94 StingRay Floor Replacment

[StingRay_90V4]

So i am part way through tearing the origanal floor out of our boat. The stringers and transom are in really good shape. So would the floor be except Sting ray thought the ski locker wiuld be a great idea and is is soft only around the cut out. So i am going to cover over it with the new floor. Is that okay to do ? Also , there is a large amount of foam. Or what looks like mono foam ( expanding foam. ) under the floor. But only on the outside ofnthe stringers closest to the side of the hull. Is that from the factory like that or is that from someone else after the fact. Because the foam is wet. It is holding a fair amount of water. I wont be surprised if i pull a hundred or more pounds of wet foam out if tye boat. Is the foam needed ? Do i have to refaom it under the floor or can i just leave it open and empty ? My boat is going to loose a lot of weight.

 

[tpenfield]

Factory foam flotation . . . you need to pull it out and re-do it, else the stringers will rot. Once the foam is out you will get a better look at the stringers. I'd be surprised if you did not need to replace the stringers, as they are probably soaked from the foam.

It sounds like the floor has been leaking into the foam chambers for quite some time. Initially the foam will resist the water, but over a number of years the foam will become saturated.

Post some pictures when you can.

 

[Scott Danforth]

I would make some test drills. Most likely stringers are wet

 

[StingRay_90V4]

They seemed good and strong and didnt look wet really. I will double check though. They are only 1/2 ply coverd in a ton of fiber glass. Im thinking the fiber glass may have kept the water out.

 

[StingRay_90V4]

Also.... Do you absolutly have to redo the foam ? Or can you get away without it ? Also... How muxh could all of that wet foam weigh approximately in a 16 ft boat ? Im guessing its going to add up and my boat will weigh a good 100 or more pounds less.

 

[Woodonglass]

It depends on the degree of saturation but most of the time it's 2-300 lbs. You don't have to use flotation foam but...It's HIGHLY recommended

 

[tpenfield]

Also.... Do you absolutly have to redo the foam ? Or can you get away without it ? Also... How muxh could all of that wet foam weigh approximately in a 16 ft boat ? Im guessing its going to add up and my boat will weigh a good 100 or more pounds less.

Yes, replace the foam. It provides structural support and flotation. Your boat needs structural support, you may need the flotation.

 

[StingRay_90V4]

Yes, replace the foam. It provides structural support and flotation. Your boat needs structural support, you may need the flotation.

Flotation is a good thing. Would the boat sink or something without it ? Or is it mainly for if it fills with too much water ? And as far as the foam it self goes. Is there a marine grade foam I need to look for ? Or is it just plain old mono foam ? That ypu can buy at any hardware store and use to fill coids and cracks ? Thank you for all the help.

 

[chevymaher]

It is structural to a certain degree. It quiets the pounding of the waves. And it keeps the boat from sinking if it fills with water. Keeps it at the surface.

It is a 2 part expanding foam. I got mine at US Composits. 2 lb foam is what most use in their boats.

 

[Scott Danforth]

Also.... Do you absolutly have to redo the foam ? Or can you get away without it ? Also... How muxh could all of that wet foam weigh approximately in a 16 ft boat ? Im guessing its going to add up and my boat will weigh a good 100 or more pounds less.

many times its about 600#+ of water in the foam. yes, you need to redo the foam, your talking $50 in materials. wet foam will rot out your boat.

you need to test drill the stringers and transom. if the wood shavings are dark and wet, you need to replace the wood. if the wood shavings are light-colored and dry, you can simply epoxy the holes and keep going.

 

[kcassells]

Hmmmm not sure if antone mentioned it yet. You will need to replace the foam.
2# foam for flotation, other foams like 4# and up are structural. You'll have to research to see if your is structural. Smells like a total rehab. Need pics.

 

[tpenfield]

Flotation is a good thing. Would the boat sink or something without it ? Or is it mainly for if it fills with too much water ? And as far as the foam it self goes. Is there a marine grade foam I need to look for ? Or is it just plain old mono foam ? That ypu can buy at any hardware store and use to fill coids and cracks ? Thank you for all the help.

The boat will sink without it. The foam stiffens the structure significantly so that the boat will not flex as much as you go through waves, etc.

