Info on Nidacore

[Spud]

I'm thinking about building a sandwich (i.e. composite) 16' skiff or semi-V to be powered by a 15hp outboard. I have plans for the Indian River Skiff and like the looks of beateau.com's OB15. I'm looking for strong and light, so I've been considering substitute materials for plywood. I ran across Nidacore and have reviewed their site, but find their English a little strange. Saw mention of Nidacore in one thread on this site, but it was inconclusive, so I have a few starter questions. Have any of you builders worked with it? How does it compare to working with plywood? I read somewhere that the problem with substitutes for plywood is that you wind up having to put so much fiberglass on them that the weight reduction gained by using them is negated. Is that true of Nidacore or is it strong enough that a single glass coat will suffice? If it is a suitable substitute, how do you deal with the open edges created when you cut it?

As you can probably tell from the questions, I don't have a whole lot of experience - just one cedar strip canoe to my credit. I really enjoyed that experience, though, and want to build a boat this year.

Spud:confused:

[Baywatch Towers]

I use a fair amount of NIDA core when building fiberglass panels for the boat towers I fabricate. I very much like using it. The panels that I make are either laminated once on each side with 1808 or 1815 biaxial fiberglass cloth. One layer generally gives me 1/16" laminate per side. Then I begin my finishing process. NIDA core has a great compression strength when laid up correctly. But it does not like to hold a screw very well. Because of the make up of the core. When I prep the edeges, I dig out a small groove with a razor knife and fill with some type of polyester filler. Microballoons works really well. Then I finish the edge (usually bullnose) and glass a layer of finishing cloth. Once all this is done, it's time do do all the prep work for painting. I hope this has been helpful.

[tja]

I use a lot of Nida Core and it works well for the boats i build. But in your case I'd stay with what the plans call for plywood. Good Luck, Tom.

[Spud]

Thanks for the helpful response. One more question. What would you say is the weight difference between what you'd wind up with working with Nidacore as opposed to plywood?

Spud

[Spud]

Thanks for the reply, Tom. Could you tell me why you think I shouldn't try Nidacore? Is it hard to work with, no real weight advantage, not for the inexperienced or what? Thanks again. Any further info you can supply will help me to make a valid decision as to whether or not to give it a try.

Spud

[brainsboy]

Never heard of Nidacore, but I can tell you I personally will never work with wood again. After a quick stop at a local epoxy warehouse years ago I found that they have more types of "Core" material then you can shake a wooden stick at. Core material not only comes in different types of material but also are rated by densitys. They do make Core materials that are as strong as wood and are lighter, but be prepared to pull out your wallet, because they are not cheap. So why would you want to use this material? Most of these core's can be ordered with long pre cuts, this allows the material to bend or stay straight, what ever your trying to mold the core will adjust. Also keep in mind, that most cores will absorbe more resin then wood. This adds to weight but also makes it stronger, and you wont need as much cloth or mat. Think of how strong wood could be if it was filled with resin. Anyhow another advantage over wood, is that your less likely to have delamination. I'll take some photos of some core material I have. I obtained most of this information for building a custom rocket powered airplane. I gave up on the project and started in on boats. Also you didnt mention what type of resin your using. This is real important. Core material, cloth, carbon fiber, kevlar can not be choosen until you know what type of resin your going to use.

[Baywatch Towers]

NIDA core is definately worth using to save the weight. Go to the NIDA core web site and see if you can get a weight specifications.

[tja]

I don't think that the Nida Core would give you any thing near the ridgidness of wood without using a lot of glass. It just isn't very workable for the application you have. I don't use it as a core for the hulls that i build. I use 10mm in the floors, under shelves, and in the transoms. When using it in the transoms I stack multipal layers with glass in between each piece with several layers of 1708 next to the gelcoat and on the inside of the transom to distribute fastner loads. I hope this explains why not to use Nida Core.

[kach22i]

There is also Plascore Inc. located in Southwestern Michigan.

The hovercraft guys have found that putting resin on the single fiberglass layer works in non-critical structural situations. However sitting in the sun the air in the chambers expands and inflates the cells a little causing some puckering of the skin.

Hovercraft Material Link:
http://www.hoverclubofamerica.org/forum/index.php?showtopic=646&hl=nidacore

[Spud]

Sure does. Thanks, tom.

[Spud]

. . . you didnt mention what type of resin your using. This is real important. Core material, cloth, carbon fiber, kevlar can not be choosen until you know what type of resin your going to use.

What I have on hand is Epoxy Plus from Clarkcraft. It's a two part one:one fairly slow setting epoxy.

