Good morning
I have a problem .After finishing the bonding of the all holes in canoe I had some resin left, so I smeared the whole canoe and the next day I poured water and come white surface appeared but not where I put new patches. What happened what is causing it How to get rid of it.
Please help me 

Which resin are you using?

What has happened is moisture absorption into the epoxy making it go milky.  Most epoxies are moisture sensitive during the cure process and for a few days into the full cure.  If exposed to a lot of water then this effect can happen.

You may be able to place it somewhere very warm and the heat drives the moisture out as it cures, however if it has gone too far in the cure, you will need to sand it back and recoat.

In future I would recommend allowing it a few days to fully harden before going too mad with water.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant