Fiberglass Repair Advice on an 17' American Fiberglass

[bamidon46]

Hey everybody,


I've been mulling over sailing for quite some time but had held off for years. Recently I got an opportunity to get a 17' American Fiberglass Sailboat to learn on. It was quite cheap, so I figured what the hell. Anyway, the reason being is that the keel housing has some cracks in the fiberglass. A couple are substantial. It looks like someone did some work on it before as well. I'm a fairly handy guy so I figured I could work on it in my spare time over the next year or so while I do some land-side learning. I've tried to talk to various people at numerous harbors for a little direction on where to go with the repairs and everyone directs me to a contractor or local shop that will do the work for me. Not at all what I'm looking for.



Can anyone here give me a quick list of what to do/buy. I'll do more research and digging myself, just a general direction on where to go with this.



Here are the pictures: https://imgur.com/a/TOY2yp8


A big thank you to anyone who takes the time to help.

[Flatswing]

I would start with Andy Miller’s Boatworkstoday.com He is another chatty but will walk you through virtually any FRP repair so that you will understand how & why in an easy to understand format.

[Spot]

Ahoy Bamidon46, welcome to CF.
The pictures do not look too bad. You might get more 'foot traffic' if you get them to show up in your thread. It would also be good to have a 'scalar' object in your pictures: a ruler, coin, pencil...something that indicates length and width of crack. Is the boat in a shed? Will you be able to flip it over and remove the swing keel for repairs?


Quick List:
1. epoxy resin and hardener (not 5 minute hardware stuff)
2. gloves, mixing containers, sticks, spreaders, chip (cheap) brushes 1-3"
3. 6oz fiberglass cloth or 'tape', glass micro spheres, fumed silica
4. 500 gram scale or graduated containers for measuring epoxy components. If using a scale and plain weave cloth, you can weight the cut cloth and make a matching epoxy batch for repairs
5. isopropyl alcohol, citrus soap, white vinegar (all for clean-up)
6. plastic sheeting to protect workbenches, masking tape, paper towels
7. sanding disks in various grits 40-180, dust mask for sanding

Normal procedure is to grind out cracks 1:12 slope, wet the ground area with mixed epoxy, and fill from the bottom up with cloth and resin laminate, not too soupy and not too dry. Once back to the surface, sand back extra cloth and make filler paste with the epoxy and spheres and silica and 'bodywork' the surface as fair as needed. Best to locate some videos like Boatworks Today or Sail magazine did an 8 part series with the guys behind West System Epoxy to watch other hands do this work. I do not use West (prefer lower blush water-clear types) but have to give props on how much how-to directions West (Gougeon Brothers)provide people.

Wear your gloves, learn cleanup procedures with each 'sauce' (iso, orange soap, vinegar) and do not sand until epoxy has cured and only with ventilation and/or mask. Allergies to epoxy can result from cumulative exposure and are aggravated from skin contact, inhalation, and using stuff like acetone for skin clean-up.

You could make a similar size crack in a piece of wood and practice, just paint the wood with a little extra mixed epoxy before adding more cloth and resin.

Also, for that size of boat, the crew at the 'Trailer Sailor' forum can also help https://forum.trailersailor.com/forum.php?id=1

[tkeithlu]

Let me recommend pretty careful examination of the damage you are repairing. In particular, remove the swing keel as Spot suggests and search inside the trunk. The cracks look like she took a whallop from the side, maybe being laid down in surf or comparable. Remember that you can build up from the inside, patching the broken area, without doing any cosmetic damage.

Nice project, and I hope that you are on the water soon.

[guyrj33]

Don Casey wrote several good books that could be helpful.
"This old boat"
"Sailboat hull and deck repair"

[Cheechako]

Most anything fiberglass can be repaired. That is darn ugly though. American boats are noted to be pretty cheap builds. Hard to tell but that looks like all choppergun layup in the one place I can see original (?) glass under the Gel Coat.
I agree with taking everything apart around the area, analyzing a bit. Then grinding deep and wide to real fresh looking layup before glassing. Even if you end up with glass a little outside the normal hull shape it wont effect performance that much for what you are doing.
It doesn't look like an area where you would normally have hull impact damage, but could be. One wonders if that rotten chopped strand glassing just started stress cracking. Especially if the hull is rather thin and flexes. You could be chasing your tail on this one if that is the case.
Contrary to what many believe, fiberglass layup does degrade, especially in the sun and if poorly done in the first place .
Some cheaper boats have zipped right apart in rough water along the toerail over the years etc.

