Who has made a light weight floor?

[tunnels]

tunnels, im guessing the woven stuff is far less rigid because the strands are pre kinked, which make them softer under compression and tension. I would try some +/- 45 1700 like i did my recore with. its pretty light weight and is super rigid in the hull. I dont see why it wont work in the floor. Im guessing the floor wont see the same abuse as the hull

Yes 45/45 for the top of the floor and if you peel ply there's a pretty good chance it will get sealed 99.9% !! , but the underside 0/90 that will make it more ridged to stand on !! its virtually the same as woven and uses the same glass but is much flatter and much more stiffer !! because it not using the woven pattern ! The floor is quite important and once glassed in place goes a long way in preventing twist happening to the hull ! so yes it gets a similar abuse that the hull gets but in a different way !!
Using the right fabrics in the right place and making them work for you and getting there full advantage and not adding lots of extra weight is what its all about !! good luck !

[aaron78viper]

Yes 45/45 for the top of the floor and if you peel ply there's a pretty good chance it will get sealed 99.9% !! , but the underside 0/90 that will make it more ridged to stand on !! its virtually the same as woven and uses the same glass but is much flatter and much more stiffer !! because it not using the woven pattern ! The floor is quite important and once glassed in place goes a long way in preventing twist happening to the hull ! so yes it gets a similar abuse that the hull gets but in a different way !!
Using the right fabrics in the right place and making them work for you and getting there full advantage and not adding lots of extra weight is what its all about !! good luck !

thank you for the help tunnels, I figure any floor is better than the stringers in my boat as is. so far it has held together just fine, im guessing with your advice i can make it light and much improved

[One Oldman]

Pay attention to tunnels he knows his stuff

[aaron78viper]

Pay attention to tunnels he knows his stuff

honestly ive found him to not only give a good suggestion, but also a good reason. I looked to him first about this topic and I am glad to have guys like that on this site. All who posted here are good guys and I cant say enough for the willingness to share experience.

[XstreamVking]

So you are using epoxy resin?

[tunnels]

Pay attention to tunnels he knows his stuff

thank you ! always here to help where ever possible !

[tunnels]

So you are using epoxy resin?

if you are using ply wood Yes you should use epoxy !!But before you lay your glass roll a slightly thinned coat of epoxy all over the wood first !! The thinned resin will penetrate into the ply through the outside veneer to the glue line and help prevent moisture penetration !! Pay special attention to the edges of the ply as end grain allows water to wick and soak up a long way very quickly !!!

[XstreamVking]

Tunnells!!!!!!! the glass you recommended will only work with epoxy!!!!!!!!! if they are using poly they would need mat for a good bond!!!!!!! Don't forget to tell the whole story when railing on about the exotic types of glass you "need" for a small floor that will never see any abuse!!!!!!! What a waste of materials. And money. But, by all means carry on...

[tunnels]

Tunnells!!!!!!! the glass you recommended will only work with epoxy!!!!!!!!! if they are using poly they would need mat for a good bond!!!!!!! Don't forget to tell the whole story when railing on about the exotic types of glass you "need" for a small floor that will never see any abuse!!!!!!! What a waste of materials. And money. But, by all means carry on...

Yes I didn't forget because the post is all about using epoxy !! . Poly wasnt mentioned !!Never use poly or vinylester over plywood for a floor or anything apart from Stringers because later with time the stuff used will possibly disintegrate and leave just the glass and resin to do all the work !!
My choice would be to use non structural foam and make the shape needed and use the appropriate glass lay up all over that and never have to worry for the life of hull ! ,But a drop in grid would be even better any way !!
Has lots of advantages , 100% fiberglass floor support, hull stiffening from end to end ,Under floor storage ,under floor fuel tanks maybe ,100% Glass construction distributes all the loading over a much bigger area so little point loading , And weight wise even with a solid glass transom could be lighter !!, and you have only the core that's a different material

[GregAdams]

the glass you recommended will only work with epoxy!!!!!!!!! if they are using poly they would need mat for a good bond!!!!!!! Don't forget to tell the whole story when railing on about the exotic types of glass you "need" for a small floor that will never see any abuse!!!!!!!

This sounds like propaganda straight out of the epoxy resin brothers sales/user manual.
Multiaxial fabrics work great with both vinylester and epoxy.

[XstreamVking]

Strongly recommended that you put mat under any woven glass when using poly....Don't do it and it will not get the bond strength. Vinyl is a hybrid, but still needs the matt. Epoxy, knitted goes right on with no matt. That's the propaganda I have been taught by several glass Mfg's. But as usual carry on with whatever you want to do.....

[GregAdams]

That is standard advice for polyester resin, and I would follow it. I doubt anyone is using poly in here.
Although I never believe everything my suppliers tell me
My experience with vinylester is based on destructive testing (test panels). And it is also based on decades of abuse on the racecourse.
However, Aaron's floor is probably around 4 square metres in area. So, adding a 225 CSM either side of the plywood will only add about 5.4kg.
The extra CSM is not necessary, but it won't do any harm.

[XstreamVking]

Well... http://www.boatdesign.net/forums/fib...mat-23520.html

[tunnels]

Strongly recommended that you put mat under any woven glass when using poly....Don't do it and it will not get the bond strength. Vinyl is a hybrid, but still needs the matt. Epoxy, knitted goes right on with no matt. That's the propaganda I have been taught by several glass Mfg's. But as usual carry on with whatever you want to do.....

Understanding that csm these days is perfectly ok to use with any kind of resin ! Not like the older glasses !! Working with wood should use epoxy always !Unless you been and done proper priming with poly it highly likely to eventually lift off as it gets older !!

[W2F a V-King]

if you are using ply wood Yes you should use epoxy !!But before you lay your glass roll a slightly thinned coat of epoxy all over the wood first !! The thinned resin will penetrate into the ply through the outside veneer to the glue line and help prevent moisture penetration !! Pay special attention to the edges of the ply as end grain allows water to wick and soak up a long way very quickly !!!

I am not a pro at this, BUT have done several complete restores in the past, last one a little over 20 years ago. Not to mention a handful of "modifications" involving wood and glass.

I always used poly, and only plywood for structure work. Epoxy being really expensive back then was not an option. And never heard of composites back then either...they may have been around I don't know, but I was always on a budget.

Always used mat under cloth, what ever the type I used back then, and NEVER had any de-lamination or structural failures. That's the way I was taught. I did tend to over build things, and maybe that's why I got away with my ignorance of "proper" procedures. However I was shown by a man that did do it professionally. So there may be some differences in opinions on how things are done.

Maybe there is more than ONE way to do these things?

So to say you should use epoxy when using plywood may be professionally correct, but is not an absolute. And anyone who doesn't wet out wood using ANY resin before laying the glass is asking for trouble. IM-unprofessional-O