GEL COAT REPAIR INSTRUCTIONS Repair Kit Items. Instructions: 1. Cut out loose gel coat chips with utility. Mix Gel Coat with Cabosil Powder until it reaches the. Gelcoat Scratch Repair. By Don Casey. Revised by BoatUS editors in April 2012. Surface scratches can be buffed out of gelcoat with polishing compound, but deep scratches must be filled. When the gelcoat surrounding a scratch is in good condition, the filler of choice is gelcoat paste, which provides both filler and finish in.
Gel Coat: Repairing gelcoat on fiberglass boat The topic of Gelcoat is often a mystifying subject for boat owners. Aside from the durable shiny luster gelcoat adds to any fiberglass boat, most owners know little more than wash and wax it frequently. If you are looking to do some DIY gelcoat repairs, this brief primer will help achieve adequate repair. The following will help you gather all the necessary supplies, select the right conditions and finish with an acceptable repair.
There is no succinct short answer for gelcoat, it is an art that takes some experimenting to perfect. But you need not be an expert to make a simple repair. These simple guidelines will get you started. A little trial and error is all you need to make those blemishes disappear. What is 'Gel Coat'?
Boat builders start with a permanent fiberglass mold that is supported by metal on the outside (to make it structurally sound) and on the inside, a gelcoat over top of the fiberglass to make it smooth. When making a new fiberglass piece from the permanent mold, the mold is covered thoroughly with a release wax. This allows the newly laid molded boat part to pop out once cured. After waxing the mold thoroughly, a polyester-based material called is sprayed on every square inch of the mold. The fiberglass laminate is laid in over this.
Thus, when popped from the female mold, the gelcoat becomes the exterior finish. Gel Coat is a unique material. More than adding gloss, it also functions as a water barrier to the fiberglass underneath. Especially with the production polyester fiberglass, the gelcoat protects against weakening of the fiberglass laminate from water intrusion. Though smooth and relatively durable, gelcoat, like any finish, is prone to dings and scratches.
Extensive spider cracking common on older boats is due to aging of the gelcoat. This can often be heard cracking underfoot. In such cases, grinding off the gelcoat for wholesale refinishing is the best approach. This handy guide is for localized repairs.
It gives a DIY boat owner the ability to repair gelcoat using a few other simple materials easily obtained. For Additional Hints, Please Refer to these JD Tech Tips: • • • Gelcoat Repair Techniques Surface Preparation of Repair Area• De-wax an area twice as large as the diameter of the repair with lacquer thinner or dewaxer. Wipe solvent on with a clean paper towel, rag or scotchbrite pad and immediately follow wiping dry with other hand before solvent flashes off. • Apply around the perimeter of the de-waxed area. Roll/fold the edge on the work side of tape back to make soft blended edge. Use to protect the boat from overspray.
If there is a molded bodyline or corner near the repair, you may want to extend the color patch to that point. The same is true for a painted or vinyl stripe. • Sand the entire taped off area out to the tape line with 320-grit paper. This total area will be gelcoated. • For scratches and gouges, a conical or spherical rasp that fits into power drill works well. Grind out the scratch making a V notch to increase bonding area.
Be sure to sand away any loose chips. If damages cover a broader area, use a coarse 80 grit to grind out the area in a shallow bevel, thus increasing bonding area.
• Sand the entire taped off area out to the tape line with 320-grit paper. This total area will be gelcoated. Deep Gouges, Chips & Dings Deep repairs that are beyond the superficial scratch will need some filler before gelcoat application. Link Download Game Ninja Baseball Batman. For small scratches mixed with the gelcoat to a peanut butter consistency will suffice. For larger areas the cabosil mix will shrinkback and mudcrack, so instead use an.
Be sure to let filler cure fully and remove any blush with a wetsand. Prepare the gelcoat mix• Determine the gelcoat batch size for the size of the repair--approximately 80 square feet per gallon of gelcoat (20 sq. 2 sq meters per Liter). Color Matching• the batch of gelcoat to match the color of the boat. If the boat is fairly new and the manufacturer is still in business, you may be able to get gelcoat that will be a very close color match. If this is not an option, you will need to purchase the gelcoat resin. We offer and.
