracks are from 30 years of dropping cannon balls and prawn traps on deck and in the cockpit.

Keep meaning to get around to them, so I'm all ears on successful repairs.

 

[FlyWright]

If I spent time fixing spider cracks, I'd never get out boating...and we can boat year round here! I say forget the little stuff and go boating. If it's just a vanity issue, slap some duct tape on it and go boating! When you return, take off the ugly duct tape and it'll look much better! (Of course, I'd use white duct tape on a nice boat like yours.) If it's a structural issue then, OK....it needs to get fixed.

Of course, I'm the guy who has to do the work on my boat, so it's easier for me to make that call. If I had unlimited funds and was hiring a guy to do the work, then I'd just hire the best and not try to figure out how he should do it. He already knows.

 

[what_barnacles]

Paint cures all spider cracks. But you know that.

Gelcoat hates to flex, it's really brittle. Unless you fix the flex problem, it will crack. Paint is way cheaper.

 

[psneeld]

All my spider cracks are from 30 years of dropping cannon balls and prawn traps on deck and in the cockpit.

Keep meaning to get around to them, so I'm all ears on successful repairs.

Sounds like diamond plate and doubler wood strips where the traps come over is the ticket

Take the lead from any commercial fishing boat....

My glasswork is so so...but I do work for prawns and beer.

Maybe when I am done with those blackened sockeye on Kevin Sanders boat next early summer test running his grill choice....a swing by for glasswork on your boat might be arranged.....

Then maybe on to San Diego...who knows!!!

 

[Gordon J]

Psneeld,

Prawns are easy. I'll let you know if I tender an offer On this boat. Meanwhile, still three cracks come back if I paint with awlgrip, or is there a better product?

Gordon

 

[Gordon J]

Paint cures all cracks

What barnacles,

Is one paint better than another?

Gordon

 

[psneeld]

Psneeld,

Prawns are easy. I'll let you know if I tender an offer On this boat. Meanwhile, still three cracks come back if I paint with awlgrip, or is there a better product?

Gordon

paint never conceals cracks....gel coat is better if just a gel crack...not good if a stress crack.

 

[cappy208]

I looked at a 2001 Ocean Alexander today that had hundreds of gelcoat cracks on The deck. I do not exaggerates the numbers. Is there a simple way to handle such a large number. This is purely a cosmetic issue, but I have never seen so many cracks on a boat.

When you were walking on the deck did you 'jump' a little? Could you hear is cracking? Could you feel it flexing? If the entire deck is covered with spider cracks then I bet the core is done. One of the best things to do on a lookover is to have a friend walk the deck while you're down below listening to the creaking as they jump. (brokers hate this.... as well as owners)

There is a part of molding that may be the issue. When the gelcoat is sprayed into the mold. If they don't do the gelcoat or the first layer of glass correctly it can cause alligator craze. This is usually not spider cracks, but actual valleys and ripples. Think sort of what the surface of a raisin looks like, only inches long and wide. If it's alligators then they can be ground down and re gelcoated. If they were previously repaired alligators then they are just re done. again. Here's the technical poop on alligators. "It must be applied uniformly, as thin areas will wrinkle (“alligator”) when a second gelcoat, or laminating resin, is applied. Also, it is important to allow the gelcoat to cure before proceeding, as inadequately cured gelcoat will alligator. On the other hand, too long an interval will result in a weaker interlaminar bond between the gelcoat and the next layer." I believe this is where a lot of spider cracks come from, 'almost alligators' that take years to 'pop'.

 

[Gordon J]

Not the issue, me thinks

Thanks cappy. There are so many cracks, literally hundreds that I believe'll it is faulty gel coat. The deck feels firm. Moisture meter reads ok.

Grinding out cracks and filling would be a lifetime undertaking..literally. The hull Is Blue gel coat and I saw no cracks there...

 

[cappy208]

Is this a specific area? Or is it the entire molded deck component? If it's just an area, then the simple solution would be to grind the entire surface and have a professional application of top coat done. Unless you grind through the gelcoat into the fiberglass, then you would have to regelcoat. Is this non skidded area? If it's non skid then you would need to reapply a nonskid texture to match the rest. Tough job. Is this a specific area that may have had extremely hard use (like shipping a dinghy, or usual route from cabin to dock for years?)

 

[Gordon J]

Whole deck

Cappy,

Whole deck. Not confined to any one place. It its so bad, i am somewhat surprised that the manufacturer did not get involved.

Gordon

 

[cappy208]

Well, if it's the entire deck, and it is so noticeable I would expect the price reflects this.


If it's non structurally caused, then you have two choices. Live with it, or do a top coat of a good quality paint. BUT, likely the spiders will just reappear. If the spiders are down to the fiberglass then you need to re seal them.


Personally I would live with them. (depending upon price)


Is this the classico in Va or Stamford? Wow. Pictures inside are stunning of the one in Va! Is this shed kept? Amazing if it is shed kept and has all this spidering. Think how it will be if you don't keep it under cover?

 

[Northern Spy]

Going out of the box here, but if there is spider cracking of the entire deck, perhaps the previous owner was a large person. As in load exceeded design, and decks flexed.

Test drove a 2 year old car once where the seat foam was completely compressed, and the seat back was loose.

 

[Gordon J]

This is the one in Stamford.

 

[cappy208]

Gelcoat Crazing by Don Casey - BoatTECH - BoatUS

Likely this is what is going on. A variant of alligatoring. Called crazing.

 

[cappy208]

These are illustrations of the differences. Personally, I wouldn't buy a boat with this much crazing. Unless the price was SO low to allow for needed repairs. You are leaving yourself open to too much water penetration and soaking into the deck.


This is caused by a poor layup of the original gelcoat not adhering to the fiberglass.

This is alligatoring which some is broken to the surface, and some hasn't broken to the surface (yet). This is caused by poor gelcoat luyup, But it adheres to the fiberglass.

 

[cappy208]

And this is a spider crack from physical damage or weakness of the underlying fiberglass. Could as well be the deck, around stanchions or corners on the deck/house. The spider cracks usually center on damage of some type.

They are seen on hulls usually just forward or aft of hull to bulkheads where impacts have 'sprung' the fiberglass from hard landings and smacks. The fiberglass flexes a lot before and after the bulkhead. But not so much AT the bulkhead.

 

[Gordon J]

Not the case

It is not even close to this bad, but yet bad enough that individual repairs would be a BIG job.

 

[siestakey]

not for your job but works great on small areas

 

[Codger2]

This is exactly the kind of product I'm looking for! Thank you!

 

[siestakey]

your welcome I have used a few tubes in areas and it works well

 

[Gordon J]

I saw this yesterday and was thinking i could finish in a year if I did about 10 or so a day

 

[cappy208]

@ Siestakey, I may have to try a tube of that. Looks too easy to be true!! Thanks for the heads up.

@ Gordonj, Are the defects you saw spider cracks, or crazing?

 

[siestakey]

@ Siestakey, I may have to try a tube of that. Looks too easy to be true!! Thanks for the heads up.

@ Gordonj, Are the defects you saw spider cracks, or crazing?

it was actually almost as easy as it looks in fall I will using a few more tubes

 

[Gordon J]

Re cracks

Neither really, more like random cracks, but there are hundreds of them