Fiberglass damage

kebwi

Member
I turned my new (very old) boat over for the first time to inspect its state. There's a variety of damage, including areas where the gel coat has worn through to reveal the mesh beneath, some cracks that are wider than hairlines (concentrated at the front of the daggerboard trunk) and hairline spider-veining. I've included photos with a key for size reference. I don't know which of these require repair and if so, what that process consists of. Obviously, I'll dig into Google and YouTube to see what I can find in the way of instructionals, but I thought I'd bounce it off this forum to see what people think. I appreciate your input and guidance.

Thank you!
 

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Those defects are awful! :eek:

You should sell that boat to me--right away! :(

Heh heh. I know. I just want to eliminate any leaks. As good as it is overall, I'm not sure if water enters through the two gauges that reveal the mesh or the cracks around the daggerboard. It's really old and has sat on a trailer for twelve years through all variations of Seattle weather. I've already made some nice upgrades and want to keep spiffing it up.

I can't get the drain plug open, and I hear sloshing when I tilt the boat back and forth.
 
These look like mostly minor repairs, though the daggerboard trunk sure looks suspect for that leaky hull.
You definitely want to get the deck drain open. Do you have a very large flathead screwdriver (one of my favorite tools) and a can of PB Blaster?
After cleaning up the dings (removing all loose material, dremel or file as necessary, wipe with acetone) you can use Marine Tex as directed. The smallest 2 oz box will be more than enough for your needs. Be careful not to apply too much inside the fitted daggerboard trunk (if any is needed- a leak test first would be helpful)
L&VW is referring to putting ‘plastic film’ (I use Saran Wrap) over the repaired area. Stretch it tight over the Marine Tex, then use your finger to smooth out and blend in the repair. Leave the film on til the next day then it easily peels off.
It will make for less sanding (Marine Tex says on the box ‘Hardens like Steel’) and a nicer look.
 
These look like mostly minor repairs, though the daggerboard trunk sure looks suspect for that leaky hull.
You definitely want to get the deck drain open. Do you have a very large flathead screwdriver (one of my favorite tools) and a can of PB Blaster?
After cleaning up the dings (removing all loose material, dremel or file as necessary, wipe with acetone) you can use Marine Tex as directed. The smallest 2 oz box will be more than enough for your needs. Be careful not to apply too much inside the fitted daggerboard trunk (if any is needed- a leak test first would be helpful)
L&VW is referring to putting ‘plastic film’ (I use Saran Wrap) over the repaired area. Stretch it tight over the Marine Tex, then use your finger to smooth out and blend in the repair. Leave the film on til the next day then it easily peels off.
It will make for less sanding (Marine Tex says on the box ‘Hardens like Steel’) and a nicer look.

I already chipped the bronze flat head slot once. I'm afraid to work on it now. I haven't tried PB Blaster yet though. Frankly, I'm tempted to wedge the whole thing off and put in a new plastic plug.

Also, I noticed that if I flip the boat completely over (that was how I took the photos) it slowly drip-drains out the bow. I think it was coming from the screw holes of the handle, not around the lip under the trim. While that was serendipitous in light of the sealed drain plug, I suppose it indicates that water can get there as well. I'll have to the drain open one way or another -- or install a deck access hole.

Thanks.
 
The blaster will work. You should have a screwdriver the full width of the slot. Don't try to remove it in one shot work it let it work it again.
 
The blaster will work. You should have a screwdriver the full width of the slot. Don't try to remove it in one shot work it let it work it again.

Well, I have a pretty big screwdriver, but I'm not sure it's worth the cost of a really larger screwdriver plus a can of PB Blaster when I can replace the entire thing for $15 or so. Ah me.
 
I already chipped the bronze flat head slot . I'll have to the drain open one way or another -- or install a deck access hole. Thanks.
One of my six Sunfish arrived six years ago with a 3/16ths" hole drilled through the drain plug. I thought that was an excellent alternative to replacement. Then, PB Blaster can reach behind the plug. I plan to use my left-hand drill bits to remove the plug. Maybe next off-season? :confused: Plug substitutes are available in stainless steel and nylon. Ask for the "set screw" drawer.

