How common are spider cracks on 1999 SAN?

[ksdaoski27]

How common are spider cracks on 1999 Super Air Nautiques?

It was a python engine boat.

Had pretty significant cracks around the rear air intakes. Didn't take any photos-


Thanks

[NautiDave07]

cracks

My ols super air had some back there that looked like hairlines but nothing major. IF they are large the boat has probably been loaded very heavy or with lots of lead.

[ksdaoski27]

I really wished i took photos of it but they were pretty bad. Like half a dozen to ten per side

[steve-o]

I have some. Hairlines from bumping docks and such. It's an old boat.

[WakeSlayer]

Pretty sure I have zero on mine. They are harmless, just don't look good. It does give you an indication of how the boat was cared for.

[Chexi]

I have zero on my 99 Air (not SAN), but I think it is fairly common.

[NautiDave07]

If you would consider them bad, don't buy the boat. I would not say it is a direct indication of how the boat was cared for just more of an indicator of how it was ran and weighted. I babied mine and I never ran an ounce of ballast that wasn't water bladders or people and mine got them. I Think the hey is to find out if the places these cracks are is common. In your case they are common there. without seeing them there is no way fr us to tell if they are excessive. I do know mine were there and never got worse over the five years I owned the boat. Just remember that if you repair them it is likely they will come back.

[ksdaoski27]

I was just really surprised at the severity of the cracks. I owned an 88 Prostar 190, 22 year old boat, and never had any. I've also been looking at MC's of similar years as the SAN, 1998-2003, and they didn't have any. So i was really surprised to see so many. Again, wish I took a picture. One was even "C" shaped, about the size of a silzer dollar. The others were 6-12" in length. Seemed pretty severe to me, again after past boats I looked at had none-

[WakeSlayer]

I would not say it is a direct indication of how the boat was cared for just more of an indicator of how it was ran and weighted.

I have to disagree with the above entirely.

[Chexi]

So what is the cause of spider cracks? It appears as though we have theory (a) that would stand for spider cracks being the result of adding ballast (presumably that the added weight causes stress beyond spec) and theory (b) that would stand for it being a matter of how well a boat is cared for (presumably that wiping down, washing and waxing or perhaps how you store a boat help avoid spider cracks). So which is correct? I know that I sometimes see spider cracks around fastening points (like tower mounts). Those are probably stress induced by torque on the tower, but not ballast induced, and are probably a major function of tower, and specifically fastener system design.

I am asking this question genuinuely, as I have zero now and want to keep it that way. Since I just added a custom ballast system and now run with more weight, I want to know definitively if this is going to cause my gelcoat to start spider cracking. Alternatively, I would like to know what maintenance procedures prevent spider cracking.

[NautiDave07]

I did not mean that adding a lot of weight was gonna spider crack your boat. You just need to use common sense on the type you use and its placement. Steel and lead weights could shift and cause pressure at specific points that may cause a spider crack or hairline crack. Wakeslayer and I disagree on this topic I guess. I was simply stating that someone could take very meticulous mechanical and cosmetic care of thier boat but also fill it full of lead or steal tractor wieghts that shift and cause damage. I have seen theis first hand on friends boats. These guys take excellent care of their boats but try to find anything they can to weight them down. On my buddies old 220 he got spider cracks in his gel from where an edge of his lead bar impacted the side of the hull while driving doen the lake. Take it for what you will but having owned that particular boat, having taken excellent care of it, I did in fact have a few small hairline cracks in that exact place and at the mounting feet for the tower. I was the second owner and know the guy I bought it from. He loaded it pretty heavy and put almost 400 hrs on the boat in two seasons. You can wax, wipe, and clean all you want but different conditions effect every boat in different ways so it is really impossible to say what caused the cracks and if they would get worse. The ones on my boat never got worse.

[steve-o]

Just to add, my spider cracks on the exact same boat are around the intake vents. Very faint hairlines. One side on mine looks to be caused by a previous owner bumping a dock, and no indication of anything as to the cause on the other side; although if it is this common, it might not be from that. It has that "C" shape you are talking about. I thought it looked like an impact point. My gelcoat is in excellent shape other than the cracks and the interior of the boat is in very good shape. I only this year replaced parts of the 11 year old vinyl. Boat has been well cared for and has cracks. No indication that it was ever heavily weighted in the rear. There are indications there was weight in the belly and the nose of the fixed static type.

[WakeSlayer]

I will dial it back a little.

I think that one or two incidental dings in your boat are not indicative of poor care of your boat. Stuff happens, especially in busy lake environments. But, to have a boat that has many of them shows that it has been run into a dock, or bumped into in storage, or lead bars sliding around, more than just a couple times. That is not taking care of your boat.

I am not overly anal about mine, but I am careful with it. My boat is a 99, and I don't have any. I weight my boat plenty and work her hard sometimes. I do have a couple minor scratches, one I did, the other came with it. My old 92 BFN had one big spider crack that was obivously bashed into a dock. My 90SN had none.

[icewake]

One cause of gelcoat cracks comes from drill holes that were not chanfered. The screw or bolt running trough the hole hits the gelcoat and makes it crack. Just remove the object bolted, take a chanfer bit, chanfer the hole, put some sikaflex in hole and screw or bolt back object.

[ers906]

I removed all of the bolts/screws from the areas that contacted the gel coat and chamfered the holes in my last boat. Didnt have any cracks in the gel coat (other than those there when i bought it). Have done the same with this one, but have only had this SAN for five months so the jury is still out