GRP repair

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Ian_Rob

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My anchor locker has a raised portion through which the chain runs when the hatch is closed and the chain or the anchor shank has managed to take a 30 X 20mm chunk out of its leading edge. What is the best way of making a repair that will last. I could try Plastic Padding GRP filler but the GRP is only 5mm thick and I see can any repair being easily damaged again.
 
I'd either repair with some chopped strand mat and resin probably 3 - 5 layers. Wouldn't fuss about a pretty job so just grind off some surface around it, remove any loose material and apply CSM above and below (like a sticky plaster with 50mm overlaps) add another couple of layers above with 75 and 100mm overlaps. Will be strong. Coat with flow coat. BUT will still break is the anchor attacks it. So I'd then add a protective strip as suggested. Aluminium might be an option. Doesn't need to be structural. Depends if you are going for functional or beautiful or both.

BUT if there is actually a design flaw that means the anchor will hit it every time I'd tink about cutting back the lip and making it further back in a half circle type way to avoid the anchor fouling it...
 
As a typical ham fisted GRP amateur, I repaired the gunwhale on Cobblers quite successfully. I found the easiest way was to use small strips of mat, pre-wetted on a board rather than wrestling with full sized sheets cut to size. Don't know if this is relevant to your particular application, just a general tip.
 
You can get fibreglass woven tape by the metre from chandlers. It makes quite strong repairs. I use it with West epoxy,
this is expensive but very strong. Alternatively Halfords used to sell some kits with resin, hardener and a piece of fibreglass matting. As suggested by the other posters, if it is subject to wear a piece of metal underneath would be good, perhaps one of the strips they sell as backing plates for deck fittings bent to shape.
Phil
 
When something like this happened to my chain locker lid, I neatly cut back the lid to make a squared off cut out then fixed a strip of aluminium bar on the three sides of the cut out with screws. Finally, I made good the surface of the cut, blending it into the aluminium strip with gel coat repair stuff. No further damage to the lid and it doesn't look too bad either!
 
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As said a metal chafing strip might be the best bet. However if you want to repair with GRP then use epoxy resin and get some Kevlar cloth for the reinforcing. This is incredibly tough. You will have trouble cutting with scissors. (sharpen them) and will also have trouble grinding it to shape whne hard but that toughness will resist chafe by the chain if that is the problem. good luck olewill
 
It was the practicalities of forming a suitable metal piece that was [is] putting me off. Milling a suitably stepped and rounded section in 316 is easy enough but I am not sure how easy it is going to be to then bend it to the required curve to follow the profile of the 'chain-way'. I have tried previously to bend 16mm stainless steel rod to a 30mm radius heating it with a blow lamp [butane/propane mix] and it didn't work. I assume it wasn't hot enough. Whatever else, the 'fix' must look as though it was always part of the original design.
 
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Ian_Rob said:
It was the practicalities of forming a suitable metal piece that was [is] putting me off. Milling a suitably stepped and rounded section in 316 is easy enough but my I am not sure how easy it is going to be to then bend it to the required curve to follow the profile of the 'chain-way'. I have tried previously to bend 16mm stainless steel rod to a 30mm radius heating it with a blow lamp [butane/propane mix] and it didn't work. I assume it wasn't hot enough. Whatever else, the 'fix' must look as though it was always part of the original design.
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Use aluminium strip rather than stainless, much easier to work and if you find it wears away easy to replace.
 
Ian_Rob said:
It was the practicalities of forming a suitable metal piece that was [is] putting me off. Milling a suitably stepped and rounded section in 316 is easy enough but I am not sure how easy it is going to be to then bend it to the required curve to follow the profile of the 'chain-way'. I have tried previously to bend 16mm stainless steel rod to a 30mm radius heating it with a blow lamp [butane/propane mix] and it didn't work. I assume it wasn't hot enough. Whatever else, the 'fix' must look as though it was always part of the original design.
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Annealing SS is challenging, and bending something with that section more challenging still. Would it not be easier to fabricate from plate? A photo of the area in question might garner better advice.
 
Sorry to butt in here, but the thread's title is sure to attract voices of experience so I hope I can add my question to Ian's.

My vang is rubbing deep into the GRP of the bevelled edge where my cockpit's forward bulkhead meets the deck near the mast-foot...

Screenshot_2015-11-01-19-43-57_zpsoqylml7k.png


Screenshot_2015-11-08-11-36-39_zps5ikdmzfz.png


...primarily on port tack, for reasons I can't understand...I also don't understand why the damage seems to be happening now, whereas the vang doesn't seem to have made contact with this edge during the last 40 years...maybe the mast is meant to be raked more.

Anyway, this rubbing contact is really quite deep, not just through the paint - it's bored 2 or 3mm into the GRP, on less than ten breezy days this year; I'm sorry the photo doesn't do it justice...

Screenshot_2015-11-08-11-38-33_zpsafmqlfic.png


...so, I'd like to cover both port & starboard edges with something which won't be so easily damaged; and if possible, will add rather than detract from the boat's appearance - so maybe since I have chrome rowlocks and sockets, a very light strip of stainless steel bent through 90° to fit on the bevel will do it. Anybody know where I might find such a thing?
 
I'd move the vang so it can't make contact to be honest. If you toughen up the surface you just wear through the vang quicker.
 
ShinyShoe said:
I'd move the vang so it can't make contact to be honest. If you toughen up the surface you just wear through the vang quicker.
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Thanks for that, but it's not very obvious how the vang ought to be set up, to avoid contact with the deck.

Besides, knowing how effectively that yellow line has burned straight through my top-coat, undercoat and deep into the grey glassfibre beneath, I'm not very nervous about the line's durability if it encounters something smooth like stainless sheet steel.

No-wear_zpsn20itkv7.jpg


EDIT: Thanks LW395, those flexible pads look perfect! :encouragement:

At risk of drifting from the theme of the thread, have you any idea why this problem is arising with my vang? It's not obvious to me.
 
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Force 4 catalogue p126 for self adhesive stainless strips or probably better 8" long solid stainless strip @£6.95. Used that for the furling line coming over the coaming. Smart and effective.
 
dancrane said:
....

At risk of drifting from the theme of the thread, have you any idea why this problem is arising with my vang? It's not obvious to me.
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You may find it's something like the tuning/evolution of Ospreys has moved the mast forward relative to the deck over the years, or the kicker fixings have been moved on your boat.
When your boat was new, it may have had a simpler system, or a drum winch, or a lever?
Or people may have simply eased the kicker to run square in those days, it's a common enough problem.
There are thousands of boats with bits of brass or paxolin etc to solve this problem!
 
lw395 said:
...people may have simply eased the kicker to run square in those days...
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Ah. That'll be it... :o ...singlehanding the Osprey in a breeze, I have been known to neglect certain sail controls... :rolleyes:

It's likely to get worse next season too, when I dare to distract myself even further with the spinnaker. :eek:

I'll get the stainless strips from Force 4, thanks to all. :D
 
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