Londons Autobody

How To Repair Fiberglass Cracks On Boats

Discovering fiberglass cracks on a boat is every boat owner’s nightmare. Although fiberglass can be considered as a sturdy type of material, cracks cannot be avoided due to the constant stress a boat can encounter on sea. Every year, maintenance costs can set back hundreds of dollars on a boat owner’ wallet. But this need not be the case anymore. If you’re a boat owner looking for a way to maintain your boat without having to spend so much money on it, then why not learn how to repair fiberglass cracks on boats yourself?

Do you want to know how to repair fiberglass cracks on boats? Then you need to need to know the basics about fiberglass first. You have to understand that the advantage with fiberglass is that it is one of those materials that are easy to fix. You don’t need to order in special supplies or tools just to get started. Most of the things you will need to know how to repair fiberglass cracks on boats are readily available in your tool shed.

To get started, you have to check the cracks on your boat if it is just a simple stress crack or if it is a void. It’s really easy to differentiate between the two. A stress crack looks just like a crack an eggshell could get. As soon as you find a crack on your boat, try to get it repaired immediately so that the crack will not cause further damage that will be more difficult to fix. As for a void, you’ll be able to assess a void by touching it. If it feels like there’s a dip on any smooth part of the boat, then most likely it is a void.

Knowing how to repair fiberglass involves having a little know how on how to use a sander or buffer. A sander or buffer is needed to ground out the stress and any other damages the boat has achieved. After achieving a smooth surface on the damaged part then it would be the perfect time to start applying the new fiberglass. Always follow instructions included with different solutions you’ll need so you can start applying the new fiberglass. Make sure you choose a crack sealant that is both affordable and very effective so you are able to get your money’s worth.

If you’re an avid sailor, knowing how to repair fiberglass cracks on boats can prove to be a very essential skill. As long as you have the right tools, supplies and a positive mindset, then you’re all set. Not only will it save you hundreds of dollars in repair bills, but it also gives you the fulfilling feeling of being able to fix your won boat.

Roberto Bell

Please click these links if you want to know more about how to repair fiberglass cracks on boats or how to repair fiberglass cracks on boats in general.

Tags: boat repair, body filler, Bondo, fiberglass cracks, fiberglass mesh, fiberglass repair

Bondo Basics – Apply and Sand

Bondo Basics – Apply and Sand (part 2)

This is a follow up to:  Bondo Basics – The Art Of Body Filler

When applying and sanding bondo your gonna want to be fully assured you know what you’re doing. This will save you time and materials in the long run. Don’t bother starting with the bondo until you have made sure your damage is pulled, patched, ground down, blown off, wiped clean and ready.

To Begin you have to make sure your area you are applying the body filler to is completely roughed up. Grind the area thoroughly with 36 grit sand paper or at a minimum of 80 grit. Take your air gun if you have one and blow off all the dust and grit from grinding. There are steps people like to avoid, I’m guilty too, but you learn some shortcuts pay and some don’t. Here’s one commonly overlooked. Wipe it down. Take the wax and grease remover and treat it as though you were painting it. The bondo has to stick completely or it will chip and flake, in other words it won’t feather for you and it will tick you off and waste time and materials. If your damage is repaired right you shouldn’t have to apply more than two or three coats to have a finished repair.

Alright, to the tools needed. Generally you want a 5 – 9 inch sanding block. The sandpaper you need will be the common 36, 80, 120 works well sometimes, 180 then 320 for feathering before primers etc. A DA Sander is used by some, but the same sandpaper applies, choose the same grits.

The methods: Depending on the size of the damaged area, mix only enough to fill the damage completely. Be sure to apply enough – this takes a little to get used to. One important note is that you will not spread the bondo perfectly, it shrinks in an you will end up with a low spot. Apply enough body filler so it’s built up a 1/8 or so. Not more than that, you will be sanding your butt off, this gets old Take your 36 grit or 80 grit, depending on the amount  of area you will be sanding. If you think you can lightly sand and feather in one or two coats, then stay away from the 36 grit unless you know when to stop. It puts some pretty deep scratches in the bondo and the area around the bondo where you will be sanding over. Use 80 grit to avoid excessive scratches. For most larger dents you will want 36 grit and your larger or largest file board.

With the panel prepared and the bondo spread,  let it harden. If you have a mess you can carve on it with a knife to get some of the stragglers you slopped on it off. If you wipe on body filler when it is not set up it will surely stick and you’ll have to sand them off. Let it harden and pick it off later.

