So what say you ??? what would be your approach??
All winter to determine my approach to this bow repair
- Thread starter tkwhalen
- Start date
So what say you ??? what would be your approach??
Ouch!... I thought I did that same thing one time when we were motoring in to our slip which is a tight maneuver and in current. I missed the slip entirely and hit our dock finger head on. it stopped an 11,000lb boat so suddenly that i just knew it had to have crunched the fiberglass.... but not even a mark.
but if it I had to make the repair, I would grind it back (feathered) at a 10:1 ratio or more, then lay it up with fiberglass roving... then use mat on top of the roving with a couple layers of cloth on top to finish it out..... than gel coat or paint.
when doing the lay up, I would start out with the smaller pieces of glass first, working up to the larger pieces.... make sure to use a laminating resin, and NOT a finishing/top coat resin. you can lay up 3 layers at a time.
make sure you dont have any voids, and that the voids are filled with fibers and resin, not just resin alone... keep the resin content just barely enough to saturate the fibers and not dripping out.
whenever possible, especially when working against gravity, I will use a piece of plastic (large leaf bag) and place over the work, then back it up with a piece of 3"foam rubber with a piece of plywood on that and block it in place snuggly..... this sponge helps hold the mat/roving tightly against the surface at all points, no matter how rough the surface is, and it also helps prevent the resin from dripping.... but it should be removed within a couple of hours, or soon after the resin sets.... if the surface is still tacky, lay up another 3 layers and do the same... but if the surface becomes tack free, then the surface should be ground a little to rough it up..
but if it I had to make the repair, I would grind it back (feathered) at a 10:1 ratio or more, then lay it up with fiberglass roving... then use mat on top of the roving with a couple layers of cloth on top to finish it out..... than gel coat or paint.
when doing the lay up, I would start out with the smaller pieces of glass first, working up to the larger pieces.... make sure to use a laminating resin, and NOT a finishing/top coat resin. you can lay up 3 layers at a time.
make sure you dont have any voids, and that the voids are filled with fibers and resin, not just resin alone... keep the resin content just barely enough to saturate the fibers and not dripping out.
whenever possible, especially when working against gravity, I will use a piece of plastic (large leaf bag) and place over the work, then back it up with a piece of 3"foam rubber with a piece of plywood on that and block it in place snuggly..... this sponge helps hold the mat/roving tightly against the surface at all points, no matter how rough the surface is, and it also helps prevent the resin from dripping.... but it should be removed within a couple of hours, or soon after the resin sets.... if the surface is still tacky, lay up another 3 layers and do the same... but if the surface becomes tack free, then the surface should be ground a little to rough it up..
HMMM not sure how I would get fiberglass roving and or matte into the bottom of this hole. I think I need to do some grand canyon filling first with something like west system 403 microfibers or some chop as the hole gets shallow then move to matte and cloth with cloth being feathered out 10 to 1 then finish with gel coat. At least that is my current thinking ...
Assuming you can't get to the back side, I would fill it full of spray foam. Once the spray foam cures, you can trim it to shape, so you can form the fiberglass over the hole. Assuming you can get the foam to completely seal off, I would vacuum bag when glassing over. The reason is that the vacuum will draw the epoxy into where the old fiberglass splintered. If you don't have a vacuum pump, an automotive engine generates quite a bit of vacuum.
Hence, the grinding back at a 10:1 ratio to do away with the biggest part of the rim so there isnt a hole to fill.... just a proper layup..
to just chunk stuff in the hole and fair it out would be the simplest thing ever, but if you are trying the build the strength back into it, that isnt going to do it.... what will likely happen with the simple fill and fair is, next time there is a mishap like what caused this one, the "plug" you would be putting in, will be drivin backwards thru the rest of the layup and break out to the inside of the boat, leaving a hole with water pouring in, rather than just a severe blem.... which is a much more involved repair.
the reason it would do this is, even though the resin or epoxy may adhere tenaciously to the fibers that are exposed, those fibers are already damaged and cant be trusted to remain connected to their roots...