[bamidon46]

Thanks for the replies, everyone.


The largest crack is about 12-14'' length with 1/2'' width. Currently the boat is on a boat stand and I have full access to the entirety of the keel.



It's got a trailer as well and had been sitting for a few years in someone's back yard. Where the cracks are and how it sits on the trailer made me wonder if some of the damaged was worsened by the trailer. It's kind of an old thing, not much in the way of padding.


As for the actual work, I've got a respirator, mask, head cover, thick clothes and several different types of gloves. I do a lot of different construction work so I should be pretty well covered. I'll be cautious though.


I'll start getting into the books and videos y'all mentioned and check out the trailer sailors sub-thread.



Anyway, I'll keep ya posted. Again, thank you! I don't feel like I'm bumbling in the dark anymore!

[Spot]

B46, sounds like you have a handle on this. A couple other things:
-Only mix up enough epoxy that you can spread and work within a reasonable amount of time (withing pot life of the epoxy) and spread out the epoxy onto the cloth instead of leaving it sit in a container. This will prevent a runaway 'exotherm' in the cup. It is usually better to mix a little less and make a little more to finish than to overdo it at the start.
-Make sure surfaces to be repaired are clean, dry, sound. For most stuff this is freshly sanded and wiped down.
-Follow temperature instructions specific to your epoxy (could be using a different hardenrer or bringing the boat into a warm shop if cold outside). I have seen others come to grief over trying to do fiberglass in too cold of temps. I have used heat lamps to keep small areas warm during a lamination. I have a 10 year old repair to my concrete garage floor lip that was done in freezing temps+heat lamp with leftover epoxy that is holding up great. Many chipped spots on my garage floor have benefitted from the 1 and 2oz (30-60g) leftovers of other projects. Key is not stepping in/on it before it cures...
-If you are going to stay with blue, you could add 1-3% blue+a little white pigment (universal color dispersions or resin-specific colors) to the mixed epoxy for the outer couple layers. The amounts needed are very small.

[alaskanviking]

Boatworks on Youtube is a really good resource on this. He also covers the different resins, and gelcoat. You can pick up a west systems epoxy book from several places, and it is fairly detailed on repairs and epoxy. The prep work is the most important piece of the repair you are talking about, followed by using the correct amount of overlapping reinforcing layers of glass.

Epoxy resin is more expensive, but stronger and waterproof. It doesn’t smell. I would not use this if you intent to gelcoat after, although gelcoat will stick to it, it’s just an adhesive bond, so nothing I would use on a critical or structural part. Very easy to use. You get the metered hand pumps so your mix is 1 pump resin to 1 pump hardener, no chemistry, measuring, or precise volume control. Pick the hardener based on temperature and strength you need. Slow hardener is best for high temps but is weaker, fast hardener can be used at 30-40 degrees and is the strongest. Try to use fast hardener at 90 degrees and you have a hard smoking hockey puck in 15 minutes. I have been using Slow hardener in the 90’s, making bigger batches and haven’t had any issues with time, hour or more easy. Epoxy almost sticks to everything. Never seen anything about old epoxy. It always seems to work. I have successfully used 2-3 year west systems epoxy, although for any structural stuff I’ll get fresh epoxy. Some epoxy’s like west systems cures with an amine layer that has to be scrubbed off with soap and water. Not a big deal but it’s an added step that isn’t always easy. Now a days I use amine free/ low amine epoxy’s from us composites and MAS. It’s a thinner laminating resin which makes it easier to soak into the glass. Thin resins are also good to thin out with alcohol or acetone to soak it into wood. Penetrates deeper, then coat with a coat of regular mix. I have saved some water damaged wood this way. Us composites is cheaper so I don’t mind using it to make a thick epoxy with fillers, but anytime you use a thin laminating resin for this you have to use a lot more filler powders to thicken it up. If I was specifically going to use a lot of thickened epoxy or fairing compound fillers, I would start off by getting a thicker epoxy. There are a lot of different brands of epoxy, they are more or less the same for what you are doing and any of them should work well for you. You will find more how to’s and 3rd party information and videos on west systems however, which I found is fairly easy to get.

