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Advice on repair.

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Created by MagicCarpet4 > 9 months ago, 11 Jun 2020
MagicCarpet4
NSW, 36 posts
11 Jun 2020 2:44PM
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Any advice would be welcome. I got out to the boat recently after being away for a awhile and found this damage to hull/deck joint or toe rail . Having considered the job I think it is beyond my level of expertise. Can anybody suggest how I might put a temporay fix inplace that could be reworked by a shipwright later to effect a propoer repiar. My thought was to sand the egdes and lay a couple of layers of glass matt over the damage to seal it and then that could be sanded away easily leaving all of the substraight inplace so the shipwright could then sand to the required depth and lay new glass, resin and gell coat to effect a proper repair. I would probably need the temporary repair to last for six months.

Thanks

Toph
WA, 1838 posts
11 Jun 2020 1:38PM
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Some of that glass fibre looks broken (it also looks like a fairly dry lay up to me too), so it is more than just a gelcoat patch/fix.

But with a little more care, your 'temporary fix' is not much different to what a shipwright will do. Sand back to clean glass and follow that crack that goes up to the right of the photo to ensure that doesn't go into the glass (it could just be a gelcoat crack) then lay up your new matt. Match the gelcoat (the hardest bit of the whole lot) apply, sand, polish.

A shipwright will probably do it quicker and a nicer job first go if your time is limited or if it becomes a bigger or structural job.

Check out Andy's videos from www.boatworkstoday.com

Kankama
NSW, 683 posts
11 Jun 2020 4:32PM
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Im with Toph - but do it yourself if you want to learn a new skill.

Great news - you now have a reason to go to Bunnings and buy a battery operated 4 inch angle grinder. Play with it at home ansd learn how it moves. Then get out to the boat and grind away the gelcoat and any damaged glass. You may like to put a small amount of filler in any crevices and then glass. Get light chop strand mat and rip it into small pieces and place on the the repair and wet out with polyester resin. Increase the patch size as it builds up. Cover with filler and sand fair - this will take some attempts. Then buy some flowcoat - not gelcoat - of the same colour and paint on. You can wet and dry and polish to finish. Now you have a new skill and a reason to head down to the boat even more than before.

cheers

Phil

2bish
TAS, 815 posts
11 Jun 2020 5:03PM
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Do you know how the damage happened? Did some one run into the boat or something?

I'm with the guys, if you're willing to do a temp. repair, then maybe bite the bullet and have a crack at a permanent repair. You'll definitely gain some skills and may save yourself some money. Worse case scenario is that you're not happy with the end result, but you'll at least have a temporary waterproof repair, and then you can have it done professionally down the track.

southace
SA, 4776 posts
11 Jun 2020 5:14PM
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Hard to tell is that just a toe rail? If so not structural , I would be just filling with expoxy filler. A 500ml epifill might do it. Epoxy undercoat , gel coat or two pack in a can to finish it.

RubikRedDog
WA, 29 posts
11 Jun 2020 3:54PM
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This book has some great info on most aspects of maintenance. Like it says on the cover!





r13
NSW, 1551 posts
11 Jun 2020 7:04PM
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Not good by any measure. Some issues, some mentioned above;

1 The chopped strand mat area is very dry of resin and very clearly an air void in the laminate which should not have occurred in the original build.

2 Exactly how did this happen? If you are in a marina berth I would be asking focused questions to the boss of the premises. If on a swing berth not associated with a marina then tracing the source would be difficult.

3 Also whereabouts along the deck length is it? If it is around midships then the magnitude of the alternating stresses there due to the hull hogging and sagging in a seaway may be a future problem for a repair which is not done effectively. If it is close to the bow or stern then the alternating stresses will be less. Whilst a grp hull/deck joint/toe rail like this might not be a large influence on the structural integrity / bending stiffness of the hull overall, it will still experience alternating stresses due to its proximity out from the hull beam neutral axis in bending and if the fatigue resistance of the repaired area is not adequate then further damage will probably occur.

4 When you look from inside the hull and up to the damaged area - is the internal laminate still intact? I would assume / hope so.

5 Realise that the photos attached are very zoomed in but they look a tad nasty.

6 Hunter Yachts are now www.marlow-hunter.com/ you could email them and ask their direct advice, and how such a dry laminate and air void could have occurred in the original build...........if they are any sort of customer service organisation they should respond promptly and fully.

7 If you are going to grind out the whole area and lay new polyester resin and glass cloth into the dry laminate and air void area I would make sure the whole cracked area was ground out so that no cracks were left which would continue to propagate in length into the future.

8 Would blend it out for sufficient length so as to allow overlapping laminates as each new one was placed on - as per Phil. The blend out ratio would suggest be at least 5:1 - this being the taper of the blend to the laminate thickness.

9 I would add biaxial glass laminate to the repair not just filler - whether epoxy or polyester. I would use epoxy resin and biaxial cloth, the resin poured in to fill the void and dry original laminate for whatever volume is needed - then the biaxial glass laminate added in successive layers to the original toerail cross sectional shape for the toerail length needed, and finish with 2 pack polyurethane. If done well this would hardly be noticeable as a repair.

