Small crack in hull repair

[jaymasta]

I got a new roller trailer for my boat, and during the process of setting it up I have put a small crack in my hull. I have an idea of what I need to do now but I thought I would get some advice here before I tear into this. I figure I will need to cut a hole in the floor of my boat, and patch it with fibreglass from the inside
and then do some sort of gel coat repair on the outside. If there is anyway I can fix this from the outside? that would be much easier. I have done very little
fibreglass work in my time but I feel I can deal with this little hole. If I do in fact need to cut a whole in the floor I need some advice on the type and ammount (layers) of fibreglass that I should use. And any other tips and advice for this project.
Thanks in advance.
My Boat

Crack

Inside of boat

Area in the boat is in between the seats underneath where the battery is, so this is where I would need to cut the whole.

 

[Woodonglass]

Re: Small crack in hull repair

Some questions first. Is the "Center Section" of the damage Soft or wet? If not, then you should be able to grind and feather the area back about 6 inches, and lay in 2 -3 layers of CSM and Poly Resin Sand and Fair. Use a Foam roller or brush to apply some gelcoat, spray some PVA on it to let it cure, wet sand and buff and be done in a day.

If it's soft and wet then, yep you will need to do and inside out repair. Cut the hole, Grind and feather the inside just like the outside. Lay the CSM AND some 1708 Biax for strength. Then do the outside as described above.

I have included a drawing to help visualize the process.



(Click the pic to Enlarge)

 

[Yacht Dr.]

Re: Small crack in hull repair

From the pics it looks like there is either a previous repair .. or there has been a coating in that damaged area.

Typically you can repair your strake from the outside only if they used some kind of fillet after the skin coat.

Your pics dont look "normal" for the damage .. looks like a previous repair that has some makeover to it.

Get to the inside and see what happened there ...

YD.

 

[jaymasta]

Re: Small crack in hull repair

It is wet because I had to put the boat in the water after the damage was done to get it off the trailer to readjust it, so I guess I am doing an inside outside repair. I can't get 1708 BIAX locally and I would like to get on this project ASAP, however my understanding is its just a mix of CSM and some woven. It looks like there is a previous repair because when I first noticed the damage and I needed to get it off the other trailer so I went and slapped a bunch of 3m 4200 on there to try and prevent water intrusion, the damage didn't initially look like it does in the picture it was just cracked gel coat but all the way to the foam since then I have peeled all the cracked gelcoat away for the pictures. I will be tearing into this in the next few days hopefully and will take some more pictures and post for any updates.

Some questions first. Is the "Center Section" of the damage Soft or wet? If not, then you should be able to grind and feather the area back about 6 inches, and lay in 2 -3 layers of CSM and Poly Resin Sand and Fair. Use a Foam roller or brush to apply some gelcoat, spray some PVA on it to let it cure, wet sand and buff and be done in a day.

If it's soft and wet then, yep you will need to do and inside out repair. Cut the hole, Grind and feather the inside just like the outside. Lay the CSM AND some 1708 Biax for strength. Then do the outside as described above.

I have included a drawing to help visualize the process.



(Click the pic to Enlarge)


View attachment 106740

 

[jaymasta]

Re: Small crack in hull repair

I went and priced everything out today and talked to a guy a industrial paints and plastics.
I have a few questions now, the actual hole is about half the diameter of a dime with the surrounding area of the size of a dime damage. Should I be using CSM and Cloth or woving, The woving at the store is almost 4 times the cost of the cloth and since I can only buy it by the running yard I am sure I will have more then enough cloth as long as it will work for this application. So my initial thinking is to buy a yard of CSM and a yard of Cloth and lay down like this

4in by 6in CSM which would completely cover the damaged area by about an inch on all sides.
5in by 7in CSM
6in by 8in Cloth
7in by 9in CSM
8in by 10in Cloth
10in by 12 in CSM

Does this sounds reasonable for this type of repair, and can I do this all in one go, eg. Wet area with resin, lay FG wet it out, lay FG wet it out, lay FG wet it out etc..or will I need to let it set up after a few layers and then start again?

 

[Woodonglass]

Re: Small crack in hull repair

You got it!!!! All in one shot, no need to wait. Sand and feather it all back, wipe it down with Acetone then lay it all up. You'll be done in an hour.

 

[oops!]

Re: Small crack in hull repair

you are allmost there.....

BUT....where are you?....ips is expencive

when you glass.....the cloth is never larger than the csm under neath it......so.....it should read.....



