fiberglass damage from rot

[jee70611]

Hi everyone,<br /><br />I don't usually post much, but I read the board daily. I have a problem with my project boat. It has a major crack on the port side in what looks to be an outer keel of some sort(is that what it's called?) from where my uncle was an idiot and ran it with a rotten stringer. I was considering just cutting the bad part out. It would leave a rectangular hole in the bottom of the boat about 1 foot by 2.5 or 3 feet long. I was thinking that I could take the old piece and use it to make a mold. Then I could rebuild the piece and put it back in place. I will be using west system epoxy resin for the job. Do any of y'all have any suggestions on what to use to keep the new mold from sticking to the old section and the new section from sticking to the mold. What should I use to fill in the gap between the new piece and the hull? Which type of material should I use to attach the new piece to the hull(woven roving, mat, or cloth)? How should I support the hull to prevent warping until the patch is put in? Does this seem like a good way to do it? This is my first project and I have to say, it's become more of a project than I expected . It's hard to see the extent of damage in the picture, but you can see the worst part. There are also what looks to be stress cracks that extend outward from the "V" to like five or six inches. Here is a link to my boat pictures. The one named "Boat 3" is the one showing the bottom damage. <br /> Boat Pics <br /><br />Thanks,<br /><br />James<br /><br />PS: The boat looked A LOT better when I got it. I discovered major rot though so in I went. I'm almost ready to pull the deck off.

 

[davecharles]

Re: fiberglass damage from rot

It's hard to tell from your pictures, but it looks like one of those jobs that you can manage. First, DON'T cut a large hole in the hull, it will only make your work. The section of glass that you would be cutting out only weighs a few pounds and may have some strength. Leave it in there. Grind the inside of the hull so that you have a good clean surface to lay up to. Lay up several layers of heavy roving, or biaxial cloth over the broken area extending at least 6 inches into the undamaged area. Your hull will be thicker in the damaged area but the extra few pounds will be unnoticable in a hull of that size. You hull will now be as strong as new. Now all you have to do is grind out the cracks from the outside, fill them, Gel coat and you are done. Sounds easy doesn't it. It's lots of work but not too difficult. I'd use polyester resin instead of epoxy because it's cheaper and gelcoat will stick to it better.

 

[tmcalavy]

Re: fiberglass damage from rot

you have received good advice on the repair so far. i would add this: drill a hole with small bit at ends of each crack, then proceed as advised. this helps stop the crack from spreading.

 

[crab bait]

Re: fiberglass damage from rot

i'd go about it all differently..<br />i'd grind off those thing/things .. they're called skegs.. grind 'em off flush.. then i'd roven than cloth over the void of the grinded off skeg.. <br /><br />repete until it's as thick as the rest of the hull..<br /><br />then replace with a piece of NON ROT wood ..such as teak or mohogony..<br /><br />thats it... done..<br /><br />don't try/no need to cover over with fiberglass anythin' cause it'll never conform to the thin an abrupt 90 deg. outside angles of the skeg wood..<br /><br />no need anyway.. the wood will never rot anyway.. <br /><br />use epoxy only for everythin' .. an marine tex epoxy putty for the cracks an for adherin' the skeg wood to hull.. no need to gelcoat.. marine tex comes in white.. an it's on the bottom .. WHO CARES..!!<br /><br />you get that floor open.. you'll find a <br />aother<br />big ole can-o-worms...

 

[Kenbo]

Re: fiberglass damage from rot

jee, Looks like you have your work cut out for you here. I would not cut out the bottom of this boat as you propose. D Charles is on the right track. If you use poly resin and a combination of chopped strand mat alternating with woven roving over this area from the inside, you have a better chance of retaining the original hull shape and performance. Looks like you will have to do some stringer work as well from your description and the photos. If it was mine, I would get that rotten deck out of the way and do a thorough assessment so you can better plan the job. Good luck!

