BarraMan's Mangusta 21 barraboat in Townsville, AUS

[OlivierP]

Interesting, I've never glued cloth upside down (nor down under...) so interested to see how it goes.

Did you consider a keel guard or keel shield type protection ?

[BarraMan]

Interesting, I've never glued cloth upside down (nor down under...) so interested to see how it goes.
Did you consider a keel guard or keel shield type protection ?

Its awkward, but doable! I used an engine crane to lift the front of the boat so that I could get to the affected area.



Now I am on to graphite, high-build priming, and painting!



I had a Keel Guard on the boat when first built. At that time the boat was on a bunk trailer so the keel was not resting on anything. Unfortunately, one fishing trip to the remote north of Australia destroyed the torsion bar suspension on that trailer, so I had a new custom built trailer made with roller-rocker spring suspension. The builder convinced me to go with roller support for the boat. As that meant to Keel Guard would be sitting on a roller ladder, I removed it as they say not to use Keel Guard with rollers.

I now intend to fit Keel Guard to the boat again, but only run it to just before the keel touches to first roller - which should protect the vulnerable area. Where we fish mostly has a sand or mud bottom, so I think the damage occurred at the dam where we ski at Xmas time, which has a stony bottom. I will be more conscious of that in future. We'll see how it goes, in the meantime I am happy to have an additional 6x layers of glass between the external hull and the wood core.

3x coats of graphite/epoxy 1/3:2/3 by volume!

[Fuzz]

Lee how many layers of glass did the hull have where it was worn through?

[OneWayTraffic]

I'd rethink that keel guard idea. The FAQ for Keelshield says that if there's weight bearing rollers, even if just when loading or unloading that it can become an issue.

I glued an aluminium strip to mine. Just a bunnings 2mm by 30mm profile. Glued with gflex. On the sides I have UHMWPE flame treated then also glued with gflex. Both of which should be a lot more resistant to rollers than a Keelshield, at a fraction of the cost.

[BarraMan]

Lee how many layers of glass did the hull have where it was worn through?

9 x layers of 12oz biax
4 x coats of graphite/epoxy
4 x coats of epoxy primer (sanded back somewhat)
2 x coats of 2 pack polyurethane under coat
2 x coats of 2 pack polyurethane top coat


The rubs are only 2 areas each about 2” long - so my repairs are probably overkill!

95% of the ‘at risk’ area now has 15 x layers of 12oz biax to get thru before the wood core is exposed!

[BarraMan]

I'd rethink that keel guard idea. The FAQ for Keelshield says that if there's weight bearing rollers, even if just when loading or unloading that it can become an issue.
I glued an aluminium strip to mine. Just a bunnings 2mm by 30mm profile. Glued with gflex. On the sides I have UHMWPE flame treated then also glued with gflex. Both of which should be a lot more resistant to rollers than a Keelshield, at a fraction of the cost.

I already have the Keel Guard so I’ll give it a go. If it doesn’t work out I’ll run an aluminium strip when I have the boat out on hard stand!

[fallguy1000]

I'd rethink that keel guard idea. The FAQ for Keelshield says that if there's weight bearing rollers, even if just when loading or unloading that it can become an issue.
I glued an aluminium strip to mine. Just a bunnings 2mm by 30mm profile. Glued with gflex. On the sides I have UHMWPE flame treated then also glued with gflex. Both of which should be a lot more resistant to rollers than a Keelshield, at a fraction of the cost.

I already have the Keel Guard so I’ll give it a go. If it doesn’t work out I’ll run an aluminium strip when I have the boat out on hard stand!

What about getting rid of the front rollers and making some glide bunks..you know where to put them!

[Fuzz]

Seems like a lot of glass to rub through. Are you sure you have not been "rubbing" on some rocks at 30 knots or so

[BarraMan]

Seems like a lot of glass to rub through. Are you sure you have not been "rubbing" on some rocks at 30 knots or so

Well, I have had two big “hits” with the boat on unknown rocks/pinnacles in the middle of nowhere, but they were taken by the skeg not the hull!

I guess I should have taken pics of the rubs, but they were only 2x spots about 2” long each, separated by 1x foot or so.

I have run aground unexpectedly many times but only on sand or mud!

My only explanation for the rubs is that they have happened over a number of years during our annual Xmas holidays when we spend a week or so waterskiing at a dam where the shoreline is stoney where I park the boat when launching and retrieving - no pontoon!

Some other rub areas down to the graphite only, but like you, I am surprised at the rubs through 9 layers of glass!

[OlivierP]

My experience too, glass is not so resistant to rubbing. Waves impact, torsional forces yes, but for rubbing kevlar cloth will likely be more efficient.