That was good - thanks, NotWal.
While sea-kayaking around Tasmania's Macquarie Hbr for a week, I sailed at quite some speed into a submerged rock. Another kayaker gave me a tube of marine putty. Never opened, but was old; couldn't knead it properly - it crumbled and cracked rolling it in my hand; but it was a cold day?
- do I need to remove the lumpy product from the kevlar hull? Manufacturer suggests no need - www.whitworths.com.au/j-b-weld-waterweld-epoxy-putty-57g
- How do I work on the leading edge of my composite sea-kayak when it is V-shaped? Resin will run... Tape off area well? Work in several thin layers of resin/catalyst mix, and like the man in the video says, sand coarsely between each layer?
- My kayak; www.phseakayaks.com/kayaks.php?kayak=Cetus%20178%20MV
An auto body filler wont sag too bad as they're designed for vertical panels. Even better, 15min cure in this weather. So 2 or 3 applications to build it up isn't too bad. I'd use a 2 part filler to bog it, reshape and then glass over with just a layer to even it all out. Fill thinly with same again, and blend edges in, then sand
Does good surfboard epoxy leave a soapy residue ?
Ive never washed and sanded between glass layers and never noticed a problem .
Should I wash and sand ?
I obviously sand between filler and top coats but never wash .
I've never washed between, coats. Sanding before a coat should be enough to get rid of any contaminants.
Even polyester filler/finishing resin that does have a wax coat on top, I've only ever sanded.
Epoxy curing creates an "amine blush" on the surface. It is best to wash it off with soap and water before applying more layers / paint. I have had success with sanding but people recommend washing before sanding for best results.
You can add fillers to your resin to make it thicker, but they don't add much strength. There is a wide variety depending on what you are doing. https://www.westsystem.com/the-105-system/fillers/
You can even use talcum powder.
Select to expand quotedecrepit said..
Mark's approach will work, but if it's actually a hole through the hull I'd tackle it differently.
I'd sand back an area a couple of centimetres around the hole, tape over the hole from the inside. Then wet a few layers of fibreglass on a piece of plastic, and apply to the hole. The glass will stop the resin running.
The j-b-weld stuff looks like a putty so shouldn't run, but I'd only use that if there's no hole all the way through the hull.
Yeah - oops I thought he meant work on that vertical edge after fixing a hole. Didn't read it properly.....
Yes - decrepits method.
Sunfisher- water alone is best to remove amine blush. Its a water soluble whatsadicky that rises to the surface.
Then a sand.
Some fillers do add strength like milled fibre (fine glass fibres)
So you can make say resin, milled fibre and q-cell to have something very light but still stronger than just a normal filler. Loses the easy sanding that the filler is supposed to have though, so different stuff for different jobs.
Amine blush is why West system epoxy advises to keep laying up just as first layer goes tacky. Chemical bond is a superior bond. Way less work. Way less cost. No sanding or buying sanding consumables n no washing or wasting time. In the real world this cant always be achieved though.
Gougeon Brothers (west system) do a great book on Epoxy use.