 

[jee70611]

Re: fiberglass damage from rot

Thanks for the replies everyone. I had planned on getting the deck off of it soon. It's just that with work and school all the time it's hard to make time for it. Maybe I'll get a lot done during the summer, I hope. I think I would rather try one of the ways y'all proposed. I think it would be a lot easier and less risky. Those pictures are pretty old. I've cleaned it out and cut away a lot of the flooring since then. the port side stringer is pretty rotten all throughout. The Cross frames were shot too. I'm not sure about the starboard side stringer but I'm gonna just go ahead and replace it as well to be safe. I know it's probrably been mentioned before, but what would be the best wood to use for the stringers? I was gonna use epoxy because it's supposed to be easier to work with. Will I have any problems getting the epoxy to bond to the old fiberglass or would y'all just say to go ahead and use poly instead? I don't really know what is the best way to go because this is my first project boat ever. I can follow instructions well though so I should be ok. I don't plan on re-gelcoating it either. I'll just paint it with interlux or something when I'm done. Any more suggestions?<br /><br />Thanks,<br /><br />James

 

[sea wolf]

Re: fiberglass damage from rot

if it was my boat & i planned on keeping it for a while i wouldn't use poly, period. especially under the water line. if u apply it under the water line you're wasting time, $$$$ & energy because it won't hold up & doesn't have nearly the strength of epoxy. and i wouldn't be cutting strakes out of the hull either as it may effect you're hull's performance. i would cover the bad area on the hull as best i could with a good brand of epoxy such as west system & fiberglass mat & hope for the best. if u want to save $$$ i suppose u could use poly on the stringers, but not under the water line. just my .02. by the way gougeon bros. that makes west system epoxy has some literature that they will send u free, {u may have to pay shipping} which addresses repairs such as yours. it's very informative. i don't have their # handy but they must have a web site. good luck.

 

[Kenbo]

Re: fiberglass damage from rot

Jee, I don't understand the reluctance to use polyester resin for this repair, the rest of the hull (even the part below the waterline) was originally manufactured using polyester resin. With proper surface preparation and proper application, poly resin will provide a quite satisfactory repair at lower cost. The epoxy resin will also make a very servicable repair, I just don't see a significant advantage that would offset the additional cost. If you have your heart set on using epoxy resin, you should keep a few things in mind: First, don't use chopped strand mat with the epoxy resin, there is a binder used in the mat which does not dissolve when using epoxy resin. Second, epoxy bonds well to polyester laminate, polyester resin does not bond as well to the epoxy surface, if you decide to use epoxy, you will want to use it consistently throughout. For example, you might not want to do the hull repair using epoxy and then use polyester for the stringers. Check out http://www.legnosboat.com/ and click on the technical advice link for some useful info on both poly and epoxy resin. Just trying to help, Good luck

 

[Bondo]

Re: fiberglass damage from rot

I have to agree with D Charles,+ Kenbo....<br />The repairs Got to be done from the Inside.... By the looks of your photos, You'll be there Anyway....<br />For this boat,Kenbo is Right... Poly will be More than sufficient.... This is a production line boat..... The spider cracks in the other photos will Never go away... <br />10gals. of Poly..<br />Yards of cloth....<br />Some sheets of 3/4" CDX...<br />Lots of Sandpaper,+ Grinding Discs....<br />A couple gals. of Paint....<br />Have a Good Time Building it, Then Playing with it...<br />And, Don't grind those Strakes Off.... You'll be Looking at the Sky.....

 

[johndoe]

Re: fiberglass damage from rot

I don't know if this is the same type of repair, or not, but when i asked a question about repairing my old 1966 Chrysler Fiberglass boat, someone replied with the below link... the company seems to lay out fiberglass repair, and the product comes highly reccomended.. I am ready to order some products but not sure which way to go... How do you know if you should be using poly resin, or ??? Too many products out there...<br /><br />Any way, check out this web site...<br /> http://www.rotdoctor.com