Swim Platform "soft spot"

[WChapelle]

When I purchased my 1997 330 DA my surveyor mentioned a soft spot on the swim platform. I could feel it when I stepped on the spot getting on and off the boat, I tried to avoid it whenever possible. Now that it's out of the water I could take a close look and see tiny hairline cracks in that area (on top). Is there an inexpensive fix for that?

 

[Chatuge]

It might be that the gelcoat has cracked but thats only masking a deeper problem.

 

[Lazy Daze]

I do not know the construction of your swim platform. But, if you can crawl back inside and inspect the underside of the platform, you may be able to find out some more info. You also may be able to tell if it's all fiberglass or if it has wood.

You could also drill an 1/8" exploratory hole in the center of the soft spot. Do it slowly and look at the bit's threads when you pull it out. You'll be looking for wood (and hopefully not wet).

If it's all fiberglass, there's also a possibility that the spot is simply a thin spot.

Any of the above things could cause the spider/stress cracking that you are seeing.

These are just ideas/suggestions. You might need a professional to take a look at it.

 

[Alegria]

When you had the survey and the surveyor mentioned that spot did he tell you what the moisture readings were at that spot. Did he/she mention it was higher. Just wondering as if there was moisture there then you will need to eliminate that and fix the issue. If it was normal then a PO might have fixed the leak but the problem, mold/rot continued.

I don't know if that area is solid or cored. I would imagine it is cored as I had to re-attach the aft back rest on our boat and got pretty intimate with that transom locker. I drilled and re screwed it on and found that the transom is cored for sure. I reseated it all with 4200.

I don't know how easy it is to get to the under side of that as from what I can see where the hot and cold shower lines go in the ER.

I have asked some other 330 owners on here as I have soft spot on the bow around the forward hatch. They commented that they had it professionally repaired, ground out the old fiberglass and then replaced core and repair. The trouble I see is that its on that non skid and replacing that pattern will take some artistic talents I don't have.

I don't think you are looking at a very expensive repair. I had both raw water exhaust outlets fixed last year and it ran around $700 to grind it out and rebuild with fiberglass. They turned out very nice..

 

[Sweet R & R]

If the platform is the same as on my 1999 310 then it is a cored platform with balsa coring. The soft spot is likely caused by water intrusion and the core getting wet and deteriorating. The easy check is to drill a hole from the bottom large enough to see what is going on.
I had a "soft spot" that the surveyor said was "not a big deal" but after a few more years I had to rebuild the platform. I stripped everything out including the balsa core, plywood stringers and plywood backing plates. Then rebuilt it using the west epoxy system. It was a few hundred in materials.

 

[WChapelle]

Thanks everyone. It was hard for me to tell if it has a wood core or not, I did look under the platform - it's out of the water. I'll check that out. The surveyor said it may be an easy "epoxy fill" fix. We'll see...

 

[kindredspirit]

I'm guessing you and I are in the same "boat". I wish I had seen this earlier......how far along are you? On my 1998 310 the platform is balsa cored, and balsa doesn't handle water very well. I removed the platform and layed it upside down on a couple sawhorses. I then drilled a few pilot holes to see how big the damaged area is.....don't drill through the bottom as you don't want to try to match the non-skid. If you drill down 1/8 inch you will be through the first layer of fiberglass and into the balsa. Try to figure out how the water got in there to begin with. You will need to stop the water getting in so you protect what you have rebuilt. Let us know what you find. Pics help alot.

 

[WChapelle]

Well, I'm really not sure how bad it is. Like I mentioned when it was surveyed a soft spot was mentioned, that was in August. I was looking at it a couple of weeks ago while the boat is on blocks and did see some spider cracks on the surface, maybe as large around as a coke can. I was going to have the marina check it out before I relaunched in the spring. The surveyor mention some type of epoxy filler as a fix. That's where I am.

I'm going to see the boat tomorrow I'll try to take a picture and post for you folks to check out.

Thanks

 

[tobnpr]

Pictures won't really help.
The fact that the gelocoat is cracked only confirms that there is excessive flex in the area in question, but not the underlying cause.

Could be that the fiberglass skin had become de-bonded from the underlying core (probably balsa as stated). If that's the case, epoxy injection (probably what your surveyor was referring to) could re-establish that bond.

If it's a rotted core, there's two ways to tell: a moisture meter- which, if your surveyor had one, he would have used- or; a little "destructive" testing. Take a small drill bit, around 3/16" to 1/4", and from the bottom side (so it won't show) drill up underneath the area in question into the core. Be careful not to go all the way through!

If the shavings come off the bit wet, you need to cut out and repair the coring. Epoxy won't do a thing with a wet core. If they come out dry, patch the hole with thickened epoxy or Marine-Tex, and then try the epoxy injection from the top side to get the glass re-bonded to the core.

 

[keokie]

I don't think you will be able to learn anything by going through the bottom. The 310's, have a bolt on platform that is easy to remove and repair.... relatively. You're boat has an integral platform, which essentially means it is like a dual pane window (there is dead space in the middle). You might be able to get into that dead space from inside the boat. I would send a PM to RobF300. I haven't seen him post in a while, but if he is still hanging around, he can give you some good advice.

Correction: Many 330's had a bolt on platform in addition to the integral one. The bolt on one sits a step lower behind the integral one. Is this how yours is? Is it the lower bolt on one with the problem?

 

[WChapelle]

it is a bolt on, I'm sure of that. I took a ride over and took another look, that didn't help much. I think I need to drill a little pilot hole from the underside to see what might be happening.

 

[Plane 2 Sea]

Our '96 330 'Dancer has the same issue, alot of moisture in between the top surface and the bottom. Found it at survey, only issue with the boat. Unbolting the optional swim platform in a couple of weeks, will flip it over and proceed to grind out the wet areas. Will use West System products to rebuild.