Large hole in fiberglass hull. Need to repair.

[brazenarticle]

Thats a big hole in a tough spot, but consider the price of the boat. Spending a boat buck or two to make a fifteen or twenty thousand dollar investment whole may make sense. On the other hand if after all is afloat a year from now and the boat is still worth $1000 dollars you're just patching a hole in the water.
Perhaps this is a good learning experience - once you are no longer afraid of big holes in fiberplastic sailing life is just a little bit better.
You can't really make it worse than it is. Grind it out till it looks way worse then start filling a layer or two at a time.
When done the formerly cracked area probably will be the strongest point on the hull.

[boatpoker]

Originally Posted by Cheechako

I think your plan is pretty solid. Make a form for the inside. Formica with wax on it might work. Anything flexible with wax on it, or they sell sheet wax that is good for making forms. Brace it in place.
Of course first you need to grind the edges feathering/tapering them out for a good long bond area of overlap. I think 12:1 is the number often used.... so a 1/4" thick hull would be tapered out about 3".
Overhead epoxy glass work wont be that difficult. You are going to need to grind it fair and probably fill with filler here and there to make it nice anyway... so if some drips sag and harden... no big deal.
Finally, remove your form and glass the inside also in the same manner. Or as noted above, do the inside first.
It aint rocket science, Hal Roth did it on a beach in Chile!

I'm with Cheech, this is a long way from rocket science and you are on the right path, Anyone with a little effort and 3oz. of grey matter can do this.
Follow the West System or Gougeon instructions and you'll be fine. My son, 13 at the time built a 13' FRP sailboat by himself without my assistance or advice, 30yrs later he still has it.

[captjcook]

If you need a backer, cover a piece of thin Formica with 6-8 mil polyethylene sheeting and use a few sheet metal screws to hold it in place. Lay in one layer of mat from one side and build out, grind out first layer of mat from opposite side to remove bubbles and build again. Use a bubble buster, do not use wax, do not use epoxy. Look up posts by minaret...a true pro!


Sent from my iPad using Cruisers Sailing Forum

[smj]

Hole is below the waterline so no need for gelcoat or a cosmetic fix. I would personally spend the extra few $'s and use epoxy as it has much greater adhesion to old polyester....... and the hole IS below the waterline where a bad repair could mean your last day of boating.

[boatpoker]

[QUOTE=captjcook;2096098] do not use epoxy. Look up posts by minaret...a true pro!
/QUOTE]

You are quite simply, uninformed.

[HappyMdRSailor]

Lot of great advice, good advice, and mediocre to poor advice here...

Honestly, you can do this on the cheap (well relative cheap)...

I personally would be doing this repair from inside the boat...

You've got to grind-grind-grind all the way out until there is no more damaged (cracked) glass... Then 12:1 taper the perimeter edge... For 1/4" thick hull that's 3" past the perimeter...

Tape some peel ply or plastic sheeting on the outside of the hull, reinforce it with a flexible backing. Skip any wax or release voodooooo ... Tape some clear plastic on the inside over the hole and mark it for your multiple layers of glass a la typical FG repair... (reads the gougon or the internets) Go WAY past your hole... 3ish inches past the taper... Your ground out hole is likely to be 30"x10"

I personally would be using 1708 biax for glass, probably epoxy for juice, but poly is fine with enough thickness...

These guys will have what you need without breaking the bank
Fiberglass , Epoxy , Composites, Carbon Fiber - U.S. Composites, Inc.

Get a couple rollers too so you don't squeegee out all your juice with a spreader on your learning curve project...
Fiberglass Rollers Bubble Rollers - U.S. Composites, Inc.

Fair and paint...

Keep us informed of the progress!

[HappyMdRSailor]

You can learn a lot from these vids... Amateur comedian alert...

https://www.youtube.com/watch?v=i9hfpOCnzEs

[smj]

[QUOTE=boatpoker;2096114]

Originally Posted by captjcook

do not use epoxy. Look up posts by minaret...a true pro!

