What material for an under-deck reinforcement panel

[security6]

I've got a 2000 Larson 234 Escape. The driver's chair is a pedestal type chair that is screwed into the fiberglass deck. Last year I noticed that a few of the screws were stripping out and coming loose. I tried putting some fiberglass epoxy into the holes and putting the screws back in, but it didn't help much. The screws are under a significant load fairly often because passengers regularly pull laterally on the driver's chair.

I would like to add a panel to the underside of the deck and then run bolts through the deck and panel to secure the chair. By removing a storage area, I should be able to get a 2' x 2' panel underneath the deck. A couple questions:

What should I use for a reinforcement panel? Plywood? I'm looking for a material that will distribute the load over a greater area of the deck.

Any reason why the reinforcement panel wouldn't be a good idea?

 

[mommicked]

Re: What material for an under-deck reinforcement panel

Im no expert, but I have used commercial type white polyethelene? cutting boards for various mods to my fishing boat.its somewhat cheap and very strong,pick up a thick one and try to bend it.It holds screws well,(I drill small holes first) I would use large stainless washers and bolts/nuts for your fix, maybe some construction adhesive in the sandwich.you can find a size to fit or cut it w a skilsaw.there are marine products made of tough plastic also.

 

[metriccrescentwrench]

Re: What material for an under-deck reinforcement panel

When you have hardware pulling out of the deck it's often the first sign of rot, so you should do a thorough investigation. If you're sure that's not a problem I'd first thoroughly soak the existing screw holes with epoxy to prevent any water intrusion. If you're sure you can get to that area under the deck I'd lean to using some 1/2" PT plywood as a backer, and instead of screws I'd go all the way through with s/s 1/4-20 panhead bolts or similar, and put large s/s fender washers and self-locking nuts on the underside.

 

[security6]

Re: What material for an under-deck reinforcement panel

Sounds like I'm on the right track. I had thought about pressure treated wood, but hadn't thought about the plastic cutting board; I might have to check it out. I have already purchased stainless steel nuts and bolts.

About the potential rot issue: Do you think there my deck is a fiberglass/wood sandwich? The topside has a gel coat on it so I can't tell what it is made of, but the underside is unfinished and is definitel fiberglass. Is it common for boat manufacturers to make the decks out of wood and fiberglass? Any way to tell besides cutting in to the deck? I will be sure and seal up the holes real good, just in case.

 

[produceguy]

Re: What material for an under-deck reinforcement panel

As far as I know I would believe that the deck is wood with glass on both sides and gel coated on top but if they glassed the bottom you shouldn't have a rot issue, but you could.
You can do a search on your boat or call the manufacture.

We need pics.

If you just do the reinforcing on the pedastool, I would use ex ply and fully glass the entire piece.
Fill all screw holes with 5200.

 

[security6]

Re: What material for an under-deck reinforcement panel

I've poked around on the internet but haven't been able to find anything. I'll have to try calling the manufacturer. I do think that rot is unlikely because with the way the bilge is setup, I'd need to have half the engine underwater before any standing water ever stayed near those screw holes.

I still might investigate the plastic board (e.g. cutting board) idea, but I could get some plywood and cover it in epoxy if I need to.

My boat is in storage (haven't seen her in 6 months now and it is 36 degrees today and raining), but the picture below is identical to mine except for colors. I even have the snap-in carpet like this one does.

When somebody is sitting more or less directly behind the driver, they often grab the driver's seat to help pull themselves up. This puts a pretty good lateral load on the top of the seat, so the seat/base end up acting like a big lever on the screws.

 

[produceguy]

Re: What material for an under-deck reinforcement panel

NICE boat. I like the set up.

How do you have her stored?
Covered?

Is there anyway that rain water or any moister could have gotin into the holes and caused it to rot?

 

[security6]

Re: What material for an under-deck reinforcement panel

Thanks. We love the open seating on it. One of our requirements when looking was a boat that could hold a lot of people, and this one is rated for 14.

I've only owned the boat a little over a year, but it sat on the dealer's lot (covered with a roof) for at least 1.5 years. Right now the boat is in a warehouse for winter storage, but during the summer it sits in my driveway under a custom boat cover. I don't think there would be any water sitting by the seat base because I keep the tongue up pretty high, but I have hosed out the interior of the boat before which certainly would have had water near the seat base. Of course, I am in the midwest so humidity might be an issue. At any rate, I've never had any standing water near that area.

When I pull the seat I'll look for soft spots underneath, but I don't think I want to go any further than that (unless I find some soft spots). I don't want punch a bunch of holes in the deck looking for rot that may or may not be present.

 

[produceguy]

Re: What material for an under-deck reinforcement panel

Yea, I would say if theirs no soft spots in the deck your good to just fix to ped.
I don't blame you, I wouldn't want to tare into something that nice.

 

[bluto3166]

Re: What material for an under-deck reinforcement panel

I'm in the process of rebuilding the stringers/deck of my 1990 Renken. Renken did a lot half-@ssed, but they did one thing right, under the deck they installed 1 inch plywood as seat support.