Best fix for small damage in hull

[sune]

Hello everyone,

I'm a new boat owner so forgive me my newbie questions.
I bought a fine old 24 foot sail boat here in Copenhagen, Denmark.
It's a Bandholm24, fibreglass hull, built in Denmark in 68.
She's mostly in good shape but not entirely.


My first question is regarding some damage in the bow over the waterline.
Looks she took a beating by the dock.


- What's the best fix here?
- Should I grind around the holes, clean with acetone and then fill with epoxy?
- This is this gelcoat, right? (I'm new to fibreglass but learning)

- I think the hull is solid fibreglass all the way through, I don't think it has a wood or foam core. Does that sound right for a 68 construct?
(displacement 4850 lbs., ballast is 2425 lbs.)

Thanks in advance

[thomm225]

You might want to put a little epoxy on it to keep the water out, but
I wouldn't worry too much about it until I was going to repaint the entire topside hull.

You may damage the bow in the same spot again while you are learning to dock the boat after you put it back in the water especially if you are a single hander and are new at docking

Everyone is different though. Some folk will make their boats perfect then totally freak out when docking worrying over the first scratch

One of the good things about old boats is that they will take a beating.

Knocking a few docks out of wack while not hurting your boat much to me is just part of the learning process!

[SailsWithFists]

Originally Posted by sune

My first question is regarding some damage in the bow over the waterline.
Looks she took a beating by the dock.
Attachment 158889

- What's the best fix here?
- Should I grind around the holes, clean with acetone and then fill with epoxy?
- This is this gelcoat, right? (I'm new to fibreglass but learning)

- I think the hull is solid fibreglass all the way through, I don't think it has a wood or foam core. Does that sound right for a 68 construct?
(displacement 4850 lbs., ballast is 2425 lbs.)

Thanks in advance

For a boat of that age, what your picture shows is not considered damage, but character, and should not be a safety concern unless you detect cracks in the actual fiberglass. Chips in the gelcoat are common. The easiest repair is with gelcoat, tinted to match the faded color.

Your hull should be solid fiberglass.

[twohapence]

Hi,

I suspect your boat is probably built from polyester resin and not epoxy. Now epoxy is a great material but it needs care and attention and can be very tricky to work with.

Polyester resin is much easier, doesn't need such careful measurement of the hardener and is generally much more forgiving to work with and you can extend the working time by reducing the quantity of hardener. Polyester will stick to polyester. Epoxy will stick to Polyester. Polyester won't stick to epoxy.

I suggest you start by reading something like the fibreglass repair manual by Allan H Vaistes. Don't be too ambitious or in too much of a rush. Practice before rushing in.

The probem with the repair will be matching the colour of the hull afterwards.

Cheers

Ian

[deblen]

There is much information on the web that may help you.
Here is the first in a series of gel coat repair videos,though you will have to find equivalent European materials.
Hope this helps. / Len

https://www.youtube.com/watch?v=iWEE6SFUdpg

[sune]

Thanks guys,
I really appreciate your answers.

Good to know that I don't necessarily have to fix it for now, and thanks for the extra info that it's probably built from polyester resin, I was wondering just that.
Is the gelcoat layer also polyester based?

I've been watching quite a few of BoatworksToday videos on youtube, they are great. Will check out the book you mention.

Would it be good to treat the topside somehow before it goes back in the water? Polishing and waxing perhaps? Or does that not matter at all?

[Nicholson58]

Originally Posted by twohapence

Hi,

I suspect your boat is probably built from polyester resin and not epoxy. Now epoxy is a great material but it needs care and attention and can be very tricky to work with.

Polyester resin is much easier, doesn't need such careful measurement of the hardener and is generally much more forgiving to work with and you can extend the working time by reducing the quantity of hardener. Polyester will stick to polyester. Epoxy will stick to Polyester. Polyester won't stick to epoxy.

I suggest you start by reading something like the fibreglass repair manual by Allan H Vaistes. Don't be too ambitious or in too much of a rush. Practice before rushing in.

The probem with the repair will be matching the colour of the hull afterwards.

Cheers

Ian

Epoxy is like type 'O' blood. It will repair polyester or vinyl ester. I always use epoxy. I suggest minimal sanding to reveal cracks. Repair cracks as necessary with fiberglass. If all you need is a filler then use MarineTex white and possibly follow the instructions to tint the putty. Use polyethylene film against the filler to make it stay without sag. Tape the film to the hull. You might be good enough to paint match the color. After you sand flat with a fine grit.

There are many on line videos to show you how to do various repairs. We$t Marine has one but it features We$t Marine products. Do not use hardware store epoxy. It will not hold up in a marine environment.

[Cyrus Safdari]

You don't have to fix it now but I'd cover it with something like fiberglass filler in the meantime to prevent water intrusion especially in cold place like Denmark where it can freeze expand and cause delamination. There are commercial, two-part products you can use. When the time comes you just have to grind down the area and redo the gelcoat, then fair prime and paint.

[sune]

Thanks again,

Just so I understand how it works.
Is it a layer of tinted/coloured gelcoat, or is it gelcoat with paint on top?
I suspect it's coloured gelcoat.

[Cyrus Safdari]

Originally Posted by sune

Thanks again,

Just so I understand how it works.
Is it a layer of tinted/coloured gelcoat, or is it gelcoat with paint on top?
I suspect it's coloured gelcoat.

Could be both. I have yet to see a boat whose topsides were not painted. The "paint" of course is usually itself a fiberglass-like resin product like gel coat but just runnier

[Cheechako]

That appears to be only cosmetic gel coat damage. You could get some gel coat matched by an expert and fill those in, Wet sand smooth and polish. But the odds of accurately matching a green faded color like that are pretty bad.

[Sailmonkey]

Originally Posted by Cyrus Safdari

Could be both. I have yet to see a boat whose topsides were not painted. The "paint" of course is usually itself a fiberglass-like resin product like gel coat but just runnier

Most boats are not “painted” they’re covered in gel coat. The gel coat is just polyester resin with pigmenting solids added.

[Sailmonkey]

Originally Posted by sune

Thanks again,



Just so I understand how it works.

Is it a layer of tinted/coloured gelcoat, or is it gelcoat with paint on top?

I suspect it's coloured gelcoat.

It’s most likely pigmented gelcoat. Gelcoat is nothing more than polyester resin with pigment added. Repair is easy, color matching is hard.

[hellosailor]

No matter how you repair that, unless you find an ace at color matching patches, you will always see a repair. So I would suggest cleaning it up a bit, filling in the dents with epoxy putty, sanding them down.

Then have a stainless steel or bronze "taco" shaped plate bent over the bow and epoxied over the area. That gives you some scratch and chafe protection from the anchor and from docks, and folks will never know there was an imperfectly patched repair under it.

And yes, it will add some minor strength over what a fiberglass repair would be.

[barnakiel]

To my eye, it looks like green gelco. Color gelco is not easy to match. But it is very easy to fix otherwise. Clean, wipe acetone and apply matched green gelco into the scratches. Let it dry well (some gelco requires taping over to block air). Then open when dry and gently sand down excess (I use very very fine sanding paper, wet) then buff and wax.

I tape with masking tape which is easy to remove as gelco tends not to stick to the glue.

Nice boat. We nearly got a Bandholm 28 back in 2002 when we took up long range sailing.

Cheers,
b.