For large dents that you know will need at least 3 coats of body filler it’s best to have a rasp or body file hand plane. It works somewhat like a cheese grater. Let the bondo set up real good, feel the bondo and it should be a little warm but not cold….if it’s cold it will be too hard for the rasp if it hardens.  Take the plane and begin filing in one direction. This is very rough but effective way to cut your panel. This takes a little getting used but it will save you quite a bit of time, sandpaper and your lungs from tons of dust. Use it on the first coat only, the rough coat. You will be turning right around and spreading another coat of bondo over it, after you blow it off real well of course . This is used to help get the filler straight. The low spots will not be filed. Note: To help Identify the low spots… spray the filler with a cheap flat black paint, the cheapest fastest drying kind you can find. DO NOT USE ENAMEL SPRAY PAINT, you don’t have all day to let it dry. Find a cheap lacquer paint, Walmart brand works good at .94 cents a can. Simply dust it, don’t put a full coat of paint on, just enough to add contrast to the body filler to identify where you have sanded. This will greatly assist you identifying what and where you are  sanding. High spots are gonna sand first of course. Keep attacking them as you sand until  all the guide coat paint around them is off. If you have sanded the filler and panel is free of the spray paint you applied, chances are you are real close to a finished repair. But there are other things to look for and consider.

Take your inline sander or manual long board of choice or hand sander and begin sanding in a criss-cross (X) pattern. This is extremely important if you do not want waves. Sand at a 45 degree angle in all directions to each other. This helps cut the filler evenly. If you sand in a straight line…. you get a straight line. This is not rocket science and there are no tricks. You have to watch what you are doing. Don’t go nuts sanding, do it methodically. Sand And Feel, Sand And Feel. Pay attention to body lines. They will have to be included in your sand and fill process. For straight lines use tape and sand up to it, reverse and sand down to it. Use tape when applying bondo to get a straight line. Apply the body filler over the edge of the tape and remove the tape before it hardens. If the filler hardens you’ll be sanding the tape too, so pay attention.

Apply bondo as many time as it takes to fill the low spots. If you have high spots you’ll know it. If the metal is showing and the bondo isn’t sanded… you have high spots. These will not go away. There are two ways to deal with this, only one is the right way. You can fill the whole panel up with body filler and sand and sand, or you can take your pick hammer and carefully tap them down. Tap them down!!! Don’t be afraid to use the hammer, you will need it until you are finished and satisfied. Don’t cheat, if it’s high… tap it down lightly…tap, tap, tap.  All the bare metal showing is high so tap the bare metal and beyond an inch or so. Stop sanding if you see this, they won’t go away and you’ll be getting further from straight. You’ll have to tap them all down and apply more body filler.

When you know your getting it close switch to the light grits. Use 80 grit paper and feather all the edges of the bondo and the paint together. It may feel a little rough and that is normal. You are filling the dent, the primer you use next will take care of the small scratches.

Another note: When mixing the bondo try to avoid flipping it over like taffy. Roll it over and spread mix it. You don’t want to let air get trapped in there. You will end up with pinholes eventually. Pinholes are just that. Small little pits in the bondo. These can be filled later with a glazing putty, but try to avoid excess air when mixing.

After the 80 grit sandpaper begin to taper down on the sand paper. Use 180 to feather any scratches in the paint near the filler. Finish with 320 to assure you won’t have sand scratch swelling later on down the road. The smoother you get the panel from here on out the nicer the repair will be as a finished project.

Wipe it down, look for pinholes, fill them with glazing putty if you have them. If not get that primer ready and spray on 3 good coats. Dust your primer with the black spray can and begin sanding again. I’ll write about the primers next.

Good Luck with your project. You’ll learn from experience, you can’t screw it up if you know these basics to bondo. It’s easier to do than explain

For further reading on Body Fillers  go here:   Bondo Basics – The Art Of Body Filler (part 1)

Tags: autobody techniques, body filler, Bondo, corvette repair, fiberglass repair, heavy weight gold filler, pinholes, sanding techniques

Fiberglass Basics – Easier Than You Think!

Fiberglass Basics – Easier Than You Think!

Does the word fiberglass intimidate you. When you think of fiberglass maybe your thinking you need a whole new set of skills. If you have ever used, or should I say mixed bondo, you are half the way there.

