Fibreglass mat or fibreglass cloth?

That's a mess, but not uncommon in some past time frames of boat manufacturing.

It looks like a poor design that was built by a crew that wanted to get to the Pub early.

"Coth" is a specific type of fabric that has no real place in this repair, and if you use epoxy, CSM (chopped strand mat) has no place in this repair either. You need structural fabrics that can hold up to the abuse and stresses seen in this area.

Most of the time there's not a huge benefit in using epoxy compared to VE or polyester on a polyester boat. but in this situation it's probably your best bet.

Without looking at it in person it's hard to determine the best options for repairing it. Cutting it all out and rebuilding a new section would be great, but it may be a very challenging project for a rookie. Grinding off 90% of what's there and rebuilding it back up with the correct materials would probably be quicker, easier, and adequate. But that's from just looking at one pic.

That mess has been busted up and repaired, or maybe I should say cobbled back together, multiple times, nothing there is worth keeping except for the general shape. Thats where grinding off 90% of it comes into play.

You want to grind away as much material as possible and still keep the shape, then you apply better materials over that shape to significantly improve the likelihood of it surviving future stresses. You may need to increase the thickness a bit if there's room to do it and not interfere other things in the area. After rebuilding it you can make it look as good, or not so good as you desire. And making it look good doesn't need to be done right away, and it can be done in stages, or as your skills improve you can update the cosmetic aspect at any time in the future.

 

Correct, there's a mast load there, this part is holding the forestay.

 

Hi ondarvr, appreciate the detailed comment, very useful.

Yes - the previous owner tried to fix the damage (probably caused by the anchor), and this "mess" of course needs to be cleaned and repaired properly. But by poor design you were referring to the boat built?

This is excellent advice, confirming earlier what others have advised.

By structural fabric you mean 1708?

The biggest question for now is this: as the plate is also holding the forestay, is it safe to sail as it is and postpone the complete repair until only a few weeks in the sea? The boat is in the Mediterranean Sea and I have planned only a short sailing season (max 3 weeks), followed by taking her out of water in August for osmosis treatment. At that stage I want to scrap everything, and I could then focus on this damaged area while the boat is drying a few months. I'll then remove all the layers, including gelcoat, and grind that area further if necessary after I see how deep the damaged have gone.

 

There is no way someone can say if it's safe to sail from one pic. Although people did give you options on how to possibly secure the anchor.

Bad design in that if the damage is only from the anchor, that should have been taken into account and those surfaces should have been protected better. If the damage was from other stresses, then it was designed and or built wrong.

Frequently what the engineer put on paper isn't reproduced in a good way in production.

 

I wouldn't be sailing anywhere with the boat in that condition.I might motor it across an estuary,but not on a bumpy day.If it lets go,you are going to be faced with a bill for a new mast and if it is insured,posting here images of the condition would likely invalidate the insurance.I think ondarvr has it right about somebody being in a hurry.Whether it was to achieve a target time and trigger a production bonus or trying to reach an unrealistic repair estimate time doesn't affect the need to fix it properly.

Once again we see evidence of the common American practice of beginning the bonding (tabbing in US speak) with the widest strips first.After the last instance I commented on,I thought back to the eight or so composite engineers I have worked with.One only dealt with wet layups,three dealt with wet layups and prepregs and four only dealt with autoclave cured prepregs,yet they all specified narrow pieces first and successive laminates overlapping.Maybe it is connected to cooler northern European temperatures.

 

"By structural fabric you mean 1708?"

1708 is for VE and polyester, 1700 would be for epoxy. The "08" part is CSM, it's not typically used with epoxy, it uses more epoxy and bulks up the laminate with comparatively little added strength.

 

Okay, if you need to make a temporary repair, that can probably be managed. As others have already mentioned, it's all about preventing movement. Not sure what you have handy, but if you can get your hands on a stout timber scrap - like 6 x 10, or some 2 x 12 framing timber scraps, you can fit a timber under the forepeak mess and bog it in. As far as the timber goes, chainsaw accuracy is fine. Clean the surfaces with acetone, plastic off the entire anchor well and topside, mix up about half a gallon of polyester putty in a five gallon pale, apply 1" thick to the plug, and smoosh it in there and clamp it loosely to the deck. You want about 1/2" of putty in the gap. Babysit it while it starts to harden, because there is a magic ten minute window when you can clean up the squeeze out without making everything worse.