4in by 6in CSM which would completely cover the damaged area by about an inch on all sides.
5in by 7in CSM
5in by 7in Cloth
7in by 9in CSM
7in by 19in Cloth
10in by 12 in CSM

however i fear.....the cloth you are using is the thin 6 oz that ips sells......that has no structural value and wont do you any good.
the only purpose for that kind of cloth is to cover csm and make the final layer smooth and easyer to finish.

call around to the boat shops in your area and see if they have any 1708 bi axe scraps....you dont need much.....and mist likely they would throw that amount away any how.
ips does not sell it.

look for a composites one dealer in your area and ask who his retail outlett is.

if you are in my area i will give it to you

 

[jaymasta]

Re: Small crack in hull repair

Iam in Victoria
At IPP today they had four different kinds of cloth 4 different kinds of CSM and 2 different kinds of wovin which was stupidly expensive.
What kinda weights of these fabrics should I be looking for? If they have the heavy weight cloth would that work fine?
I asked IPP about any scraps they had and they said they bag everything up until they get enough and then sell them as scraps and they didn't have any at this time. I will try calling a couple places close by tomorrow to see if there is any other supplier around, Iam trying to get this done this friday so I don't have any time to shop around or drive far to get the supplies.

 

[Woodonglass]

Re: Small crack in hull repair

10 oz to 17 oz cloth would be fine if it wovne roving. Just don't use the crap from Home Depot or Lowe's

 

[jaymasta]

Re: Small crack in hull repair

I started the repair today, I removed my seat, cut a hole in the floor of my boat with a chain saw, being very careful (although on my first cut I hit the top of the stringer) removed the foam cleaned the area acetoned the area, sanded the area acetone the area then layed my fibreglass. I spent about 45 minutes talking with a guy at a local marine supply store today and he convinced me to go with west systems epoxy, after much explanation he ended up giving me the pump kit for free so total price it only cost me about 18 dollars more to go for the epoxy over poly all said and done...

All my supplies ready to go

Hole cut in floor

Me getting ready to do the dirty work

Area cleaned out, sanded and acetoned, I might have gone overboard with the sanding as I enlarged the whole quite a bit

5 Layers of Fibreglass cut to size increasingly getting bigger

The finished product on the inside of the boat, next is the outside

 

[ingalp01]

Re: Small crack in hull repair

Looks like you've definitely got it sorted out... I had never worked with fiberglass til yesterday, and I was very impressed after it set up. It's not nearly as intimidating once you get your hands dirty... Good job and keep us posted!!!

 

[Woodonglass]

Re: Small crack in hull repair

Just remember, If you use Epoxy on the outside, you won't be able to gelcoat over it. Gelcoat does not adhere to epoxy, at least not unless you go to great lengths to prepare it and even then it still has issues. You should, in my opinion, use poly on the outside IF you are going to gelcoat. If you are going to Pant the epoxy will be fine.

 

[oops!]

Re: Small crack in hull repair

the guy at the marine store conned you.

he obviously does not know what he is talking about....he just sold you the equivelent of wallmarts fiberglass kit...except with epoxy. (wich he makes a bigger mark up from.

now your working time goes from a few hours to a few days waiting for that carp to cure.


i get sooo pissed about these ...store salesmen that just want to sell the higher priced stuff, and not give the customer what he needs.
the roving you have is the stuff i warned against.....it has no structural value at all. and you are working on a chine!
you cannot re finish the repair with the super hard time tested gellcoat, but now get your choice of colored marine tex wich would have patched the hole all by it self in the first place, ( with out all the agony of a nice grinding job inside and out.) by the way...the marine tex will also just look like a patch forever. or...you could go with paint !....

ARRRRRGGGGGGHHHH !

sorry....i dont mean to rip a strip into you. im just sooo dishartened about these sales people...
one guy walked in to ipp looking for marine paint, they sold him 3 gals of gellcoat and didnt tell him he had to caytilize the gellcoat...just roll it on like paint!

i know those guys at ipp in victoria.....i bough a lot of product out of there a few years ago...i used to live there and do radio at CKDA/CFMS...i beleive you call it the ocean now.

any how......your repair will work..its not going to be as strong as it would have been with different materials. and for the out side finish....just do the best you can
may i say your prep work looks great bud.

sorry this turned into a rant from me......but i have seen this far too often. for 40 bucks....you would have walked away with the same kit in poly resin from wallmart.

 

[jaymasta]

Re: Small crack in hull repair

I don't care how the finish looks on the outside its an old boat that doesn't have much value on the used market that I only use a few dozen times per year. I am a little bummed on the fibreglass though, it is 5 layers of 10oz mat. Like I said before I can't get the 1708 biax here and the roving they sell at ipp here was $29.00 a yard vs $8.00 for the mat I got. For the outside I was just going to sand it out a bit, mix up some epoxy and thicken it with the 403 stuff and get some white pigment for it. From my understanding though I could just leave things how they are and it would be fine, as the epoxy is 100% water proof. I'll keep the post updated with pictures as my progress continues.

 

[oops!]

Re: Small crack in hull repair

your work does look good bud.