Trojan Boat Forum

I have removed My swim platform to rebuild as the inner wood was waterlogged and starting to rot. I was able to cut the bottom section with a circular cut off tool that was laminated to the wood all around the edge and remove in one piece. I then with a chisel and hammer removed all the rotted wood. after removing all wood i used a grinder w 80 grit to remove remaining wood and fiberglass resin so both the "Top" half of the platform and the "bottom" half are clean of any remaining glue, wood or resin.
It appeared as in was just plywood as the core and I would like to know what is the best product to replace it with? And does it need a wood core or can it just be filled with layer after layer of fiberglass resin and fiberglass mat? I want to make sure it is plenty strong enough to support standing on it ,but also don't want to have to do it again any time soon.
My Dad owned a auto body shop that I worked in for many years and we did work on a few corvettes so I have worked with fiberglass some but, this is my first swim platform that with need the strength it had and be completely sealed from the H2O.
Thanks in advance Eric

You could use pure glass but it would be real heavy too heavy IMO, marine plywood would be good to use or maybe some other marine coring

My platform is made out of teak. If you want to make yours out of teak instead of rebuilding yours, I can post a picture for refference.

I have the same project to do. I was planning on using Coosa Board. Spendy when compared marine plywood, but is 30% lighter than plywood and won't absorb water.

My F-32 is tail heavy enough with all the down riggers and fishing gear, so I like the weight savings, but I also like having a platform.

Link for materials http://www.boatoutfitters.com/coosa-com ... board.html

If you use just glass, it'll be really heavy by the time you get it thick enough to be structurally equal to having a core. The other thing you have to worry about is that if you don't know what you're doing, you can warp the platform with that much glass. As it cures, it will want to pull in certain directions. There are tricks of the trade to counteract that. You can brace specific key areas with a core and have solid glass in the rest. This will reduce some weight but at that point, you might as well just core the whole thing.

There are a few synthetic core materials on the market but I prefer using plywood. Some will use regular ply, I prefer marine grade as it's more structurally stable. Either way, the key is to ensure that when you fasten something to it, you must do it in a way that will PERMANENTLY prevent water from ever being able to get to the core. In spite of some claims, some synthetics will retain water.

Simply adding caulking to a hole and inserting a fastener will eventually fail over time and you'll end up with a wet core again. The best way to keep water out forever is to bolt through or screw into an epoxy plug instead of the wood. To do this, drill your hole out 2-3 times larger than the fastener, tape out the area around the hole, wet out the wood core in the hole with epoxy and let it soak into the wood for a few minutes. While it's curing, take the rest of the epoxy and thicken it to a peanut butter consistency. Before the epoxy in the hole cures, fill the hole with the thickened epoxy and let it cure. Now drill the plug to the correct size and insert the fastener. This way, you're drilling into the epoxy plug and fastening into it or through it instead of wood, and if it ever leaks, the wood never gets wet. The plug will also prevent you from collapsing the area and crushing the glass and core if you tighten the fastener too much. The alternative is to drill the fist hole to the same diameter as the fastener, dig out the core around the hole, then follow the steps above. You'll end up with a plug that extends into the core beyond just the diameter of the hole. I use this method when a bigger hole might not get covered by what I'm fastening.

Thanks to all...going with the coosa board.

If plywood is being used as a core, you can also soak it in a penetrating epoxy to make it much less susceptible to rotting.

I recently saw that Jamestown Distributors came out with their own line of epoxies including a penetrating one. They are marketed under the Total Boat brand name -- I have not used any yet, but am considering it.

Instead of replacing all the area that was wood, could you make an aluminum tube frame to put in the void. Glue it, bolt it or something.
It would be lighter!

Not familiar with the cooosa wood. However, make sure you have the area that you connect to the brackets is well supported. If this material is not as strong as wood or stronger, you can risk cracking the shell of the platform. I started from scratch on ours and used solid wood with foam filler and it has held up perfectly. Ditto on the full cored drill through connections to eliminate water intrusion. It is a pain, but well worth the effort.

Search 11 meter swim platform. It is on here somewhere step by step if interested.

I have never done my swim platform,but when I replaced the wood in my radar arch,I used fiber board instead of wood so I'ld never have to do it again.I also used it under some of my upholstery,but not my seat bottoms ,I used marine grade plywood .