Fiberglass and Epoxy Boat Repair

Fiberglass & Epoxy Boat Repair & Building How-Tos

Fiberglass Hull Repair (Video)

The experts at Metan Marine Restoration show how to repair a small section of damaged hull, right down to the new gelcoat application.

Video Transcription

[Tom] Hi I'm Tom Richardson for Boating Local and today I'm at Metan Marine Restoration in Halifax Massachusetts. Now Metan is known for doing some amazing restoration work on classic boats. They've handled everything from 34 foot formulas to 13 foot classic Boston Whalers. They've done a whole bunch of those and maybe you've seen them at the boat shows in new England.

Anyways today I've brought them something a little less challenging. It's a 1984 AMF Sunfish that my son bought over the winter. It has a slightly damaged hull section and we're going to see how Mike Burrelli and the folks at Metan go about fixing such a problem.

Well I'm here with Mike Burrelli. He's the founder and president of Metan Marine Restoration so I know I'm in good hands. What do you think so far Mike, you think it's something within your capabilities?

[Mike] No I mean it's a really easy one. It just demonstrates a pretty straightforward little fiberglass repair. Right now all Scotty is doing is wiping down the surrounding area so we can get a good look at it. Also what that does for us too if it was a bigger repair. A lot of people don't realize this if you have a fiberglass crunch say about this big. Well after you wipe you can find out that this crunch is about this big because the cracks carry out. Then you have to grind out all the cracks to properly fix it. So sometimes something like this might start out as only this, but it might turn into this.

In this particular case it looks like you bumped something off the trailer or maybe you hit a little rock. The reason why this area gave in is it's actually a little factory void.

[Tom] Oh really no kidding.

[Mike] What year is this thing?

[Tom] It's a 84.

[Mike] Well that thing has been there for thirty years, thirty plus years. You just happen to hit it in the right spot and it busted open the void. You can clearly see it was originally a void. You can actually see a nice clear perimeter of where it hit and just collapsed in that void area. Also a good clear sign is; if you look and see the top laminate is actually all dry okay. So that means it was a resin starved area and watch this. And you can see it as we peel it away, you see the gloss. You see how the fiberglass strands have no resin in them whatsoever. So this is a common problem. Just because it is Sunfish or any other boat, this is something that we run into all the time especially with all the warranty work that we do for different manufacturers. Listen, nobody's perfect so this is going to be a pretty straightforward repair. Scotty is going to grind this out and you can actually see. Look how dry all the fiberglass is. Alright Scotty do your thing, give this a little grind out. What we'll do is we'll add a little bit of glass, a little resin. Fill it up, do a little faring , come in with your magic with a little gel coat and we'll be all set.

[Narrator] The first step after opening up the void is to smooth the edges around the damaged area by using a grinder.

[Mike] You can see how that little void at least turned into this. And you can see now we are down to solid laminate. We got rid of that void. Scotty will come in, lay in a couple of pieces of glass, will grind the glass down and shape it. Put in a little vinyl, next the filler on it, fare it and you can prep it for some gel coat.

[Narrator] Next Scotty places tape around the repair area to prevent excess resin from getting onto other parts of the hull. To help him cut the precise thickness of fiberglass, he places a piece of plastic over the damaged area and traces the shape of each fiberglass layer.

[Scotty] I start with one full piece that covers the whole repair because I'm going to stay on the back. You don't want to take all your layers off. So you just put but the same amount of layers that in this.

[Tom] So there is like three layers there you are marking?

[Scotty] Yeah, and what you do is you go out from the outside and you bring it in a 1/4 of an inch, you bring it in a 1/4 of an inch and then you put the last one on top.

[Narrator] Next Scotty cuts out the plastic template and uses it to cut each fiberglass layer.

[Scotty] And then you got this piece of glass. So what I do is I just trace it out. You can somewhat see a piece. Now I have the pieces cut out I just put them back in order the way it was. I just take my pieces and I bring it over to repair. What I do is I just put it on top just to make sure it feels good and looks good. Usually you tell by the feel if it needs one more layer or not. I think that's pretty good. One more piece just to be on the safe side. I like the way it sits.

