Plascore polypro honeycomb for cabintop core?

[Tupaia]

Originally Posted by Simi 60

Can't say I agree with you there.
I have made test panels and been involved with drop tests on various cores, cedar. Foam, duflex, Kiri and Polyvore stacks up well

See below vid, do you thing walking exerts the same loading as essentially sledge hammer blows?

Watch to end to see comparison against actual panels of other cores taken from other boats

https://youtu.be/hgrEjZqsKJY

Interesting tests. In my experience, I have polycore, phenolic paper honeycomb and foam sandwich cores on my boat and they are all good but lend themselves best to different applications.


The polycore is best described as squidgy if walked on. My bimini is polycore and it is totally water proof but I do not walk on it. I think walking results in a fatigue type failure, soft spots and delamination. I have seen this on a friends catamaran where it was used for decking and it failed dismally, maybe due to the skins, but I would be reluctant to use it for high traffic areas. My internal floors and decks are foam sandwich and have passed the test of time with no such problems. Most of my furniture is phenolic paper honeycomb which is extremely stiff and light but not waterproof. It would certainly work ok as floors as it is used for freight decking in aircraft.

[Simi 60]

Originally Posted by Tupaia

Interesting tests. In my experience, I have polycore, phenolic paper honeycomb and foam sandwich cores on my boat and they are all good but lend themselves best to different applications.


The polycore is best described as squidgy if walked on. My bimini is polycore and it is totally water proof but I do not walk on it. I think walking results in a fatigue type failure, soft spots and delamination. I have seen this on a friends catamaran where it was used for decking and it failed dismally, maybe due to the skins, but I would be reluctant to use it for high traffic areas. My internal floors and decks are foam sandwich and have passed the test of time with no such problems. Most of my furniture is phenolic paper honeycomb which is extremely stiff and light but not waterproof. It would certainly work ok as floors as it is used for freight decking in aircraft.

Paper honeycomb failed dismally in OZ, pretty sure it was ATL composites making it with ply veneers and I remember some major fail in floors and transom steps.

The Polyycore I know has been used in a 55ft powercat for Hull's, decks, everything and has been in use for over 15 years now.



I also know of a few sailing cats of similar vintage, no issues at all that I am aware of.

Maybe it was how you used it?

[Sailorman Ed]

Polycore will resist very light traffic but will not support being walked on. I know of a boat that used it for decking and it crushed so badly it became very bouncy due to internal delamination to the extent that the whole area was cut and filled, now very heavy.

I disagree, I walked all over my bimini, numerous times. I also used it replacing waterlogged plywood on my old Prout Snowgoose aft deck, I remember several guys standing around on it. Now granted I wasn't dropping weights from 1 or 2 meters onto it but I try not to drop heavy weights onto any parts of a boat.

I am confident enough to be using it on my next bimini project.

[rslifkin]

Delamination from walking will likely depend on how thick the skins are and how thick and stiff the overall structure is (and how it's supported). The more the structure can flex from being walked on (and the more flexible the upper skin and therefore the more crush load can be applied to the core), the more stress the core will be under and the more likely it'll delaminate.

[Tupaia]

There are lots of differing views on this



Post #136 onwards

https://www.cruisersforum.com/forums...-22948-10.html


Post #4
https://www.boatdesign.net/threads/p...tamaran.36740/


I have used it for my bimini but it doesn't get walked on and probably would last if I did.


The phenolic paper honeycomb I used was e-glass and Kevlar skins certainly no delamination. It is painted no veneered.

[Tupaia]

Originally Posted by Simi 60

Paper honeycomb failed dismally in OZ, pretty sure it was ATL composites making it with ply veneers and I remember some major fail in floors and transom steps.

The Polyycore I know has been used in a 55ft powercat for Hull's, decks, everything and has been in use for over 15 years now.



I also know of a few sailing cats of similar vintage, no issues at all that I am aware of.

Maybe it was how you used it?

Pretty sure this is the original Liquid Assets, renamed maybe. To my knowledge the entire forward deck had to be replaced and or filled with resin. Please correct me if I am wrong.

[Simi 60]

Originally Posted by Tupaia

Pretty sure this is the original Liquid Assets, renamed maybe. To my knowledge the entire forward deck had to be replaced and or filled with resin. Please correct me if I am wrong.

It is liquid assets
I was not aware of deck issues.

Interesting how the deck could have issues while the hull that takes actual loads is not mentioned.

I wonder if it could be a air/sun/ expansion thing?
I did wonder about it when I first saw the original (I think) nidaplast but figured smarter people than me would have thought of that