[adamfocht]

I've used alot of Nida-core and have nothing but good things to say about it where weight is the primary concern. It's properties also include sound deadening, floatation, complete resistance to rot and decay as well as having insulating properties as well. Everything I have done with it has been in flat panels, always vacuum bagged and in thicknesses of 1/2" (13mm) up to 1 1/2" (40mm). I have found that when using fasteners with Nidacore its best to stay with thru-bolts (when possible) and to use an inch pound torque wrench, a large backing plate or fender washer and a dab of 3M 5200. Once the 5200 cures, the bolt is basically going along for the ride. Anyplace where any type of heavy stress was being applied to the fastener (such as a cleat in a deck) I would either replace the nidacore in that section with plywood, or a composite plywood replacement, or I have injected the individual cells of the honeycomb with a thickened resin and haven't had any problems to speak of.

The only thing I have found Nidacore is a poor choice for is where the part is subjected to extremely cold temperatures, and have had the inner structure of the cells shatter on an occasion where a boat was tested in frigid conditions.

Whenever using Nidacore I find that the rigid core works best unless you have a bunch of radius' and contours, then use the scored. When using the scored product, be sure to 'open up' the scores by hand in all directions so your sheet doesn't have any memory. I also vacuum off the sheets before using them as they have plastic shavings from the cutting / mfg process on them that can interfere with bonding.

[rturbett]

The latest epoxyworks magazine published by West Epoxy (free) has an excellent article comparing core materials, cost, weight, and strength. There are weight savings to be had by using Nidacore, but at a price.

[henryblowery]

Sorry to get off topic, but where do you get Nida-Core? I've looked at their website and googled but I can't find a supplier or price list. I'm thinking about getting a Pearson Triton 28 and if I fallow through, I will have to recored it. Sorry for hijacking your thread.

Gray

[adamfocht]

we use composites one for 99% of our fiberglass / lamination materials...
i dont know if you can buy factory direct or not to be honest tho
might want to check with nida-core itself and find out the closest supplier to your area http://www.nida-core.com/intro_static.htm

[Herman]

I have used Nida-Core (Nida-Plast in Europe) for some 4 meter racing dinghies:

Things I liked:

-conforms to shape, can be bent in compound curves, thus the complete hull could be made from only 5 pieces of Nida.
-huge damage tolerance

Things I did not like:
-actually too heavy for my appication. With the knowledge I have today, I would opt for either 60 kg/m3 PVC foam, or Core-Cell A400 or A450. This has a certain weight advantage over the same stiffness.
The surface of Nida is covered with a veil, I think this soaks up just as much resin as filling the structure of a foam core. So let's keep that even...
-Nida has a low shear strength. Of course this gives it the damage tolerance, but the panel is less stiff than a PVC or Core-Cell panel.
-The cells do have the tendency to telegraph through the skin, after about 1 year, the pattern was visible on the outside (outer skin was 1x carbon 200 gr/m2, 1x carbon/aramide 175 gr/m2)
-I used a very thin inner skin (1x 175 gr/m2 carbon aramide). One of the boats has been parked flooded with water for some time. The water had made it's way into the cells. I took the boat to Italy, just to get rid of the water in the cells. (Italy is much warmer than Holland...)

I do see applications for the material, but not in boat hulls. I would use it where damage tolerance and sound deadening properties are important, and weigh is a factor, but not critical. And away from water.

Price is OK for the material. Balsa is pricewise a good second. Then PVC, then Core-Cell.

[Grantman]

Sorry to get off topic, but where do you get Nida-Core? I've looked at their website ...SNIP
Gray

try one of their sales reps:
http://www.nida-core.com/english/contact.htm

[JR-Shine]

a 1/1 epoxy is fine for stitch and glue plywood construction - not for foam core or nidacore. A 1/1 is not stiff enough.

We (the guys who you got your plans from;) ) have done a lot of work with nida-core. In fact we have tried to adapt it to your building method - its doesn not work well for the hull. The main reason id your molds are at least 2' apart with the stitch and glue method. Plywood is stiff enough, but nida core will sag between mold, so will foam core. With some work, you could adapt the mold by adding intermediate stations and slats - this means you need to learn lofting.

A nida-core of foam core hull on a OB15 (shell of the hull only) will weigh more than the plywood version. Where you save the weight is on the inside part. Stingers, bulkheads, sole, casting deck, etc… Do ing these out of nida-core will save much more weight and it’s A LOT easier to make flat parts.

[Russ]

I can see that many of you are really trying to learn as much as possible about core and more. I would like to suggest a source of good information for all your needs. See the Sourcebook!
GO TO "WWW.COMPOSITESWORLD.COM"
You will find a lot geared to aircraft but many of the material are the same now. CHEERS, Russ