Gel coat crazing

[geardownthreegreens]

I noticed this a while back so thought i'd best ask.

Either side of the drive leg where it attaches to the boat are rising crazing of the gel coat. They are approx 12" long by say 2" wide and follow the pitch of the hull upwards,so not vertical.Each side have approx several hair lines criss crossing each other to give you some clue.
Is this a concern? what causes this to happen and what exactly is happening? Anyone else seen this or have this problem?
Si

 

[gjgm]

not sure what you mean. I think the transom on sportsboats is commonly a thick ply, glassed in, with a hole cut according to the outdrive leg templates. I cant see how the ply and fibreglass can be damaged, so maybe the leg's transom shield isnt firmly bolted, and its moving a fraction. Gel is brittle, so any pressure will cause it to craze. This is all a bit of a guess, I should add.
Certainly doesnt sound right, especially 12 inch cracks, so I d get someone to look. When was the leg last off, and how old is the boat?

 

[geardownthreegreens]

Hi
Thanks for your reply.Maybe it sounded far worse than it actually is.
Your right,its a sportsboat, a rinker 212 thats 1998. Were not talking about opened up cracks or anything real serious, only it looks like,how can i put this, as if strands of womens long hair had become stuck to the transom.Hair line cracks. Yes,the rear is made up of ply,your quite right. The leg was serviced only a couple of months ago and was removed but i guess its just down to age.
You know,i'm sat here reading and writing this,and i've just been picturing it sat on its trailer. The main weight is on the keel of the bottom rollers and the bunks are actually doing very little indeed to support the boat. I'm now thinking that a lot of this is being caused from the way its parked on the trailer.It is actually making sense now.If the main weight is straight on the keel,when the boat is on the road,any little bump in the road would reverberate through the hull.Trailer is in a bit of a state as it is so i'll look into getting her up onto the bunks more.

 

[[2068]]

Several possibilities, none of them are particularly good.

Gelcoat is quite brittle, so it will crack or craze if the thing it is attached to is flexing, expanding/contracting, or has too much pressure applied to it, or there was too much gelcoat applied at the factory.

e.g. it could be that the transom is flexing a bit, causing the gelcoat to crack, or there could be water intrusion in the transom.

Either way, probably best to have it checked out by a pro, just in case.

dv.

 

[[2068]]

Some pictures would make it easier to help.

dv.

 

[geardownthreegreens]

Cheers dv.
As you say,flexing.With the boats keel sitting on the trailer and the bunks not giving much support at all, then i'd say the flexing is coming from the trailer.The pounding that would reverberate up through the hull whilst on the road could be severe enough to do this.
Thanks for your advise.

 

[geardownthreegreens]

Your quite right. I'll have to do a follow up on this story as i wont be going down to the boat til at least the weekend, but yes,i'll take a couple of pics to show.

 

[powerboats]

The keel of your boat should be more resilient to point loads imposed by the bouncing of your trailer than the flatter sections you will be placing the load on if you take up further weight on the bunks.

As others have mentioned it is difficult to say without pictures of the problem but I think it is unlikely to be caused by towing. Has the drive leg been grounded at any point? How old is the boat?

 

[geardownthreegreens]

OK point taken there.
I wouldn't know if the leg has hit the ground in the past,certainly not whilst i've owned her.
She's 1998
I'll take some pics next time i'm now, only my next question will be, how do i get photo's up on a post ?

 

[A_8]

If its been run aground at high speed it may well show up like you describe.
Another not so good scenario might be that the (typically) thick plywood inside the fiberglass layer(s) have gone rotten and made your transom soft. This will cause excessive flexing and show cracks in the gelcoat.

 

[geardownthreegreens]

Thanks for the good news Michael /forums/images/graemlins/grin.gif

I do hope its not the latter you describe.
There are signs of slight repair to the lower bow where she's probably been driven onto a beach etc.
Anyway, another 2 very good suggestions which i'll check out.

Typical really, i'm in 2 minds as whether to sell or keep,doh !!