After years of suffering chronic stress cracks around the windshield and having Larson fix them under warranty, I finally took matters into my own hands.

Larson was annually fixing these cracks for about five years. Each year the fight got tougher. They eventually said that was it… no more. Of course this didn’t go over well with me because in my opinion, the original problem that was causing these cracks was never fixed. I kept asking them to fix what was causing problem. I gave in because the Larson dealership I was having the repair work done at was really ticking me off. It was getting to the point where it was more of a pain to have them fix it than it was for me to just do it myself (I think they deliberately do that).

Anyway, as a spring project, I decided to take my windshield off to fix the cracks. Some of these cracks went 6” long. After fixing the cracks, I put fresh ½” thick rubber gasket between the windshield frame and the gelcoat. The junk they had on it was about 1/8” thick and had no flexibility. With the choppy waters I boat on, this didn’t provide much protection. But what really upset me was how the windshield was attached to the boat. They used self-threading screws directlty into the gelcoat except for two screws by the bow window. All my cracks were coming from where they had self-threading screws. So I decided to throw out those screws and replaced them with thru-bolts to attach the windshield. I’m hoping that between the new ½” rubber gasket and thru-bolting, I’m done with the problem (my fingers are crossed). The silver lining is that I’m getting pretty good at gelcoat work.

This got me wondering… how many other manufactures don’t use thru-bolts to mount the windshield. This seems like a no-brainer to me. Especially for those manufactures that bolt the bimini brackets to the windshield too.

How is your windshield mounted?

Mine is mounted with self-threading screws. definitely not thru-bolted. in fact, my screws tend to loosen up so i took them out, put some sealant on them and tightened them back down.

Any evidence of hairline cracks with those self-threading screws?

No, fortunately, I haven't noticed any of those.

I'm curious to see if your new setup will hold. If self-threading screws by itself would be the problem I think manufacturers wouldn't use them. Perhaps it's a combination of screws, shock absorption and hull flex that is the cause here.

IMO this is the cause.

My windshield WAS screwed down the same way. My biggest issue was working loose, not cracking.

I finally glued blocks of 3/4" thick wood UNDER the deck, drilled completely thru, and put SS machine screws with nylocks on. No further issues.

The rear side mounts (which mount the ends of the top rail at each end (similar to a horse-shoe, 1 piece), have never been an issue. Don't even know for sure how the mounts are secured, although I'll bet SS sheet-metal screws just as the rest of the windshield was.

Phatboy
I'm curious too. You bring up good point... hull flex. Bow riders lack the rigidness that cabins offer. I'm sure my hull will "Twist" more than a cabin. Maybe thats why they don't make big bowriders.

If self-threading screws don't cause that problem then why do quality boat builders use thru-bolts? If I'm not mistaken, Cobalts use thru-bolts.

Lowrider,
That’s encouraging news. I hope you're right.
There is wood encapsulated in fiberglass where the windshield is mounted so I didn't need to add the wood. But I like what you did.

Can you take some pictures of the area's in question?

My windshield has what looks to be 5/16" bolts, at least the ones I can see at the top. But we do sit on top of the windshield at the helm.

firecadet,
The project is done so I don't know what a picture would do for you.

I'm trying to envision where the windshield mounting screws were on my Sea Ray.

Those screws are covered by a black rubber strip on the outside of the windshield. The rubber strip that wraps around the entire windshield can be easily removed and wedged back in. You just need a small screw driver placed between the rubber strip and the frame to pull it out. Once started, just pull.

My 2003 Four Winns is just self threading screws --- they did come loose once or twice in the last year or so -- but no cracking --- they have come loose after we are on the ocean a bit in heavier seas --- so far just retightening has all it has taken ---

Interesting question. I'll have to look closely at my windshield, unless there are other Cobalt owners that have the answer as to how the windshields are attached. I'm guessing that they are thru bolted, but am unsure. I do know that the windshield is VERY sturdy.