You want the pour-in 2-part urethane foam . . . Most are USCG approved, but check the product information to be sure. The foam, initially poured in as a liquid will expand in the chambers of the hull structure and adhere to everything it touches, creating a sloid structure of the hull. The foam itself cures to a very hard, but light, consistency.

 

[StingRay_90V4]

The boat will sink without it. The foam stiffens the structure significantly so that the boat will not flex as much as you go through waves, etc.

You want the pour-in 2-part urethane foam . . . Most are USCG approved, but check the product information to be sure. The foam, initially poured in as a liquid will expand in the chambers of the hull structure and adhere to everything it touches, creating a sloid structure of the hull. The foam itself cures to a very hard, but light, consistency.

The local marine supply store i talked to today said they sell the expanding foam they call it. In a kit. It is a 2 part mix. That mixes about 7 to 7 1/2 Litres of mix. That i can pour in and let it expand and dry.. The kit is about $100 . He said it might weigh 15 lbs worth of foam. Which will cover 7 to 8 Cubic feet. So far i figure i have pulled about 150lbs of water wet foam out of the boat. No dark spots in tje striger or runners yet. I drilled a few holes and the wood looks dry and white. No black or wet yet. I beleive the stringers and runners have a lot of fiber cloth and resin over them that have kept them dry thankfully. This project of replacing the floor has taking a bit more. Actually a lot more work then o tought. Im on the second afternoon of just tearing up the old floor and removing the wet foam. Im almost done that part though. Next time i go back i should be able to get it ready to start poring the new foam mix. I will take some before and after pictures for this thread. Im almost scared to see how the boat works after this. If i pull out near 200 lbs . Im pretty sure it will just jump out of the water even faster now and very possible run too high in the rev range. Im at about 5600 ish to 5700 ish rpm. If i drop 200 lbs and the boat is that mich lighter. It will rev too high i would think. But thats another topic.

P.s - Any garbeled words are a result of me typing on my cell phone. Sorry...

 

[StingRay_90V4]

Well juat a small update. After pulling the floor up and removing all of the foam. Whixh i would say we pulled about 200 lbs or nore of wet foam out. Its not hard to see why it was holding water in the foam. The entire rub trim where the upper cap meets the hull was leaking on both sides. About 2/3 of the way up the boat on each side.

 

[StingRay_90V4]

And then this happened. The grinder was obviously sent through the side of the hull . what isbthe best way to repair this cut in the hull. It is abiut 1\8 thick by about 3 or 4 inches long. It is feom a grinder wheel.

 

[Mad Props]

The best way would unfortunately be to grind back the gel and glass on the outside and feather it out and layup a layer or two of csm and then gel and try to blend it back in, then do the same on the inside but with 1708.

But, you could probably get away with stretching plastic sheet tightly over the cut on the outside and tape it in place. Then push some gelcoat down from the inside with a small paint brush until you get a decent build. Then fill the rest of the cut with thickened resin and finish with a couple layers of 1708. Then pull the plastic sheet off the outside and blend with wetsanding and compound.

 

[Woodonglass]

I'm assuming you have access to the cut from the inside. If so, Tape over the outside and then fill the cut with Thickened Resin then lay a couple of layers of 1708 over it . On the outside grind and feather the glass and then lay one layer of 1708 and 2 layers of CSM Sand, fill and fair then Gelcoat or paint. 2 hour job

 

[StingRay_90V4]

I do indeed have access to the hole from the inside. So the best way is to repair the hole from both the inside and outside as well. And then re-apply some gel coat.

 

[Woodonglass]

Yup easy job

 

[JASinIL2006]

Well juat a small update. After pulling the floor up and removing all of the foam. Whixh i would say we pulled about 200 lbs or nore of wet foam out. Its not hard to see why it was holding water in the foam. The entire rub trim where the upper cap meets the hull was leaking on both sides. About 2/3 of the way up the boat on each side.

I'd be a bit worried about the integrity of the blackened wood in those stringers, especially near the transom, and (in the second picture), in the length of the stringer on the right side of the photo. That does not look like good wood. You can see it better, of course, but that wood doesn't look good.