Unusual GRP keel caps just peeling off.

[Tammany]

Was scraping the antifoul today and got to what I assumed were keel caps at the bottom. Except one was lifting off at the edge and water was seeping out. Further investigation and looking at pics of other tomohawk 25's revealed that it's not supposed to be anything their and these have been added at some point. I think they've been on their for some years as their were several coats of antfoul on top. I assume someone has put them their as extra strength for drying out but they didn't do a very good job as they fibreglassed straight onto gel coat and that just doesn't work. To cut a long story short they peeled off in pretty much one bit and their was stinky mess of mud, water & sand behind them in places. I don;t know why they did it too be honest as the bottom of the keels are in reasonable order with just some chips out of the extra thick resin that's at the bottom. Very odd diy bodge?? Anyways I've stripped them off. Is it a good idea to fit a hardwoord cap at the bottom though? I've seen this on a few over the years. The rudder skeg has a bronze cap, it's a pity they didn't do the same to the keels.

This is what it was like before, notice the bulge at the bottom.

This is what it's like after levering off the 'extra' thats been added. A bit chipped out here and their but easier enough to fair up with epoxy filler.

One of the parts that peeled off, their was no strength in the layup at all as it was on top of sanded gelcoat by the looks of it. Notice how clean the joint is, it literally just peeled off with some levering.

 

[Tammany]

Question is is just to leave it as GRP as from the factory or add wood cap or maybe thick rubber??

 

[PuffTheMagicDragon]

What you have removed is a sacrificial shoe, put there as a 'first defence' against damage to the keel itself, which would lead to possible ingress of water into the keel structure.
You mention using wood. How do you propose to fix this to the keel? Simply screwing it on would cause more damage to the keel.
Personally I would replace something similar to what you removed, adding extra thickness to the bottom face, and making a better job of attaching the shoe to the keel probably through the use of a good bonding agent like Sikaflex or similar stuff.

 

[oldsaltoz]

I suspect the lack of preparation was to ensure poor adhesion to make life easier when it came to replacement. Had they used an Epoxy resin it would take a bit of grinding to remove them.
Personally not a fan of placing timber below the waterline as it just means more maintenance.
Consider looking in the metal scrap yards for some 316 stainless steel. Stronger and will last for many many years.

We recently added 'V' shaped caps to the cat keels.

Good luck and fair winds.

 

[Tammany]

I searched on here and found a thread where hardwood was glued to the bottom and then edged with glass tape. Stainless steel would be a good option though.

 

[VicS]

I searched on here and found a thread where hardwood was glued to the bottom and then edged with glass tape. Stainless steel would be a good option though.

I basically agree with Puff

My Seawych has similar keel shoes. I m sure just intended as sacrificial protection to the bottom of the keels.. They were not even thoroughly wetted out glass mat IIRC and certainly not gel coated. I suspect they may have only originally only been intended to protect the keels during initial handling and fitting out.

However we can buy replacements from the owners association and if/ when they are lost replace them. I lost, and replaced one of mine many years ago.

If I were you I would make up a male mould to match the shape of the keel, lay up a replacement and fit it to the keel. A couple of layers of resin and glass mat will attached it if you clean and slightly roughen the surface. Epoxy resin will make a stronger bond if you feel the need but I rather like Puff's suggestion to use an an adhesive sealant such as Sikaflex or PU40.


This is what happens to encapsulated ballast if the keel becomes damaged and water enters.







This boat came within a hairs breadth of being scrapped but was in fact repaired.

 

[fisherman]

I just scuff the gel coat and apply what seems like enough layers of mat/resin and finish with flocoat. Did a sacrificial patch where pots rub the hull, between tides in 2001, as a temporary fix, it's still there. In Porthleven the boats tend to run forth and back on their chains and more than one rubbed through due to lack of any protection.

 

[William_H]

The shoe that has now come off obviously did it's job for some years. As said it may have been intended that it not be a specially good bond to original keel or maybe just bad material and work man ship. It doesn't matter much anyway. I would suggest you replace the shoe in much the same way as the old one. Use polyester resin and chop strand mat for bulk. Perhaps take the shine off the gel coat for better adhesion. A bit of filler over the csm to make the final antifoul paint smooth. Or use epoxy and a lot of layers of woven glass.
It may be damaged by rocks etc in grounding but it will do it's job of protecting the original grp. olewill

 

[Tammany]

After much research I'm replacing them in a similar manner as suggested but using epoxy & kevlar. Kevlar is the most abrasive resistant & strongest laminating cloth you can get so ideal for a keel shoe.

 

[LittleSister]

Kevlar is the most abrasive resistant & strongest laminating cloth you can get so ideal for a keel shoe.

. . . . unless you ever want to remove it!