What material for Risers?
 

I am putting a new floor in my 1977 20 Seacraft Master Angler. Floor and risers look like water soaked untreated plywood. I am correcting the deck drainnage problem with through transom scuppers which will require me to raise the floor 2". My question is what material do people use for risers? I was thinking of using resin and some type of hardwood. Also, will 1/2 Marine plywood treated with resin and fiberglass be stiff enough for a floor in this boat ?
Thanks Jon

For the MA box stringers running some 2x4s cross wise will raise the floor. You could laminate plywood together outlining the box stringers to prefered height or even cover the whole stringer w plywood and laminate to height you want. I did the 2x4s on my last MA. Raised the floor 4" and worked out perfect. May want to go alittle higher since you are already raising the floor. I used 3/4. 1/2 can work but no more $$ 3/4 is I wouldnt go w 1/2.
Check out my rebuild on here under "parrott" and "seacraft84" usernames

What are you considering risers? The stingers? if so they should be solid fiberglass with foam in them if that is the case. No wood to rot there. Far as the deck 1/2 marine ply like douglass fir or such would be a good wood choice. Aquatech is popular as well. You need to make sure you get the fiberglass lay up right due to most of the strength comes from it and not the ply wood. The wood is just a core and adds some strength but the true strength comes from the glass lay up on both sides of it. Far as raising it up, parrot's 2x4 idea works well and many others just raise the box stringers up whatever height the want. The project boat I started this weekend had sections cut out of my stringer tops to refill with pourable foam so I will just raise mine cause the stringers need new tops any way. If yours are in good shape I would just add to the top of them with stacked 3/4 marine wood strips layers to you get the height you want or the 2by idea would work well too. You might want to check to make sure your foam in the stringers is dry first cause if it is wet you will have to cut the tops to get it out any how and that might determine the best way to rebuild them higher.

Stringer material
 

Thanks for the replies, this is my first Seacraft and first boat rebuild. The floor sits on risers, the risers sit on top of the fiberglass stringers, right? Hope my terminology is correct.
Do you screw the risers into the stringers or glass them on?
Hear are some pics of the floor before and after cap removal
Thanks again

The floor sits on a bed of putty on top of the stringers

That's what I was about to say. Big ol globs of potter puddy. No screws. That will leave a place for water to get in. Use resin thickened with cabosil. (Similar to original potter puddy) Run a thick bead and bed the floor down in it. If you use epoxy it will bond together well.

This is how I plan on doing the floor in my 20' cc. Billythekid did an awesome job on this one. Your stringers may be the twin wide ones instead of the quads but you can do it about the same way. Molding the floor section will make for a lot less sanding in the end vs laying the wood down, laying glass on top of it in the boat then fairing and sanding your brains out.

http://www.classicseacraft.com/commu...=18607&page=14

Wow!
 

I don't think mine will come out like that. What a great job! I did pull the floor up tonite and this is what I found, see pic
I am picking up 3/4 marine plywood tomorrow and will probably use the plywood to get the correct deck height.
Any reccomendation on which scuppers to use for through transom?
Thanks again to everyone replying, the expertise on this website is great.
Jon

That floor is nice but time consuming also. I just like the fact that running some ss screws in the deck is that much more secure. Done right u shouldnt have to worry bout water intrusion. And running the cloth from one side of the floor to other ties it in well. I know the three different floors ive ripped up came up pretty easy w just the potter putty.
Fish u could just take 2" strips laminated together and outline the box stringers to desired height. plus u will want something around the perimeter of the hull for the floor to rest on too.

I agree with the time consumption, I takes longer to mold a floor but you dont have to do all of the fairing and sanding to true it up vs screwing it down and glassing in place. You will spend time either way. I rather spend mine making a mold table vs sanding and fairing. It still will take longer doing the mold but I feel like it makes a better looking, truer, straighter floor.

Far as the screw thing, The screws hold well till water gets in around them and soaks into the wood. I have pulled several redone floors apart including the one I am working on now and it seems like there is always more rot around the screw holes. The top of the screws gets sealed well but you cant really get to the back side to seal the wood where you added it to raise the stringers. You can back them out and add resin then put them back in and that will help but you will not have the same waterproof as if it was left just bonded down with thickened epoxy. I have used screws in the past myself but have tried to stop doing it under the deck area...

Either way it will last a long time, The main reason I started doing floors this was is I dont like all the sanding and fairing.

More than one way to skin a cat! Thats just my 2 cents. Im not a pro so take it for what it is worth.