While it drains slowly, the entire hull needs to be emptied of water, and quicker is better. The interior was built with a bulky adhesive that absorbs water, increasing your hull's weight. Excess weight makes the "Sunfish experience" less enjoyable. :oops:

Using a bathroom scale, your hull weight should register about 130 pounds. The rest is absorbed water, and an inspection port may be called for. The various dry-out techniques can be found using the search feature. (The magnifying lens icon in the upper right corner). Depending on your particular approach, dry-out could take weeks or months.

This is not to say you shouldn't go sailing, the dry-out process can wait for the off-season. ;)
 
There are different ideas on how to do repairs.

The areas you show are mostly superficial. The cracks are likey more work to fix then it is worth doing. The areas where the get coat is chipped off should be sanded out so the existing gel coat is tapered into the glass area then filled with thickened gel coat.

The cracks around the dagger board should be sanded back to glass to make sure the damage does not go into the fiberglass. Then covered with gel coat.

You level the gel coat with like 220 sand paper for basic level then sand 400 and then 600. Then you can compound and buff. If you want really pretty you can sand to higher grit papers first.

You would need like $40 in gel coat, some thickener, plus the cost of some sand paper. If you had a friend with gel coat you could have then you would be set. You would not need much to fix these. Like 12 tablespoons or so. Yes, I use stainless measuring to do these small quantities.

The Marine Tex is an epoxy that is be bought in a thicker consistancy. It can be white but will get an odd off white to yellow color over time in the sun. People lay out the Marine Tex for structural repairs or even to cover the gel coat. You put plastic wrap on top of it to smooth it out. I am not a fan of the Marine tex in place of gel coat. It can fix holes, but people use it not realizing you really still need to sand out the area to give something for the epoxy to gram a hold of for the repair.

There are videos online about doing gel coat. The tough part is finding ones about fixing the small areas and thin glass like on a Sunfish.
 
Hmmm, that's the second post to express concern that the damage around the daggerboard might be problematic. While I want to solve any real leaks that are present, I'm not keen on sanding otherwise thing cracks way back to reveal the fiberglass just to inspect the state of the fiberglass for additional damage. I'm not sure I want to build up the level of skill and knowledge we are talking about here. My plan was to fill in all of these minor issues with Marine Tex and be done with it. I'm willing to sand back a little, say to taper the edges or generate some rough texture for add-ins to grip, bit it Marine Tex, gel coat, or anything else. But I don't want to effectively remove the gelcoat around a crack so much as to reveal the fiberglass below just to inspect it. I suppose you're saying that if the fiberglass is genuinely damaged and leaky, then Marine Tex over the top won't prevent water from getting in, and that therefore a patch job is essentially worthless in terms of reducing water problems.

Hmmm...I don't want to have to become a professional fiber glass and gel coat installer to fix up the boat, but I do want it as waterproof as I can reasonably get it.

Thanks.
 
If that deck drain screw is still stuck I’d just carefully pry up the drain assembly, saving those two pins. Cover the small hole in the forward cockpit with tape and do a leak test. Have a helper, ideally. Don’t over-pressurize. The leak test will tell you where you need to make repairs. Don’t forget to take tape off hole when done.
 
Yes, I second doing the leak test. If the boat doesn’t leak just do minor repairs.

if it does leak, the Marine Tex would most likely fix the type of problems you have. but if the daggerboard cracks are where it’s leaking, you will want to open up gelcoat by the crack so you get a very solid bond and fill all voids with Marine Tex.

for a boat of this boat’s age, I personally would not try to get a color match with gelcoat - I’d just use white Marine Tex.
 
I'm not very concerned about color-matching the bottom of the hull. Only the fish would have any opportunity to judge me for it.

All right, I'll figure out how to leak test and consider what would be involved in pulling the gel coat on the dagger board trunk cracks back enough to analyze or fix it properly. Thanks.
 
The leak test could introduce non-existing defects. :oops:

Why not pull the drain, as Breeze Bender suggested, plug it, sail it, drain it, and see how much water got through. It may not be worth the effort to "fix" something that ain't broke.

