Fiberglass repair

[RyanMac14]

So I know this is supposed to be in the boat section, but you guys know everything and I trust you. I have a small fiberglass jon boat which i load in and out of the back of a pickup. The constant scraping has done some good damage to the bottom and has resulted in a small pencil size hole that goes into the hull and Id also like to repair a little where it has been worn down before I end up pushing it too far. I'm not the handiest guy but I would like it to be a somewhat permanent fix. Anyone have any advice or even a place that would take care of it?

[jimmythegreek]

just goto autoparts or homedepot and get bondo and filler. sand any areas to be repaired and fill them in following the mixing guide. Put a patch of glass in the hole inside and out and do the same. sand when dry and do another coat if you need to or leave as is or paint. really simple to do

[RyanMac14]

I cant get to one side of the hole since it is located under the floor of the boat. Would it be okay to just put new fiberglass on the outside?

[Ken Lyons]

The best boat repair fibreglas is G Flex from West Marine. Both strong and slightly flexible so it's less likely to crack.

[RyanMac14]

Cracking isnt my problem, its scraping. How would it hold up to constant dragging?

[Sleeper-6]

What kind of tools do you have? Fiberglass repair is pretty easy, but it takes a couple of things to do it right.


Supplies:

You're going to need something to clean up the area, and grind down to into undamaged fiberglass to give your repair something solid to bond to. an angle grinder with some 24 grit sanding disks is ideal, but anything that can remove the damaged stuff and feather out through the paint/gelcoat a few inches out around the area will do. You want to do this right before you actually make the repair, Don't grind the week before and let it sit.

You want a quality unwaxed resin. Most of the over the counter stuff (Bondo, etc.)contains wax, it must be ground down between layers layers so the next layer sticks. With an unwaxed resin you can keep going as soon as it sets up enough to keep things from running and sagging. A polyester resin will do just fine, odds are it's what your boat was made from in the first place. You can get additional adhesion for vinyl ester or epoxy resins, but the price goes up accordingly and abrasion resistence will not be any better. I like to grab some extra hardener (MEKP) when I order. Sometimes it's necessary to use a little more in cooler weather.
Chopped strand mat (CSM) will be the glass you use to build up the repair. You can layer in glass cloth too if you wish, but given the size of your repair area you won't need that.
I purchased most all my supplies from US Composites.
Other assorted stuff you will need are mixing cups, something to measure resin and hardener, cheap disposable brushes, disposable gloves, a dust mask/respirater and eye protection for grinding and sanding.

The Process :

Grind or sand the repair area to to expose the undamaged glass and feather the edges out. This will give your repair something solid to bond to. This is the worst part, wear your mask and eye protection, a cheap painters suit will keep most of the itchys off you, baby powder on your skin ahead of time really helps too. Vacuum up the mess and wipe the repair area with acetone to be sure it's clean. The better you clean up now the less that stuff will make you itch later.
Next prepare you CSM, Tear it into strips the right size for your repair. Start small directly over the hole and keep increasing in size for as many layers you will need to bring you back up to the original hull thickness. Once you mix your resin there is no time for this.
For the actual repair, it's easiest to flip the hull so your in comfortable position to work and gravity helps keep everything in place for you. Mix your resin in small batches to minimize waste. Nothing is worse than having a cup of start to warm up and gel before you are done. Once it starts to thicken, throw it out, you can't make a quality repair with resin that's turning to Jello on you. Be sure to keep a box of gloves and an garbage can handy. Fiberglass is sticky and messy, it's much easier to just toss it in a garbage can than unstick it from everything around you when you are done.
Hold your strip of CSM over the area and use a brush to stipple the resin into it. Once it wets out ( it will be translucent), it should stick nicely. You goal is to use the minimum amount of resin necessary, the strength is in the glass not the resin. Air bubbles are weak points, You want your glass completely laminated to the layer below. I would let your first layer or two begin to cure before continuing. That will help support the rest of your layers and prevent air bubbles from rising from the backside. From that point on, just keep layering on the glass and and wetting it out with mixed resin the same way until you have build it up to the desired thickness. Laminating your layers wet on wet will produce the strongest bond between them. Strong is good.

Finishing:

Once your repair cures , you're ready to fish. If you want to make it look pretty, you can fill, Sand, and paint. When ordering your supplies, if you get glass balloons, you can mix them with your resin to make a filler. Keep in mind, there is no structural strength in filler and you want to keep it's thickness to a minimum. Regular auto body filler is not recommended below the waterline, it has a habit of absorbing water failing when used there.

Good Luck!

[RyanMac14]

Jesus, thanks for that guide. While very in depth and sounding somewhat simple, I simply dont trust myself to complete to ensure it is completed correctly. Any advice on a place that would be willing to complete such a small job?

[RyanMac14]

Or anyone willing to meet up with me and help? Ill pay or pick you up some gear to fill your supplies for the upcoming season

[jimmythegreek]

can you post a pic of the bottom hole/scrapes and the inside that you say is in the way?


also what area are you in?

[RyanMac14]

Okay they are attached. I am in Old Bridge right by Cheesequake State Park, but obviously would be willing to meet up wherever is convenient. Also jimmy I had messaged you about the FF you had on classifieds, is it sold?