1997 Sport Nautique - Floor question (WTF am I dealing with?

[mrbobolina]

I bought my boat about 3 years ago, I knew it had been in some salt water, and based on everything I could see it really just need some TLC. I am the kind of person who actually enjoys restoring stuff so I sort of liked the idea, and I got a pretty sweet deal.

This season I decided the carpet is due to go and I ordered new carpet for those who care it 40oz grey Nautique carpet from Nautique $17/linear foot 7 feet wide.

Okay so anyway, get the carpet up and that was a pretty simple task overall. Then to my dismay I see a area of the floor near the rear seat on the left side where there appears to be a slight hole. ****! Well I am pretty well versed in fiberglass fabrication so I am really not that concerned with mending it as the hole is about 1cm in diameter (1/2 inch roughly. It is not even really a whole as the fibers between are still in tact. I proceed to scope out the rest of the floor, and everything else is good.

As I look closer I notice the floor which is fiberglass is even from side to side, however not flat. There are slight waves in the fiberglass. I think wtf? Then I stop and say no way did Nautique do a crap job on this. I go home and ponder then call a bunch of boat shops they all say the hole could have happened from maybe an anchor or something - I buy that.

The waves however sort of like warping is not a characteristic of fiberglass nor Nautique.... So today I decide let me look a little closer, perhaps it is the stains of the glue marks that give the perception of waves? Nope there are waves - huh? So I then proceed to pick at the hole. Nautique said if the foam inside is in good then just mend the hole. Well the hole is now about 3 inches wide (for those who are not fiberglass versed this is not a bid deal at all).

What I found odd is that the fiberglass is set around what looks like a thin sheet of balsa. It could be plywood, but the wood is way too airy in my opinion to be plywood. I have searched the forums, I don't know if this is normal? Is a fiberglass floor basically insulated balsa? Seems odd to me if it is.

When i do a knock test on the floor the sound is much different in the area where the wood is versus other parts as well. It appears perhaps there may have been a repair at some point; however it is on both sides of the engine bay as well. Now before I go and start tearing my 3" hole into a 1 foot hole and so on, I want to know what the **** I am dealing with.

I feel that what occurred is the balsa got wet and expanded and sort of ballooned the fiberglass causing the waves. If so, is this a "real" cause for conce

[SkiTower]

RE: 1997 Sport Nautique - Floor question (WTF am I dealing w

All I can add is post 1993 CC's were wood free...Sounds like a bad repair job...

[TRBenj]

RE: 1997 Sport Nautique - Floor question (WTF am I dealing w

Pictures.

[DavidF]

RE: 1997 Sport Nautique - Floor question (WTF am I dealing w

Ok, first take a big sigh. Now, no worries, everything you are describing is normal (except the hole) and the way the boats are built. First a bit of education on how the floor is constructed. Very simply:
1. Expanding foam is sprayed into the hull of the boat.
2. Once cured, it is cut flush with the top of the fiberglass stringers.
3. Finally, the fiberglass floor is hand layed on top of the foam.

The foam is actually load bearing and provides most of the load support. CC does not worry whether or not the floor is perfectly flat as carpet does a wonderful job of covering that up (which you can attest to as you did not notice until you pulled up the carpet). The "airey" balsa you encountered is a inner core material used to strengthen fiberglass laminates. The forward deck of closed bow boats also have this core material to strengthen the deck against people who walk on the deck. Basically, it builds up cross section of the laminate (necessary for strength) without adding weight and saving resin (the heavy part), thus cost. I can also imagine that if CC had a low spot in the floor (because too much foam was removed) they might use the core material to build up the laminate floor quickly to fill the low spot. Again saves weight and builds cross section.

I suspect the hole you found is simply a fabrication error where the fiberglass matt/cloth was not fully saturated with resin. Keep in mind that the foam does NOT absorb water (like the older boats used too) and that the fiberglass floor is adhered to the top of the foam, so any water that found the hole had no where to go. Fix the hole and you should be fine. And you can now sleep at night knowing your boat is like all the other CC built.

I know all this as my '93 was exactly the same way and having done extensive fiberglass repair on said boat, and encountered everything you described.

[mrbobolina]

This is good stuff. I will seal away then

[mrbobolina]

So after a quick seal job I combed the rest of the floor to find about 4 other spots where the resin had broken down between the fibers. My guess is there was an air pocket trapped in manufacturing. This entire labor repair process took about an hour, which includes sanding.

