We use cookies to make wikiHow great. Change ), You are commenting using your Facebook account. Applying gel coat correctly is of utmost importance to making aesthetically pleasing and long-lasting end products. Gelcoat that is over-initiated can result in excessive shrinking and premature release from the mold. If the surface is paint, then the paint would have to be removed before applying the gelcoat. Our technicians recommend using Dyekum Steel Blue to be very thorough. It will take a minimum of two coats of gelcoat if you are changing colors. You can make your own gel coat using fiberglass resin and Bondo auto body filler. Be sure not to use foam rollers, as they tend to leave bubbles. We are ready to gelcoat! Gel Coat must cure without presence of air; it's often done in a mold so it cures between the object fiberglass and the mold. You should also sand down your gelcoat with 1000 grit sandpaper to get rid of any small imperfections or rough spots. It’s used on the final coat, only. Posted on November 11, 2015 by Kristin. Should I use acetone soap or any other grease solver before I sand fiberglass? Is there a thinner for gelcoat for fiberglass? Can You Roll Gel Coat . % of people told us that this article helped them. If you want reflective gelcoat, consider using wax instead. If this is going over a patch, we recommend 2 coats at least, to get a nice, uniform surface. Please help us continue to provide you with our trusted how-to guides and videos for free by whitelisting wikiHow on your ad blocker. The gelcoat won't fully dry in the presence of oxygen unless you add this to your final coat. Your second coat will consist of the same amount of Catalyst, but if you are doing one more coat, your next coat will include Sanding Aid, or ‘wax.’ You will mix in 1 oz per quart to the gelcoat, which will seal the surface from oxygen, causing the gelcoat to dry tack-free. I am an architect designing and building geodesic moduled vehicles, but a novice with fiberglassing, so I am gonna need help. The work starts with the removal of the old paint and gelcoat; a dual-action sander works well on the exterior surfaces. 18 mils is approximately the thickness of a matchbook cover. wikiHow is where trusted research and expert knowledge come together. Clean the area with water and use a dry towel to wipe. Step 2 - Apply the Gelcoat. This will help in removing the oxidized gelcoat on the boat. If you are using our brushable gelcoat, you will want to let it sit overnight to ensure it’s completely cured. during sanding. We recommend 1-1/4% to 1-1/2% by volume, which means 13-15cc’s per quart. Application Instructions Apply a small portion of Aqua–Buff 1000-W or 2000 on the surface using a brush or microfiber cloth (stick to a small area) Use a spray bottle to mist the surface with water. Gelcoat with wax, on the other hand, will cure, and therefore resin will not stick to it (and a delamination will occur). Not exactly! Be sure not to use foam rollers, as they tend to leave bubbles. If you are using our standard Exterior gelcoat, you will be ready to sand and buff your freshly gelcoated surface. Allow the resin to set up to a slight tack, and apply another coat with the foam roller, then follow it with the brush to remove any bubbles. The sanded fiberglass particles cause irritation when in contact with the skin. Not quite! For applying your gelcoat, you can either roll the gelcoat on, like paint, or you can spray it on. Avoid spreading the gelcoat too thin or you’ll get stroke marks. The amount is very small. Please consider making a contribution to wikiHow today. Thanks to all authors for creating a page that has been read 338,884 times. You can buy a gelcoat spray gun online or at your local paint store. How do I apply gelcoat on a fiberglass pool? Exactly! At that point, you can apply the gelcoat to that to get a nice finish. You can’t apply gelcoat directly to Epoxy Resin. Inspect the boat's finish to see if it is still shiny or has imperfections. COVID-19 Small Business and Paycheck Info. ", "Gave me a good basic understanding of gelcoat.". References It will bond and be of similar hardness. We also sell a Brushable Gelcoat that can be applied with a brush. At 70 degrees, you get your 15 minutes, but at 90 degrees, you only have about 5 minutes. Nope! Can gel coat be applied over epoxy resin??? It’s the first coating in a mold. All antifouling paints may be applied over TotalProtect. Applying gelcoat to fiberglass is simple if you have the right tools and take care to mix your gelcoat properly. Then fill the cracks with a polyester filler and let it cure for about 10 minutes before sanding again. Amid the current public health and economic crises, when the world is shifting dramatically and we are all learning and adapting to changes in daily life, people need wikiHow more than ever. Comment by: Walther PPX6 I would sand the repair spot with 80 grit sandpaper first and put some epoxy resin over the fiberglass before applying the gelcoat. First, decide if you need one or two coats of gelcoat. Many of our customers are hesitant to use it, thinking it’s too complicated or they think they can’t end up with a good finish. This article has been viewed 338,884 times. To apply the gelcoat with a brush, dip the brush in the gelcoat so there’s a liberal amount of gelcoat on it. Once the surface is clean, you want to get going pretty quickly; if the surface sits for any extended amount of time, you will want to re-clean the surface. To start sanding, begin with 320 grit sandpaper and sand the surface completely. ( Log Out /  Pick another answer! Change ), You are commenting using your Twitter account. 