Repairing glass fibre damage where you can't reach

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andynormancx
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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Wed Mar 27, 2019 7:43 am

Well, I'm pleased to say that the acetate didn't stick to the resin.

It ain't pretty, but nothing a lot of sanding and some gel coat won't fix ;)

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Wed Mar 27, 2019 10:46 am

I've sanded it back as much as I dare, I can tell that I'm now cutting into the woven cloth layer, so there are only two layers of CSM and one of cloth across the repair.

The repair is still a fraction of millimeter proud of the surrounding hull, the hull really must be very thin here.

I'm really wishing I'd put a bit a glass where I put that bit of foam (I could have used the same trick with the bit of wood to get it in place). I suspect I'll be revisiting this repair in the future...

As you can see in the photo, I didn't do a perfect job of wetting the woven cloth on the edges.

On the plus side, the repair seems sound, the hull feels like it has an equal amount of give both sides.

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Re: Repairing glass fibre damage where you can't reach

Post by Chris Bolton » Wed Mar 27, 2019 11:07 am

Looks OK - I'd fill the voids first (flowcoat would do), so that you can sand it all flat, including the hull surface round the mend, then flowcoat the whole area. If it all ends up a mm higher than it was before it will make zero difference to how the boat handles. Is the Tiderace logo moulded in?

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Wed Mar 27, 2019 12:06 pm

No, the Tiderace logo is a sticker. Curiously, printed in ink that dissolves in isopropyl alcohol...

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Re: Repairing glass fibre damage where you can't reach

Post by Jim » Thu Mar 28, 2019 11:27 am

Chris Bolton wrote:
Wed Mar 27, 2019 11:07 am
Looks OK - I'd fill the voids first (flowcoat would do), so that you can sand it all flat, including the hull surface round the mend, then flowcoat the whole area. If it all ends up a mm higher than it was before it will make zero difference to how the boat handles. Is the Tiderace logo moulded in?
All my race boats have skins so thin that were I need external repairs they end up as a slight bump, flow-coated and polished. It will create less turbulence than a gouge or split.

Most stickers lose their ink in most solvents other than water, sometimes I mask them, sometimes I peel them off, occasionally I replace them. At least the labels on the gel coat tins I have don't dissolve in thinners, the labels on the catalyst bottles do though.

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Fri Apr 05, 2019 3:13 pm

My attempts at gel/flow coating the repair are best described as "functional"...

Image

All a bit of a mess.

I did some other gel coat repairs at the same time, those are pretty much invisible because they were small and the holes I was filling were actually below the surrounding gel coat.

Maybe I'll have another go later. Though I'm always going to be struggling because the repair is proud of the surrounding surface.

I really wish I'd put that first bit of glass on the inside of the hole, so I could have had one less layer on the outside raising the patch above the surrounding hull.

Next time...

Just need to work out what to do with the remaining 2.9kg of flow coat ;)

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Fri Apr 05, 2019 3:18 pm

I've seen some advice since, which I wish I'd known about before:

- start out with brushing the flow coat on horizontally
- let it go off a bit and get tacky
- now brush some on vertically
- let that go tacky
- now brush some on horizontally again

Supposedly reduces the deep brush marks issue, makes sense.

(on the small repairs I did I didn't have to use a brush, which helped)

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Re: Repairing glass fibre damage where you can't reach

Post by Chris Bolton » Fri Apr 05, 2019 5:01 pm

I've never heard that advice, which doesn't mean it's wrong, but if you want for it to go tacky you'll have to make another mix. It goes off faster in the pot (less heat loss) than on the boat. Nor have I had brush marks in flowcoat. I would put the boat on its side so that the area was mostly horizontal and just laid it on thick and let it self finish. It's a difficult question, once you have a raised area, how much to extend the area you're working on to get a good taper on the edges. You naturally don't feel it's right to be extending the patch over the existing smooth gelcoat, but it helps. For example, there's no downside to filling and smoothing right back to the stern, it just makes the stern ("sternpost?") a bit thicker.

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Fri Apr 05, 2019 6:02 pm

I did have the boat on the side, I got plenty of of brush strokes in the flowcoat :(

The advice may not have used the word "tacky", I was probably overstating it ;)

When I get time I'll have a play with some scrap fiberglass to see if I can get any better at it.

It looks like I might have my third fibreglass repair to do, I've spotted that the cockpit rim on my Xplore is no longer entirely rigidly attached to the boat. When I flex it the rim moves more than I'd like and I can feel a small crack opening/closing all round the inside of the rear of the cockpit where the rim attaches.

Thankfully no need for gel coat on that one though.

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Re: Repairing glass fibre damage where you can't reach

Post by Aled » Sat Apr 06, 2019 11:48 pm

andynormancx wrote:
Fri Apr 05, 2019 6:02 pm
I've spotted that the cockpit rim on my Xplore is no longer entirely rigidly attached to the boat.
Happy to assist/advise with troubleshooting this...

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Sun Apr 07, 2019 11:40 pm

I didn’t have time to puzzle over it too long, I’m off for my sea kayak leader training tomorrow. So for now I’ve just done a quick fix of slapping a couple of runs of CSM along the crack.

That seems to have firmed things up a bit, there is still a bit of flex but seems to within the rim itself and feels “normal”. The movement before did not feel right, the rim and the gel coat or filler or whatever it is between the rim and the hull are no longer moving now I’ve covered up the crack.

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Re: Repairing glass fibre damage where you can't reach

Post by andynormancx » Sun Apr 07, 2019 11:43 pm

I can give some more lucid details in a week, not exactly thinking straight after doing my core coach training over the weekend and then frantically packing this evening for my sea kayak leader training on the other side of the country.

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