Spongy spots in the floor

[eusscmp]

Hello to all,

I have a 18' bowrider, and in 2 or 3 spots the floor feels spongy, like it might be rotting out. I talked to some people and they suggested drilling small holes in the soft area and injecting it with a fiberglass resin. My question is will this work, if so how long will this last?

Sponge Bob

[TheFisher]

Hi Bob,

I wouldn't do that, unless of course you would want to visit your namesakes

There are a lot of posts regarding the sponginess of floors and the way to repair them. Read them thruogh and you'll get an idea of what you're in for. If you have any questions after that there are many who are willing to offer advice.

I have a 20 foot bowrider that had the same symptoms. I found that the stringers are rotted out and the foam was water logged. I haven't started that project yet as I am currently working on a 22 foot cuddy boat that is halfway thru being rebuilt.

[eusscmp]

Actually, It didn't seem like a good Idea, I just didn't want to tear-off the flooring if I didn't have to. Since I'm not up to speed with all the nautical terms, I'm assuming the stringers are the cross-members of the hull. Anyway there is a small storage/inspection area in the middle of the boat. Inside there the floor is very wet and is starting to rot from the inspection hole outwards. I brased it up for now. I'm hoping I can still use it this season and repair in the fall. If it's not obvious How do you check the foam for water, Is there suppose to be any water in the area where the foam is? Sorry for all the questions, I have been looking for some how to manuals as I usually can fix most things. Any suggestions.

[Lawrence Marine]

Originally Posted by eusscmp

Hello to all,

I have a 18' bowrider, and in 2 or 3 spots the floor feels spongy, like it might be rotting out. I talked to some people and they suggested drilling small holes in the soft area and injecting it with a fiberglass resin. My question is will this work, if so how long will this last?

Sponge Bob

For a small fee, charged to your credit card, we will answer any question you may have concerning your repair. We have been building and repairing fiberglass boats for over 14 years. Call us at Lawrence Marine (936)336-9416 M~F from 7:00A to 4:30P CST. Lawrence Marine, 2507 Beaumont Ave., Liberty, Texas 77575 ( less than 1hr. east of Houston, TX ).
Reference info: check eBay fishing boats Item number: 2463411180

that last post brought an authentic "fishy smell" to a marine forum

[PAR]

There are a few products available (Get-Rot, etc.) for filling localized areas of rot or delaminating. Polyester resins shouldn't be used, but epoxies may provide some temporary relief from the sponginess. If the rot hasn't been allowed to spread too much (you caught it in time) then you may be able to freeze it out buy drilling the effected area(s) and injecting some epoxy. This a very tedious and time consuming effort on your part as hundreds of holes may need to be drilled for a relatively small area to get coverage. Very large areas will be quite a bit heavier then they're supposed to be, full of epoxy, so it's a judgment call.

Log onto the www.WestSystem.com site and look up the epoxy techniques you will need to understand. Have them send you their free books on the subjects you may require help in also.

If the area(s) affected are too large or if you think there are other issues, like soft stringers, broken tabs and other structures then the floor (sole) needs to be removed, repairs made and everything reassembled again. This is the correct way and the most costly and time consuming way. 'Glass work isn't very hard, but does demand you pay attention to some rules and procedures for good results to be expected.


Lawrence Marine should be directed to the web host or site management if advertisement is their interest.

[Dr. J]

Great pseudonym Bob. As the others have said, signs of excessive moisture is never a good thing.There shouldn't be water present anywhere on your boat. Your problem, unfortunately, is fairly common with runabouts. For an 18 footer like yours, many builders sprayed foam most of the boat's length from the access hatch (inspection hole...), out to the chines. It's purpose was/is to provide strength, flotation, and a certain amount of sound dampening. The problem was that not much attention was paid to bedding the seat bases,hatch covers, liner cleats etc... , and water eventually got through the plywood deck via the fastening holes and into the hull below. Spray foam is cheap and easy to spray onto the hull prior to installing the decking, but it also absorbs water like,well... a sponge. It will easily add up to a few hundred pounds to your boat. Your boat will sit lower in the water than it was designed to,thereby placing your outboard/leg lower as well. In addition to being unsafe, it will also slow you down and add to your fuel costs. unfortunately the only way to know for sure is to gain access to the foam and get to the lowest point where the foam lies.(Probably on the other side of your access hatch.) Jab a screwdriver deep into the foam and you will soon know how bad your problem is.As has been suggested, it is fairly easy to remove the decking and foam as well as replace the decking as long as you take the time to carefully plan your approach. B.T.W. a stringer is a longitudinal structural member that serves to strengthen and stiffen the hull.Just like a frame would transversly (crosswise). Invest in some P.F.D.'s (life jackets) if you plan to use the boat before you thoroughly check it out.