3 years ago. Wipe the boat again with a rag, damp with styrene. You can also use a paint scraper, but it doesn't work well on irregular surfaces. Not exactly! Once applied, you want to wait about an hour and a half, for the gelcoat to set. Two-part polyester resin for use as a final or finish coat over laminating resin. Will fiberglass resin adhere to the gelcoat? MEKP will help your gelcoat start to harden, so it's pretty important. What do I do if my gel coat is chalky and has no shine after each coat? For applying your gelcoat, you can either roll the gelcoat on, like paint, or you can spray it on. Please consider making a contribution to wikiHow today. Rubbing compound will make your gelcoat look smoother and shinier. It's a good idea to clean your fiberglass before you apply gelcoat, but if there are cracks, there is something else you need to do first. Gelcoat does not cure in the presence of air. Rubbing compound won't change the color. I did my test gelcoat last evening.. over fgci vinyl Ester resin. How to repair and re-coat gel coat finish on kayak or boat hull using DIY methods. With gelcoat, we recommend at least 2 coats. If you decide to roll on the gelcoat, be sure to use a solvent-resistant 1/8” or ¼” nap. Nope! First you would apply a release agent to the mold, then brush on the gel coat. Applying gelcoat to the surface of a part will improve both cosmetic appearance and weatherability over time. Spraying gel coat is recommended for more accurate and consistent coverage. Wash away amine blush with water and an abrasive pad such as a 3M #7447 Hand Pad. I out mekp at just between 1.75% and 2%, out side in temp was 67 Dec, but part was in Sun a few deg warmer. (First time working with gelcoat). Add color tint drop by drop according to manufacturer's directions. I have a couple of questions to ask to better help you. You can apply gel coat with a brush if you are building a fiberglass project in a mold. Wear gloves and eye protection. Click on another answer to find the right one... Did you know you can read answers researched by wikiHow Staff? How To Apply Gel Coat Over Fiberglass . Use this towel to gently wipe the fiberglass. Read on for another quiz question. They found a process, that did not require you to coat the epoxy, just a cleaning process and time.. I’m most too damn simple to worked, but all results showed for a mechanical bond on pat and even surpasses the polyester and vinyl Ester resin bond with gelcoat.. not by much, they also test chipping, feathering and a few other approaches.. it all started with a customer.. who found a way.. .. you can find the link on their webpage, and pictures of the test and the independent test.. If the finish is dull in some places and shiny in others, it is probably time to apply gelcoat. of coloring agent per quart of gelcoat. Spraying Gelcoat Over Old Gelcoats . Apply gel coat in 4-5 layers at approximately 5 mils each, allowing 15-20 minutes between layers for a total thickness of 20-25 mils. Discard the curing gel coat/resin. Guess again! As with all our products, if you have any questions, we are here to help! The gelcoat with no wax, brushable, added pigment, let sit for 18 hours.. trying to sand it and it just gunk up my sanding disk each time.. How to successfully apply a gelcoat finish over WEST SYSTEM Epoxy. This will give your surface a slightly raised edge, which will help the gelcoat … You'll need at least three layers of gelcoat on your fiberglass. You want there … What paints are compatible with TotalProtect? Applying Gelcoat To Boat . We recommend using Acetone, as it doesn’t leave a residue and evaporates quickly. As hard as it is to get up and going, it can be even harder to go and gelcoat or work with Epoxy. If the surface is already coated with gelcoat, or if the surface is a fiberglass or polyester resin, then the application of gelcoat is a snap. I tried to just take the first layer off then switch to clean pad, still even middle is gunk.. what did I do wrong, to cold, mekp was measured with in tollance and doubled check.. Was the sanding disk cleaned with water before use? Applying gelcoat to fiberglass is simple if you have the right tools and take care to mix your gelcoat properly. At this point, you can use an 800 grit compound to compound the gelcoat. Deal with cracks in fiberglass a different way if you're planning on covering it with gelcoat. Make sure that you give your boat a thick layer as a thin layer may not