Done with transom, floor next....

[mikevr007]

I have a 1985 Checkmate Enticer. I'm done with the transom and am now starting the floor and the rest of the interior.
My question...
The boat is on the trailer. Should I raise the boat off the trailer to get the weight of the boat off the hull before I set the floor in? Or, should I just set the floor with the boat on the trailer?
Thanks again!!
Mike

[Techno]

The floor shouldn't be a structural part of the hull. You can yank it out and put a new one in on the trailer. If this was a concern the hull would still need to be supported so the parts that made it stiff locked it in the required shape.
Before you make some massive floor panel make sure it will fit in through the coaming opening, other wise...

[mikevr007]

Thanks for the reply Techno. That's what I figured, just wanted another opinion. I've already ripped out the old floor and made new floor panels. Making the new ones to fit was fun....not too bad though.
Ok...I have an(other) question(s). From the factory, the old floor was supported by a 3/4 plywood "beam" running up the middle of the floor (which I plan to replace) AND foam. Do I need and/or should I put foam back in? When I tore out the old floor, the foam was quite wet (from the failing of the floor) and since that cavity was "sealed" there was no place for the water to go. When I put the floor back in I am glassing the beam to the floor (not mechanically fastening with staples, nails, or screws) and I am glassing the entire floor, not just the edges as it came from the factory. SO, I am hoping that the floor will "never" fail again, hence there will be no water in that cavity. My other thought was to put drain holes at the stern so any water that does get in can just be pump out at the bilge. Anyway, if I do put the foam back how do I calculate the amount so I don't bow the floor? Also, the deck material is 1/4" plywood impregnated (soaked) with epoxy resin and will have a layer (or two) of glass on both sides.
Thanks!
Mike

[Techno]

The foam is usually just a former for the glass that was laid over it. You can use a half of PVC pipe or even cardboard tubing. Both would remain in. Or you can form a stiffener by several methods then bond it on. Form it over the pvc and then install after it's cured.
The closer to square this is the better. The larger the distance from the 2 surfaces the better. A 1" seperation is 4 times stronger than a 1/2" seperation. Like wise a 2" would be 4x a 1" or 16Xs a half. On a round or triangle you have less of a "2nd skin" if you see what I mean,they sides don't count that much(strangely) the seperation of a 2nd surface like an I-beam or a foamed core.
I made a Top hat stiffener mold for doing this. It isn't too difficult to make but I needed quite a bit of them. I go into it in more detail here top hat mold
If you do use foam use a solid foam stuff -sheet and layer it or cut the shape you need. You dont' fill it with expanding foam. You lay the glass over the foam. Styrofoam probably has no strength and the klegecell doesn't absorb water but is sold as a structural foam, I would skip it though.

I did the drain thing on my old switzer. It worked out really well. Just be sure to put screens in or you'll be losing quarters and stuff in there along with leaf bits. The vents for house eaves are perfect for this, I think they're about 3/4" or 1" and don't rust and push right into the hole. You can pull them out to eyeball the innards too when you want.
The other thing about my switzer is it had 2 drain plugs. The under floor area was a sealed area and I didn't really like that. Any water that did find it's way in had no venting and this led to the floor flaking, it wasn't sealed.

[mikevr007]

Great! Thanks for the info and the ideas. You've helped me make up my mind about what I am going to do.
Thanks again!