Crystic Gelcoat 253PA is designed for use with wet lay and vacuum injected epoxy systems. Gelcoats are modified resins that are applied to molds in a liquid state. Or is there another product you can suggest? Ideal for color matching gelcoat and tinting epoxy for art applications, river tables, furniture, and woodworking projects. Just wondering why you did not test the high build???? Click here to see this product & more on Fibreglast.com:http://bit.ly/1PtienNremium Gel Coat with over 900 color options! If the repair is above the waterline, high-gloss paint or gelcoat are often used to reproduce the original appearance. A hour or two later lay up another patch. More than 95% of all boats, truck & car bodies made of fiberglass are made primarily of E-glass, an orthothalic polyester resin and isothalic polyester gelcoat. Polyester resin will not cure on the surface in the presence of air. Hope this helps! per square inch, while a polyester resin can hold less than 500 lbs. If you brush on the gel coat, make sure to use a solvent-resistant brush. To do it right you should strip the gel your just asking for trouble not stripping it down, that will be where your fiberglass work will start delaminating from. The most common gelcoats are based on epoxy or unsaturated polyester resin chemistry. In repairs above the waterline, gelcoat applied over properly prepared WEST SYSTEM epoxy has a great track record. This is a film that forms on the top layer of epoxy that will inhibit the cure of polyester material as well as create bonding issues. Gelcoat or 'Gel Coat' is a material used to provide a high-quality finish on the visible surface of a fibre-reinforced composite. Hi Andy * A natural by-product of epoxies curing process is something called amine (or amine blush). Gelcoat derives its name due to it high viscosity and ability to be applied thickly on vertical and overhead surfaces in one coat. The graphs show very little change in the adhesive strength, and much of the variance is within the tolerance of the test method. Ok gelcoat over epoxy. They call it flow coat and add styrene to slow the cure rate. epoxy gel coat vs polyester gelcoat. Resistance to Wear. An epoxy's relative strength can hold up to 2,000 lbs. Show excellent weather properties. Use the epox to repair a polyester laminate is correct? I am guessing, if I use gelcoat I would need to let the gelcoat fully cure, washing away blush, prior to epoxy layup? Gel Coat is a specially formulated two-part polyester resin that is designed to be the first layer of resin applied in a mold . How about same prep, epoxy over gelcoat? We generally use a high build epoxy primer, and then a finish primer and then a 2 part polyurethane. I would be more interested to see a test of gelcoat over unknown epoxy and left in the weather for a few months. I am thinking about sanding down stress cracks on a Laser hull and then laying in fiberglass cloth using the 206 epoxy based on your test followed by bottom paint. These included using 742 Glass Fabric (6 oz), 407 Low-Density Filler, and 410 Microlight. WRAS Approved range of coloured Polyester Gelcoats. One set of PATTI studs were pulled for a baseline value. There is a common misconception, fueled by some gelcoat manufacturers and by some expensive failures in the field, that gelcoat will not bond to epoxy. MEK Peroxide Catalyst for Gelcoat/Polyester 2 ounce $ 3.99; Add to cart; Polyester Resin, 1 Gallon $ 50.98; Add to cart; Facebook Youtube Envelope Instagram . * Clean, Clean, Clean Make sure that the surface youre bonding to is very clean. You want to make sure that all of the hardener is incorporated into the resin. $$$ - Gelcoats formulated with polyester resin are much less expensive than epoxy. Two popular gelcoats were used, Minicraft and Evercoat. Gel Coat Black Gel Coat 3 Gel Coat Dump Gun 4 Gel Coat Pigment 5 Gel Coat White No Wax 3 Gel Coat White with Wax 4 Gelcoat Clear No Wax 1 Neutral Gel Coat 4 Tack Free Additive 2 Tooling Gel Coat 3 Gel Coat Quick View Black Gel Coat No Wax gelbkhp $9.99 Quick View Dump Gun Tips ESFN1 $16.99 Quick View DURATEC HIGH GLOSS ADDITIVE 904-001 DURATECP One gallon of gelcoat weighs approximately 10.5 lbs. Concern about adhesion occurs in situations where boats are in the water constantly and need to have a high level of finish on their bottoms that requires gel coat. RESIN COATING. For comparison, we also tested gelcoat adhesion to a polyester laminate using West Marine Boaters Resin. Gelcoats are modified resins which are applied to moulds in the liquid state. Polyester or epoxy? When the repair will be finished with gelcoat . 30 drops is approximately equal to one cc. per gallon). We stock a wide variety of colors in marine and tooling gelcoat. Self-etching primers do not work well on an epoxy coating because of epoxy's chemical resistance. VIBRANT COLORS blend easily into epoxy and polyester resins, and won't fade or discolor VERSATILE PIGMENTS are ideal for a variety of marine, woodworking and craft uses. Logically the test results should be independent of whether epoxy is applied to gel coat or gel coat is applied to epoxy. Figure 1. per quart (2 oz. The manufacture has a mold that they coat with a hard-glossy film called Gel Coat. Gel coat is used as an in mold coating on composite parts to produce a durable part surface. Epoxy has a lot of appeal for repair work (extended work times, stronger mechanical bonding, better moisture protection, etc). For more details please visit our website. Once cured, EG60 is hard-wearing, chemical resistant and a suitable tool surface for the production of epoxy-based parts. This resin is a laminating resin. Therefore, items constructed with these materials should be repaired with the same or compatible material. We know polyester gelcoat can be used over WEST SYSTEM Epoxy. Fiberglass Tape; Biaxial Cloth; . Scrape the sides of the mix cup, scrape the bottom; repeat, repeat, repeat!. Polyester Gelcoat is used to provide a high-quality visually pleasing finish on the surfaces of a fiber-reinforced composite material. This coating is allowed to cure and the epoxy laminate is applied directly to the paint. Sep 17, 2017. These results may surprise you! Figure 1 (right) lists the different material combinations that were sprayed with gelcoat. Epoxy is more resistant to wearing, cracking and peeling, and corrosion or damage from chemical or environmental degradation. If youre looking to prevent stress cracks from coming back, Id sand the surface down to bare glass, then apply the new material followed by bottom paint. Thats pretty much the exact steps I take when spraying Awlgrip I put this demo together for folks who are looking to use epoxy for their repairs but still finish off with gelcoat to blend their work. Other GelCoat Features Low Odor, Low VOCs Inherent Chemical Resistance High Adhesion High Gloss Retention GelCoat Product Information Mix Ratio 1.5:1 by volume Working Time 20-30 minutes biaxial glass over meranti marine plywood. GC50 is a clear, UV stable polyester gelcoat designed specifically for use with epoxy resin laminates. If you feel that you absolutely need to have a gelcoat finish over the repair, then use vinylester resin which is a close second to epoxy but which will accept gelcoat. This experiment was done using. A wide range of Epoxy and Polyester colour paste pigments are available. Scrub the surface with clean water, wipe the surface dry with a clean papertowel and this detail is taken care of. Backyard Boatbuilders. #6. The only conditions are that the epoxy needs to be thoroughly cured, well abraded and scrupulously clean. It is not recommended for use in any application which is subject to continuous immersion in water. Some as limited as 90 days. 6 oz/yd^2 of carbon weighs exactly the same as 6 oz/yd^2 of glass. The most common gelcoats are thermosetting polymers based on epoxy or unsaturated polyester resin chemistry. September 09, 2022 in on-policy model errors in reinforcement learning No Comments 0 . Thank you again for your wonderful videos. As epoxy is chemically very different to polyester, it doesn't react with the surface, leaving it partially uncured. Available in 9 popular colors, sold separately, or as a kit. Laminate a square of epoxy and glass up one end. Im not saying that its common practice, but in certain circumstances its something that I have done successfully. By. If you require a bespoke colour, choose 'Clear' which may be pigmented to your desired colour. One reason for this is the ability of epoxy to form a stronger mechanical bond to a damaged laminate than polyester resin. In most cases, a final finish needs to be applied over the repair. Now I have a doubt. This will ensure that all the hardener is well incorporated. Most production boats a constructed with polyester resin. I get so frustrated at gel coat that wont set up. Heres the link: Next video will show the results of the tests! The test included a variety of finishing processes. ADDRESS Unit 17 & 20 Abbey Business Park Mill Road, Newtownabbey Co.Antrim BT36 7EE CONTACT phone 028 90 861992 email sales@mbfg.co.uk If its not fully cured youre going to run into problems. Hi Andy. Mark Bowdidge has been using Gelcoat over the epoxy on his boats for years but only on the inside of the