@HomeDistiller You are correct in saying that 20 mm is about 3/4 of an inch. However the term 'mil' does not refer to millimeters (or milliliters). It is a standard English measurement term for 1/1000 of an inch in thickness.
@tlgoldendc You can use a product called Surfacing Veil. It is specifically designed to prevent 'print-through' , which your are concerned about. Besides that, you might want to consider using Knytex. It contains three layers stitched together. One layer is mat, the other two are roving. You can put the mat side against the Surfacing Veil. Knytex is extremely strong and works well with epoxy.
@Breeze8488 You can use the same process as described in the video, except you would grind from the front, do the lay-up, and then top coat with gel coat. I would also recommend applying expanding foam under the pan after you open the hole and before you do the repair. That will add support.
Gel Coat will stick to most plastics, including Lexan, unless they are carefully prepared with a mold release. Two plastics that gel coat does not stick to are polyethylene, and poly propylene. If a mold is made from those plastics, no mold release is required. The molds used to make boats are made out of fiberglass with a highly polished gel coat surface. They are carefully prepared with mold release. Otherwise the new gel coat would bond to the gel coat in the mold.
If it is made out of fiberglass, then you probably can. However, the auto industry uses a variety of resins, so no guarantee. You can run a test by using some resin to bond half of a piece of fiberglass or even a piece of wood. Let it dry, then use the unbonded half of the fiberglass fabric as a handle and try to pull the fiberglass off. Same procedure if you used wood. That will give you an idea of the bond strength.
That depends on what the surface of your boat is. Some boat hulls are painted below the water line. Gel coat would not be appropriate there. If the surface is gel coat on a fiberglass hull, then gel coat could be used. Proper preparation is crucial. Also, realize that gel coat does not 'self level' like paint, so it will need to be sanded and buffed to create a smooth surface. That is challenging for large repairs.
@jjkewll First, clean the hole thoroughly. Perhaps the best repair material is epoxy mixed with either chopped strand fiberglass or milled fibers. The epoxy will provide the strong bond and the fibers will give the structural reinforcement. To hide the repair, sand it flush, then either use a matching marine paint or pigment some epoxy to match the surrounding area. The surrounding area is probably gel coat, so it would seem logical to use gel coat for the surface.
@1851davidb The video recommends a gel coat thickness of 18-20 mils. 'Mil' is a term used for .001 inch, not a millimeter. So 18-20 mils is 18-20 thousandths of an inch, about the thickness of 4 sheets of paper.
The formal answer is always mix according to instructions, however mixing slightly less hardener should not be a problem. Tacky surfaces result from other causing mostly from not thoroughly mixing the material, temperature, (both air and material) moisture in the air, or scrapping the sides of a mixing container where unmixed material may cling.
@homesellnow The holes must be thoroughly clean before any repair can be attempted. They may contain silicone caulk, dirt, oil, etc., all of which will prevent anything from bonding. You may even want to drill out the holes to create a clean fiberglass surface for repair. Several repair methods are possible. Here is one. Pack the holes with Dyna-Glass (you can find it in the fiberglass repair section at our website).
@13098519 Surface cracks are usually the result of flexing that is greater than the gel coat can withstand. So any repair must address the flexing issue, or the problem will recur. One solution is to inject foam under the shower pan as demonstrated in our video 'How to Use Expanding Foam.' If the 'surface' crack is deeper than the surface, then the fiberglass needs to be ground out to the non-damaged layer and then re-built.
@emolater2 That depends on what your canoe is made out of. Plastic/polyethylene canoes cannot be repaired with standard fiberglass techniques. Epoxy canoes should be repaired with epoxy. Not sure what you mean by 'plasticpadding' in your repair question.
@jjkewll However, gel coat has a hard time bonding well to epoxy. In a tiny area like a screw hole, that probably would not be an issue. See our video on gel coat repair to see that process.
@MgavaJ Go to our TAP website. You can order material on line, or click on the locations tab to find a local store. MEKP stands for Methyl Ethyl Ketone Peroxide. It is not an acid.
@tapplastics Thanks for explaining that. Just that I'm in the building trade and I'm so used to measuring everything in millimetres and hearing the word "mill" or "milli" referring to millimetres. :-)
The purpose of grinding is more than just cleaning. The damaged area of fiberglass must be removed. The structural reinforcement (fiberglass fabric) of the repair should duplicate what was removed as closely as possible. A patch placed on top of a damaged area will not be as strong. If the repair is strictly cosmetic (not structural), then wiping with acetone is probably adequate, though certainly not a guarantee that all contamination has been removed.
When you say 'shred the edges of the patches', do you mean fraying the fiberglass pieces before lay-up? If so, that might create smoother transition from one layer to the next, but is certainly not necessary for this type of repair.
@YANKEESRULEMLB It is difficult to give a precise answer without knowing the size of the damage. This will be a general answer. You will need to adjust it for your repair. First, grind out a 'scarfed' area as described in the video. If there is a hole in the fiberglass, it will need to be closed so that more fiberglass can be applied. If the hole is 2" in diameter, cut a 3" diameter circle out of cardboard.
I am restoring a 1967 Hydroswift. structurally the fiberglass is perfect (no damage). But cosmetically it is in VERY rough condition. The paint (gelcoat i think) is pretty much nonexistent, faded, and pitted everywhere. Can i simply sand, fill the pits, and repaint this? Or is there something else i need to do. I'm a automotive tech, but this is my first boat, and might as well be the surface of mars to me lol.
@YANKEESRULEMLB For the final layer, use mat, not some course weave fabric. When it is all cured, clip off the wire, and grind the repaired area smooth to a level just lower than the surrounding gel coat. Wipe with acetone and apply gel coat. You can then either apply Mylar to the wet gel coat for a mirror finish, or allow it to cure then sand a buff.
Your video was great,but, I would like to use this process in my shower as my shower floor has a hole in it. How can this be done since the underneath side of the shower floor is not accessible? Is there another method that can be used that is just as strong? Thank you, in advance
A properly done repair can be as strong as the original. However, areas of stress, or complex shape require a high level of expertise. The repair materials must match the lay-up schedule and structure of the original. This is often difficult for the novice. Repairs that have safety concerns should only be attempted by someone with experience and knowledge of fiberglass structure.
@YANKEESRULEMLB Put a wire or string through the center and knot it on the back side. Fold the circle in half and slide it in the hole. Once in the hollow space, it should pop open. Use the wire to pull it tight to the back of the fiberglass. Now, do the fiberglass repair as described in the video.
Is it just as strong as it was before? I have to fix a boat and the point where it is broken can be under stress and people can get hurt if it isn't. And how much does all this stuff cost?
Dyna-Glass is a polyester resin loaded with short glass fibers for incredible strength. Pack the hole so there are no air pockets. Do not bring the Dyna-Glass fully up to the surface of the bow. Once cured (10-20 minutes), apply Dynalite to smooth the repair flush with the bow. Once cured (10-20 minutes), sand the repair smooth. Finally, apply Gel Coat to match the color of the hull. Watch the two-part video, 'How to Repair Gel Coat' at our website for a fuller explanation.
Yes, it can be repaired, but that depends on the type of hot tub you have. Your best bet is to call a spa repair company. Do-it-yourself repair is possible, but it is more involved than most people are willing to do.
i hate to say but 20 mm is 3/4 of an inch or if its referring to another measurement then maybe don't use the term "mils" because that mean millimeters in metric countries (or milliliters when talking about fluids)