give a complete seal. Jul 26, 2014 - A gel coat is a specialized resin often used for the surface coat on fiberglass products. Let each coat dry for at least 4 hours before applying the next coat. Your first coat will simply consist … Would Evercoat white gelcoat be opaque enough to use by itself over the maroon or would I have to lay down a grey catalyzed epoxy primer, etc. Continue rubbing until the surface gets a glassy shine. If gel coat is not applied properly it ultimately can increase the cost of the product made, as often is the case, cutting corners in this process will not prove to be worth it. If you roll or brush your seconding coating, be sure to go the opposite direction from the previous coat, allowing a uniform coating. Sand, paint, or apply gelcoat upon full cure. Oils, grease and road grime from trailer rides accumulate on the hull, where they quickly break down the protective boat wax, and strain and pit the gelcoat. Good day! Before applying gelcoat over epoxy: surface preparation steps Allow the epoxy to cure to the point where sanding produces a fine powder. How should you fix cracks in your fiberglass before applying gelcoat? Nope! Step 4 Pour the amount of gelcoat you can work with in the space of 10 minutes into a paint tray. So, gelcoat is used as a sealing, asthetic coat. If the surface is already covered with gelcoat, or if the surface is a fiberglass, or polyester resin, then applying gelcoat will be a snap. For small sections of fiberglass, apply the gelcoat with a brush. Properly applying gelcoat is the key to a good finish. We know ads can be annoying, but they’re what allow us to make all of wikiHow available for free. Support wikiHow by Thanks, P.s. wikiHow marks an article as reader-approved once it receives enough positive feedback. Fiberglass Repair – Using Gelcoat Over Epoxy. Before you gelcoat fiberglass, fill in any cracks or gouges with a polyester filler and then sand the damaged areas down with 80-grit sandpaper. The wax, or Sanding Aid is an additive that allows the gelcoat to dry tack-free. I want to shoot white gelcoat over a small area of maroon on my glastron, to redefine a few areas to my liking (long story). When resin starts to gel before getting harder, is it still good to use? as a base coat of sorts. Clean the fiberglass with soap and water and wipe it down with a rag soaked in acetone, and immediately removing it with a clean dry rag. We have two types of gelcoat; the brushable and the standard. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. Dust and dirt particles are your enemy here, so be thorough on the cleaning. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Sand it down with 80 grit sandpaper until it’s flush with the surface of the fiberglass. Take a towel and apply some rubbing compound on it. Start by sanding the surface with 150 grit or lower sandpaper. What will applying a rubbing compound do to your gelcoat? Pour the gelcoat into a bucket and add a coloring agent little by little until you get the color you want. Steel Blue is a dye you wipe on. It also requires more coats than a typical tie-coat primer, at a very specific mil thickness, and has a 3:1 mix ratio by volume. Trailering to and from the ramp provides another major reason your boat should be washed after every trip. If available, you can use a spray gelcoat. Learn more... Gelcoat is a liquid that hardens to form a thick layer that's used to protect fiberglass and give it a shiny, smooth finish. Choose another answer! Brush the gelcoat onto the fiberglass using short vertical strokes. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Nicks and dings in your fiberglass are common to any boat, whether or not it gets used often. You want to sand the surface to create a mechanical bond with the gelcoat. Clean with soap and water and wipe with a rag damp with acetone to remove old wax, oil or grease. Change ), You are commenting using your Google account. If you look at a pool, or even a boat, the gelcoat is the color you see. Even though fiberglass was invented more than 100 years ago, it didn’t become commercially viable until around World War II. Not exactly! TotalProtect is made specifically to prevent osmotic blistering on fiberglass/gelcoat boats and should be overcoated with antifouling paint. Spraying with Clear water?? For tips on how to sand and wax the gelcoat once it dries, keep reading! It will no longer be useful after it starts to harden. Two additives will help with a desired final finish. A good wash will ensure that your fiberglass has a smooth surface, and therefore that the gelcoat will pour or spray evenly onto the boat. It’s a quick, easy way to see the thickness of your gelcoat. Change ). If you decide to roll on the gelcoat, be sure to use a solvent-resistant 1/8” or ¼” nap. Choose another answer! This method is much easier and faster to apply to the base of your boat and you will have fewer areas that … ( Log Out /  If you brush it on, be sure to use a solvent resistant brush. This will remove any old gelcoat that is adhering to the