Ice grinding.

[sigurd]

I drove through a cm ice in my 20' glass/foam cat. It lifted the boat so I almost thought I was going to drive on top of it. I wondered if it would grind down the skin if I continued for a long time. What outer skin fiber would stand it longest? Aramid? Carbon? Glass? Would it help to use mostly longitudal fibers?

[sbsboats]

if you are making an icebreaker...I vote for a steel hull!

[sbsboats]

actually I have no idea ....all of those materials will abrade on ice

[DanishBagger]

I vote for steel as well, but other than that, I figure graphite saturated epoxy will do well on top of Aramid.

[nero]

Aluminum or glass powder, or other hard element mixed into epoxy barrier coat. Think of protecting the fibers not exposing them to the friction.

Drink enough vodka and you would avoid the whole situation to begin with. smile

[sigurd]

I don't need an icebreaker, a steel hull would be too heavy.
the boat weighs only 200kg.

nero: do you know about anyone who tried hard powders for that purpose?

[nero]

No. It would stand to reason that the abrasion resistance could be supplied by a coating. The impact resistance probably would call for a plate of steel that would spread the load of the ice impacting the hull.

What motivates one to go to sea in such cold weather. Or are you sailing on a lake?

In the med. nobody seems to worry about ice. smile

[Ike]

I've seen a lot of ice. I would vote for steel. Ice is to a hull what loose gravel is to a car. I can do a lot of damage. And not just to the hull. The prop will take a beating.

[sigurd]

nero, the harbor (Bergen, Norway) is less salt so sometimes, but not often, there is ice. motivation is mostly money and food, going fishing.

I was thinking, my glassfiber pulk has taken me on many trips when I was little, and is still going strong. The coat looks like gelcoat.

My Tornado needs a new primer coat asap (probably not until summer, I need to use it for the time being, and it probably needs to dry out for a while?), I am worried it can suck water into the core. But the outer skin is so thin I am reluctant to grind down the existing paint (not gelcoat I think, under the water line). Anyway it would be the right time to improve the abrasion resistance.

A steel or alu keel strip might be interesting, but bonding it without making water entrances sounds difficult - I think there is foam even in the keel. So I think I will put some carbon rovings or uni there instead. Maybe uni the whole bottom, it is not a huge area. So, carbon will hold longer than aramid you think? I remember a site (epoxy.com), used to have a lot of additives and epoxy stuff, they even had stone and graphite powder, and loose chopped aramid fibers. what do you think of those, as well as glass and alu powder?

[nero]

Just had a flash. What about a rubber coating like the stuff the americans spray in their truck beds? It would absorb the energy from the ice. Is very wear resistant. Two mm of this stuff would also deaden the sound from the ice. It is easy to apply also.

[Ike]

Here's what ice can do.

Sinking liner evacuated off Antarctica BUENOS AIRES, Argentina - A Canadian cruise ship struck submerged ice off Antarctica and began sinking, but all 154 passengers and crew, Americans and Britons among them, took to lifeboats and were plucked to safety by a passing cruise ship.
http://news.yahoo.com/s/ap/20071124/...TC1zdyPmWs0NUE

[DanishBagger]

A rubber coating will be ripped and cut within a day or two. It will only work for sound proofing a bit, as you mention.

Try using a sharp bread knife on some rubber and you get the the picture.

[sigurd]

There ya go; another ship without powder coat down

Like I said; 200kg, no 200 000 ton

a cm more ice I could have slid on top of; must install knife before the motor.

[alaskamokaiman]

Rhino lining is not rubber and it would take the beating, I don't know if they can put it on smooth.

I use my Mokai as an ice breaker here in Alaska , on the rotten ice in the spring it sucks water through the ice and goes over the top. In the fall it will break ice to about 3 inches thick with no hull damage, I hit the ice at WOT.
This boat is made from HDPE. You can see it at mokai.com.
Cheers