Friday, August 17, 2012

Deck Work

Our deck is now filled with this good stuff!
When we got the marine survey for our new boat, we were a little unhappy to find out that the results showed some moisture in her deck.  This is not an uncommon phenomenon but it can be a real pain in the butt if it's not dealt with properly.  A fiberglass boat's deck is often put together like a sandwich.  The part you walk on is the top piece of "bread", the coring in the middle is the "meat", and what you see from the interior is the other piece of "bread".  This 'core' is made from any number of materials and when moisture penetrates it - usually through a poorly bedded deck item like a stanchion, cleat or windlass - it creates weak spots that might not be obvious until too late because coring is famous for hiding and misleading leaks.

You would never have known our deck had moisture in it when you looked at her.  In fact, her deck looks pristine.  Walking around, we didn't feel any bubbles or soft spots or anything to indicate any problems. There were no obvious signs of leaks from the interior either.  Like anything though, sometimes issues lurk below the surface where the naked eye cannot see.  Enter:  the Moisture Meter.  The moisture meter works like a stud finder, but instead of finding studs, it gives moisture readings.  If it wasn't for our survey, we would never have known we had a soggy deck.  Point for technology!

Because Scott and I are not interested in DIY'ing with this boat (if you are just joining, start at the beginning of this blog and you'll see we did PLENTY of DIYing with our first boat!) we were able to negotiate the price of the boat down to compensate for this hefty repair.  As with anything boat, there are probably a trillion ways to fix this issue depending how much time and money you have.  The man we hired to do our work suggested fixing our deck from the inside rather than the outside and chose to replace the coring (the stuff between the outside and inside) with Divyincell H60.  It's got to be better than the plywood tiles that were in there before!

See the moisture up there?  This kind of moisture was prevalent in the bow and both gangways.
Wet and rotten wood removed.
Re-cored and re-glassed.
The interior is a construction zone!
The deck work is complete, and the interior cabinetry is now being put back in the boat.  Now onto the next projects!!  Sure feels good to know things are getting done while we're not there...

Love,
Brittany, Scott & Isla

6 comments:

Dan K said...

Marine plywood is the heaviest and worst of all core materials in cored laminates generally. It rots like balsa and can delaminate over large areas fairly quickly like foam core materials.

Divinycell is a great material for decks since it is a rigid foam. Airex, a ductile foam, is better for hulls below the waterline, since it crushes and helps absorb the damage from any impacts. Combining Airex core with a laminate that has some kevlar in it makes for a very puncture resistant hull.

Dan K said...

I'd also recommend bedding most of the deck hardware with BUTYL TAPE rather than the more common "modern" marine sealants. The requirements for using butyl tape as your primary sealant are simple:

1) above the water line
2) not exposed to fuel or petrochemicals on a regular basis
3) the hardware is mechanically fastened by through-bolting.

If the hardware meets those requirements, your probably going to be best off using butyl tape.

Don't forget to counter sink the fastener holes slightly to improve the sealing ability of the tape. The countersinking allows the butyl tape to form a thicker "o-ring" that helps keep water out.

Also, don't forget to dig out the core and pot the holes with thickened epoxy... you only want to re-core the boat once. ;-)

Dani said...

A second for the butyl tape! It's cheap (like $5) for a 15ft roll and available at many RV stores.

The grey color seems to work the best.

I like the method of going underneath the deck to fix the rot:D. Looks like they did a great job.
Dani

Mid-Life Cruising! said...

Wow, seeing all this scares me! We didn't have a survey when we purchased our sailboat. May have to find one of those moisture readers and keep our fingers crossed!

I do know we have to replace our bulkheads and we've already addressed blisters ... hope that's all!

She's looking great ... I know ya'll are excited!

Anonymous said...

Dan K. has a very good point in that plywood is horrible coring material. The choice of Divinycel is a top notch selection. I might argue his Airex in the hull reasoning, but I'll give that to him as an acceptable material much better than a cellulose based material. Having been in the marine industry for more years than I care to admit, many boats have ugly lurking issues that may have started when they were built. You have the potential of a very reliable vessel under way.

Windtraveler said...

@Dan - thanks - you sure you know your boat stuff!! Nothing below the waterline was wet, so we don't need to do anything there (luckily) - just the deck. As for the hardware, it has already been re-bedded though, but I will get a roll of that tape because we'll be doing more rebedding as we go (obviously!)
@Dani - good to know! And yes, going at it from below seems to be the way to do it...otherwise you end up having a deck that needs to be repainted.
@MLC - I'm sure all is fine! Curious why you didn't do a survey on her?
@ Anyonymous - thanks - we knew that coming into this boat, and yes - it appears the problems have been lurking for a long while! Time to nip that in the bud!!

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