on his M-20, M-18 or Acats? If I get one I'm trying to anticipate repair difficulty. It will not lead a sheltered life. Steve

On my Tornado, I believe it was Nomex.

Ductape and plywood and you'll be fine.

Lee

Here's a close-up of Bundy's boat after he was tagged by the French in the 2007 Tornado NA's:


Looks like Nomex to me. Either that, or some well trained bees.

Marstrom Core Materials that I know of:

In 2002 the A-Class and M18 the hull and beams are solid carbon. The boards are hollow core. The mast has some kind of closed cell foam at various places. Repairing thin solid core carbon is tricky. It's thin and you have to taper or bevel the repairs.

I think the M20 is the same as the A

Tornado uses a honeycomb Nomex PAPER core. I spent a lot of money once to buy some NOMEX HONEYCOMB and found it was not the same stuff.

Really? Is this not the same stuff? I was considering purchasing some of this.

http://www.aircraftspruce.com/catalog/cmpages/01-00488.php

Aircraftspruce is very pricey.
Try http://www.plascore.com/

That's a good link - I've found aircraftspruce to have the best pricing on several items (and they ship to me ground with next day delivery due to proximity). I don't have any sources to compare core pricing with.

What kind of prices does Plascore have for 1/8" nomex core?

Jake
Did you miss this?
"Typical applications include lightweight non-structural"
Boat applications would qualify as "structural" except for interior applications in yachts. I would suspect that the Nomex that Aircraft Spruce is selling is different than what Marstrom uses in their boats..

Regards,
Bob

That looks like nomex paper. What I had looked like a really thick piece of lace coated so it did not wet

Hey, that's my photo <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Knew I should'a put a copyright on it <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />

Yup, it's Nomex honeycomb in them thar Marstroms. Not sure of the dimensions for it. Anyone know?

there was an article some time back in Seahorse that talked about Marstrom. I think the article quoted the laminate to be 10mm nomex core (didn't give the density) with a 15oz. outside laminate of S glass. I also remember reading something about a 10mm core in the A Cats as well.

That is a glass skin! Aren't Tornado's allowed carbon hulls?

Nomex is a specific brand of Aramid paper in a honeycomb form. I believe there are other generic forms of honeycomb cores.

Honeycomb is certainly a structural core material, all the AC boats have it as their hull and deck core.

I'm still missing it - where did you see that?

Jake, the passage that you have questioned, is on the page that you, previously had presented a link to.



GARY

Nomex is tricky stuff to use. It plays all sorts of tricks when you try and do curves with it.How they get it into a Tornado shape I don't know! Maybe heat will make it stretch a bit?

Also its easy to overdo the resin and start filling up the honeycomb which kinda defeats the point in using it.

p

I can't believe that you guys have missed the sacreligous nature of this thread, this dude is saying he's gonna buy a maarstrom and trash it ??, he's either winding you up and you've swallowed it hook line and sinker or ?????, makes me think of the guy that trashed a new f16 dragging it over rocks.

Surely Hobies were built for these peeps and the punishment they like to inflict on their cats .

Maarstroms are the best built high performance cats I've seen , why would anyone contemplate how he's going to repair it after giving it a good thrashing is it a sado/macho thing ?

"Honeycomb is certainly a structural core material; all the AC boats have it as their hull and deck core."

I was not saying that "honeycomb" or “Nomex” was not a structural material...what I was pointing out was that the "type" of Nomex that Spruce Aircraft was advertising specifically stated it was for non structural purposes. Due more research ncik and you will find umpteen different varieties of honeycomb reinforcement out of all types of material....and several varieties of Nomex as well. PN1 Commercial grade Aramid Fiber Honeycomb is used in boat hulls. PK2 Kevlar N636 Para-Aramid Fiber Honeycomb used for boat decks. PN2 Aerospace Grade Aramid Fiber Honeycomb used for aircraft wings, missile wings, helicopter rotor blades etc.

Regards,
Bob

I've just done a hull repair on my Tornado. The core was compressed over a region about the size of my hand and the outer layer of glass had a crack. It was in a non-critical load area (below water line and just in front of main beam). After stripping away the paint & primer (no GelCoat on Marstroms), you could clearly see the Nomex core honeycombs beneath the translucent glass layer. Lots of the cells were visibly darker than the surrounding cells. I thought it was excess resin. My repair consisted of drilling 1/8" holes through the outer skin spaced evenly over the compressed area. These would later be injected with thickened epoxy via syringe. Before injecting, I cleaned up the area with alcohol followed by acetone, including using a sprayer to squirt it up into the holes to flush out drill debris and/or sanding dust. While using a heat gun on lowest setting to dry it all out, I notice a fair bit of liquid seeping and then dripping out of the holes. Kept at the heat expecting the excess acetone to quickly evap away, but the liquid kept coming. Eventually it became a nearly constant trickle. Realized then it was actually sea water, not acetone. The dark cells of the core were actually holding water, not resin. The heat was causing these to boil & steam and the water would find it's way to the holes and escape. Took more than 1 hour of this gentle heating to get to a point where no more water was coming out and for the cells to become light in appearance.

The crack in the outer skin did not in anyway cross all the affected cells...so either the compression had damaged the cell walls enough to allow water through or water got in there from normal absorption processes. The latter would mean most of the boat would have similar quantities in the cells!! <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />

you can get over expanded (ox) nomex that will bend nicely in one direction and not too bad in the other. with a 10 mm core, it should not be too bad to get it into a small beach cat hull.
when you are applying nomex to a part that is not to be cooked (non pre preg) you take a flat work surface and secure some plastic film to it, coat the film in a thin layer of epoxy, pat the bonding side of the core into the resin then stick the core onto the part. you need a thin layer of bonding putty on the part. apply vacuum and voila.