[Narrator] Once the three layers of fiberglass are cut, Scotty mixes up some vinyl ester resin and hardener and carefully wets out each section.

[Scotty] You will see how it absorbs right through. How it just changes the color. I just flip it back over just to make sure that it's all nice and absorbed. Now you take your first piece and put it right over the whole repair and just dab it in. Get rid of all your air pockets. You could put them all together and just throw them on but now you're taking the change of putting an air bound pocket in one of the layers. Now if you don't get all of the air out now you're starting the process all over again. So I just do one.

[Tom] You're creating another void basically.

[Scotty] Right so I do one layer at a time, tap it out to make sure you have got no air pocket. It might take a few seconds longer but you are guaranteed not to have a mess. Alright I got my one last little piece, right over the setup.

[Narrator] After the resin soaked fiberglass has been applied. Scotty covers the repair with the piece of peel ply. [Tom] The peel ply you called it?

[Scotty] Yes this is peel ply. It's like a silky fabric. And what you do is you put it over the top of your repair. It gives it a nice smooth surface plus it also holds the heat in.

[Tom] Why is it important to hold the heat in, so the cure is more effective?

[Scotty] It helps it to cure a little faster and with this on here you can actually see your shape if it's low or if you put enough pieces on. All right now I'm clearing my surface.

[Narrator] The way for the resin to setup; Scotty cleans the hull to get a better idea of its true color so he can match it with the gel coat.

[Narrator] After about 30 minutes the fiberglass is hard enough to sand smooth.

[Scotty] I try not to leave any glass on the gel coat. I want the glass on the repair itself, you know what I mean.

[Narrator] After a little hand sanding Scott cleans the area with some acetone. To fill in any low spots and pin holes in the repair area Scotty applies a thin resin-based skin coat.

[Scotty] Well this just fills in any low spots if there is any and if there's any pin holes it fills it.

[Narrator] Finally it's time to mix up the gel coat. To match the existing hull color Scotty must play part chemist, part artist.

[Scotty] When we put in the color against your boat it's just a shade off. So what I'm going to do it is I'm going to try darkening it up a little bit. I put a little bit of yellow in it, after the mix I'm going to spray it in.

[Narrator] Once the gel coat is hardened Scotty wipes the area with some acetone to remove any waxy residue.

[Scotty] If you feel it now you don't see any fingerprints or nothing, it's solid.

[Narrator] The final step is some light wet sanding to make a seamless transition between the repair to the rest of the hull.

[Tom] Scotty, Mike amazing job I can't believe it. Looks like a brand-new boat. In fact I don't even know if I want to use it.

[Mike] Go ahead and use it, you're just going to screw it up again.

[Tom] Yeah I know. I'll be back right. But it's amazing how many steps are involved in what is seemingly a small minor repair job. I mean there's a ton of steps involved. It really shows what you guys go through on a daily basis.

[Mike] Well you know what it does. It's going to give the consumer the idea to of what it takes to fix a little ding like this. You know when somebody calls and says “I only have a little ding. You know you tell them it's four or 500 bucks. They are like “What. They don't realize it just took one of my guys four hours to do that repair.

[Tom] It did, it was four hours.

[Mike] And you know if you want a professional repair done and as they can see from the video there is no down time. I mean that's Scotty for four hours hustling in 85° temperature so everything is kicking off quicker, and in the wintertime we use infrared lights and all that to accelerate it, to make our sun. So it's in our best interest to get the job done the quickest we can anyway but we still have to keep the quality up.

[Tom] Well it looks great, the quality is there evident in Scotty's craftsmanship today. Thanks a lot Scotty I really appreciate it and Mike. We'll be back to bring you more of Metan Marine Restoration's restoration magic. I'm Tom Richardson from Boating Local, thanks for watching.

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Fiberglass Hole Repair (Video)

A step by step process of how I restored a fiberglass boat console. Large holes are filled with fiberglass resin and fiberglass mat. A little filler is applied and the holes completely disappear ( after a lot of sanding ).

