Experience with soft decks or flexing spots on the deck?

[GreatBarrierReef]

Has anyone experience with springy or soft decks, and do you know what material is inside the decks of the M’s and X’s?
I assume it's plywood, but would love your expert advice and opinion if this could be easily fixed.

I'm looking to buy a MagGregor26 ( or ), and I noticed some boats have soft spots on the deck.
One particular 2012 M which I am interested in has a soft spot on the portside near the mast, and it worries me. It has several parallel cracks in the gel-coat near the mast, which can be seen from the photos here: http://imgur.com/a/tnPlh. The cracks are left and right from the non-skid area above the front window of the portside, and the deepest cracks are next to the mast.

I have no idea how old the cracks are, but an area of approx. 40x40cm (16x16”) is pretty soft and makes a crackling sound when you step on it. (I’m well under 80kg / 170 pounds, and I’m very concerned about both the flex and the cracking sound from the fibreglass), as this may lead to much more damage if left unrepaired.
On the same boat, the starboard side next to mast is much stronger and there’s almost no flex. Maybe it’s because the vertical timber compartment from the head serves as a stable support from underneath, or maybe there’s just no moisture or damage inside that part of the deck. In any case, I’m worried about the soft deck on the portside.

Q1) If there is a soft spot on the deck (portside next to the mast of an M), is this normal or should I expect rotten plywood underneath?
Q2) Looking at the cracks left and right of the soft spot on the deck, should I stay away from this boat, or is there a proper and long-lasting way to fix a soft spot?

The boat is not a bargain (not at all), but one of the few M's nearby, so I'd really appreciate your advice if this a deal breaker.
Cheers
Rob

[Cougar]

Hi Rob,

First of all, welcome to the community! If anything, it's not plywood. MacGregor used to apply balsa for the core structure, but switched to foam sometime in '99. Thus, balsa, or any other wood core, should be absent on later and all models. Nonetheless, my has two soft spots too, one on the cabin floor and another one on the deck, on the port side near the mast. But there's no visible damage on the deck. My is from about the time that the wharf switched from wood to foam and I'm pretty optimistic they used foam for my boat. I hope to fix the soft spot someday, probably by injecting fluid epoxy. Although the cracking noise is somewhat annoying, I haven't noticed any deterioration of the soft spot over the last 3 years and we use the boat almost every weekend during the season.

[BOAT]

I would stay away from any boat with soft spots in the deck. First off - the M has no support at all from that bathroom bulkhead - I have removed mine many times and have already proved it has zero effect on the deck above. The daggerboard trunk is the only support and it's doing all the work of the central deck support. The deck is supported by molded splines that were created using foam inserts that were layered up with fiberglass cloth and resin - the foam that is left inside the spline is gone on most boats - the foam does not do anything - all the strength comes from the spline. I am very heavy (I'm fat) and I walk all over the boat and there are NO soft spots, no creaking, and no cracks. The only spot that squeaks is the rear hinge of the port gasoline locker door when i step on it - that's it.

I would not buy the boat if the deck has soft spots.

[Lee Ward]

I'm going to disagree with Boat here, at the risk of, well, disagreeing with Boat!
I have a 2009 with the same spidery cracks portside at the mast. I can feel a tiny bit of flexing there.
Boat is correct about the foam, if you watch the production vid closely you can see them laying strips of liquid foam with a gun. That is soft, open cell foam designed to hold the splines formed by the glass until they dry. Think of a corrugated roof inside between the deck and liner. The correlations give strength. There are only 3 or 4 of these running fore and aft as far as I can tell by looking at the stbd side same place.
I think the extra structure to the right of the daggerboard trunk where everyone mounts electronics (and the aft bulkhead for the head attaches) makes that side stiffer, with less span fore and aft to support. I agree the bulkheads don't add support, by design that's done by the daggerboard trunk.
Long story short, don't stand there if you can avoid it. Stand on the right side. I still haven't come up with a fix yet to stiffen it, but am leaning toward injecting a chopped glass mixture common in aviation maintenance, called a potted compound repair. It's not used for the same purpose, only to patch punctures in composite structures, but I think in this case it would work to stiffen the area.
If that's the only example of this, like on my boat, I say no big deal. It's confined to an area 6 or so inches square on my boat, not a big issue. The biggest problem is the cosmetic issue of fixing gel coat that's textured for non skid, as is the area of concern.
That's not to say all are the same, however. I was turned off to the powersailer for years after seeing one of the first production 19s at the Jack London square boat show years ago. The decks felt like a trampoline. I actually walked the decks of a late M before considering one again, and was pleasantly surprised to find them quite stiff considering the lightweight construction overall.
The slight flex is nothing like problems normally associated with soft deck coring, which is usually end grain balsa, which can be a nightmare, ask me how I know. (Hint) I used to own a Cheoy Lee, better known as a Cheoy Leaky...