One at a time, remove the four screws from the anchor roller and replace with bolts that run right through the chunk and through a backing plate. I assume there is a stout lug in the anchor well to make the chain off to. Run some 1/4 rigging wire down from this plate and fasten it to the lug (easiest to make a backing plate with a welded ring). I'd expect the forestay to be 1x19 5/16 wire, with all others 1/4. You're looking for about a 12,000 load capability from your fix. That isn't too hard to manage for a year or so from wood and wire. But I'd like to see a section about 4" x 6" under the channel. Take a couple small plates and run four 3/8 lag screw 6" long into the ends of the chunk from the outside. The bolt holes should be at least 3" square on center, more would be better. Plates should be about 1/4" thick. If you can't get 1/4" plates to lay flush, thinner is okay, but use as thick as you can that you can shape to match to the hull.

Strength-wise, this is a bit of overkill, but the real issue is completely eliminating movement so that the other cracks don't grow any bigger during the next year.

 

What nonsense to bring into the discussion. The reason for largest first is to reduce air entrainment in follow on layers and to reduce sand through.

Pretending it is evidenced here is a form of boat builder blasphemy. I guess you have xray vision to see tabbing layers under all that cracked up gel.

Geesh.

 

Can you provide some references for that?

 

The previous (second) owner bought the boat back in 2021 - the boat has been sailing extensively and there's no visible change in this area since then. It's most likely a surface/gelcoat damage caused by the careless use of anchor and chain. My intension when I bought the boat was to properly fix this, but this must be done in stages. When asking about a risk of sailing, I wanted to assess if it makes sense at all to repair it temporarily (cleaning, filling the gaps and possible fibre mat on top), or it can wait for later this year to be done correctly.

Although a bit from a different angle and with an anchor covering one part, a picture from 2021:



And from 2025:



And again a fresh one from early this year, 2026:

 

Super useful idea bout the temporary reinforcement.

I've just posted a comparisons of pictures from 2021, 2025, and 2026 showing there's no progress of the damage, no new or change in cracks. The boat has been sailing a lot between 2021-2025, and my intension is only to move her to another location in the Mediterranean Sea (600NM), have short 2-3 weekly sails, before moving her out of water in August to scrap everything for the osmosis treatment. While it dries, I'll have plenty of time to fix this part properly. Given this, do you still suggest this reinforcement?

As I see it know, there are a few temporary fixes. Does point 1 and 2 makes even sense? Is there any added value as a temporary fix (= by temporary fix I don't mean 1 year of sailing)?

1. Cleaning all the cracks and filling it with filler with microfibres (eg https://www.svb24.com/en/west-system-filler-additive-403-microfibres.html).
2. Application of a few layers of fibreglass mat.
And then
3. Reinforcement with a wood chunk and a backing plate:

 

A temporary cosmetic fix is all you're talking about then, since it hasn't changed over several years it appears to not be getting worse.

It thats the case then it makes no difference if you do it or not, it just creates work now and more work later. Unless you grind everything out and reglass it you aren't doing anything to really fix it, so whatever you do to make it look better now has no value other than for cosmetic purposes. And anything you do now will need to be totally removed to actually fix it later.

 

Lean on the stay and see if the area moves badly.

The assessment is rather simple. If it flexes in areas where there are cracks; then you ought to fix now.

If the damage is all anchor and cosmetic; it won’t move from pressure on the stays. We can’t decide for you. Based on the chain rub locations; things appear mostly cosmetic.

No reason to do a half arsed cosmetic repair. Verify the problems are not structural and movement is not caused by stresses on the rig.

 

Thank you a lot for the response.

I'll make sure that nothing flexes there, do a short passages, and start repairing this properly in a few months.

Again, thanks a lot.

 

Dear All, thank you so much for all of the advice. It's been extremely informative and valuable - I initially wanted to ask about the difference between the mat and cloth, and we ended up in digging into the fundamental problem here!

I'll learn and try to repair this properly in a few months - will document all the process, and will post some updates, I will for sure have some questions on the things yet to be discovered!

Thanks again.