10 Note that polyester gel coat won't stick to epoxy long term or even short term.

southace
SA, 4776 posts
11 Jun 2020 9:07PM
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Select to expand quote
r13 said..
Not good by any measure. Some issues, some mentioned above;

1 The chopped strand mat area is very dry of resin and very clearly an air void in the laminate which should not have occurred in the original build.

2 Exactly how did this happen? If you are in a marina berth I would be asking focused questions to the boss of the premises. If on a swing berth not associated with a marina then tracing the source would be difficult.

3 Also whereabouts along the deck length is it? If it is around midships then the magnitude of the alternating stresses there due to the hull hogging and sagging in a seaway may be a future problem for a repair which is not done effectively. If it is close to the bow or stern then the alternating stresses will be less. Whilst a grp hull/deck joint/toe rail like this might not be a large influence on the structural integrity / bending stiffness of the hull overall, it will still experience alternating stresses due to its proximity out from the hull beam neutral axis in bending and if the fatigue resistance of the repaired area is not adequate then further damage will probably occur.

4 When you look from inside the hull and up to the damaged area - is the internal laminate still intact? I would assume / hope so.

5 Realise that the photos attached are very zoomed in but they look a tad nasty.

6 Hunter Yachts are now www.marlow-hunter.com/ you could email them and ask their direct advice, and how such a dry laminate and air void could have occurred in the original build...........if they are any sort of customer service organisation they should respond promptly and fully.

7 If you are going to grind out the whole area and lay new polyester resin and glass cloth into the dry laminate and air void area I would make sure the whole cracked area was ground out so that no cracks were left which would continue to propagate in length into the future.

8 Would blend it out for sufficient length so as to allow overlapping laminates as each new one was placed on - as per Phil. The blend out ratio would suggest be at least 5:1 - this being the taper of the blend to the laminate thickness.

9 I would add biaxial glass laminate to the repair not just filler - whether epoxy or polyester. I would use epoxy resin and biaxial cloth, the resin poured in to fill the void and dry original laminate for whatever volume is needed - then the biaxial glass laminate added in successive layers to the original toerail cross sectional shape for the toerail length needed, and finish with 2 pack polyurethane. If done well this would hardly be noticeable as a repair.

10 Note that polyester gel coat won't stick to epoxy long term or even short term.

10 note, you can apply viny ester clear coat resin onto epoxy repairs followed by polyester gelcoats

Ilenart
WA, 250 posts
11 Jun 2020 8:44PM
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For a temporary fix I would use gaffer tape to stop any ingress of water. Then if you cannot fix it yourself you have a couple of weeks to find a shipwright (or a couple of months if you replace the gaffer tape every month).

Ilenart

Ramona
NSW, 7584 posts
12 Jun 2020 8:41AM
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I had a look at that damage the other day just out of idle curiosity. Not sure what actually caused the problem as it's a lot higher above the waterline than the suspect boat topsides. I'm guessing the bowsprit came down on it in the rough conditions.
The area is a lot smaller than what I was expecting too after first looking at your photos. I would just carefully mask up the area and fill with epoxy and micro balloons. Do it with several applications, start with a runny mixture to wet out all that loose stuff. Then move to a thicker mix about the consistency of toothpaste. Either sand smooth and paint or fill to just below the level and finish with car body filler and paint. Swing by and I can give you some micro balloons.

MagicCarpet4
NSW, 36 posts
12 Jun 2020 8:43AM
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Thanks for all the advice. I think on the back of this wisdom I will have to cover it with Gaff tape and investigate undertaking permanent a repair. I'll check out all the links and send a picture to Hunter Marlow to see what reaction/advice I get from them.

The damage is amidship and as I am on a swing mooring there is no whay of knowing what/who did the damage. There was no sign of any other debris in the damaged area so it would seem it was not a tree floating down the river etc. The size, shape and height above the water line would lead me to surmise it was a bow sprite. But that is just a guess....

Below is a photo for scale with my mancky foot in the shot.




2bish
TAS, 815 posts
12 Jun 2020 10:05AM
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Ah a hit and run MagicCarpet, what a bummer! It's worth asking around to see if anyone saw it happen. With all the confusion and stress during a collision, they may be unaware of the damage they caused. Yeah I'm being generous I know, but I do know of a recent collision down here where this was the case. When I heard about it from someone who was onboard, I prompted them to go and have a close inspection and yes they found they'd done some damage and followed up by contacting the owner.

MagicCarpet4
NSW, 36 posts
12 Jun 2020 11:03AM
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2bish said..
Ah a hit and run MagicCarpet, what a bummer! It's worth asking around to see if anyone saw it happen. With all the confusion and stress during a collision, they may be unaware of the damage they caused. Yeah I'm being generous I know, but I do know of a recent collision down here where this was the case. When I heard about it from someone who was onboard, I prompted them to go and have a close inspection and yes they found they'd done some damage and followed up by contacting the owner.


Thanks 2bish. I ma moored about four boats down from Ramona and di put the pictures on the Greenwell Points FB page to see ifanybody had seen anything. No luck though.