[Starscream]

Hi Rob,

Thus, balsa, or any other wood core, should be absent on later and all models.

Hmm, my 2002X certainly has SOME balsa in it. Here's a core sample:



I seriously can't remember where I took this from. The only hole I remember drilling is in the forward hatch for a Nicro ventilation fan, but the hole there is bigger than this core sample. What is wrong with my memory? The underside is unfinished fiberglass so it must be from one of the sliding hatches I just don't know why the piece is so small compared to the big hole I have in there for the fan.

[sailboatmike]

a close look at those "spider cracks" makes me think its only gel coat cracks and wouldnt allow water intrusion into the deck core.

My guess is the core is delaminating from deck causing the soft spot and movement, hence the cracking of the brittle gelcoat, as said before a drill and injecting epoxy into the area should fix it.

Would I buy a boat with the problem? Yes but I would use this as a bargaining point to drive the price down, fixing is cheap and easy.

More the issue is the expensive things on the boat are in good condition such as the motor, mast, rigging, sails and of course the trailer.

I saw a X for sale the other day and the mast was bent like a "S" and the spreaders were bent, I just hope some poor sucker doesnt pay big dollars and end up with a $4000 plus bill for a new mast

[Lee Ward]

Again, think of the deck there as a peanut butter sandwich, the deck is the top slice of bread, the middle, corrugated section is the peanut butter, and the overhead liner is the bottom slice. Anything you inject will have to be viscous enough not to flow away. That's accomplished with glass fiber in the mix. This is not like an epoxy repair to a wood cored deck where you inject epoxy. Water intrusion on a wood cored deck causes swelling and delamination probably not present on your M. I think what we are feeling is a space between corrugations too long to be stiff enough.
I am only speculating this would work because a potted compound would flow out like peanut butter and make a thick wafer, if you will. I estimate the space to be about an inch and a half depth, based on my experience re-wiring the boat.

[GreatBarrierReef]

Thank you very much for the warm welcome to the forum and your replies!
It's a real pleasure to get up in the morning and see very useful responses - I am really grateful for your advice and opinions.

I'll have another close look at the boat at the next opportunity and plan to bring an experienced person (sailer/surveyer and fibreglass repairer) to assess how bad it is and how much it would cost to fix it.

Thanks again, and honestly, I am very impressed with your responses!

[Lee Ward]

Yes, you wouldn't want to try this over at Sailing Anarchy. They're not known for their warm welcomes, especially for Mac owners...

[jimmy alonso]

2004 looking with the black cover removed and foam blocks removed, there are the ribs with soft foam inside. I have heard some cracking while on top also, some of the ribs as you can see the glass ribs are brittle and crumbles when squeezed in places . Been meaning to put some glass over them for a few years now.

[Lee Ward]

Interesting Jimmy. Can you say exactly where that location is? Is that the right side of the mast step looking forward?

[BOAT]

I don't know what to say - I have no softness or flexing or creaking at all. There are no cracks in the boat - none. If fiberglass bows like a thin hull section that's not really a indication of damage, but he said "Soft Spots"

My brother went through hull with a Hunter and the chain plate delamination failures and rotting squishies in the structured hull grid - and oh what a mess - never again - plywood rot is easier to deal with than that crap - soft spots are usually plywood rot from water (cracks will let the water in). Bowing and flexing a large section of fiberglass that has no wood in it is okay, but a wooden deck with a soft spot is bad to me.

In my book "Soft Spots" is always an indication of delamination and water damage or rot. If I walked any boat and hit a soft spot I myself would not buy it. That's me.

[jimmy alonso]

Interesting Jimmy. Can you say exactly where that location is? Is that the right side of the mast step looking forward?

Its the starboard side. Above the 2004 galley to the right of the dagger board trunk.

[NiceAft]

Do you have access to any other mac's so you can actually compare. What you are experiencing may be normal to the or boat. We are not like other boats. See if you can gain access to another or , and maybe speak to a skipper.

Ray

[dlandersson]

I believe early model X's (2000 and before )had some balsa on the cabin roof. I have a 98 X but I don't have (I'm 200+ lbs) any flexing.

Hi Rob,

First of all, welcome to the community! If anything, it's not plywood. MacGregor used to apply balsa for the core structure, but switched to foam sometime in '99. Thus, balsa, or any other wood core, should be absent on later and all models. Nonetheless, my has two soft spots too, one on the cabin floor and another one on the deck, on the port side near the mast. But there's no visible damage on the deck. My is from about the time that the wharf switched from wood to foam and I'm pretty optimistic they used foam for my boat. I hope to fix the soft spot someday, probably by injecting fluid epoxy. Although the cracking noise is somewhat annoying, I haven't noticed any deterioration of the soft spot over the last 3 years and we use the boat almost every weekend during the season.