/QUOTE]



You are quite simply, uninformed.

Sorry but I don't personally know Minaret so l have a hard time recommending him due to his presence on an Internet forum, though I'm sure he is a skilled worker. I was taught to use epoxy, maybe polyester above the waterline for a small cosmetic repair.


Sent from my iPad using Cruisers Sailing Forum

[HappyMdRSailor]

Be nice rule alert!

Lots of ways to skin a cat (boat)... and even a catboat...

[rwidman]

Originally Posted by HappyMdRSailor

Lot of great advice, good advice, and mediocre to poor advice here... ..............

How would you rate this advice:

While this repair may be a "piece of cake" for a pro or an experienced amateur, the OP has no experience. This is a very large hole and possible structural damage below the waterline. Any failure of the repair could be catastrophic and result in the loss of the boat and loss of life. This is not a good first fiberglass project to learn on. He's not going to get second chance if he doesn't get it right the first time. It's a job for an experienced pro.

[HappyMdRSailor]

Originally Posted by rwidman

How would you rate this advice:

While this repair may be a "piece of cake" for a pro or an experienced amateur, the OP has no experience. This is a very large hole and possible structural damage below the waterline. Any failure of the repair could be catastrophic and result in the loss of the boat and loss of life. This is not a good first fiberglass project to learn on. He's not going to get second chance if he doesn't get it right the first time. It's a job for an experienced pro.

Ron...

1/2 way between Great and Good!

I would say one could have a fairly good idea of the stoutness of the repair... Bang on it with a stick and if it stings your hand it's game on...

I kid...

Here's mediocre advice.... Have somebody who knows what they are doing with FG repair look before, during, and after the repair if you the OP want to do it yourself...

[cruisersfarm]

You have the correct information here.

Form inside, feather the edge (after removing all damage) - grinder, lay up using laminating epoxy.

The epoxy will drip a little, but not much, as you aren't painting it, you are wetting out the glass layers. It absorbs into the glass. Any drips were extra anyway.

What I would suggest is to use very lightweight cloth. 6oz or 8oz or so.

Spend time putting many layers of this on and build it way up. At the feathered edge, you'll invariably end up with proud spots if you bring the glass up to full thickness in the center of the hole. Simply grind those flush after cure.

Doing this, your repair is actually stronger than the original construction method, so no worries about any issues with the repair.

As said earlier, keep on grinding back that hole until there is no damage and you can do a nice, smooth feathered edge on undamaged hull.

Hardest part of the job is the form.

Since it's a pretty irregular shape, also make sure you vary the way you cut the new glass so the seams are lapped and staggered differently everywhere.

[hellosailor]

Reminds me of the first time I did arc welding. Heavy "security" bars to reinforce security gates. So my friend says, how do you know if that weld's gonna hold? I picked up the bar and slammed it hard against a concrete wall. I said "Well, I guess that's good enough, isn't it?"


Some things, really, just ain't rocket science. There is SO much clear, simple, unambiguous information out there about doing frp repair work, that the hardest and riskiest part of doing a "large" patch is mainly a question of how well the OP can color match the gelcoat afterwards.


And I'd bet YouTube has a trove of knowledge for those who are reluctant to read.

[boatpoker]

Originally Posted by hellosailor

Reminds me of the first time I did arc welding. Heavy "security" bars to reinforce security gates. So my friend says, how do you know if that weld's gonna hold? I picked up the bar and slammed it hard against a concrete wall. I said "Well, I guess that's good enough, isn't it?"


Some things, really, just ain't rocket science. There is SO much clear, simple, unambiguous information out there about doing frp repair work, that the hardest and riskiest part of doing a "large" patch is mainly a question of how well the OP can color match the gelcoat afterwards.


And I'd bet YouTube has a trove of knowledge for those who are reluctant to read.

+1 ..............

