I purchased a boat from a dealer that rents cats at the beach, and to protect the hulls, the dealer put a protective material on the bottom of the hulls. I would like to take it off.

It is medium dark grey, and hard as rock. Any ideas as to what this stuff is? and any ideas on how to safely remove it?

Thanks!

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Ted
Hobie 16
South Carolina Lake sailing
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It might be epoxy and aluminum powder.There could be Kevlar fabric on there. Epoxy will soften with heat. Get a variable temperature heat gun and a putty knife. Start at a low temperature. I've done this to an H14 without trashing the original gel coat. Don't get impatient with the heat!
You'll end up with hulls in need of refinishing. Is the current surface that ugly? You're in for a lot of sanding one way or another. Will the current surface not sand out? I take it the dealer doesn't know what's on there. Keep us posted, GH

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'82 Super Cat 15
Hull #315
Virginia
Previously owned: '70 H14, '79 H16, '68 Sailmaster 26, '85 H14T
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I think I would have asked the dealer about it before buying the boat....

Spray on truck bed liner?
Grey Marine Tex?

You could try hitting it with a sanding disc or belt grinder and see if it comes off. Or you might just be better off leaving it alone. If it isn't slowing the boat down much, it might be worth keeping there.

sm



Edited by Dogboy on Jan 04, 2016 - 01:09 PM.

Definitely ask the dealer what it is, so you can make an informed decision about what to do with it.
It could be a dozen different things.

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Sheet In!
Bob
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Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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I spoke to the dealer (Ocean Motion) and they stated it is Iron-crete from Mantek.

http://www.mantek.com/pro…+States&pName=IRON-CRETE

They also stated it might chip off. They have had some of this stuff fall off.

I suppose I need to be prepared to restore the bottom finish when I get this stuff removed.

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Ted
Hobie 16
South Carolina Lake sailing
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yelkenli1

I spoke to the dealer (Ocean Motion) and they stated it is Iron-crete from Mantek.

That sounds like a lot of work to remove, and no telling what you find underneath.

How much of it is there?

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Damon Linkous
1992 Hobie 18
Memphis, TN

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It runs the length of the portion of the hull that typically sits on the beach, to protect against damage from dragging on the beach - a long length. I can sand it down some, and smooth it out if not remove it completely. I will probably have to do this next winter when I have a garage. Or I could buy an F16.

Here is a reply to an inquiry to Mantek:

Quote

Iron Crete is an epoxy which is identical (exept for color) to the epoxy resin which is mixed with glass fibers to form fiberglass.

Any chemical that will remove our product would damage the fiberglass, and a temperture high enough to soften it would also damage the resins in the fiberglass.

Sanding or grinding are your only good options. The product can be sanded or ground when fully cured.

Edited by yelkenli1 on Jan 06, 2016 - 07:55 PM.

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Ted
Hobie 16
South Carolina Lake sailing
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Quote

Sanding or grinding are your only good options. The product can be sanded or ground when fully cured.

40 grit is your friend

I would use a side grinder with a 60 grit flapwheel to start.

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Greenville SC

Offering sails and other go fast parts for A-class catamarans
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The obvious solution is to buy an F16! We've got a decent fleet of them where you race Ted.

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Mac
Midlands South Carolina
AHPC Viper USA 366
A Cat USA 366
Super Cat 17
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Removing the cured resin (aka concrete) is not really necessary, another solution is to add MORE filler on both sides and fair in a new profile for the bottom. Wet sanding will yield a nice fast profile that is also a great protective "bottom job." "Fairing in" is much easier and less damaging than removal in many cases.

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'life is too short to drink cheap beer'
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Photos?

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--