Keel damage on GRP hull

[BogMonster]

I was shocked this morning to discover when launching the RIB that the keel is worn away right through the gelcoat into the GRP below. Photo attached. I have no idea how long it has been like this, but it's obviously just wear due to beaching when I launch and recover, it is pretty smooth and as if somebody has sanded it away. I used to keep a careful eye on the keel for damage but it never seemed to get any worse so I hadn't been paying much attention recently.

The boat has never been left in the water even overnight and is always on the trailer in a dry garage, so I am praying that there is no water ingress - the GRP is firm and there is no visible degradation.

The only repair materials I have here (bear in mind I live in the Falklands) are half a tube of two-pack gelcoat filler. I might be able to get a bit more of something similar, but anything else is about 2 months away.

What's the best thing to do as an immediate repair - should I just put some gelcoat filler over the top of this and sand it smooth? Should I try and key it first? The RIB is still going to get beached (no other option) so I am not sure if the filler will stand up to that. Can I just leave it as it is pending a permanent repair? (I'm not that keen on that idea)

Long term I think I will need to get some sort of keel guard which I wish I'd fitted when it was new now, but I was advised against it at the time.What are the options worth looking at, and what would be best for this given that it gets beached on either gravel or sand (depending on tide) every time I launch? And what is best to stick it on with? I see some seem to come as kits with adhesive etc included.

The keel doesn't touch the trailer rollers, so it is not something that has to take the weight of the boat on a point loading such as a roller, and it is just to protect the forward part of the keel that takes the hit when beaching.

Suggestions gratefully received, thanks

[GuyC]

I think I'd repair it using the gelcoat filler and then invest in some keelguard. If you are constantly beaching it, would a stainless 'shoe' be a better way to go in the long term? Someone might have some experience of them.

[diver 1]

Difficult situation given you're location. I'd do the best repairs you can with whatever you have available then definitely consider fitting keelguard / keelshield.

I had it fitted the full length of a 5.85m Ribcraft hull and it seemed really tough and durable. I've viewed a few commercial type ribs which have had bronze or stainless keep strips fitted with numerous countersunk and sealed screws. I wouldn't go that way if you can avoid it. Screws = holes and with the best sealants ever eventually you will likely end up more water penetration into your hull. The keel shield / keel guards are self adhesive so no drilling.

[Tim M]

If you're just using it daily and not keeping it afloat for any length of time I personally wouldn't hesitate to carry on using it as is, order some materials and repair properly when they arrive. It's not going to suddenly turn to mush in eight weeks because of a bit of missing gelcoat.

[jwalker]

In your photo I don't actually see where the gel is completely missing and the glass showing. It looks to be deep gel scrapes, perhaps there's a bit not visible.

Anyway, as Tim says, I'd leave it until you can get some resin and gel coat. If the fibers are actually showing you need it bone dry before applying anything. Any glass that's showing will have tiny spaces, ideally there shouldn't be any at all but that's unlikely with simple hand laminating, you need thin resin so that the glass can absorb it, firstly to seal the glass and secondly to give good adhesion.

Does absolutely no one on the island have resin, an old car repair kit or someone who casts shells into resin to make ornaments? - think outa the box, you might find something. Once you've got a layer of resin well stuck you could build up using the filler then protect it with something substantial. Just had a thought...often if a tin of car body filler is left for a good length of time the filler powder settles out of the resin and you get a resin puddle, it could be enough to give you a seal layer onto any exposed glass.

Good luck with it.

[Erin]

It looks to me like you’ve worn quite a lot of material off the keel there. If it were me I would give it a couple of coats of epoxy to seal it then build up the area with underwater epoxy filler so that it can take a Keelguard strip. Buy the proper keelguard with cleaner/primer and 3M adhesive.

[paintman]

Originally Posted by jwalker

In your photo I don't actually see where the gel is completely missing and the glass showing. It looks to be deep gel scrapes, perhaps there's a bit not visible.

Bang in the middle of the photo. Blow the pic up. Immediately to the right of the deep scratches in the white gelcoat. The long greenish bit with the blackish strip in the middle, the latter being the GRP showing.

I'd stick over it whatever you can get your hands on to build it up so you can continue to use it until repair stuff can arrive.
Agree that you need something on the lines of keelguard or some sort of keel iron to stop the problem in the future.

[gtflash]

It looks to me like you have flattened the bottom off. No filler, be it gelcoat or epoxy will make up the missing part of the V and be durable enough if that is the case. If my assumption is correct it’s a pretty decent repair. If however your just referring to the scratches, in the white stuff, your gelcoat repair will likely do the job.

I wouldn’t leave raw un gelcoated glass exposed forever. Any exposed strands might absorb water and possibly lead to osmosis. Epoxy resin would seal it but then you couldn’t gelcoat after. Paint is safest bet on top of epoxy. Or the keel guard if you must.

Filler is not structural. Perfect for cosmetic only. Simple.

[BogMonster]

Thanks all. The worn section is the long thin dark patch in the middle of the photo. Sorry - not the best photo - it was bright outside and hard to get one.

It's basically worn off the peak of the V so it is through the gelcoat to the base layer of GRP but it's smooth and progressive - as if somebody has sanded off the point of the V, which is basically what has happened over time. There are a lot of small cosmetic scratches either side, I'm not really worried about those as I can touch those up with the filler I used before.

I was thinking of something like a stainless keelguard just for a 2-3 ft long section of the keel where it touches (always the same place) but it would need to be formed in 3 dimensions (folded and then formed to suit the fore-aft curve of the hull) so I suspect it's not something that I could get as somebody would probably need to form it on the boat.