Polyester resin – stinky stuff everyone things of when you talk about fiberglass. In-expensive, but not waterproof, not as strong as epoxy. If you’re doing a thick layup of glass you use this resin to keep cost reasonable. When you hear talk about blisters under the waterline your talking about polyester resin. It’s common to add a couple coats of epoxy barrier coat over polyester resin so that its waterproof and prevents blisters. Your working time is low, so small batches at a time. It won’t fully cure hard and will remain sticky if you don’t coat it with something that seals it from air, usually wax additive or mold release. You get resin without wax for laminating several layers in one setting, and you use a resin with wax as your final layer to cure everything, I still coat everything with mold release just in case. There is chemistry, math and ratios you have to work with to mix this up, so not as easy to use as epoxy. Hardener is MEK and you adjust the amount based on total volume and temperature. Small batches you use a dropper bottle of MEX and count drops. Larger batches you measure out. Mistakes may prevent your resin from curing at all, so it stays a semi hard sticky mess that you have to scrape and remove later to try again. Polyester resin doesn’t stick to everything. Gelcoat is a polyester resin, so you get a strong chemical bond between the fiberglass and gelcoat. Gelcoat is the reason its worth learning to use polyester. Has a decent shelf life. I have been told ~ 1 yr, but that may have been just gelcoat. Have seen old polyester used successfully.

Vinylester resin. I haven’t used this, kind of a mix of the strengths of the other two resins. Mixing is by volume chemistry like polyester. It’s stronger than polyester, and waterproof. Cheaper than epoxy, not as strong. It is compatible with gelcoat or there is a vinylester version of gelcoat (not 100% on this). The big negative with this is it has a short shelf life of a couple months I believe. One of the boatworks videos compares the t=different resins and they couldn’t test the vinylester because it was passed its shelf date. So you buy this just before using it.

Specialty resins – there are specialty resins, or hybrid resins made for specific purposes. You don’t see these as often. Fuel safe resins to coat your fuel tanks, potable water safe resins, 2 part resin foams etc.

Gelcoat versus paint – if you are going to paint than just use epoxy. It’s more expensive but more user friendly and easy to mix. You could try to experiment with gelcoat over epoxy, not my recommendation for a first time user. If you are successful with polyester resin than gelcoat is not much different, almost like a thick paint. However it is really hard and a pain to sand. It has to be sanded with finer and finer sandpaper and then polish it. It was so easy and looks good initially when you put it on that the first time I patched a bigger spot I thought later I may spray my whole hull to renew it. Weeks of sanding and polishing have completely canceled that idea and I have decided if I need to do larger gelcoat patches ill just paint since it looks good and is less work. When it’s done right it looks good and is durable, but Pure misery sanding gelcoat, like doing millions of arm circles over your head. There can be more chemical mixing oops with gelcoat just like polyester resin. I learned some new cuss words watching someone that had to remove gelcoat that didn’t cure from poor mix.

Regardless of the resin don’t buy the premade thickened stuff. I found it’s easier to mix your own and faster to use, if you get the powders and do it yourself. This lets you mix exactly what you need. Polyester kitty hair is often too stringy and can be a pain for more detailed work. But you can mix up something similar with short strands that works better in your application. I used to buy the premixed west system thickened epoxy in the caulking tube. Its $40 a tube at west marine. You get two of the special mixing nozzles with that. Otherwise you buy additional nozzles in a 2 pack. You don’t always need that much in one setting and it goes to waste. I remember always going out of my way to make sure the two sides didn’t contaminate each other and harden. When you have the powders and additives you can mix the stuff to the consistency you need in the amount you need. Very easy. I got a 5QT bucket of cabosil/silica for $8, the west systems equivalent is $20-$30. You can also use a easy to sand fairing compound additive/powder to make a fairing compound that chemically bonds to the layer before, rather than the expensive purpose made fairing compounds.

I use mainly epoxy. It’s more expensive but I can buy in larger quantities and keep leftover in the lazarette for the next time I need epoxy. I have a Fiberglass boat, but the furniture and bulkheads are teak marine (maybe) ply. I have found I need to treat more wood with several coats of thinned epoxy as the boat gets older. Polyester you need a full mask due to the vapers, very smelly, it will stink out your boat for a while after it cures. So epoxy avoids that in close confines, garages ect. The working time and ease of use makes it my go to stuff. Currently using US Composites 635 Thin Epoxy Resin System as it seems to be the best deal I found cost wise and I found I like it a lot because it’s easy to wet out. I call and order and they ship it in a few days without issue. I liked MAS a lot too. Don’t buy your resins from west marine, its 3 times as much there as you can order it including shipping. Also don’t buy the west systems fillers, the fillers are the same and you can get the same stuff elsewhere in larger quantities for cheaper. The exception is some of west systems specialty fillers like barrier coat, graphite maybe, metallic powders ect.

