Advice Please On Repairing These Dings

[andyatos]

Hi again,

I've got 4 areas I need advice on. One is a glass and epoxy repair, the other 3 look like gel coat fills.

The first photo is of a 4 inch long repair. The previous owner told me about this one when I first made contact, sent me a photo and said it was, "professionally repaired". I had my doubts about this repair claim but when I saw it in person and ran my hand over it, I had to agree.

It is completely filled in to the edges of the gel coat, matches the contour of the bow perfectly and is TOTALLY smooth. If you ran your hand over it with your eyes closed, you'd never know there was a repair there. Like a mirror.

So all I need to do there is "paint" it. There's no evidence of the fiber glass on the surface of the repair so the bonding surface looks to be 100 percent resin. Will gel coat adhere to this resin? I'm wondering if a white epoxy paint would work well here. Roll/paint on several coats then sand to a smooth finish? Let me know what you think.

The other 3 areas are dings/wears that have penetrated down through to the glass but not into the glass. Should I fill these with gel coat then sand?

Thanks very much in advance for any advice you can provide.

- Andy

 

[Voodoo 158546]

Hi Andy.
The three dings are easily filled, either with a gel coat filler - a 2 part kit cost £10/$17 ?
As for the repair, you could either a: ignore it
b: sand it back a very fine amount and using your gel coat filler re cover it ( presuming it was polyester resin, gel coat filler won't stick /stay stuck to epoxy resin)
c: sand it back very neatly and patiently and apply a layer of 'flow coat or regular gel coat,taped over ( gel coat will remain tacky on the surface exposed to air, if its taped with parcel ape for instance it will cure dry.
d: rub it back and paint it with 2 part polyurethane, ( undercoat and several topcoats).

Unless you're doing the whole hull I wouldn't bother with d - 2pack polyurethane is expensive man...£70/$120 for the whole hull and its gotta be done properly.
Me? I'd do B or C.

 

[torrid]

Two options for filler. Gelcoat or Marine Tex. Give the age of the boat and that it is white, I would I'd go with Marine Tex. It won't be glossy, but will reasonably match the color. It is also easier to work with.

You'll want to clean out the chipped areas to some degree. You want a clean, unoxidized surface for the filler to bond to. However, don't want to sand it out to a bigger repair than needed. It's kind of a judgement call.

Mask off the area around the chip as close as you can, then apply the filler. After it's cured, start sanding it down using a sanding block of some sort. You want to sand the extra filler, but not any of the original gelcoat. Keep sanding until the filler just starts to feather in. You'll be amazed at how smooth and flush you can get it with a little patience.

Had a ding like this not long after I bought my boat. I bought some bright white gelcoat, but it turned out the gelcoat had a very light grey tint to it. The repair work turned out very well, but there is distinct color difference. Had I known how well the repair would work, I would have tried to match the color a little bit better.

 

[andyatos]

Hi Voodoo,

Thanks for the detailed response. What about a white, epoxy paint to cover that repair in the first photo? It's a small area, the surface is perfect so all I want to do now is to make it white. Or is that what you were essentially talking about as option D?

I left a message with the previous owner to try to track down who did the repair so I can ask them if they used polyester or epoxy resin.

- Andy

 

[andyatos]

You'll want to clean out the chipped areas to some degree. You want a clean, unoxidized surface for the filler to bond to. However, don't want to sand it out to a bigger repair than needed. It's kind of a judgement call.

By this do you mean those small angular surfaces within the chipped areas need to be sanded (somehow) or would something like a fine, wire brush work?

- Andy

 

[Voodoo 158546]

Ahh ok, lets get specific.
You'll need...
To clean up/ prepare the wound ......
80 grit sandpaper, acetone, blue paper towel ( automotive industrial paper cloth) nitrile loves

Gloves on ( the sweat from our fingers can contaminate )
Small peice of 80 grit, you just want to mechanically key the area and form a 45 degree angled edge while rounding out the wound ( round, oval same same, just not jagged chipped frayed gel coat hole)
Acetone onto blue cloth and clean off sanding debris ( don't blow the sandings away - breath = condensation)
Let sit a few secs while acetone evaporates, then repeat with a fresh acetoned cloth ( avoid vapours).
The acetone is chemically keying also.
Use Sellotape to mask up the good stuff surrounding the area.
Once your happy the wound is keyed and clean, make just enough mix of the filler and with a lolly stick ( sharpen one end to an angled point, the other square off - use the 80 grit ) squared end make your mix, with the pointed angled end, apply it right in there.
Once your happy there's no void, top out the wound to ever so slightly above flush and cover the job with more Sellotape. Smoothing the tape with the side of your lolly stick to create a lovely flat finish.
Leave, in ten to fifteen minutes it will be set, in twenty minutes you can peel the tape away and sand it back to flush with the existing gel cost using 400 grit.
Finish with 1000 grit and leave until tomorrow before polishing.

Re: the epoxy repair.
Yeah man, epoxy paint will do. Just a very ginger sand 240 grit or higher ? to clean off any detroitus or amine blush residue and acetone wipe again, paint on thinned out epoxy paint in couple of layers ( thin out epoxy paint with 10% acetone)
Leave to cure, wet sand with 1500/2000 grit and buff later...
Have fun with it....

 

[Voodoo 158546]

This was done as described above using gel coat filler but instead of using Sellotape to mask off, as I was painting the complete hull I used the first thinned out layer of 2pack epoxy paint as a physical barrier.
There was about 180 ish scratches from repetitive beaching..( not by me, I had just bought it )
There was two scratches that were fairly deep & prominent, so I used an old fashioned potato peeler to gouge/ bevel / clean them.