Video Transcription

Hey everybody, Joe Kristel here. Recently I had to make some repairs to a fiberglass helm on an old boat. And I thought I would show you guys how I got it done. Basically what we did here was, I had this old dirty helm with a bunch of holes in it. They are holes from speakers and accessories and all that. But what I wanted to do was to take this helm and flush it up, get rid of those holes and make it look good as new.

I did this project using pretty much over-the-counter products of basically fiberglass resin and fiberglass mat from a story like Lowe's or Home Depot. So I'm going to show you how I got it done. So the very first thing I did is I wanted to prep the holes that I was going to be filling a little better. And what I did is I took a rotor and I basically took the clean edges of these holes and made them a little bit wider. So I just took like a sand paper bit on a Dremel and basically soften the edges on the holes. I did that for all the holes I wanted to patch. Now that I've got the outside kind of rough sanded and prepped, I really need to work from the inside out. What I need to do is make a backing for these holes. So what I'm going to do is work from the inside of the helm.

The first thing I'm going to do is actually rough sand the large area where these holes where I'm going to fill. And again after I sand those areas I'm going to wipe them down with acetone. I know what we're going to do is we're basically going to build a backing here significantly larger than the holes themselves. So what I do is I precut some relatively large sheets of fiberglass mat or cloth. In this case I think I used three pieces of fiberglass mat. Our goal at this point is just to make a structural backing. We don't want to fill the holes at this point. So I need to create some way to fill our holes so that when we put our backing on it doesn't fill with the fiberglass resin upfront.

So what I did is I cut cardboard circles the exact shape of the circles that I need to fill. I took those cardboard cutouts and I taped it to another piece of cardboard. I then put wax paper over the circle and shut that up in a hole from the outside and then tape that cardboard down. What this has done is that cardboard is roughly the thickness of the walls of our fiberglass helm so this will give me a flat surface to work on from the inside.

So to create a structural backing, what I do is I mix up some fiberglass resin. I paint the resin down over a large area much larger than the hole itself. After I paint that risen on, I actually take a layer of fiberglass cloth or mat and lay that over that fresh resin. I then push that cloth mat into the resin, make sure it gets a lot of resin in it and then I actually paint some more resin on. Then I put another cloth on and again I push that cloth down into the resin and make sure the resin gets absorbed into the cloth. And I repeat this process. I think I put three sheets down for these holes. So what this is doing is it's given us some structure backing building up the wall of our helm. After we put the mat down and the resin on, we want to wait several hours for the fiberglass resin to cure. So we go ahead and tap it and make sure it's tough. If it's tough, it's hard and not sticky. Then what you can do is we can take our cardboard backing off and here is what it looks like. Now we still have a recess hole but we have a backing to work up from. We have a structural backing that's going to help us build a strong, secure fill for this whole.

So now we need to fill this whole. But we want to fill this hole structurally. So we get about an eighth of an inch to fill here. So what we did is similar to what we did on the reverse side. So we want to build this up with fiberglass resin and cloth. So what I did is I cut precut holes of fiberglass mat roughly the diameter of this whole. Went ahead and mixed up resin, I painted it on and then I laid the cloth mat down and tampered it in. And then put more resin down and then I put 3 to 5 layers of cloth in this case. After I was done with this I let it cure again.

Now we've got pretty much a nice solid structural repair over this hole. But you still don't have the whole completely filled. So this point what I do is I like a rough sanding over what you just did and this kind of notch down the high spots. So it gets its level with the walls of our helm. But now we're left with some voids and we want to fill those voids.

