New floor 69 tri-hull

[yorab]

I am going to replace the floor in my 15.5' 1969 tri-hull in the next few weeks. I have been looking online for a guide, but I haven't come across anything yet. I am developing a pretty good mental picture of the procedure based on tidbits of info that I am finding in this forum. I do have a few questions though.
1) What type of foam should I use?
2) How much foam?
3) How can I physically separate the floor from the hull along the edges of the floor without damaging the hull?
4) I am going to seal the floor top and bottom before installation. Because it will be sealed, is PT or marine grade necessary?
Thanks

 

[sdunt]

Re: New floor 69 tri-hull

What type of foam should I use?

Building foam, Foamular or similar. ALLLLLLLLL 2 part pour in place foams will absorb water: http://www.shareaproject.com/pages/imageDetail,p,148,i,2768,00.html

Testing Foams:
http://www.shortypen.com/boats/oday19/float/index.htm

2) How much foam?

As much as you can pack in the boat.. Water weighs 62 lbs per cubic foot, so each cu ft of foam you put in the boat will float ~~ 60 LBS of motor, gas tank, batteries, children. A 2 inch thick 4 ft x 8 ft sheet of foamular is 5 1/3 cu ft = 320 LBS of flotation. Assume the fiberglass hull itself = neutral flotation

3) How can I physically separate the floor from the hull along the edges of the floor without damaging the hull?

Use 4 inch right angle grinder and grinding / sanding discs. Work slowly, basically you want to sand down joint on the inside to the wood, then you can start to separate it from the hull

4) I am going to seal the floor top and bottom before installation. Because it will be sealed, is PT or marine grade necessary?

I went with Jim Anderson recommendations and treated Standard A/C exterior plywood and left the bottom unsealed. Any water that migrates into the floor will pass out the bottom and not be locked in the wood to rot it out: http://www.shareaproject.com/pages/imageDetail,p,148,i,2794,00.html

a little reading list for you:

Runabout Renovation: How to Find and Fix Up an Old Fiberglass Speedboat by Jim Anderson
http://www.amazon.com/Runabout-Reno...0255336?ie=UTF8&s=books&qid=1176991542&sr=8-1

The Fiberglass Boat Repair Manual by Allan H. Viatses
http://www.amazon.com/Fiberglass-Bo...0255336?ie=UTF8&s=books&qid=1176991609&sr=1-2

Fiberglass Repair and Construction Handbook Author: Jack Wiley
http://www.amazon.com/Fiberglass-Re...9355330?ie=UTF8&s=books&qid=1180026258&sr=1-1

Video on Fiberglassing:
http://www.youtube.com/watch?v=x6BIr0Kq0Bs

Boat Repair and Restoration Articles @ West System
http://www.westsystem.com/ewmag/proj_repair.html

West Systems User manual
http://www.westsystem.com/frames/tier1/usingepoxy.htm

"The Epoxy Book" Systems 3 Epoxy
http://www.mertons.com/Epoxy/documents/epoxy_book.pdf .

Suppliers:
http://www.uscomposites.com

http://stores.ebay.com/Tordoff-Supply

Estimating Materials:
http://www.fgci.com/howto/ht006estimating.html

Catalyst Chart
http://www.fgci.com/howto/ht005catalyst_chart.html

Fiberglass Learning center (includes link to West System Manual)
http://www.fiberglasswarehouse.com/learning_center.asp

Chemotherapy for Rot:
http://www.angelfire.com/nc3/davecarnell/rot.html

 

[yorab]

Re: New floor 69 tri-hull

What an absolutely incredible amount of useful info! Thanks sdunt. I'll start researching right away.

 

[dex76]

Re: New floor 69 tri-hull

its ppl like sdunt that keep me comming back here, very informative answers and helpful ppl