Fixing hairline cracks in gelcoat

[lturkevich]

My 2003 HiFly Madd (Sandwich Carbon) has some hairline cracks in the rail just aft of the nose (see second picture). It doesn't seem to be due to the mast hitting the nose (for once), and there doesn't seem to be any water intrusion or any soft spots.

What's the best way to repair the hairline cracks: Sand then gelcoat-only, paint-only, or gelcoat-then-paint? (I'm thinking of color matching as well).

While I'm at it, I'll probably want to repair the one-inch nose-chip in the second picture at the same time (maybe the same way instead of resorting to a ding stick).

I have no idea what caused the hairline cracks, but I figure the nose chip is some idiot (me) bumping the nose while moving the board around.

Thanks, Leon,

[U2U2U2]

2nd photo is scary , the length and area that's cracked.
Reason cracks are there....? Both sides ?
Boardlady.com
For great advise.

I would sand both and probably use west systems epoxy with micro balloons
On the rail, the nose I would sand then add 1/2 layers of fiberglass with same mix above.

West systems have multi additives to the fine marine epoxy to help.

Forget about color matching , either get close with a good hardware store spray can, or contrast with a design and color.

The nose could be helped with ding stick or other products, marine tex... Jb weld , list goes on, they are all called temporary repairs, so last longer than others.

Doesn't appear anything serious here, but if you are going to fix it..do it right

[lturkevich]

Thanks, U2, I had forgotten about microballoons.

The hairline cracks are only on the one side, no idea what caused them.

Any additional prep work before using a hardware store spray can (or is there any particular type to use or avoid)?

TIA

Leon.

[U2U2U2]

Cracks ...?
Could be just bad materials that gave out during normal use.

Sanding , so prep work when painting is very important. I usually use 3M MARINE PUTTY, to fill in small gaps, scratches, bubbles before painting.

I highly recommend primer before the actual paint, Walmart primer is fine, I usually use Walmart paint, or Ace Hardware, of late had good results with KRYLON, FUSION , FROM WALLY.
I WOULD SPEND A little more for better quality paint than the cheapest stuff.
Matters a lot how it sprays as well, the Fusion spray top works nice, but some others do as well, some like to clog and spit drips.

I would not use auto paint, it's probably lacquer, and may bubble interact with existing paint.

[lturkevich]

OK, just to make sure I got it right:
-sand down everything, glass over the chip at the nose;
-epoxy w/ microballons, fair w/ 120-150 grit when cured;
-touch-up with 3M Marine Putty, fair w/150-220 grit;
-prime (I'll be using Krylon Colormaster Plastic Primer (made with Fusion));
-paint (Best color match seems to be the Krylon Colormaster Paint + Primer in "Gloss Blue Ocean Breeze") (for all those Madd owners out there )

Cheers, Leon.

[U2U2U2]

The grit on sandpaper, is not written in stone, I use 320 / 500 wetpaper sometimes 1000. I use a electric sander from start with 80/100 to knock down the initial mess, for me thatS SOP.

There are many variations of material and procedure that will produce a good result. S Glass or carbon will make it stronger, but 2 layers of fiberglass will make it close to new.

From your posts you are on top of things, take your time and you will have a nice result. PM me if you need my 2 cents ...

Is this. Twin fin ?

[lturkevich]

Yep, twin fin.

[bred2shred]

My guess is the cracks on the side of the rail are from the mast banging against the board during up-hauling, etc.

The repair method proposed is a good general instruction, but you really can't define the exact repair method until you grind off the paint and get a good look at the actual damage. If it is in fact just cracked paint, with no structural damage to the board, then all that would be needed is to fair the area and re-paint. If the glass is actually fractured, then you need to grind out the damaged glass, repair the glass, fair, and re-paint. If the damage extends through the glass and into the core, then you have to take it even a step further and grind out the glass and the damaged core material and build back up from there.

Again, you really can't define the full repair procedure from just looking at cracked paint. You need to dig deeper first (literally and figuratively).

sm

[U2U2U2]

What you have said makes sense, if however damage was under the cracks it would be soft, course it could be...

But yes the need to investigate further.

Mast against the rail, why only 1 side then ?