crack in fiberglass deck

[toolsinbox]

ok I dont have a pic of the crack just the boat and you cant see it in this photo, so i will try to explain this as best i can.
21 ft wellcraft scarab.

The crack is on the deck just below the wind screen, in the dark grey area, in the center of the deck, and runs down tword the bow, about 7 inches long. The crack is situated on the grey part of the deck that starts to incline up to the windscreen, if looking from the bow to the stern. The total area of the incline is about 10 inches in width. so the crack almost reaches the flatter white portion of the deck and is a few inches away from the windscreen.

I do have some experience with fibreglass reparing but where this one has me stumped is the fact that the two edges are not on the same level. the port side of the crack is about a quarter inch higher than the starboard side. So it is missaligned. The starboard side of the crack is smashed down some. looking at the damage it looks as if a tree fell on it or a good swing from a sledge. I checked from underneath and there is this fluffy white stuff glued to the entire underside of the deck, in the cuddy, that I can only describe as some kind of flocking of sorts. In anycase I felt around and looked very closely and cannot see or feel any damage, leading me to think that there could be two seperate parts of glass in that area. one being the raised area on top and the flat area underneath consistant with the rest of the deck. where the top skin of glass has the damage. so in short i cant access the underside of the damage. The damaged area is rock solid so I cant bend any of the glass to re-align it. It would take a lot of filler to fair this out but that sounds better than cutting the area out and trying to re cloth it. I am not sure what the correct approach should be. Maybe I dont want to know. I am partially covering my eyes and ears waiting for responces.

Thankyou all very much for taking the time to read this to help me out.

[ondarvr]

Sounds like we need a pic, it helps a great deal in getting a good answer.

[Landlubber]

toolsinbox,

Most likely you will be getting a cutting disc on the grinder, run down the centre of the crack line and remove the tension (yes you will be cutting right through). After that, simply realign the two parts, you can use a jack or just timber supports, and then do the standard repair job as per what you would normally do, seeing as you do that sort of work anyhow. Don't bother to try to match the gelcoat, just respray the area when finished, faster and easier.

[gonzo]

If there is a foam core it could be crushed on one side

[toolsinbox]

I will get a pic of the crack right away when it is light out.

This would be the most advanced repair I have made on a boat thus far. i have done a lot of chip and scratch repair and a lot of spraying. I figured I would paint all the gray areas of the boat after the repair. I have a quart of red concept but no cat for it. Have to think how red would look.

Gonzo- That foam core idea might be right as the area wont flex at all. hard as a rock. I will try to poke something through the crack to see if I hit foam. I cant do any jacking as the underside is not part of that raised area. Ok I am on my way to take a pic.

[toolsinbox]

Ok the cracks are not quite as I remember. Sorry about that. The low spot is above the crack that goes side to side and is smashed in in the whole area. If you slid down there you would get some bad road rash. The crack goes right through the glass in some of the area especially where the " S " is but I cant get anything in there to see what is under.

I know you would need a crystal ball to be sure but any ideas what could have caused this?

So what is the proceedure to fix these cracks?

Thank you all so very much.

[Fanie]

Something rammed into that area to crack the glass like that.

You're going to have to get in on the inside. Check to see if there are damage to any structures ie bulkheads, this is important, it can cause other or further problems.

If some of the structure shows damage that would have to be fixed up.

Else the whole area will have to be glassed over in such a way that the new glass layup would want to wedge itself into place instead of want to come loose, so you'll have to make a summory of the existing structure.

Thumb suck I would say 5 or 6 layers of 450g waven. Remember to put peel ply over the last layer to smoothen it out.

I have found it easier in some cases to wet the precut glass on a board outside the boat and then put the wetted cloth in place. Either way it's a shitty job, but worth doing well. Work when it''s cool, get good lighting and ensure good ventilation.

You can then proceed to fix the outside up.

[Itchy&Scratchy]

I think you ll find that there is a void in the foam directly behind the damaged gel and laminate.
Itchy

[toolsinbox]

what is the significance of that.

[Fanie]

If it is foam filled and if it is the pour foam I think it is then the foam will sand the still fixed foam away. It will reduce itself to powder over time. That is an insulation foam and not a booyancy foam.

Furthermore, moisture getting in there will accumilate and gain extra weight over time - water has a tendancy to get in and not out. Imo you can use that foam above the waterline but not below and would serve for emergency booyancy only.

If I was you I'd take the damaged part apart and see what's going on in there.

[SamSam]

It's hard to match the glitter gelcoat and printing, so that could be a bigger problem than repairing the crack. At least as far as looks.

[toolsinbox]

I cant stand metal flake. i will paint the thing. Just not sure how to approach this to fix. I know I will have to open up the cracks. i think I will follow with grinding and epoxie to get it strait. there is a fresh engine in this boat so I think I will clean this one up and run it like a rental.

[missinginaction]

For me it's almost impossible to diagnois this without more data. The cracking looks to me to be caused from repeated flexing. If you're running the boat can you notice any movement of the glass in that area as the boat works through the waves?

FWIW I think that itchy & scratchy may be on the right track. If the glass is thin and unsupported in the area on one side of the crack and SUPPORTED on the other side of the crack the differential support could cause the problem. It creates a hard spot.

Still need more information...............


MIA

[toolsinbox]

I havent run the boat so I dont know. Just got it

[toolsinbox]

thanks missing. that is a possibility. flexing seems to be a reasonable cause for this as i see no impact mark. I have to say that when i first saw it I thought maybe the boat went over a big bump while it was on the trailer. just hope I can fix it and it lasts at least 5 years--about the time a good paint job remains looking new.