These gelcoats sold at Jamestown Distributors have wax additive unless otherwise stated, meaning other patch aid type additives are not required. Select the base gelcoat that is closest to your existing color and then tint to match. For this, you will also need (called Epoxy Gelcoat Coloring Agents) to tint the base color to obtain a good match. We do not offer the patch additives. Instead, we recommend using the gelcoat with wax additive already included in the resin. There are several gelcoat patch additives that, when used properly with gelcoats without wax additive, make matching a repair easier. These are clear, low-viscosity resins which are not air inhibited.
These products are mixed with the pigmented gelcoat in place of a wax solution to provide a tack-free cured surface. They also provide the added benefit of thinning the gelcoat without changing the color of the cured patch the way acetone or styrene can.
A is available for small, simple repairs. Matching the repair color to the color of the boat is probably the hardest part of the entire job. Best matches are achieved in bright daylight. Professionals workshops often rely on a to simulate true daylight. You will find that most gelcoat colors change as they cure. As you, apply a small amount of uncatalyzed material to the sanded area surrounding the repair. Use your gloved finger to spread this into a sample the size of a quarter.
Wait a couple of minutes for the solvents to flash off. Any color variation will be evident. If the color match is not acceptable, change the color by adding small amounts of. As you adjust the gel coat color, try to think in terms of the basic colors, i.e.; the color needs to be blacker or redder or bluer or greener.
This will help you identify which of the pigments to use. Use very small amounts of the pigments. You may even need to dilute the pigment with to weaken the effects. Apply an uncatalyzed smear with each change of color no matter how small. Leave each of these smears on the surface until you have the color as close to the boat color as you can get it. When you are satisfied with the color match, wipe away all of the test smears with. Adding Catalyst and Applying Gelcoat• Divide the batch into a 2/3 portion and a 1/3 portion.
• Mix the 2/3 portion of matched gelcoat to desired consistency. If spraying, a for spray application. Mix in catalyst following the recommendations of the gelcoat supplier. Over or under catalyzation may prevent the product from reaching a proper cure. Apply this mixed gelcoat to the surface of the repair with a.
Apply several light coats, feathering each one farther from the repair area. Allow the solvent to flash off between coats.
You may need to apply five or six coats to hide the shadow of the repair. Most gelcoats colors will dry lighter in color if they are too thin. Most manufacturers recommend a total film thickness of 15 to 20 mils. A common mistake is to apply two or three heavy coats, causing solvent entrapment and improper curing. This may also have an effect on the color of the cured repair. Mixing Instructions: For Isophthalic, NPG gelcoat with wax additive for an air dry post applied application, sold by Jamestown Distributors.
Mixing instruction depends on the temperature and preferable dry times. The higher percentage of catalyst the faster it will dry. Air and surface temperature will also affect the drying of the gelcoat. The colder the air temperature, the higher the percentage of catalyst you should use. Do not go below 1/2% or above 2%.
Gelcoat Scratch Repair By Don Casey Revised by BoatUS editors in April 2012 Surface scratches can be buffed out of gelcoat with polishing compound, but deep scratches must be filled. When the gelcoat surrounding a scratch is in good condition, the filler of choice is gelcoat paste, which provides both filler and finish in a single application--but not a single step. Because the surface of the cured paste will be uneven, sanding and polishing are required to smooth the repair and blend it with the rest of the hull. Except for color matching, gelcoat repairs are easy and straightforward. &nbsp Gelcoat Choices You will find gelcoat available as both a resin and in a thicker putty form called paste. For scratch repair you want paste.
Repair kits comprised of a small amount of gelcoat paste and hardener, a selection of pigments, mixing sticks, and sealing film can be purchased for less than $20. Buy a flexible plastic spreader if you don't already have one. You will also need sheets of 150-, 220-, 400-, and 600-grit wet-or-dry sandpaper. A single sheet of each will be more than ample to fair all the paste in a repair kit. Color Matching The hardest part of a repair to the surface of a fiberglass boat is matching the color. Professionals who do gelcoat repairs daily still have difficulty getting a perfect match.