 

[Cigelm]

Thanks for the detailed response. What about a white, epoxy paint to cover that repair in the first photo? It's a small area, the surface is perfect so all I want to do now is to make it white.

 

[Voodoo 158546]

If the surface is 'perfect' and you apply material, it wil become ' not perfect' as it will become raised.
If you're determined to hide the scab and want to paint, you will have to rub it back. Not just the scab but the immediate area surrounding the repair. Only a knats chuff though, not even a millimetre.
Pencil, draw an oval or circle a couple of inches ? around the repair. I'd use patience and 800 grit on a foam block, very lightly wet sand the area within the pencil mark. Bear in mind it will need an undercoat maybe two and two topcoats - depends on what paint and method of application ( spray, roller, badger hair brush ) but 60 - 80% of which will be rubbed back off.
Clean in the usual manner ^ and paint thin patient coats. Some like to paint on paint -wet. Me I'm more patient and leave overnight and flatten with very high grit wet n dry, clean and dry again before next coat.
Once you're happy and the discolouration has been completed covered, flatten the area and slightly beyond with 2000 grit wet sanding, clean, dry, buff with a mild compound all over...
If the paint used matches the gel ral it ought to be invisible.

 

[andyatos]

Outstanding!!! Thanks for the details. Very much appreciated. Got just a couple of clarifying questions now.

you just want to mechanically key the area and form a 45 degree angled edge while rounding out the wound ( round, oval same same, just not jagged chipped frayed gel coat hole)

I'm pretty sure I get your meaning. Here's a quick drawing I did. Is this what you mean as far as preparation? First image = side view, second image = top view.​

​

Once your happy the wound is keyed and clean...

What do you mean when you say, "keyed"? Do you just mean "prepared"?

with the pointed angled end, apply it right in there. Once your happy there's no void, top out the wound to ever so slightly...

By this do you mean use the sharp end to poke around in there to expose and eliminate any air bubbles that are trapped under the Marine Tex?

- Andy​

 

[Voodoo 158546]

Hey Andy,
your doodles are spot on, yep.
Re q2: keyed ie aggravated the surface with vv small 'trenches' for the incoming chemicals to bond into - sanding is mechanical, acetone is chemically keying.
Re q3: Quite literally using the sharpest ( smallest ) part of the stick, ensure physical contact of the incoming chemicals to the walls and trenches of the wound prior to filling it out fully, giving a good thourough coating as opposed to just squashing a blob of gear on a hole and xing your fingers


Just wanted to add in there, kinda being a bit anal but...
This guy you got the boat from claimed it ( the stem repair ) was a 'professional ' fix....
If it was that professional they would've colour matched and made invisible !
He or a friend did that I fancy, it's probably solid and will last for donkeys but worth keeping a beady eye on.
If when you sail your boat for a few outings you find a leak and the obvious ports of call seem fine I'd be prone ( if it were me ) to remove all that and re do it myself...but that's me
Good luck with it all, have fun, it's a peice of piss and once you done that you'll have no fear of tackling any more you end up getting, just don't scrimp out on chemicals or effort like some tend to do..enjoy mate

 

[andyatos]

Hi Voodoo,

I like your style. No BS, telling it like it is. I'll document the repair(s) process and post the results. Maybe I'll get another trophy!

Don't have any Laser sailing footage yet but plan to mount my GoPro on the tip of the mast, boom and anywhere else I can think of and get out in some of the air that produced your avatar photo. ;>)

In the meantime, here's some entertainment for you in thanks for all your detailed, forensic analysis. A video of Andy doing some other "sailing"... in the same bay and not far from where I took my "new" Laser for it's Maiden Voyage. Ok... let's be honest here... it's Maiden Taking-On-5-Gallons-Of-Water-Ballast Outing.

Cheers,

- Andy

 

[Voodoo 158546]

Ha wicked....did you say five o as in fifty mph at the end there, I was trying to judge it, thought about 35 knts or so but did you say 50 !

 

[Voodoo 158546]

Ere Andy, now I'm really zooming in on that stem scab, I can see cracks in the gel coat at the 4.5 inch point on the tape measure and a proper bloke wouldn't have left all those shark fins in the edges - triangle points are weak - If that was my new toy I'd definitely rip that lot off and do it properly. Not suggesting you do and make work or yourself but, those cracks will allow ingress into the laminate. Maybe turn those cracks ( streams) into purposeful wounds ( canals ) - open them up a touch and go beyond their length and fill them....you'll have the kit to hand anyways so ....

 

[andyatos]

Ha wicked....did you say five o as in fifty mph at the end there, I was trying to judge it, thought about 35 knts or so but did you say 50 !

I'm afraid you give me more credit than was due. I was probably never going more than 30 mph. What I said at the end was, "Five O" meaning a 5.0 sail size... meaning I was overpowered on the 5.5 square meter sail I was on while I was filming and needed to rig a smaller sail. A 5.0. Which I did. But an hour later on the 5.0, with all my windsurfing friends who had showed up, I got blown off that sail too!

Back to the topic at hand, I just love the Laser. Because it's such a great boat in light winds. Even super light winds. But you can still sail it in very strong stuff and go quite fast!

- Andy

 

[andyatos]

I can see cracks in the gel coat at the 4.5 inch point on the tape measure and a proper bloke wouldn't have left all those shark fins in the edges

Thanks for the heads up. Tell you what. I'll take a couple nice close up photos and then some close up video and post them here for you to look at.

Then, if you think this "scab" (I'm really liking that term) might give me problems down the road, I'll just leave it for now then do a proper repair when it's pissing down rain this winter. After all, I've got my bud Voodoo looking over my shoulder, right?

Cheers,

- Andy