Should I use Fiberglass or PVC sheet to cover pontoons?

Hello, I've got 2 (8 inch) 10ft gray schedule 40 pvc electrical/culvert pipes and am hoping to make some pontoons out of them, but they're freekin heavy, so thinking about drilling some holes in the tops of the pipe about 1/3 the way down and then covering the holes with either fiberglass or pvc sheet. And from what i've read, it sounds like the fiberglass could possibly crack from the possible flexing of the pvc pipe, so thinking about trying to find some rigid flexible pvc sheet and then using slow dry pvc cement. So just wondering if anyone has tried something oddball like this? I think i'm also going to try and shave some of the weight off internally using an angle grinder. Thanks for any suggestions!

 

It is a really bad idea. The contraption will surely sink. You can put caps on the ends of the pipes and they will float, but won't support much weight.

 

yeah you're probably right, but i hate to fork out $1700 for the Expandacraft pontoons until i'm sure that my sailing canoe idea is going to even work and i'm not good enough of a wood worker to make my own pontoons. Maybe i will order a few of those dock post caps, seal them up and take one pontoon to the river and see how it floats without drilling any holes, thanks for you inputs!

 

Oh and i guess my other option would be to shorten the pontoon down to maybe 6 feet, test it out and then go to 4 feet at a minimum, but my objective is to build a sailing canoe from an already super heavy Grumman 17 foot

 

Grey typically means schedule 80.

10 feet of 40 is a little over 50 lbs
10 feet of 80 is around 80 lbs.

Each pipe will displace about 200 lbs of water

With 40 your total flotation is around 400 lbs minus the pipe, so 300lbs. You shouldn't go over 50% of of the flotation on a pontoon.
So 150 lbs of total flotation.

80 would drop that to 90 lbs.

And that's the total for you and everything else you plan to put on it.

 

ok many many thanks for the information, yes its schedule 40 for sure and since i'm using these as outrigger pontoons, its sounds like these might work, so i guess there's only 1 way to find out and that is test it one step at a time!

 

And that flotation is for two 10' sections, cut that in half for an individual pipe.

 

well i think it should still work as the canoe will also be carrying some of the load via the outrigger arms and i do plan to eventually try and figure out a way to shave some weight off those pipes, like drilling some 1 inch holes in the upper 1/3 of the areas that aren't part of the outrigger connectors and then covering those holes with probably pvc sheet if i can find it and maybe even shaving some material from inside the pontoons using an angle grinder. I initially started out with a plan to use those concrete form tubes and fiberglassing over that, but found out that they might eventually absorb water. I looked for schedule 20 8 inch, which google says is being manufactured, but i couldn't find anyone selling the 8 inch or even a 6 inch size.

 

For test purposes you can buy inflatable pool noodles in various sizes for under $10 each. Walmart even has them.

 

hmmm will have to check that out and i did think about going with an inflatable and just might have to go that route if these pvc pipes turn out to be too much effort, but i think i can even cut the size down to 4 feet and still have them work as a counter balance to a sail, so if even the 4 foot pontoon is too much effort, then will have to go with an inflatable.

 

thanks for bringing up the inflatable idea as it looks like this raft has 3 compartments, so going to check with the manufacturer if i would be to split the raft into 2 separate pontoon sections, if so the attachments are already on those sections, thanks again for you help!

 

Go to this page, follow the instructions. Adjust the size to suit your preferences. You don't need to be a woodworker to make good outriggers.
Foam and Fiberglass Ama Construction https://amaconstruction.blogspot.com/2021/02/foamand-fiberglass-ama-construction.html

 

thanks Rumars, a very interesting design approach! I just may end up going this route as it does look like something i could do, thanks for the suggestion!

 

ok yes this is definitely the way to go, already started clearing out a spare room to make way for the build, this approach makes even more sense because there isn't any room for water to build up in the pontoon, or much water and makes even more sense/cents because it looks like it can be done fairly inexpensively!

 

https://www.lowes.com/pd/IPEX-4-in-x-10-ft-Solid-PVC-Sewer-Drain-Pipe/5016037291