fiberglass, and it will also wash away specks and stains from the surrounding surfaces. Apply gel coat to your part. Polyester filler is made of the same material as polyester resin (AKA fiberglass resin). In this case, 95% of readers who voted found the article helpful, earning it our reader-approved status. Our standard gelcoats are designed to cure in films as thin as 12mils (0.012 inches); however, we recommend that you apply them in coats of 18-20 mils to get the best cure, hide, and print block. Why is gelcoat sticky after applying to fiberglass? It’s been long believed that if you were using epoxy for your fiberglass repairs, you were more or less limited to having to use paint as your topcoat. The amount of MEKP you’ll need to use will depend on how much gelcoat you’re using and what brand it is. Spraying Gelcoat With Hvlp Gun . The glass fiber fabric is then laid on top of this and shaped to meet the requirements. "Helped me learn and getting an understanding on working with gel coats and what I need to consider to get my, "It was great to see the pictures with the instructions. For tips on how to sand and wax the gelcoat once it dries, keep reading! Gelcoat needs to be applied relatively thin. unlocking this staff-researched answer. Before you apply gelcoat, sand down cracks. Step 4 Measure the suggested amount of color tint from the color chart so that the gel will match the color of the rest of the inside of the boat hull. It therefore serves as the base layer. You can wait 24 hours or continue building your project immediately, the gel coat will not cure until it is sealed in the mold by your fiberglass layers. Unlock staff-researched answers by supporting wikiHow. What does methyl ethyl ketone peroxide (MEKP) do to your gelcoat? Like what’s gelcoat for to start. How much of the gel coat? Apply a layer of gel coat approximately 1/16 inch thick. Gelcoat products are polyester based, resin coatings used to provide a smooth, high quality finish on the surface of a fiberglass part. Next, you want to clean the surface. If you’re covering a lot of fiberglass, use a gelcoat spray gun to apply the gelcoat. Include your email address to get a message when this question is answered. If your gelcoat doesn't come with any MEKP when you buy it, you'll have to buy it separately. Repairing damage to your gelcoat and fiberglass can seem intimidating, but when done properly, can be a simple and even quick repair. Dry the surface with paper towels, or rinse well and allow it to air dry. It’s best to do a 4’ by 4’ area and go from there. Use #122-A Gel Coat Thickness to ensure proper thickness is … Pick another answer! Pick another answer! The car polishers will not work, as they spin too slowly, so you want to check the spin speed. Protect your airways with a P1 mask for the same reasons. Brush On Gel Coat . Over the years I’ve “broken the rules” on occasion and to date have not had any issues using gelcoat as my topcoat over epoxy. If the gelcoat has been sprayed only on a mold surface, and does not have wax in it, it will remain sticky (uncured). Wax in the Gel Coat rises to the surface when it is sprayed, rolled, or brushed, creating a film and barrier that enables the curing to happen. ( Log Out /  This was just a test, and also to fill scratch and build up the bow edge before I spray gelcoat next week. If you need more working time, be sure to sit the can in some cool water, or even some ice to cool it down to 60 degrees give you a bit more time. While the 1953 Corvette is widely credited with being the first fiberglass-bodied production car, Bill Tritt was using the material to build his Glasspar sports cars as early as 1949. Businesses don’t stop just because it gets cold, and that is even truer in Florida. Make sure you follow the manufacturer’s instructions so the gelcoat isn’t the wrong consistency. By using our site, you agree to our. Approved. If you brush it on, be sure to use a solvent resistant brush. How do I apply graphics to a boat that will appear under the gel coat? From then on, start going up to 400, then 600, and finally 800 grit sandpaper. Otherwise, one coat will do. Gelcoat not only serves as a base layer but also as an adhesive: it hardens sticky on the side facing the air so that the application of the fiber is straightforward. So, you’ve decided the surface is gelcoat, so it’s time to begin. Hold the cloth with the polish on it in your dominant hand. This is what a sanding aid will do. No. Made it easy to do. You need to have a smooth fiberglass surface before you apply gelcoat. Remove the paint from fiberglass by sanding it off with sandpaper. Protect yourself with a long-sleeved shirt, pants and shoes. Read on for another quiz question. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/4\/4c\/Gelcoat-Fiberglass-Step-1-Version-2.jpg\/v4-460px-Gelcoat-Fiberglass-Step-1-Version-2.jpg","bigUrl":"\/images\/thumb\/4\/4c\/Gelcoat-Fiberglass-Step-1-Version-2.jpg\/aid1366110-v4-728px-Gelcoat-Fiberglass-Step-1-Version-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"