I dont really understand the post about using sprayfoam to fill it, and then fair the glass over the spray foam filled hole?....
if you just need a quick fix to stop a leak so you can get it to the boatyard, this might work, except that polyester resin dissolves spray foam on contact.... epoxy would work over the foam, but it takes many hours and would likely wash out before it sets.... if it is leaking and you are trying to get it to a boatyard without taking on too much water, plug it with epoxy putty. this will set in about 10-30 minutes and will either stop, or at least slow the ingress down so you can motor along to the haulout...
there is a lot of reading on the internet as to how to do fiberglass repair. it isnt hard or technical, but what it does demand in every case, is preperation.... without the prep, the repair will be botched/compromised/unsound/ugly, ect....
The only purpose for foam is for backing. In other words, the shape is on an unsupported corner. If you just lay fiberglass over the existing hole, it will sag into the hole, which then would require building up and incredible amount of glass, to get the shape correct. Filling the hole with foam will give the fiberglass something to form to, so it will hold its shape until it hardens. If you watch videos of this type of repair, they will often build a form and make the patch/plug from a preshaped mold, and then epoxy it into place. While that will work, it will be a trick to build up a custom mold, perfectly formed to the original shape.That is why I suggested filling the hole with foam, so it would support the glass.
Another trick would be to glue an aluminum pipe into the hole. Cut the pipe longer than the hole. Tie a string to it, and put it into the hole and glue it into place. Use the string to hold the pipe tight to the front. Once the glue dries, remove the string, and this will give you support to lay the glass over. Of course if you can get to the back side, you could glass the pipe in. That would also give it some strength if you ever make the same mistake twice, as the pipe would disperse the load over a larger area.
Another trick would be to glue an aluminum pipe into the hole. Cut the pipe longer than the hole. Tie a string to it, and put it into the hole and glue it into place. Use the string to hold the pipe tight to the front. Once the glue dries, remove the string, and this will give you support to lay the glass over. Of course if you can get to the back side, you could glass the pipe in. That would also give it some strength if you ever make the same mistake twice, as the pipe would disperse the load over a larger area.
The hole doesn't go all the way through. The bow appears to be is several inches thick. Originally reinforced with Kevlar at the factory. Normally, I would agree with feathering back 10 to 1 but that worries me in this case as I'd have to grind half my bow away and rebuild. Thus the reason I was thinking some kind of fill. Daveinet says foam I was thinking epoxy with the 403 microfiber as filler. I would grind some of the inside of the hole to get adhesion. Then once I'm say a 1/4 inch or so from the surface grind 10 to 1 there. If half the bow needs to removed to have a proper repair then I might have to say that it is beyond my skill set. If it was just the upper two holes I'd be ok but the depth of the bottom one worries me.
if that is the way you want to do it, then yes, you have to make sure you grind it out to get most of the damaged bits out of the hole... if you do intend to go forward with the repair by just plugging it, why not use epoxy putty?... it has all the microballons or filler already in it... thats all they are is filler to thicken up the resin so it will stay put.
epoxy is strong and has a longer open time before it begins to set up
if you get a soft putty, you can work it into the space very well, especially if you use a popsickle stick to work it in a little at a time, filling from the bottom up, rather than just sticking a ball of it in there and flattening it out and hoping it fills the voids...
if you have enough behind it for support, this could work for you....
Epoxy putty sounds interesting ... how ever reading your posts and you concerns with what you call a plug I'm now questioning my approach and my ability to fix this properly .. I certainly have no desire to have a failure in the future and I don't want to grind away half to bow to replace Kevlar strands with polyester installed by a newbie at fiberglass work ... soooo I have some thinking to do and maybe some talking to do with the yard
yes, once you get the prep work done without any voids where air could get trapped, you can do the lay up on a piece of plastic sheeting, then press the whole thing into place at once... and press it in and form it with your hands on the back of plastic keeping your hands clean... this works great for overhead work.
Why not get professionals to do it? I like DIY projects but maybe this isn't the place. You have a boat that is worth a substantial amount of money. Are you going to risk having a problem selling it because a surveyor detects an amateur repair? Can't you get the insurance company involved?
If you have a so and so 22, fix it yourself. A contemporary 49' boat, get a pro.
If you have a so and so 22, fix it yourself. A contemporary 49' boat, get a pro.
