Tender Repair

[mark99]

I found this boat sitting abandoned in the long grass - I'm about to make a low offer (to the current landowner) to buy it as it will be good for maintenance tasks . Any tips how to repair the keel? I assume epoxy/glass fibre kit after rubbing down?

[Tony Brooks]

If you can see the glass strands in the damage, then I agree, but I would not go to the expense of epoxy, I would use ordinary polyester resin. However, if you can't see the strands then I think it may be some form of moulded plastic and if so there may be adhesion problems with any resin repair or filler.

[AJLElectronics]

16 minutes ago, Tony Brooks said:

If you can see the glass strands in the damage, then I agree, but I would not go to the expense of epoxy, I would use ordinary polyester resin. However, if you can't see the strands then I think it may be some form of moulded plastic and if so there may be adhesion problems with any resin repair or filler.

 

Agreed, Polyester resin which is what it will have been built with.  If it is any other composite, then epoxy resin is a better choice.

[mark99]

Good advice - I will go there later and have a good look for the presence of strands

[Tony Brooks]

The way there are bits of material "holding on" in the hole in the keel/bow, suggests it is GRP, but best double check.

 

It may well have been painted a number of times, and if so the paint needs to come off. Clean/degrease the abraded repair area with Acetone before applying the resin.

[Tonka]

I would use West systems Epoxy. And put a patch of carbon-kevlar material and carbon material. It is how I used to repair my daughter's slalom kayak when she was competing internationally.

[Alan de Enfield]

Once the repair has been effected, buy a length of brass strip the width and length of the keel - screw into to the keel having countersunk the screw holes to suit the screw,

 

You can then drag it around without inflicting damage.

Edited June 20 by Alan de Enfield

[Wafi]

1. Grind/cut/sand away the loose bits, then grind/sand the gelcoat back to bare glass, out to about 2-3" from the actual hole. Clean with acetone.

2. Fill the voids in the keel. Looks like it's currently filled with foam. Car body filler would be fine to fill the voids, or self-expanding foam (but read on for a caveat).

3. Epoxy resin will be stronger than polyester, and forms a better bond with cured polyester. Polyester is cheaper, though. Either will be fine from a functional perspective. Polyester may melt self-expanding foam, epoxy won't. Polyester stinks. Wear disposable gloves.

Wet out the repair area with a disposable brush and apply glass. I'd use 4-5 layers of 200g/m^2 woven glass because that's what I have handy, but an equivalent quantity of chopped strand mat will do the job. If in doubt, for a job like this, add a couple of extra layers. The glass needs to be properly wetted-out; but try not to add more resin than necessary. If possible it's best to do the job in one go; don't do it in multiple coats like paint. If you have peel ply handy, lay that over the top, but don't worry if not.

4. Allow to cure and remove peel ply (if used). Sand smooth and (optionally) paint

 

Kevlar (as suggested above) is very robust and wear-resistant, but will go furry if you try to sand it. Not an issue here, but worth knowing for other repairs.

 

Epoxy cures with an exothermic reaction, so only mix as much as you can use in 10 mins until you get used to working with it. If it starts to congeal in the pot, stop immediately and (if there's still a reasonable amount in the pot and/or it starts to give off fumes) put it outside away from anything flammable.

Disposable paper coffee cups and wooden coffee stirrers are perfect for mixing resin. For disposable brushes, the ones sold as "acid brushes" on Amazon/eBay are ideal (go for the larger ones if there's a choice).

[mark99]

Thanks guys. Here is a close up of the keel hole (image 2). The red ant is for scale 😀. It looks like fibre glass?

 

I have another tender (image 1) which is plastic moulded (SportsYak) on another of my ponds but the use I have for this fibre glass one is in a pond 1/2 mile distant:- saves porting the plastic one over rough land so worth repairing.

 

 

 

 

 

 

Edited June 21 by mark99