View Full Version : soft floor prostar 190

05-15-2011, 03:24 AM
There is a soft spot in the floor that runs along the edge of the hull. It still feels connected to the edge of the hull, but about 3 inches in it gets spongy until you stand on top of the stringer and then it is solid. The fiberglass floor has not raised but it feels like the foam underneath has colapsed. It is behind the drivers seat about 2 foot long and 3 inches wide. Has anyone else had any experience with a problem like this. This is my first thread, i wish it could be about something else. Thanks

east tx skier
05-15-2011, 10:14 AM
I read something about someone having a similar problem over at ballofspray.com. I'll see if I can find the thread. Welcome to the forum. Sorry for your troubles.

05-15-2011, 05:21 PM
Thanks east tx skier, that was me on ball of spray as well. Just trying to get as much info as i can before i start pulling up my floor. Apart from the small issue with the floor the boat is awsome. You guys over there in the states really know how to build a ski boat.

05-15-2011, 11:57 PM
Pulled up carpet over the area of the spongy floor. Found another issue, not sure if they are related yet. Just on the right of the drivers seat 2 inches obove floor level the hull has separated from the floor. It is about 2 foot long and 1/8in (3mm) at it widest part. Will try and post a pic. Am yet to investigate the spongy floor.

Bruce Carr
05-16-2011, 12:34 PM
What year is the manufacture of your PS190?

05-16-2011, 04:10 PM
What year is the manufacture of your PS190?

I assume it's his 1994 ps190 that his profile says he owns:)

05-16-2011, 04:14 PM
He's also from Australia.

05-16-2011, 04:29 PM
In that case all pictures must be turned upside down.

05-16-2011, 05:13 PM
1994 prostar 190. Did an inspection on the other side , seems ok. Plan on cutting small hole over the spongy area to see what's happening under there. Will take some upside down pics so you can laugh or cry with me.

05-16-2011, 06:18 PM
That's really strange to have your floor delaminating from the side. I have never heard of this before. I know a common problem is the rear center section of the floor, the honeycomb aluminum breaks down and gets weak.

05-16-2011, 09:13 PM
HA. My foot went through my floor when I tried to stand up from my seat! :o

05-17-2011, 06:32 AM
Cut a small inspection hole above the soft spot. Water seems to be getting somewhere and the foam underneath has pulled away from the underside of the floor by about half an inch. Might be time to bring in the experts.

05-21-2011, 06:52 PM
I have a 91 tristar and I just pulled up the original carpet since it was beyond worn out. I noticed a very slight give in the floor just behind the drivers seat. I was going to post a similar question since I'm not sure if it's serious or normal for such n old boat. I'll be watching this post to see what your findings are.

05-22-2011, 02:15 AM
Had a guy look at the problems with my floor. He was`nt too concerned, easily fixed. Where the floor has delaminated from the hull was probably from hitting some big chop and the original bond not holding. The foam under the floor has been wet and shrunk away from under the floor. Water could have entered in a couple of places. He plans on cutting out the area of soft floor, pulling out damaged foam , replacing foam and floor and glassing over it. Sounds easy, hopefully he does`nt find any surprises under there.

08-28-2012, 09:24 PM
I realize this is an old thread, but this is exactly what Im having on my 1990 prostar. Same symptoms. How did it turn out?

08-29-2012, 08:14 AM
My 1990 tristar floor feels a little springy on the left side of the engine.

08-29-2012, 11:17 AM
Anyone go thru this kind of repair? Im trying to figure out the best way to tackle it.

08-30-2012, 10:19 PM
bump, anyone have any ideas?

09-14-2012, 12:20 AM
I could explain how CC manufacturers the hull as a new boat, but not MC. Getting that fixed after the fact would be a bigger deal and much more involved. The foam is very similar to the expandable foam you can get at Home Depot in a can, except they use a gun. There should be an access hole where they sprayed the foam, if it was sprayed. CC got away from the spraying and got preformed foam stringers put in the hull.

I am not sure which way MC did it but my guess would be that they sprayed that foam in. Removing the wet foam, if there is any, would be the first thing to do. You could glass in some stringer ribs as support and glass those to the inboard stringer to the hull side and to the underside of the floor. Make sure you leave about 1/8" gap or so between the stringer and glass surface or it could leave print through in the gelcoat. This would require cutting a pretty good size hole in the floor. You could spray new foam in there or just leave the foam out. Most of the boats have more than enough for flotation. That is a little more of an old school way of fixing it, but it should firm that floor up.