75 Ski Nautique Floor Problem

First time poster, but have been watching the forum. Just bought an 86 bfn. Do you need to replace the foam? if so, what do you use? What type of wood do you use?   What I tore out seems like 1/2 inch plywood and also cedar solid pieces. Looking at replacing with MDO. Any suggestions?

hey brian

you will find lots of info on this site about this project..the foam part is the easy part the stringers take the time and more fiberglass than you my think..the foam is a closed cell.witch is great stuff unless water some how gets traped underneath, it never will drie out(well maybe if you live in Las Vegas and you live to be a 100 years old)I pulled my stinky wet foam out and there was water traped right up to the front of the bow. you can find boat biulding places that blow the foam in for a price or buy the 2 part and do it yourself.. I'am not at that stage for another 3 weeks so not sure what I'll do yet. your local marine supplie store sells the 2 part or go to uscomposite.com I think you need the 5 gallon combo. kit. I'll know more soon. as for the wood to use..use the marine grade..it's bonded together better and it's just better allround pylwood(why else would it be 3 time as much $$$).. look into material calles "TELC".I 've used it to seem the stringers down and also using it to seem the floor edges. its a powder that turns the resin into a glue..and one other thing I used was stuff called "S1" it treats the wood so it does'nt rot again.you CAN NOT use treated wood from the lumber store, fiberglass does not bond to it..I hope to get my pics. up soon.

hope this helps alittle

Agreed...I used standard 1/2"plywood saturated with polyester resin then glassed in w/ fiberglass roving. US Composites is the way to go on the foam. It will take the better part of 5 gallon kit (actually two 5 gallon buckets of 2 part epoxy). I had a little left over (16' Mustang). I got the Douglas Fir and paid to have them cut and glassed in. Thought it may be better to leave the structural integrity to the pros.

If your foam is wet, take the time to pull it and replace it. I estimated 600-800 lbs of water weight added to my boat as a result of the saturated foam.

Wood is long forgotten! Here at Captain Levi's Fiberglass Boat Repair we used a lot of wood over the years.We now use foam core material such as Klegecell,Coosa Composites to replace that roten wood.Inproving the boat's structural integrity,producing a lighter yet stroger boat that is rot free!Material cost on a 17' Mustang run maybe two hundred dollars more than marine plywood.Labor a lettle less than wood.Material cost to replace stringers, engine beds, bulkheads,floor on a 17'Mustang figure $1200. labor we charge 60 man hours this does not include engine and under water gear removal and instulation.If done correct this is a 0ne time replacement cost to your Correct Craft.

I've been through this whole thing my self over the past 10 months on my 78 ski nautique. I would not recomend using any type of wood in the floor other than around your ski pylon. I completly removed my floor, and my foam, and the foam was soaked, smelly, and nasty. The stringers were rotted in many places, but not rotten to the point of complete removal. I replaced my floor using a combinaiton of 2 lb. closed cell foam, a sheet of 1/8th inch PVC roughed up for a good bond, and then 1/2 inch of Polypropaline Honeycomb core. The honeycomb was used because it is VERY light, and when used horizontaly it has a lot of strenght, especially for plastic. The honeycomb sheets come in 4X8 sheets like plywood or dry wall. Order it with "veils" which are a fuzzy, furry film used to create a good bonding surface for fiberglass. Glue and screw your PVC to the stringers (after they are refinished or replaced), then rough them up with a good 20-60 grit sand paper or grinder. Then take your honeycomb and cut out pieces (very easy stuff to cut, I think i even used Fiskars shop sheer/scissors) to fit in the sections of floor. Glue down your honeycomb to the PVC sheets, and then laminate 2 coats (minimm) of glass over the honeycomb. When you are done with this, you can bet your floor will not rot again, because there is no more wood in the floor! The only place I used wood was around the ski pylon, and there I used a 4 foot piece of dry, treated 2X8, laminated on all sides with several coats of epoxy and glass. Before you do this, you will want to router or cut out 2 slots for the 2 main stringers (1 and 5/8ths inch wide). This will allow your pylon a very strong support for the high stress it goes through. If you'd like more information, and pictures of the process I'm describing, please visit my website at www.78skinautique.zoomshare.com

There are tons of pictures showing the stringer repair, as well as the construction of the floor using honeycomb. For materials at a good price visit www.uscomposites.com becuase they're the best prices I found anywhere. I come from a long history of stingy dutch people so trust me, they're the best out there. Good luck with your project!

JJ...I saw those pics of your floor...quite a job well done!