Hey Brain hope all is well with you ... It happened in Lake Oneida along the Erie canal. Unfortunately I was not aboard. I had a captain bringing it back to Lake Erie from the East Coast (we had some great sailing around Nantucket, Martha's Vineyard the Massachusetts Cape, Cuttyhunk etc.). He ran into a significant amount of debris floating in the lake despite precautions they struck something while underway. He thinks a log but it seems like a lot of damage for a log to me. What ever it was it leaves me with a decision to make by spring.
You want to repair with fiberglass and epoxy "ONLY" Nothing will bond to previously cured fiberglass better than Epoxy resin. I have used it in several repairs to include totally rebuilding and enlarging my rudder on my H34. This link is to West system products, http://www.westsystem.com/ss/why-west-system-brand-epoxy/ As far as I am concerned this is the best epoxy for marine use. They also have a great repair guide you can download for just about any type of repair you would encounter for yacht repair. "Don't use a filler" I would reinforce it with Carbon fiber and '1708' Bi axial fiberglass. I used this when I rebuilt my rudder the carbon fiber creates a structural grid that eliminates flexing that is harder than steel. this would be stronger than the original lay-up. It wouldn't need to be perfectly shaped to the the contour of the bow, that is ware you would use your micro-balloons to get the shape back.
Good Luck!
Mack
Good Luck!
Mack
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Over the years as a sailor and dealer, I learned a few tricks. When you cannot get to the backside when repairing, then a backing fiberglass plate is in order. First you will have to grind out or remove the damaged area so that you would have a clean what I call a glass cut. As someone pointed out, then I use to bevel out the edge from the inside to the outside at least at 45 degrees or more. Go on the inside and hand sand the back side of the hull with 80 grit sandpaper about 2-3 inches from the edge. At this point, I would fashion out of cardboard or chicken wire a backing plate of sorts to match the inside that was about 1-2 inches bigger than the hole and can be inserted. At the bottom of the bow is more difficult as you are dealing with various curves. I would then affix two layers of fiberglass to that temp. back plate with one or two strings that went thru the mesh and fiberglass so one can hold it in place. Add resin with addl. hardner to make it kick much faster to the two layers of glass and also coat the inside of the hole 1-2 inches from the edge. Insert your temp. back turning it in place to marry to the inside while holding it in place with the strings. Since adding addl. hardner it will get harder faster. Once holding, you can either pull the string thru or simply cut it off later. If cutting off after the glass dries, then time to cut the string at this point.
The first layer of glass should match the size of the hole with each addl. layer being slightly larger so you will not have an overlapping mess of glass. Since you are working on a vertical surface, I would suggest 1-2 layers of glass be applied and let dry. You can order a resin roller to smooth out the glass and get rid of air bubbles and when doing this immerse that roller into acetone to keep the hardner from sticking and also in cleanup. Sand each time after that drys. Of course you will need for it to be warmer if the boat is outside. Once the glass is in place, I would mask off the area and spray either gray or black. Sand to see where the pits or depressions are and fill in with glass or two part epoxy. I used Water Tite but it is a good product. Then sand with a much finer wet and dry sandpaper, apply a final coating of epoxy to fill in those minute pores and wet sand smooth. Then apply your gel coat.
I started working this morning very early due to modeling an entire basement and may have rambled her but the key to this is to put a false backing plate in first. Not only does it give you a surface which to adhere to but actually locks the other glass in place.
I learned this trick when repairing catamaran hulls where the owners did not want inspection ports put on the hulls.
The first layer of glass should match the size of the hole with each addl. layer being slightly larger so you will not have an overlapping mess of glass. Since you are working on a vertical surface, I would suggest 1-2 layers of glass be applied and let dry. You can order a resin roller to smooth out the glass and get rid of air bubbles and when doing this immerse that roller into acetone to keep the hardner from sticking and also in cleanup. Sand each time after that drys. Of course you will need for it to be warmer if the boat is outside. Once the glass is in place, I would mask off the area and spray either gray or black. Sand to see where the pits or depressions are and fill in with glass or two part epoxy. I used Water Tite but it is a good product. Then sand with a much finer wet and dry sandpaper, apply a final coating of epoxy to fill in those minute pores and wet sand smooth. Then apply your gel coat.
I started working this morning very early due to modeling an entire basement and may have rambled her but the key to this is to put a false backing plate in first. Not only does it give you a surface which to adhere to but actually locks the other glass in place.
I learned this trick when repairing catamaran hulls where the owners did not want inspection ports put on the hulls.