As I was concluding my little project - I noticed that the passenger side floor area between the front and back seat looked wrong. I stepped on the area and heard air escaping, and the fiberglass actually flexed. OH ****! I grabbed my hammer and started to hit the floor to test for sounds variance. It seemed that there was about a 3 foot area where the sound was hollow and the rest was firm. Hmmm

I stepped very heavy in these areas, and sure enough the floor moved. I busted out the dremmel, and cut the about 1/4 inch fiberglass matt in a 3'X9" square. Water had apparently been seeping in this pin hole for some time. The top layer of foam about 1/8 inch was brittle and soft. Not encouraging at all.

When I pushed the foam down, it actually moved downward. This was odd. I crabbed my scrapper and cut a square about 3"X3" out of the foam. It turns out the foam was laid down layer on layer, and somehow the top layer had moved away from the next layer allowing the foam to move, and thus the fiberglass to flex. The pin sized hole allowed water in, and now the top 1x8" of foam was crap. Ohhhhhhhh the Joy.

I proceeded to cut out the entire top layer of foam, which was very simple. I felt I needed to do this to be sure the next layer of foam was not damaged, and it was not. All of the pieces that I cut out, were able to fit back in, the challenge was what to do now? The foam used in the boat is very dense. Extremely light, but very dense. So I put all the pieces back together, then went down to Home Depot, grabbed the strongest filler foam I could find.

From here I injected the old foam between the two layers with the filler foam like a hypodermic needle, until the filler foam crept out of crack that I created when I took the top layer apart. I laid a few sheets of newspaper on it all, and put some big ole gray building bricks on the whole thing. An hour later, the foam had grown and filled every gap between the layers, and fully bonded the two.

I proceeded to use my shop vac while turn on to scrape the top layer of foam (it grew about 1/4 in taller from the filler foam) down until I had enough space to resin and lay my fiber sheets. About a half a gallon later and a ton of fiber the space was fully mended. Probably better and stronger than the factory.

The next day I did the walk test, no give. I did the jump test, not buckle. Then I dropped and anchor on it - okay no I did not do this, but it did cross my mind.

The final step was to sand it. I tried my palm sander - ZZZZzzzzzzzzz I tried my rotary disk sander - A little better. Then I busted out the belt sander, which I thought would be really messy. It was not, it chewed through the resin like a pit bull and leveled the entire 3' section in about 20 minutes. I has spent an hour with the other two getting very frustrated. Fully sanded and smoothed out the result is perfect.

I am sure I am not the only person this will happen to. Total repair time on this deal was about 6-8 hours. Total labor time about 2 hours.

- sorry no pics

[WakeSlayer]

Nice recovery!

[DavidF]

Hmmm....seems too many problems for factory issues. Seems like the floor has been impact damaged somewhere along the way. You should definately prevent people from "jumping" in the boat. Like I said earlier, the fiberglass floor is support completely by the foam. The foam is very dense and usually has not trouble supporting the load. But, someone jumping in the boat can and will crush the foam and leave a soft spot in the floor as teh fiberglass rebounds, but the foam does not.

layered foam from the factory is very weird. Something does not add up. That stuff you bought from Home Depot has almost no load carrying capacity, but if youi used it "glue" the original back in place, it might work. I am also not sure if the foam in a can absorbs water or not. For future reference, US Composits sells two part foam you mix and pour into place. It is available in several densities.

A 4.5" grinder with 36 grit pad is the best method I found for quickly chewing through fiberglass and giving you good control. But, a belt sander would work good too.

[AirTool]

.... I crabbed my scrapper.....

I may need to learn this technique.

[mrbobolina]

I was able to get about 95% of the old foam back in piece by piece. The expansion stuff from Home depo filled the small 1-5 MM gaps all around, as well as the areas that caused the space to begin with. While it was drying I had two gray cinder block on foam so be sure the expanded pieces filled the gaps and pushed all the air out.

The Home depot stuff alone is very weak. Notstrong enough to use by itself. It is water repelant, just no UV. Once it dried I actually stompped all over it.

The finishe product is extreamly strong.

I think you may be right, the floor could have been damaged (I am not the original owner). Could have been somoene jumping or maybe a anchor hitting the mat?

I know when the carpet was down there was no way of knowing. I am glad that found it before it became catastrophic. So far the carpet is coming out super sweet.

Racing the clock to Memorial Day.

[mrbobolina]

on a side note - if you use goof-off in the gallon format from Home depot and drop it into a spray bottle, and use a brass scrub brush getting the glue off everything is a piece of cake. I called Goof-0ff and asked them how to get rid of any film residue and they said the Goof-Off evaporates.

I still did a rinse with dish soap and water to be safe.