[On The Water]

Originally Posted by Brasshopper

In any case, the boat ended up with a 20" long hole in the port side, under the waterline. I want to do the repair myself. I plan on making an inner support out of something, maybe wax paper covered Formica or wax paper covered styrofoam or even foam in a can. Then I plan on building up alternating pattern and random cloth, pushing it into thick epoxy. Finally, I will cover it in epoxy filler and then gelcoat.

I have not done epoxy since I was 13 or 14...

The best advice here so far is get a pro to do, do it from the outside, forget epoxy and forget waxes , tapes etc.

So don't do it as there are so many little things you cant read from the books, little things that make the difference and then the big thing in knowledge that someone who has laminated over 10 or say 1000 tons of polyester resin has acquired not in any book

But since i have a feeling you going to do it yourself anyways and I am stuck, yeah its snowing outside, and have a few beers to kill before i turn in... and am not going to proof read this for spelling

From the images its seems there is a inner liner behind the hole.

Your own initial thought is pretty good but i would modify the approach a bit.

As it is right at the chine one could assume the bottom is also somewhat damaged.

My suggestion is to cut out a rectangle along the bottom about a 1 inch above the bottom of the hull to leave a small ledge upwards, the hole say 30" long 6" high but that depends how large the damage is so approx values.
This gives you axes to the bottom of the hull from the outside.
Strengthen that with appropriate non woven polyester laminate, (clean sand an all that) bring it up the side where you left the ledge and dont worry how damaged the material of the ledge is at this time.

You have also cleaned the insides of the sides before you comers on above lamination, from outside the best you can, this is not super critical but if you get it done perfect all the better, some 36 grit sand paper is good as you cant really get any tool in there.

Next on a flat surface like the Formica you were going to use for backing, laminate a baking, 5 x 450g/m2 should be plenty, make it 10" longer and 5" higher than the hole, drill 2 holes into it, slightly larger than a one component spray insulation polyurethane nozzle is so you can also fit some thin wire through it while the nozzle is in, trim it so you can later slide it inside the hull with ease or re design it to a two part backing, one peace is is better but not always possible, the main thing is you can get it place with ease.

Next fair "feather" the sides around the hole the best you can 6" minimum id go a whole 1 foot but the sides are pretty thin so something in between.

The next part is a bit tricky, i would laminate strips of wet fiberglass on to the on to the backing and on to the insides of the sides of the hull and the strengthened ledge you left and built up but there is a big possibility to mess up here, the other way is to try to stick wet laminates inside of a hull and on the backing while the baking plate is inside the hull but that might end up even a bigger mess, so first option is maybe better, just plan it so it slides in nice and you can hold it by the wires and remember this part is not really critical but will help to spread the load so if done well all the better. Personally i would not be satisfied if it was not done perfect. Do a few dry runs screw on a handle to hold on to it once you know where the handle wont interfere with the fitting of it in place.
One it is place with the wet fiberglass screw the sides with a few self taping screws (another possibility to screw it up ) or tension it out with wires from the whole or using the handle, you'l figure it out, might even spray some window foam insulation in at this time if you not sure what you doing, one can should do it with the inner liner so close but even 4 cans, just the cheap stuff that deteriorates in sun light and will absorb some moisture after time, might make the difference between sinking if you botch the repair. I would not spray in any but just saying.

After all is dry and nothing has bulged, it should not but make sure it can not bulge out one bit or its fed up, do the actual repair (again only non woven and only polyester) from the outside against this structural backing plate and the strengthened chine line flange against future pounding and stuff so do it good.

Anyways I am out of beer and saying I would not repair it quite like that, almost but not quite if was to keep it for myself (as would most likely just scrap it depending on circumstances) but that is the most simple method for a inexperienced do it your self that should hold even if you mess up a bit, finish of with some polyester putty, and polyester paint, slap on some anti fouling and its there.

Edit: LOL just red it, doubt anyone will understand that text.