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Swim deck ROT

Posted: May 4th, 2020, 8:41 pm
by Gary Rose
I have a 2000 356 i mounted rails on the swim deck and whe I drilled into the deck i found water and rotten wood between the 2 layers of fiberglass in one section. Appears that the deck in very soft near pull up handle for swim latter. I hear this is a common problem with this boat. Has anyone else experienced this problem and how did you repair it ?? I am thinking I am going to have to remove deck box and cut the top layer of fiberglass out and replace the rotted section and re glass it. Any other ideas????????
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Re: Swim deck ROT

Posted: May 4th, 2020, 10:48 pm
by g36
Luckily I read about this issue a few years ago and i pulled my deck box and grab handle. I only had a small amount of rot around a couple screw holes and the handle. You could try removing and probing around the grab handle with a metal rod etc. and maybe it won't be as bad as you think. Removing the deck box and checking all the screw holes is a must on these boats. Removing and applying epoxy to fill voids and edges and oversize and refilling the screw holes with epoxy and then redrilling is how i repaired mine .

Re: Swim deck ROT

Posted: May 5th, 2020, 10:18 am
by Viper
Gary Rose wrote:Source of the post .....I hear this is a common problem with this boat....
I wouldn't say it's a problem with that boat/model in particular. It's a problem on ANY brand/model if hardware mounted to the platform isn't properly sealed.

If the wet core is isolated to the fastener holes then it's an easy fix as g36 explained. It can however be difficult to tell how widespread the damage truly is. An experienced tech with a moisture meter can take some readings and sound the area. Based on their findings they should be able to lay out the area that's affected.

If the damage is indeed widespread, you'll have to cut out the top layer preferably in one piece, and replace the core then reinstall the top glass layer. You can then re-nonskid the entire platform top or just cover the top with SeaDek or a similar synthetic product as doing so will reduce the amount of glass finish work required.

Re: Swim deck ROT

Posted: May 5th, 2020, 2:49 pm
by SplashyLady
Recoring the swim platform is not a difficult job. Work from the underside, cut the fiberglass cover off the bottom, then get some 1/3" to 3/4" marine plywood to make a new core. You can use the existing platform as a template to cut the new core. take all the old wet wood out with a chisel or grinder, leaving the outer fiberglass intact. Drill holes in the new core to allow air to escape when you install it. Mix up some resin, pour some in the new core, put the new core in the old mold/platform, and use cinder blocks or something else heavy to weigh the core down to the old shell. The next day take the weight off and clean up what you can. Then put 2-3 layers of new fiberglass over the new core. The next day, turn the platform over, drill the holes for the ladder, mounts, and handles from the top and push the bolts through. Tape over the bolt heads. Then turn the platform over, tape over the screw threads, and put fresh resin over the bolts from the bottom to seal the holes. Once the resin has set, paint over the bottom with paint of your choice, remove the protective tape, and remount. Done! :-D

Re: Swim deck ROT

Posted: May 5th, 2020, 4:18 pm
by g36
The swim platform on 355/356 405/406 is not a single layer swum platform it is a 2 part molded into the hull and top deck sections and then finished together when the parts are adhered together.. There is a apx. 6-8" void between the upper and lower sections. So what the issue is with the oem rot is the damage to the upper part. He would not reasonably be able gain access from the bottom for a repair in this case. If its a widespread area it will have to be a repair from the top. He would have to cut out the bottom part of swimplatform and remove to even gain access to the underneath part of the upper platform. If it was a solid added on platform the repair would be a lot different.

Re: Swim deck ROT

Posted: May 5th, 2020, 7:18 pm
by Viper
g36 wrote:Source of the post The swim platform on 355/356 405/406 is not a single layer swum platform it is a 2 part molded into the hull and top deck sections and then finished together when the parts are adhered together.. There is a apx. 6-8" void between the upper and lower sections. So what the issue is with the oem rot is the damage to the upper part. He would not reasonably be able gain access from the bottom for a repair in this case. If its a widespread area it will have to be a repair from the top. He would have to cut out the bottom part of swimplatform and remove to even gain access to the underneath part of the upper platform. If it was a solid added on platform the repair would be a lot different.
++1

Re: Swim deck ROT

Posted: May 8th, 2020, 9:54 pm
by Gary Rose
Thanks Everyone un forchantly it is wide spread to the middle section which i will have to cut out that top section and get all rot out and replace and try to match the rest or sea deck it but the rot has to go. I am not putting a handle back in and will in stall another type latter. Thanks for all the responses it helps a lot

Re: Swim deck ROT

Posted: May 8th, 2020, 10:20 pm
by Viper
That's not surprising. Once balsa gets wet, it wicks really well and spreads quickly. Good luck with the repair Gary. Keep us in the loop.

Re: Swim deck ROT

Posted: May 9th, 2020, 9:29 am
by g36
sorry to here that. Maybe keep us updated along the way maybe pics etc. and when your done

Re: Swim deck ROT

Posted: September 29th, 2020, 6:54 pm
by MarkMaunder
Any update or pics of this project? I have the same issue - would really appreciate more info