Strachan
ACT, 47 posts
12 Jun 2020 12:55PM
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Thanks, very timely and commiserations. (Been there, done that, but fortunately my marina had it all on CCTV! Bloody high powered stinkboats.) I've been wondering if this is the time to learn fibreglassing skills too, as I have a couple of non-critical cracks in hatch covers to repair. The guy I spoke to at Whitworths said that gel coat and flow coat are the same, just that it's called gel coat when applied to the whole mould of a new boat. Are they the same? And what grade of sanding disc(s) for the grinder should I use?

Azure305
NSW, 402 posts
12 Jun 2020 1:21PM
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Not the same. I have small pots of both onboard. I understand that flowcoat has an additive (a wax?) so it's not 'sticky' when it's cured, gelcoat will remain a bit sticky inside a mold, ready to accept the next step of the layup. I'm sure someone can explain it more technically.

Toph
WA, 1838 posts
12 Jun 2020 2:34PM
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Un-waxed gelcoat won't 'set' when unsealed. It needs to be covered, either by peel ply, glad-wrap will do the job, or when in a mold, by the layer of glass..

r13
NSW, 1551 posts
12 Jun 2020 4:42PM
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Good discussion here and a video;

forums.ybw.com/index.php?threads/the-difference-between-gelcoat-and-flowcoat.458139/

I always thought flowcoat was only for interior surfaces so good learnings..............

I would get the manufacturers advice directly.............all products these days have a technical data sheet on line and if that is not clear give the manufacturer a call - most are excellent with immediate advice.

Ramona
NSW, 7584 posts
12 Jun 2020 5:48PM
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I had a look at the damage close up this morning on my way out sailing. That bit of CSM will have to be ground out. The amount of filler required is fairly small. The gelcoat is way too thick, on the inside, it's about 3mm thick! There is a previous repair on the topsides just about the window someone has done with gelcoat. The footpath is back on her mooring now and I think the damage is from the SS davits on her stern. They are the perfect height for smiting 'glass boats! I would say the damage occurred on a run-out tide and strong Westerly, the offending boat just slipped backwards on to yours. I was away when this happened.







southace
SA, 4776 posts
12 Jun 2020 6:54PM
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Ramona said..
I had a look at the damage close up this morning on my way out sailing. That bit of CSM will have to be ground out. The amount of filler required is fairly small. The gelcoat is way too thick, on the inside, it's about 3mm thick! There is a previous repair on the topsides just about the window someone has done with gelcoat. The footpath is back on her mooring now and I think the damage is from the SS davits on her stern. They are the perfect height for smiting 'glass boats! I would say the damage occurred on a run-out tide and strong Westerly, the offending boat just slipped backwards on to yours. I was away when this happened.








The gelcoat is way too thick typical dogie boat builders , it should be sprayed on at a certain thou of a inch there's a tool to test it while applied. Could have been brushed into the mould by monkeys if it wasn't sprayed.
easy repair and not structural. I would bog it and flow coat. Flow coat is made from gelcoat with wax in styrene , the wax floats the the surface and cures the flow coat to a sandable /polishable finish.

samsturdy
NSW, 1659 posts
13 Jun 2020 9:54AM
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Does this sort of incident require a request to the RMS to separate the moorings further or is it a result of the mooring servicing contractors not putting the mooring block down in it's original place ?.

Strachan
ACT, 47 posts
13 Jun 2020 2:37PM
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I've experienced it in a mooring field belonging to a private marina. Just your typical garden type greed I think in my case. And a bigger boat (not mine) would need a bigger radius to swing in.

r13
NSW, 1551 posts
13 Jun 2020 4:22PM
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A very common story unfortunately. At low tide the swing radius of all boats inherently increases. For bays where the tidal current swirls in and also eddies, and changes action when going in or out, at low tide and not much wind or changing wind boats frequently get stern to stern or stern to midships as regrettably appears to have occurred here. With stern davits on heavy displacement clunkers the interaction of the 2 boats can be nearly similar to hammering down with a 9lb fencing hammer.............

Ramona
NSW, 7584 posts
14 Jun 2020 8:03AM
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samsturdy said..
Does this sort of incident require a request to the RMS to separate the moorings further or is it a result of the mooring servicing contractors not putting the mooring block down in it's original place ?.


This was simply a mooring failure. 20 tons of concrete and a worn out chain mooring.

MagicCarpet4
NSW, 36 posts
15 Jun 2020 4:08PM
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Select to expand quote
Ramona said..
I had a look at the damage close up this morning on my way out sailing. That bit of CSM will have to be ground out. The amount of filler required is fairly small. The gelcoat is way too thick, on the inside, it's about 3mm thick! There is a previous repair on the topsides just about the window someone has done with gelcoat. The footpath is back on her mooring now and I think the damage is from the SS davits on her stern. They are the perfect height for smiting 'glass boats! I would say the damage occurred on a run-out tide and strong Westerly, the offending boat just slipped backwards on to yours. I was away when this happened.








Thanks Ramona. I will do some googling on your suggested repair and see if I can find any Ytube videos.



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