What keelguard type products are worth looking at? A search around shows a fair range from basically glorified sticky tape to some quite chunky (if rather ugly) solutions. Any direct experience please?

Or maybe the best thing is just to repair it and then keep an eye on it, repairing as necessary. The boat is never left in the water and never has been, so it's only day use but that means a lot of beach landings as there is no proper slipway for launching.

https://www.specialistsmallcraft.co....ack-keelshield

https://www.thewetworks.co.uk/produc...e-complete-kit

https://www.specialistsmallcraft.co....lar-keelshield

https://keelguard.com/product/keel-guard/

https://www.force4.co.uk/item/Force-...mx50mm-Kit/D23

[jwalker]

Steven, is it still the Humber Destroyer you have? If it is, you do know it has a planning pad so there was never a V at the stern. Obviously if it's a different boat that may not apply.

Just thought it worth mentioning.

[Matt]

That's a pic of the bow he's showing us jw.

Is this a fact - that there is no boatyard that can do any work on GRP boats on the Falklands?

Anyway - I suggest a keelguard for the fwd section of the bow would be a good thing if you know you're always going to have to beach it. Probably OK to use for the time being (that's typically a fairly thick bit of glass there), but warrants some glass repair work and then a keel guard. Is there a metalwork fabricator on the island?

[Erin]

This is what I have on my Vipermax. Get some International Watertite filler to build up the area and bung on the Keelguard.

[jwalker]

Originally Posted by Matt

That's a pic of the bow he's showing us jw.

Oh! I see. Now it makes sense! You've been beaching the boat and worn through the bow...I'm obviously getting slow on the uptake! Well that's a bit different because I agree with Matt about thickness at that area. It's often double thick because the glass is laid down past the keel from both sides. Also it's a very wet layup in that area because the resin slumps down to the keel line so the glass is likely very well impregnated and not absorbent.

If there's no resin available I'd be tempted to give it a couple of coats of antifoul or epoxy paint if that is available. Then have a stainless shoe made for future protection.

[Matt]

Yeah, a bit of epoxy paint would be a good shout.

However, being nosey, I've been googling boat builders and yacht chandlers on the Falklands and have drawn a blank.

It simultaneously looks like my ideal place to visit and also incredibly isolated if you want anything out of the ordinary.

[mikehhogg]

If you could get your hands on Sikaflex 7800,comes in a cartdrige . we used it to repair the grp blades on offshore windfarms,its as good as it gets ,goes off fast and is sandable,its structural not cosmetic and can be top coated by any polyester or epoxy product.
https://usa.sika.com/en/industry/pro...7800-blue.html

I have used this to repair the keels of several pac 22 ribs which believe it or not have very thin keel skin. Its a two component product that mixes in the nozzle of the cartridge.

The falklands recently returned a boat to us in Ireland called the illen. has been restored and is running trips again close to where i live.

http://www.ilen.ie/what-we-do-2/ilen/

[gtflash]

Bogmonster. I agree with JW and Matt. Seal it somehow and get a nice keel guard. Epoxy or epoxy paint. You could use epoxy filler but make sure your choice in keel guard attaches to the existing hull and not just the poly filler stuck on. Like you say, maybe having a well positioned stainless plate made up would look best. Scratch the hell out of it and clean with acetone prior to any repair.

A proper structural repair is a proper repair. West systems epoxy recommend a 12:1 bevel. Some polyester manufactures recommend 20:1. That’s 20 times the thickness of the existing material, tapered out around the repair. So a 1” laminate needs 20 inches of progressive laminates outwards. Consequentially I would not rely on any filler unless it had a lump of something substantial over the top of it. Stainless seems a great choice with 5200 adhesive. That will be forever.

[BogMonster]

Originally Posted by Matt

Yeah, a bit of epoxy paint would be a good shout.

However, being nosey, I've been googling boat builders and yacht chandlers on the Falklands and have drawn a blank.

It simultaneously looks like my ideal place to visit and also incredibly isolated if you want anything out of the ordinary.

That's the place


Frigging nightmare when you need anything unusual with lots of cost and shipping restrictions by air and 2-3 months by sea.


Thank you everybody, I'll concoct some solutions out of the ideas here and sort something

[GuyC]

Originally Posted by Matt

Yeah, a bit of epoxy paint would be a good shout.

However, being nosey, I've been googling boat builders and yacht chandlers on the Falklands and have drawn a blank.

It simultaneously looks like my ideal place to visit and also incredibly isolated if you want anything out of the ordinary.

Temporarily there was Malvinas Marine but they were put out of business about forty years ago. Co-incidentally we we living in the Outer Hebrides in 1982 and you could walk from one side of the airfield to the other on the wings of C-130's as the world's special forces descended on a similar environment to practice for a similar event.

[mikehhogg]

Originally Posted by BogMonster

That's the place


Frigging nightmare when you need anything unusual with lots of cost and shipping restrictions by air and 2-3 months by sea.


Thank you everybody, I'll concoct some solutions out of the ideas here and sort something

If you need something sent to you post a reply , maybe a parcel from a "FRIEND" might bypass the customs etc. and get there quicker

[Matt]

I'm not sure I feel brave enough to airfreight acetone or MEK "under the radar".

I don't mind a bit of rule breaking when the consequence of it would be trivial, but properly hazardous goods on an aircraft in an un-pressurized and/or un-heated hold - I am full nope.