Even 'factory' colors don't match exactly after a boat has been in the sun for a few years. White has the significant advantage of being fairly easy to match, and once a small repair is buffed out to a gloss, shading differences will be unnoticeable. Matching colored hulls is somewhat more challenging. A color-sample card from your local paint store that matches your hull can provide valuable help. Ask the store clerk the formula; they custom-mix the color by adding tints to a white base. The formula may call for a half-dozen different tints, but the important ones are those specified in the largest quantities.
You can use the tints in your repair kit to approximate the formula. Always color gelcoat paste before you add the catalyst. Put exactly one ounce of paste into a mixing cup and add the tints a drop at a time. Keep track of the number of drops of each tint.
When the color looks close in the cup, touch a drop of the mix onto the hull. Make needed adjustments until you are satisfied with the match — don't expect perfection--then write down the formula so you can duplicate it for the rest of the paste. Preparing the Scratch Never try to repair a scratch by simply painting over it with gelcoat. Gelcoat resin is too thin to fill a scratch and gelcoat paste is too thick. Instead of penetrating scratches, gelcoat paste will bridge them, leaving a void in the repair. To get a permanent repair, draw the corner of a scraper or screwdriver down the scratch to open it into a wide V.
Catalyzing The hardener for gelcoat is the same as for any polyester resin--methyl ethyl ketone peroxide, or MEKP. Ethics And World Politics Duncan Bell Pdf Viewer more. Gelcoat resin usually requires 1 to 2 percent of hardener by volume (follow the manufacturer's instructions). As a general rule, four drops of hardener will catalyze 1 ounce of resin at 1 percent. The mix shouldn't kick (start to harden) in less than 30 minutes. Hardening in about two hours is probably ideal. Always err on the side of too little hardener. Also be certain to stir in the hardener thoroughly; if you fail to catalyze every bit of the resin, parts of the repair will be undercured.
Spreading Gelcoat Paste Work the gelcoat paste into the scratch with a flexible plastic spreader. Let the putty bulge a little behind the spreader; polyester resin shrinks slightly as it cures, and you're going to sand the patch anyway.
Just don't let it bulge too much or you'll make extra work for yourself. Scrape up any excess paste beyond the patch area.
Covering the Repair Gelcoat will not fully cure in air. To seal the surface of a scratch repair, cover it with a sheet of plastic film. The kit may include sealing film.
Otherwise a section of kitchen 'zipper' bag works especially well because it tends to remain smooth and the gelcoat will not adhere to it. Tape one edge of the plastic to the surface just beyond the repair, then smooth the plastic onto the gelcoat and tape down the remaining sides. Sanding and Polishing After 24 hours, peel away the plastic. The amount of sanding required will depend on how smoothly you applied the gelcoat. A 5 1/2-inch length of 1 x 2 makes a convenient sanding block for a scratch repair.
Wrap the block with a quarter sheet of 150-grit paper. Use the edge of the block to confine your sanding to the new gelcoat.
Use short strokes, taking care that the paper is sanding only the patch and not the surrounding surface. Never do this initial sanding without a block backing the paper. When the new gelcoat is flush, put 220-grit wet-or-dry paper on your block and wet sand the repair, this time with your block flat. Use a circular motion and keep a trickle of water running on the sanding area. Feather the repair into the old gelcoat until your fingertips cannot detect a ridge. If the hull is curved, take care not to sand the repair flat. Abandon the block and switch to 400-grit wet-or-dry paper.
Wet sand the surface until the repair area has a uniform appearance. Follow this with 600-grit wet-or dry. Wear cloth garden gloves--the kind with the hard dots--to save the tips of your fingers. Dry the area and use rubbing compound to give the gelcoat a high gloss. Swirl a soft, folded cloth over the surface of the compound to load the cloth, then rub the compound onto the repair area. Buff it with a circular motion, using heavy pressure initially, then progressively reduce the pressure until the surface becomes glassy.
If the gelcoat shows swirl marks, buff them out with a very fine finishing compound. Finish the job by giving the repair area a fresh coat of wax. If your color match is reasonably good, the repair will be virtually undetectable.
For more information about hull damage repair, consult Sailboat Hull & Deck Repair by Don Casey.