Now in this instance I don't want to just use fiberglass resin and I don't want to use more cloth. The main reason is that the fiberglass resin is very hard and difficult to sand. So you want to use something a little bit softer that I can sand smooth flush with the fiberglass helm. We want to make these holes so you can't see them once we paint them. So there are several options what you can do here but what I did is I took fiberglass resin and mix it in something called Cavasil. Now you may not be able to find this in Lowes or Home Depots but I happen to have some around the house from an old surf board repair project. But basically what it is it's kind of like ground up resin. It's a white powdery substance. So when you mix the substance with fiberglass resins, it cures very hard like fiberglass resins does but its much more sand able. So in this case what I did is I mixed up some resin and I poured in some of the Cavasil. So I mix it together. In this case what you do is you mix the resin and hardener first, and then you mix the Cavasil into a consistency that you like. I like it real pasty. Once that's mixed up, what I did is I poured that into any remaining voids that I have on this whole area. In this case I basically poured over the entire surface. I had to fill a little bit of a holly gap. I pour the mix in there and then I allow it to dry. Once this dries there's lots of sanding to do.

Basically what you want to do is we want to notch down this filler until we get this flush and smooth with the helm walls. So what I did is start with some heavy duty sand paper. I make it eightyish and work my way up to like a 220 grit. And that's a kind of a finer grade sandpaper that leaves you with a nice smooth finish. Once I did a lot of sanding quite a bit, these holes came out nice and flush. And although they did not look pretty, because of the paint, to the touch they were very smooth. Now we had nice clean patched holes, really the only next thing to do is paint.

So what I did for paint is I actually found a Marine paint at Lowe's actually. It's a Rustoleum product. I never used it before; they said it was great for fiberglass. So I went ahead and tried it and I'm very happy with it. All I did is I rolled the paint on. I did three total coats and the instructions said let it cure about 24 hours between coats. I did that and as you can see our helm looks pretty much good as new. So that's how I did it. Some people that are really into fiberglass may have done some other steps and take it a little bit further. But for the point of what I was doing, I repair the holes, I made the helm look pretty much new and for an old workboat I'm pretty much happy with it. So I hope this was helpful, thanks for watching, I'm Joe Kristel.

How to Patch a Hole in a Fiberglass Boat Hull (Video)

A demonstration on how to patch a hole in a fiberglass boat.

Video Transcription

Today, I am here to describe how to patch a hole in your boat hull. I, unfortunately, put a rather large hole in my hull. I was using an ice scrapper on it to tear out some foam while tearing it down for a restore and I put about a 4 inch gash in it. And we'll take a look at how to fix that.

Underneath you'll see I've already patched it. I'll go over how I did that. You'll notice that it is actually quite a smooth line for taking an ice scrapper to it, that's because I actually took a grinder and ground around the edge to make it smooth. I also made an angle that goes towards the inside of the hull. That way the resin won't get caught up and create air pockets.

How I went about this, you'll see here. This is actually just normal wax paper that I stole from my wife's kitchen. I put that on the inside as a non-stick material for the poly to set against. A side benefit of it if you have non-waxed poly that you're applying the wax paper actually acts as the wax and allows it to cure nicely. On the other side is actually a flexible cutting board that you'd find, say at Target or what not. Cost about $4, this one was actually a pretty well used one, so it was due to get replaced. So my wife won't be yelling at me anytime soon.

What I did was I duct taped those two layers to the outside of the hull, tried to make it as taut as possible. The smoother it is against the hull, the better your job will come out, and the less sanding you'll have to do. Move to the inside, what I actually did was I took a piece of fiberglass, just a strip of it, about 5 inches wide, and I did three layers on the inside. I simply grouped up a little poly against the wax paper that was on the outside. So it would seal up any seams, have less air bubbles on the edges, and I did three layers of 1/2 ounce mat and I started off with a small piece and got progressively larger to add maximum grip on the hull and is thick enough so that it matches roughly the rest of the hull. It'll end up being about 1/8th of an inch thick, which is plenty thick enough to bounce the next rock off.

The next day I came back in, I tore off the wax paper and the cutting board, and it's a little hard to tell, but actually it's nice and smooth. Perfectly in line with the hull, maybe slightly indented, it may need a little bit of filler. But it's actually better to add filler than to have sand it off because fiberglass and poly sands very tough. I also had a few air bubbles, apparently I didn't stuff the poly into the corners well enough. Luckily for me I plan on flipping this hull and I'll mix up some cadasil and poly, make some filler, fill in the holes. Let it dry, sand it smooth and she'll be ready to paint.