damage to deck or water in core?

[bMcN]

I just discovered mildew in my cuddy (first pic) and a corresponding pattern of damage to the fiberglass on the deck above (second pic). My first thought was that something had fallen on the deck and made a pattern of punctures, and that water was getting in through the punctures and causing the mildew inside. But now I'm wondering if the problem is more serious, and that I've got water in the core of the deck that has caused something to rust and buble up through the fiberglass. Any thoughts on this and/or recommendations about where to get it fixed? It definitely looks beyond my skill level.

Thanks in advance,

Brad

 

[Rayvon]

It looks like somebody has removed what looks like anchor chocks from the deck.They didn't seal the old holes properly.How long has it been like that? Not a big deal to do it right,unless as you think it might have got water into the deck core,in which case the headliner would have to be removed.Is it soft headliner or fiberglass,can't tell from your picture.First step is to grind around the upper deck holes,fill and fiberglass,then regelcoat so no more water penetrates.

 

[bMcN]

Thanks @Rayvon. Not sure how long it has been like this. I'm guessing a couple of weeks, but it could be a couple of months. The headliner is fiberglass. I'll get on the deck holes ASAP. Pretty sure there is water in the deck core.

 

[terrin]

I would just reverse drill to the next size of each hole put tape on bottom then fill the hole with waxed Gel Coat and wet sand top if you like.

 

[brutus]

Definitely screw hole with a bad patch job, like others have said drill bigger holes to see if there is core damage, if not just fill the new holes properly. The core will soak water like a sponge through a screw hole not patch properly

 

[myles]

Lots of great advice so far.

Hard to tell from pictures how bad. Doesn't look horrible but I'm not jumping on the deck so impossible to tell. Nothing you can do about rot and water in the core already, but if she isn't squishy then don't open it up. If the boat is older and has wood then likely some rot anywhere there have been penetrations through the core, not a huge deal.

If it was me I would get a larger drill bit and carefully drill out the holes to make a slight cone shape (as mentioned by others). The very important thing to do is only use the drill in REVERSE. Do not drill in forward or the drill bit can grab and go right through and now you have a big hole to fix and will probably chip and crack the glass/gel (C**ty). The reverse method requires a little bit of pressure as the drill is using friction more than a cutting edge but you will get a nice little area of clean glass to fill up. After that is done get some duraglass or mix some polyester resin with cabosil so it's thick and lay that down with room for some gel on top, add some waxed gel with a brush or dropper after and you should get a nice little repair. It will be less noticeable than now and more waterproof. If this is too much for now, just fill it with some sikiflex and repair as mentioned in off season. You can substitute the gel for polyurethane paint too, it all works.

have fun!

 

[Brando]

If you have a decent counter sink it works well to prep and will not grab and pull like a drill bit will.

 

[Rayvon]

Depends how fussy you are I guess.I've done all kinds of filling of old holes and found that filling with just thickened gelcoat will show even if color is a perfect match.I think maybe it's different expansion-contraction rates but they show in the right light,probably not a problem unless you have OCD. I fill them now and then grind back enough that I can put some glass back on top,then re-gelcoat-sand-buff.It makes for a much bigger repair area,but seems to last better and not show at all.

 

[bMcN]

Lots of great advice so far.

Hard to tell from pictures how bad. Doesn't look horrible but I'm not jumping on the deck so impossible to tell. Nothing you can do about rot and water in the core already, but if she isn't squishy then don't open it up. If the boat is older and has wood then likely some rot anywhere there have been penetrations through the core, not a huge deal.

If it was me I would get a larger drill bit and carefully drill out the holes to make a slight cone shape (as mentioned by others). The very important thing to do is only use the drill in REVERSE. Do not drill in forward or the drill bit can grab and go right through and now you have a big hole to fix and will probably chip and crack the glass/gel (C**ty). The reverse method requires a little bit of pressure as the drill is using friction more than a cutting edge but you will get a nice little area of clean glass to fill up. After that is done get some duraglass or mix some polyester resin with cabosil so it's thick and lay that down with room for some gel on top, add some waxed gel with a brush or dropper after and you should get a nice little repair. It will be less noticeable than now and more waterproof. If this is too much for now, just fill it with some sikiflex and repair as mentioned in off season. You can substitute the gel for polyurethane paint too, it all works.

have fun!

Deck still feels pretty solid. Will start filling on Tuesday hoping for a bit better weather. Thanks all for the great advice.
Brad