boat. Totalboat sells gelcoat for $35/gallon and epoxy resin for $172. Im a novice at this stuff but am a pretty handy guy, your videos have helped tramendously. * Proper ratios of resin to hardener are VIP. Both are used in boatbuilding. Description For use in Polyester Based Resins, Gel Coats and Epoxy. Gelcoats & Paint. It can work, but it is not the safest method. Danny in Baltimore. Many boats have been repaired this way and are performing well in a variety of climates. I consider it to be an epoxy with a MEKP/cobalt curing system with mechanical properties equal to or superior epoxy, but it smells. It provides a chemical bond to the existing laminate with similar strength & flexural characteristics. Polyester gelcoat can not generally be used with an epoxy resin system to make gel finished parts, however, there is a tie-coat or primer that can be applied over poly gelcoat in the mold. Oz = fluid ounce Note: Using drops for catalyst measurement is only an estimate. Polyester materials can be affected by amines in the epoxy hardener. The polyester/vinyester gelcoats however are designed to not fully cure at the outside, to give a reactive surface with the backing polyester. Something that I want to emphasize is that the above steps are not only geared to epoxy. If you want to roll on a gelcoat, be sure to use a 1/8 "or 14" solvent-resistant nap. Gelcoat also lends itself well to repairs of existing gelcoated parts that have been damaged or otherwise compromised. The crack is below the waterline. Next, use a gelcoat patch kit to apply a thin layer of gelcoat to the damaged area. It has a . Also what about Pettits Tie Coat Primer? Please Like or Share above and join the discussion below in our comments section!! 2. The fillers of gelcoat vinylester for moulds, on the other hand, may contain glass beads. Gelcoat is an unsaturated polyester or epoxy resin based compound that coats the surface of the boat/pool and is highly resistant to the marine environment. The answer depends on a few things. Alternatively, did you apply the gel coat to both substrates at the same time then press the two gel coated substrates together. I have been using west system to plug holes left in my transom from previous owners accessories. by. I will typically stir for a minimum of 1 2 minutes. As a general rule, the tensile strength of a polyester bond will be around 20 percent weaker than the same bond made with epoxy. Available to buy online in a 1kg and 5kg kit. There are boat builders using epoxy layup over gelcoat in the mold and that works but repairing them is another matter. Check out his web site for all the details. The nine-week exposure may not simulate what could happen after many years, but it does indicate that the gelcoat bond to epoxy laminates is a good bond and should perform well. For this reason products like Tycoat exist. Hi, I wonder whats the difference between epoxy gelcoat and polyester gelcoat ? It is brushed on and then flecked with a spray gun. September 15, 2019. But definitely not recommend. Epoxy also provides a better moisture barrier than polyester resin. Applying gelcoat to a cured laminate relies on a mechanical bond. How ever any good modified base enamel will bond to either product and can also be used with anti skid if you need to use it SuzukiChopper Senior Chief Petty Officer Joined Oct 10, 2004 Messages 782 Nov 7, 2004 #3 Re: Gelcoat over epoxy? This laminate provided a stiff panel that simulated a patch used to repair the bottom of a fiberglass boat. Over the years Ive broken the rules on occasion and to date have not had any issues using gelcoat as my topcoat over epoxy. Gelcoats are modified resins which are applied to moulds in the liquid state. This is a sort-of obscure question be relevant. Hi, I wonder whats the difference between epoxy gelcoat and polyester gelcoat ? Can I still use gelcoat or should I paint instead, after popping the bimini from mold? Our customers fiberglass repairs range from filling a minor screw hole to completely rebuilding the bottom of a boat that ran aground. Can you apply TotalBoat polyester Gelcoat DIRECTLY over a repair faired with an epoxy-based fairing compound? If below the waterline Ill typically do any fairing with thickened epoxy as it provides a better moisture barrier. You may either roll the gelcoat on, like paint, or spray it on, to apply the gelcoat. Second issue. . Best for Applying Gelcoat, Epoxy etc. Once the gelcoat has cured, sand it down until it is flush with the surrounding area. I am using a male mold to build a bimini covering for my center cockpit sailboat. I was reading online about the renovation of a Gougeon G-32 Catamaran. Answer: Epoxy over Polyester does work if the surface of the gelcoat or polyester is properly prepared. Once the shape is right, then a coat or two of bottom paint Hope this helps! Best regards. Basically, there are only two types of fiberglass resin. This is an older . Your gel probably contains no wax additive and it wont cure until the surface is ' sealed ' from the air. Carbon isn't lighter than glass. Polyester pigments can be mixed with Polyester resin and Polyester Gelcoat, Epoxy pigments can be mixed with Epoxy resin and Epoxy gelcoat. I just bought what the guy Im buying it from said would work. Polyester is an adequate adhesive but not as good as epoxy. The overall effect of moisture on the gel coats bond to both the polyester and epoxy panels was negligible. Polyester gelcoat is not recommended for finishing repairs below the waterline. 2022 Boatworks Today. Question 1: Gelcoat is used as a top-coat, epoxy is used as a structural material (as one part of a composite structure of reinforcing fibers and resin or as a putty) and a bonding adhesive. WEST SYSTEM epoxy is a wonderful material for repairing polyester fiberglass boats. Various Types of Polyester Resin: That makes epoxy resin usually the best choice for fiberglass repair work. Interestingly, Evercoat states on their can that it is not to be used over epoxy. A. Usually gelcoat, which is more or less filled and tinted polyester resin, doesn't stick to epoxy as well as it does to polyester. However, customers often want to restore the original gelcoat finish to below-waterline repairs where the boat is kept in the water and no antifouling paint is applied. Formulated for brush application. The repair is safe? Choose from White, Black, Dove Grey, Bright Blue or Dark Olive. Polyester is more fragile and useful for temporary . If the repair is below the waterline, antifouling paint is most often applied over the repaired area. Polyester resin laminates achieve their highest strength when the bonds between layers of fiberglass are chemical or primary bonds as opposed to mechanical or secondary bonds. System Three Epoxy; West System; Clear Coat / Table Top; Epoxy Pigments; Repair / Trial kits; Resin Calculator; Metric Resin Calculator; Fiberglass. Regardless of the resin you decide to use, if the mating surfaces are not fully cured and clean it may come back to haunt you! If you will be finishing with a gel coat, it is important to use either polyester or vinyl ester resin as your laminating resin. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Because Boatworks Today, its owners or partners cannot control how the information provided through these videos is applied, we will not be held liable for any damages; incidental or consequential. Age. If the exact color you need is not available, a very true color "reproduction / match" can be achieved when mixing different color pigments together to "blend" into the color desired. Its aways best to apply glass onto glass (when possible). But he found it necessary to remove ALL the original gelcoat from the Gougeon-produced, West-System boat. For full size boats, sometimes a layer of vinylester is used between an epoxy hull and the gelcoat. An excellent surface finish can be achieved by spraying gel coat onto the mold. Such a situation might occur with a boat kept in a pristine lake where antifouling paint is often not used. 32. Youre safe to use poly above or below the waterline. Ideal for color matching gelcoat, tinting epoxy for river tables, wall art, jewelry, and more MIX COLORS EASILY to get just the right custom color for your project These customers are concerned about the gel coats long-term ability to adhere to the area repaired with epoxy. To Repair a laminate polyester of my boat which resin you advice? LBI's 301 orthothalic polyester resin is a good choice for most repairs. Do I need to coat the EZ-Fair with anything to give it a good bond to the Gel-Coat? In stock. As far as I am aware the problems with polyester gelcoat and epoxy stem from fast commercial moulding of parts where the gelcoat is put in mould followed by the epoxy/fabric/core etc layup. I will be using epoxy resin for layup. Thanks good point I havent thought about that. Keep in mind that vinylester resins have an extremely short shelf life. It is advised that you allow your epoxy to cure for at least 3-4 days before moving forward. On the other hand sensitization of the user is not an issue like with amine epoxy hardener. Materials for spray-up molds may be wood, vinyl polyester, epoxy, rubber or steel. 