Aft Deck Sag Problem

[Vincentc]

I need help.

The port side aft deck in the area of the FB ladder recently developed a sag.
Having deal with wet core in the deck near the bow pulpit I assumed wet core was the cause of the sag.

I identified the areas of the sag with a batten and marked off an area to cut out and remove the upper fiberglass skin.
After cutting a panel I tried to lift it at the area with the greatest sag, and found that it is firmly secured to DRY balsa core.
Before I go cutting up more of my aft deck, or giving up and sealing the slots that I just cut, I need a consult.

Any thoughts on the cause of my deck sag and suggestions for how to fix it will be most appreciated.

[Canuck Dennis]

My 1979 43 dc has a slight sag on the stb'd side aft deck, about2 ft aft of the entry gate, is just enough to cause some water ponding but a appears not to be "soft".

Will watch this post with interest and hope we get some expert advice..( evil grin)

[Vincentc]

Hope the "expert"controversy isn't discouraging the posting of ideas regarding the deck sag problem. I would be happy to read a reasoned guess.

i am about to take a tube of West six10 epoxy down to the boat, fill the hasty cut and try to convince my wife we will have live with the sag and occasional puddle.

The expression, measure twice cut once, might be changed to, don't assume you know the cause of the problem, and think twice before cutting.

Regards

[dsharp]

I would v out the cut about 3-4" on either side of the cut and put down several layers of chopped mat. I'm afraid if you don't you will have wet balsa shortly. I have no ideas about the sag.

[Vincentc]

I would v out the cut about 3-4" on either side of the cut and put down several layers of chopped mat. I'm afraid if you don't you will have wet balsa shortly. I have no ideas about the sag.

Thanks, good point regarding a bevel.

[Bill Allen]

There may just be some lack of bonding between the inner and outer skin. All I would do is remove the coring from it trying to get back to a non sag area replace the coring and refiberglass the sag. Build it back up with epoxy and cloth and no more sag. Doesn't seem like a big deal as long as the failure isn't to extensive. We're talking older boats here and although they're built quite well they are getting a bit long in the tooth as am I. You do want to taper it as much as you can to get as much bonding area as posible. Fair it nicely paint it and it's gone. Bill

[Vincentc]

Bill,
Your suggestion makes sense, however, Removing the upper fg skin my not be that easy or pretty. It was very well bonded to the balsa core in the center of the depression. I feel like I am doing boat surgery blindfolded and would love to be able to look at the sag from the underside before more cutting and removing.
Is it practical to remove and replace the headliner?
Has anyone done this?

Thanks

[sgharford]

The expurt has entered the building! There are (probably) 1"x6" wood beams that are stretching the span of the lower skin (between lower skin and headliner, running port to starboard). These beams are attached to lower skin with a pink fiberglass 'structural filler', as well as some screws. The pink structural filler is about 1/3" thick and very brittle. It's possible something heavy dropped on the part of deck and busted that layer of structural filler apart leaving a 1/3" space between lower skin and 1"x6" wood. With weakened support in that area, it sagged over time.

I have headliners down in my 1976 43Dc in v-berth and main saloon, not in rear stateroom - so not 100% sure those 1"x6" exist there. To check, press the headliner at the seam – if you feel wood go back from seam 5.5” or so I bet it is as described above. The v-berth only had 1”x1” wood screwed to lower deck with triangle shims for height adjustment. These are there to to staple headliner to, and are not attached as structural member.

Main Saloon
repair 027.jpg

V-berth
repair 020.jpg

[MikeP]

Wow! Mighty impressive!

Are you going to use the oem-style headliner material or something else when it goes back together?

[Vincentc]

Sghaford,
Very helpful information. Impressive project. Hope you will post more on your project. I appreciate learning from the experience of others vs my mistakes.

I found Sky's post on his headliner replacement project. Very informative.

Thanks