[alaskanviking]

Originally Posted by bamidon46

Thanks for the replies, everyone.
The largest crack is about 12-14'' length with 1/2'' width. Currently the boat is on a boat stand and I have full access to the entirety of the keel.
It's got a trailer as well and had been sitting for a few years in someone's back yard. Where the cracks are and how it sits on the trailer made me wonder if some of the damaged was worsened by the trailer. It's kind of an old thing, not much in the way of padding.
As for the actual work, I've got a respirator, mask, head cover, thick clothes and several different types of gloves. I do a lot of different construction work so I should be pretty well covered. I'll be cautious though.

Those cracks don’t appear very structural. However note that there is previous repair fiberglass. Fiberglass work is $150-$250 per hour in most areas, and this is something you can definitely do yourself, but it will take some homework. A week of binge watch boat works and other you tube videos and you should be ok. The trailer may not be made for the boat and the supports are in the wrong place. That would help crack it. Looks more like impact damage from having the keel down and hitting the bottom or stuff.
You grind out the crack and try to make a 45 degree-ish edge. You want to grind enough to expose the bottom of the crack. You want to grind it out till its nice glean glass. Then feather out away from the crack with the grinder so you can glass in reinforcements and more or less be flush. There is enough damage id want 3 larger layers Fill in the narrow gap first and then bigger and bigger pieces. Note they do say to do the opposite but I haven’t found this works well for me. You overfill slightly so that you can sand back down to correct shape after. Since you don’t know what they used for earlier repairs, there may be water ingress into the glass based on the location, and those look like impact cracks so I would use epoxy for a stronger repair.

The picture labeled “Bow Keel Housing” looks like small stress cracks in the gelcoat. I’d take a dermal bit with a pointed v tip and grind those out to explore how bad they are. You need to verify if the crack is just in the gelcoat or if it goes into the fiberglass. This can be a thin line and not always easy to see. Sometimes you have to grind out a larger area of the gelcoat to expose the fiberglass and see the crack lines. You relieve the stress by grinding through the depth of the crack all the way to the bottom. Then you fill back up with glass.

If some of those nastier looking cracks go through to the inside than you do the same prep work on the inside. Epoxy the inner most layer of glass and let it harden. Then glass the outside layers complete, then the remaining inside layers.

Due to the impact damage I see id probable reinforce the entire area around the keel housing with epoxy and glass.
6oz glass minimum, but those bigger cracks I think I’d use 10oz. 1 layer of glass followed by a layer of fiberglass matt, last layer or two is cloth
Grind with 30-60grit sanding disks on the grinder. You can use grinding disks but it is slower and easier to get away from you. You can also use the flap disks for final sanding.

Looks like there is a decent amount of work there so id paint it. Small enough boat though that I wouldn’t die from gelcoat, and gelcoat over epoxy wouldn’t be ok here. Wouldn’t be too hard to gelcoat the whole boat after.

If you can pull the mast and flip the boat upside down it will make it easier to repair, sand and paint/gelcoat.

[bamidon46]

So started working on the bottom and when I sanded through I ran into this stuff. Looks like sand and rocks...?

I drilled a few holes over the old patch and it seems be be everywhere. I did some knocking with a screwdriver and all of the hull that is in good shape sounds loud, like a "rap rap rap". The area with the old patching and cracks has a dull thud noise. Not sure if that makes a difference.

[Spot]

I would not expect sand or rocks in there and a good repair should not be a dull thud. This is sort of a head-scratcher...Maybe someone attempted to add ballast or some form to the shape before repairing it?

[bamidon46]

I thought it was for some extra weight in the keel as well. After I opened up the crack on the other side I found it in there too. So I assume it's throughout the keel housing.

[jimbunyard]

I'd be almost certain that the 'sand and rocks' wasn't intentionally added by anyone, and that your new aquisition had a period in her life that was 'rougher' than you imagine...

Sand and gravel, especially unencapsulated sand and gravel, make very poor ballast indeed, as a visit to any beach will affirm.

If she was overwintered on land in Pennsylvania, there's a pretty good clue as to the source of the cracking...

[bamidon46]

Yeah. The boat was originally from Florida. Spent most her life there and then was moved to upstate NY a few years back.

After I removed the swing keel a slow drip of water started out of the screw holes. All the sand and rock is very moist too. So I'm sure the freeze thaw cycles of NY put some stress on it.

So then, should I be removing all of this from the interior of the keel? How would it have even gotten in there?!