2. Popular answers (1) Polyester and epoxy resins are chemicaly very resistant, although there are some soluble combinations. Your videos are strike such a perfect tone; you really have a sense of your audience! Suitable for application by brush to give an even film, free from air and drainage. * Presuming the mix ratios are correct, having everything properly mixed is another important step. Each resealable bottle contains 2 oz. Correct me if I am wrong. Getting your boat ready for Fall? It was epoxy laminate into polyester gelcoat with some kind of tiecoat included in the layup schedule vacuum pressed into the female mold. Re: Gelcoat over epoxy? Catalyze between 1-2%, experiment depending on product and weather, sun will accelerate the cure. Gelcoat is sprayed into a mold before the glass fabric and resin are applied to provide a smooth pre-finished surface when the part is . Jul 18, 2014. The test program we developed was designed to determine the effect of moisture on the adhesion of polyester gelcoat applied over fully cured epoxy. 2. Proper surface preparation will prevent these problems. The person doing it is a professional boatbuilder and was working closely with West Systems people in consultation. This is the final video testing to see whether gelcoat can be successfully applied to epoxy. I'm replacing the rotten deck on a 1995 glastron bowrider, cutting out the side consoles, and making a center console. The polyester/vinyester gelcoats however are designed to not fully cure at the outside, to give a reactive surface with the backing polyester. The two layers eventually cure together with a chemical bond between them. Epoxy Provisioning for Circumnavigating Antarctica, Making Appropriate Structural Reinforcements to Your Boat. The epoxy will bond much better to bare fiberglass. Polyester Gelcoat General purpose moulding gelcoat for hand layup use in GRP construction. I really enjoy your site and the You-tube video you provide. http://epoxyworks.com/index.php/polyester-over-epoxy/, (You must log in or sign up to reply here.). The most common gelcoats are thermosetting polymers based on epoxy or unsaturated polyester resin chemistry. I was wondering what you thought. Warm water and a scotch-bright pad Amine is water soluble and is easily removed. Copyright document.write(new Date().getFullYear()) Website Acquisitions Inc. All rights reserved. Although we often suggest following the manufacturers instructions, we believe, in this particular case, the manufacturer is overly conservative. Gelcoat can be applied in coats up to 24mils. as a Paint, In-mould gelcoat compatibility with epoxy. . Here is the first of 2 videos where I look to see if theres any truth to the belief that polyester based materials (such as gelcoat) wont bond to epoxy. Gelcoat or 'Gel Coat' is a material used to provide a high-quality finish on the visible surface of a fibre-reinforced composite. Gelcoat is a material used to provide a high quality finish on the visible surface of a composite polymeric material. Gelcoat Adhesion Test. http://gougeon32.blogspot.com/search?updated-max=2016-02-16T07:51:00-08:00&max-results=10&start=6&by-date=false How to successfully apply a gelcoat finish over WEST SYSTEM Epoxy. It claims it kills the blush. After the gelcoat cured for two weeks, PATTI (Pneumatic Adhesive Tension Testing Instrument) studs were applied to the surface. Two types of gelcoat - 1. The unimould system uses a vinylester tooling gelcoat. Our test clearly demonstrates that polyester gelcoat will bond to a properly prepared WEST SYSTEM epoxy as well as to a cured polyester laminate. It's always a safe bet to keep similar products together. Where there are structural cracks in the concrete substrate, a 13-oz/.37-kg woven roving mat is layed up over the damaged area before FRP spray up begins. Boat Design Net does not necessarily endorse nor share the view of each individual post. This test confirms that polyester gelcoats can be applied over cured WEST SYSTEM epoxy on repairs below the waterline. Boats that are dry sailed or trailered have also had good success with gelcoats on underwater epoxy repairs. Put your Gel Coat Application Knowledge to the Test. In addition, we varied the length of time the epoxy was allowed to cure before being subjected to high moisture conditions. Let the gelcoat go tacky but hard as above. Here is the first of 2 video's where I look to see if there's any truth to the belief that polyester based materials (such as gelcoat) won't bond to epoxy. Laminating resin (small cans) first, scrape with razor, mask, top a bit high with gelcoat, put clear tape over to cure hard, sand and buff until happy, maybe a little wax or something to seal and polish.