Even with my ample "ultimate inspection port" access, a daggerboard repair is a lot to take on--and to get right (the first time). :confused:
 
I own three compressors, and wouldn't trust those gauges to give me "non-massive" pressures.

A blowhard posted "lung-power" was enough pressure. :rolleyes:

Start at post #67:
 
I use an electric leaf blower pointed at the drain plug a few inches away and it works fine. I don't cover the hole, I won't use a compressor for it IMHO. Yo don't need much pressure at all just a small bit to get the bubbles.
 
Well, I have a pretty big screwdriver, but I'm not sure it's worth the cost of a really larger screwdriver plus a can of PB Blaster when I can replace the entire thing for $15 or so. Ah me.
Please elaborate on the replacement option, how did you remove the old plug or did you just leave it and put a new plug somewhere else?
 
Maybe drill a hole in it then use a screw extractor on a drill running in reverse?
Search using the term PB Blaster using the search box in the upper right. Lots of discussion about how to remove the plug, most of which involve using PB Blaster.
 
As long as you don’t pump massive pressure into the hull the above is one thing you DON’T need to worry about.
I did that but read mostly about fiberglass repair and advice to use PB Blaster with a very large flat screw driver (if I can find one). It was not all that clear to me. I get the impression people cut new holes for other drainage solutions, possibly cutting out the exisiting plug, laying fiberglass over the area and then cutting a new hole for a new plug. Unfortunately I did not find the conversation that helpful. That said, I will start with PB Blaster and a large screwdriver.
 
I haven’t read about anyone cutting out the area. There are a couple years worth of threads on this problem, so the search function still can help. But the theme seems to be PB Blaster and a big screwdriver.
 
I did that but read mostly about fiberglass repair and advice to use PB Blaster with a very large flat screw driver (if I can find one). It was not all that clear to me. I get the impression people cut new holes for other drainage solutions, possibly cutting out the exisiting plug, laying fiberglass over the area and then cutting a new hole for a new plug. Unfortunately I did not find the conversation that helpful. That said, I will start with PB Blaster and a large screwdriver.
I will elaborate. If a couple of weeks of periodic shots of PB Blaster, a bit of tapping and ideally a big screwdriver don’t free up the screw simply use a regular ‘ole flathead to pry the entire drain assembly from the deck. It’s easily done. There may be some sealant around that needs to be removed, but you will see the two small pins that hold the assembly to the deck.
Save those. You might drop the deck drain into a cup and soak the whole thing in PB for another week. It may never come loose, in which case you buy a new deck drain (sometimes used ones come up on ebay) or modify with a rubber plug or stopper.
 
PB Blaster and gently hammering a reasonably large flathead hasn't broken it loose yet. I attempted another trick I've tried in similar situations, which is to file opposing sides of the otherwise round head flat to enable a wrench to get a grip on the head, but I still couldn't rotate the wrench. It certainly seems utterly fused. But I can keep playing around with it for a while. In the meantime, it'll be very difficult to drain the boat. Oh well.
 
It'll drain slower, but drill a hole in the center of the drain plug.

It's normal for such "containers" to collect condensation overnight, and why the drain is there in the first place.

Spray more PB Blaster in through the hole, to reach and dissolve corrosion on the inside. As the plug eventually loosens (and function is restored) the hole can be soldered closed again.
 
Maybe drill a hole in it then use a screw extractor on a drill running in reverse?
I tried the largest screw driver I could find (3/8) with PB Blaster first (soaked for 10 minutes). Tapped the driver with a hammer to jar things loose. Used downward pressure on the driver and turned it with vice grips. could not get the plug to budge.
 
It'll drain slower, but drill a hole in the center of the drain plug.

It's normal for such "containers" to collect condensation overnight, and why the drain is there in the first place.

Spray more PB Blaster in through the hole, to reach and dissolve corrosion on the inside. As the plug eventually loosens (and function is restored) the hole can be soldered closed again.
I haven't tried that. You are thinking a small hole in the plug? what solder do you use to close the hole?
 

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