Anyone have experience with NidaCore Polypropylene Honeycomb?

[robherc]

Hi all,

While browsing the web for materials for my "THE boat" project, I came across this stuff. Does anyone have experience with it & can give me the pros/cons as well as any construction tips you've learned?

Any info you have (even: "Don't use that worthless crap") would be greatly appreciated!

Thanks,
Rob

[Cobra1]

I was told by a sales rep for Composit One that it's not all that. The Havasu builders use it on small parts like hatch's and doors. He said that it doesn't hold up well to heat. And the reaction with resin is heat. The stuff is plastic and will melt. There are a couple of builders that use it in the whole boat, trick power boats being one of them. Here is his web site, plenty of pic's to look at. He builds a splash of the skater 21, http://www.trickpowerboats.com . I'll stick with balsa.

[robherc]

I was a bit concerned about the heat factor myself...but I also really would like to try a plastic honeycomb for a "pet project" of mine, does anyone know of a better, more heat-stable plastic honeycomb out there???

[rasorinc]

check out thermo-lite panals. Please let me know what you think of them.
expensive $$$ but may do the job. Stan

[sabahcat]

Originally Posted by rasorinc

check out thermo-lite panals. Please let me know what you think of them.
expensive $$$ but may do the job. Stan

How do you glass them with an alloy skin or have I found the wrong core?

If you are going to use something more expensive than Nidaplast/core, surely the next step would be divinicell followed by corecell, both proven in the marine industry for many years

Thermo-lite
http://www.omegapanels.com/products/thermolite.asp

Divinycell
http://www.diabgroup.com/europe/products/e_prods_2.html

Corecell
http://www.atlcomposites.com/product...lsa/index.htm#

[Herman]

Divinycell equivalents are Airex T70 and Klegecell. Migh come in handy when doing a search.

I have used Nida in boat hulls. The shear modulus however is disappointing, so do not expect really stiff panels. When crashing a panel, the cells come loose from the felt-like skin, and as they are PE and PP, this is not repairable.

I did like the ability to do compound curvature, without the need for cutting up the core in smaller pieces.

Today I probably would not use it anymore. Too little stiffness for the weight (80 kg.m3) and difficult repairs. I would go for balsa or foam.

[Alik]

Polypropylene honeycombs like NidaCore, HexaCor, etc., can be used almost everywhere in the boat excerpt bottom of planning boats. For bigger boats, shear modulus is an issue but the problem can be solved by proper spacing of stiffeners. For interoir panels, bulkheads, floorboards these cores are perfect. For topsides, decks, cabins - can be used.

We have designed a lot of boats in these materials, feedback is good. Another advantage of HexaCor honeycombs is price that is very attractive.

[Ilan Voyager]

It seems I going to sing the same song as Alik...

I've used Nidacore and Nidaplast (the brand name in France) in "low tech" applications as decks, bulkheads and phonic insulation on polyester working boats where price was an important factor. I've have also used it in the furniture of the boats.

The price (around 70-80 USD a panel 8*4 1 inch thick in Florida) is similar to the marine fir plywood that it replaces as core for polyester workboat building. Without the problems of delamination and rotting associated with the ill fated combination plywood/polyester... Well made panels are very resilient: ie rather resistant to hits, absorbing the shocks. Very good phonic insulation qualities.

The material has a very good ratio price/efficiency, and it's easy to work, accepts compounds shapes without the hassle of filling the cuts. Very good adhesion of the skins.

It's a bit lighter than balsa but less stiff; in a treacherous tropical climate it doesn't rot so it's a little advantage with not very careful people.

I won't compare with foams like Airex as the price is not the same...

So, like with all materials, qualities depend on the use. I wouldn't use it in "high tech" composites, but it works perfectly (with the right engineering) in applications like hand layed polyester fiberglass, where you can get huge weight savings compared to the usual fir plywood.

Hexacor compared with other composites?

This link treats about polypropilene hexacombs with very interesting infos. For those not afraid by maths there are very good posts by Analyst.

[pkoken]

Interesting material, I am adding this to my library of 'stuff'.

[CML UK Ltd]

I've come across Nidaplast before but was apprehensive that the honeycomb took in a lot of resin making it very heavy. Nidacore is meant to be better at staying light... I suppose these products sit between plywood and PVC core. I think they will become very popular soon as ply is getting very expensive.

[robherc]

Thank you all for your info/experiences.
So far, if I've understood everyone correctly, this is what I gather:

1. It's inexpensive
2. It's VERY light
3. It's a bit less stiff than most would like
4. It fits molds well & saves time/weight/cost of fairing
5. Very high heat can be a factor, so be careful
6. Don't trust it (at least not as a single-cored laminate) for unnecessarily high-stress panels
7. Use a few extra stiffening bulkheads for good measure

My next question, could some of the stiffness/strength issues be helped by using it in double-cored sandwich construction for high-stress/high-shear applications (ex: epoxy & glass, then core 1, then epoxy & glass, then core 2, then epoxy & glass)?

The basis for that question is that I'd like to design a "garage" area on my "big one" that could withstand having my cars & Ducati parked on it for the long trips...avoid car rentals or car transport fees.

[Alik]

For flybridge floor we use 2 layers of 20mm honeycomb. If so, stiffeners are not required even for 3x3m flat panel.

For highly loaded areas (as planning powerboat bottom) it does not help - shear strength is not enough, so this type of core does not comply.

[robherc]

Ok, so do you think I could get away with using plywood core here, or what else would you recommend?

[sabahcat]

If accepting a timber core and planning on glassing in epoxy , I would look at these over plywood.

Do a search on kiri or paulownia on this forum, similar properties to WRC, lighter, rotproof


http://kirikorpanels.com/

http://www.highpointtimber.com.au/

[Ilan Voyager]

Nidaplast and Nidacore are the same, just a change of name for American market. These cores were invented primary for making highways and bridges.

The quality to use is the 8mm cell, 80 kg/m3, with "welded" screen and polyester fiber mat. All the brands (NidaCore, PolyCore; HexaCore) have this "model". The screen permits hand lay up without filling the cells and the polyester mat allows an easy gluing of the skins.
Nidacore has other "models". The internet site has a lot of infos.

In my opinion it is the most friendly honeycomb to use for the small shipyard or the home builder. Even more friendly than most foams. It's almost impossible to go wrong with this stuff as it's so easy to use, and it's the perfect replacement of plywood cores on low tech polyester boats. Like with any core it needs the ordinary precautions with the hardware screwing.

Makes also very good panels with plywood skins.

Incredibly resilient. Trying to destroy a 30*30 cm 25mm thick Nidacore 1200 gr/m2 fiberglass/31509 Reichhold isophtalic polyester resin skins with a 1 pound hammer is a very hard task, and very risky for your face as the hammer rebounds back. An almost forty pounds aluminum dive tank falling from 2 feet high makes no damage...

Very good stuff when you use it at the right place with the proper techniques.

Abouts cars (!!!!) and Ducati Bike on your boat (whats the size???) my first solution is to rent a car while arriving at the harbour. Car and motorcycle won't last on sea...the rust will eat them. Disembarking them will be an expensive hassle, local Customs will be a pain in the a** Renting will be cheaper and more rational or to have bicycles or mopeds. And if you can afford a boat able to embark cars and bikes, don't worry; the Naval Architect and the shipyard will take of the small problem of floors material of the ship and will add the needed crane... Do you want to embark a mini car or a Hummer?