Working with fiberglass can be very effective and very simple. The key to a solid fiberglass repair is to plan ahead of time. Make sure you have the proper equipment. You will need:

• Fiberglass mesh, or preferably a fiberglass kit. It includes enough material to fix a rather large area
• Get yourself a decent pair of rubber gloves
• Depending on the size of the repair you’ll need a piece of cardboard, for mixing the resin/hardener
• Another peice of cardboard and some duct tape, (read below)
• A good industrial or at least a sharp scissors
• A old small paint brush, or some cheap acid brushes for applying the resin

When preparing to repair fiberglass, and you have your supplies as far as fiberglass necessities, of course you’ll want to analyze the damage very good. This gets overlooked very easily. When fiberglass is damaged in an accident it usually cracks, even if they are hair line cracks. They may not seem like much, but when it comes time to paint and certainly over time they will show up. You cannot build a bridge over cracked fiberglass with primers nor does bondo (body filler) hold forever. You will need to grind down all the damaged areas!

To Start wipe the area off where you are now going to grind. You’ll want to grind the area and all the little cracks down, at least a 1/16 of an inch. If you can grind further go ahead. If you can get behind the damage like say on a hood of a semi, then you can grind the inside as well. This is the proper way to do it, but I have had great success either way.

Take a tape measure and measure the area you have ground. If it’s ten inches then you  will need 30 inches of fiberglass matting. When repairing fiberglass it is essential to lay down 3 layers of mesh intertwined together to get the proper strength to hold the repair together, forever. You do not want vibrations or minor bumps to crack your repair again. Of course you cut it wide enough to fill the hole. Most fiberglass repairs will need some sort of backing plate behind the huge hole. This is where the other peice of cardboard comes in. Cut the piece an inch or so larger than the damaged area all the way around. Now the duct tape. Tape it in there real good for now. You are gonna have to find a way to get behind it. Use what works. I have had it where I can’t get behind So I tenderly have had to nurse it from the front side, holding it tight in place until it is set up, wear your gloves, you’ll be in good shape..

Now for the mixing of the fiberglass with the resin. Resin is the bonding agent, mixed with the hardener so it sets up. It is somewhat like mixing body fillers. It basically uses the same hardener,  same principle in mixing. There are a few different ways to do the next few steps:

• Pour out enough resin to be sure to coat all the pieces of mesh completely. You’ll normally need a 1/2 cup or more for most repairs. Don’t be skimpy here, you want to have enough to coat the glass. If you pour it in a container try to keep an idea how much is in there. Apply a few inches of hardener in the container and get mixing. If it’s hot you have about 10 minutes to to work so again have your fiberglass mesh ready to go. Take your mixture of resin over to the vehicle you are working on and brush liberally around the damaged are with the resin, put it as thick as will hold, but try not to let it go running onto the floor or the tires
• Another more messy technique I’ve seen is to pour out the resin on the cardboard and mix it there. Take your mesh and dredge it in it till it is coated… like chicken.  Caution though, this is very messy, I shake my head when I see this, but it will coat the mesh and probably the work bench and you really well.  Use the first method and paint it on.
• Take the cut mesh and press it around the outside where you put the resin, you want it to soak in there together.  Apply one piece of mesh at a time, this will allow you to soak each piece real good for a strong fix. If you have your cardboard backer it’s probably gonna be a permanent part of the repair. If you want it off you have to work at it carefully before the resin is set, but avoid allowing the fiber glass to fall in the hole, so let it set up a little and work quickly. Once you have the first piece on apply resin over the entire mesh, do these steps with all 3 pieces. Don’t worry if the fiberglass matting seems to be falling apart, it’s a good thing. The more intertwined the pieces are the stronger the repair.
• Let the repair set till it is hard as a rock. You want to grind on it or use a sander with 36 grit sandpaper to begin to flatten and form it out. DO NOT sand through the fiberglass around the edges of the repair, that’s why we ground it down another 1/16″. It should hold and be able to sit there without any problems, you’ll be grinding and finishing off with a couple coats of bondo.
• With the repair set up and ground down it may not hurt to test the strength of the repair. It should not give in, you should be able to push on it and see the rest of the panel moving in and out with you. If not repeat the fiberglass steps again, add a few more pieces and bond it to the strongest areas.
• If you feel the repair is strong enough, blow it off good and begin with the bondo. If you haven’t read Bondo Basics – The Art Of Bondo,  now would be a good time, you’ll want to read that before you begin with fiberglass.

Those are the basics for you, you can repair almost anything with fiberglass. Done properly you’ll patch boats, be able to put a front end on a Corvette, fix or replace a headlight bucket on your beloved Semi, I’ve even fixed bumper covers with it, to hell with the bumper repair kits!

Tags: body filler, Bondo, bumper repair with fiberglass, corvette repair, fiberglass mesh, fiberglass repair, hardener, mixing resin and hardener, repair bumpers, resin, sanding techniques, semi repair