Polyurea

Hello, does anybody know something about Polyurea coating on the outside of a steel ship hull?
For example:
How many years does a polyurea coating last? Any live examples? (I was hoping 20 years?).
Costs?
How to repair it?
Is is a good idea at all?
Does ultrasound still work - does it measure through the coating?
How thick is the coating and is it only one layer
Does it work like antifowling? or how to maintain it / clean it?
Is it still necessary with anoten?
Does it give stability to the hull?

I would be very happy to hear about your knowledge and experiences!

 

Hi Lisbeth!
I don't think you find many answers . Those polymers are incredible and I plan to test polyurea coating at the hull . I saw really wired test of polyurea : one guy throwing hand grenades on car covered by polyurea.Results was surprizing.
https://www.ripublication.com/ijaer10/ijaerv10n1_90.pdf

 

Thanks for your reply. Yes, we really want to do it as well because it sounds as a very durable coating for the hull, just mainly the part under water. But I wonder that noone has experience? Is it maybe too new?

 

Do you have specific product in mind ? It will be only layer of protection ?
I think surface preparation and application condition will be most critical.

 

It's not new, it's just that some of these products, as good as they are, don't always catch on easily in certain markets. While it is used in some composite applications, over steel may be a bit tricky due to required application methods and processes. What can easily be done on a small surface may not scale up easily to do a large steel hull and provide a reliable barrier.

 

It seems to be used over concrete fairly often. Is it too brittle for steel? I wonder if the deflection of the hull would make the paint delaminate.

 

Yes - I wonder too. If it is on a 20 meter steel hull I would not like to see it delaminate!

 

You can always use some kind of primer.

 

Polyurea & Marine Grade Products - Specguard Coating Systems https://www.specguard.us.com/polyurea-marine-grade-products/

 

Polyurea coating: Hvad er det, og hvor kan det bruges? https://danskpolyureateknik.dk/b/polyurea-coating-hvad-er-det-og-hvor-kan-det-bruges


Powłoki (izolacje) polimocznikowe, zabezpieczenia antykorozyjne. Membrany, izolacje, hydroizolacje ochronne - Compensus http://compensus.pl/powloki-polimocznikowe/

 

Primer won't help if the coating is too brittle. Further, urea is supposed to have better adhesion than any primer.

 

Yes, a primer is a completely different idea.Polyurea it's strechy and hard . First link at this thread is locked now but those India guys demonstrate flexibility.
From what they write, these are mixtures designed for steel structures. They specify roughness grades and application ranges. The costs aren't low, but this stuff is amazing.

 

It can't be both.

 

It is. I have more ideas how to use it .Some experiments are needed and knowledge how to omit expensive equipment.
Hardness Shore A30-D80.

 

You keep on making conflicting claims. Shore A30 is very different than D80. In fact, so different that are in different scales. Do you simply make up data? There is no need for experiments, the data is available from the manufacturer.