fiberglass repair clarification

godspede619

Seaman
Joined
Aug 26, 2008
Messages
54
So heres whats going on. I have a 89 bayliner trophy with a two crack on a speed strake. I have never done a fiberglass repair but feel capable. I have run through the search engine on iboats and youtube and still have a few questions. Ill go through my steps and insert the questions accordingly.

This repair must be made from the outside and im not too concerned about appearance.
1. completely remove all damaged fiberglass with a jigsaw or dremel.
2. measure thickness of fiberglass and measure a 12:1 ratio away from cut hole. approx. a 3-4 inch
3. using a grinder with a 50-80 grit wheel bevel the FG from your 3-4 inch outline toward the cut out section.
Im planning on using 1708 biaxle as my fibler glass and either a quality poly or epoxy. Can i use some mat wet with resin to stuff into the hole to get some backing before i use the biaxle? how many layers of biaxle do i need to use? do i sand between layers or apply wet?
Some posters say to use small pieces of biaxle and work to larger and some say the opposite large to small.

after glassed ima sand area and just paint and not too worried about gel coat. just lookin on some clarification in a few areas before i start. i completely understand that prep is key to the whole job. If any one know a website or a book that gives a step by step it would help with the process.
(and yes someone has tried to repair this crack before)
 

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oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: fiberglass repair clarification

uh.....no....no.....and no....!

hi....! welcome to i boats! :D

we really need to see close up pics of the crack and the overall damaged area.

someone tryed to fix it before with csm and it re cracked......

that means that the crack is bigger than you can see.......but grinding out the fiberglass IS NOT the way to fix it.

the repair might be bad enough to need an "inner-outer" repair......but i doubt it. im guessing the previous repair was not done well enough.......

so.......with out seeing better pics......
grind out the area....(rough and scuff).....till the glass is exposed...and you have a partial "dish" in the area.....do not grind out the fiberglass till its right thru the hull!.......then vacume the area and clean with aceitone. use 2 layers of 3/4oz csm....1 layer of 8 oz "veil" finishing cloth......if the "dished out area is still way below the surface area of the rest of the hull....add one more layer of csm and one layer of veil.

sand smooth with out sanding thru the new glass.........fair using a "peanut butter" then cover with gellcoat and sand smooth and polish.

that repair should not take any more than 2 hrs labor.....(not including cure times).

if the crack is totally thru the hull.....you must do the same from the inside as well!.......thats a lot more complicated......but lets cross that bridge when we come to it.....

please post detailed pics and we can help you....

cheers
oops
 

godspede619

Seaman
Joined
Aug 26, 2008
Messages
54
Re: fiberglass repair clarification

The crack is through hull. There is water intrusion and when water is in hull it drips out crack when on trailer. Im going today to work on it a bit. ill take better pics and postem up later. Im gonna remove the damaged glass today so i have a better idea what im dealing with. thanx for the reply.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: fiberglass repair clarification

ouch.....that is an inner outer repair.....

you can patch it from the out side only.....but it will have to be re done every few months depending on usage.

it will be tough to get the area dry if there is foam behind the crack.
 

godspede619

Seaman
Joined
Aug 26, 2008
Messages
54
Re: fiberglass repair clarification

some pics of the days work...
 

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godspede619

Seaman
Joined
Aug 26, 2008
Messages
54
Re: fiberglass repair clarification

So heres the deal for my thursday. I knew the crack was thru hull so i decided to cut out the crack and see what was goin on. And of course i got the "oh crap reaction". Once i cleaned out the crack i discovered that behind the speed strake are wood beams. they run laterally and are only where the strakes are. From the inside the wood is encased in fiberglass. the deal is that this piece of wood is saturated with water. I know not to glass over moisture. I opened every hatch i could and gonna let it air out. i know it coild be a long long time before i can repair this. any tips to get that wood to air out more effiently?im in san diego so no rain and its about 85 degrees right now.

I have only one 10inch circle hatch in which i can access the the inside semi close to the damaged are. I CANNOT reach the area where the actual damage is located. but you can see one of the pics i took from inside and see damaged fiberglass on the strake. this inside damage is a foot away from the actual crack and will need to be repaired accordingly. This damage is probably the cause of the stress crack.

Any suggestions on this repair would be appreciated....
 

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