Dear members;

I was wondering if anyone has been involved in any project of TSC of a ship or similar vessels? I am trying to estimate the performance of TSM esp. Zn and Al in marine applications. Although I have experience in TSC of bridges, polygon towers and similar structural steel this is a completely new area for me. I would be grateful even if you can provide some guidelines.

How can I access data related to friction and impact resistance of thermal sprayed Al and Zinc?

I need this data to compare performance of TS aluminum and zinc on coating of ship decks(friction resistance), impact and wear resistance to estimate the performance of the coating on boardside and hull, resistance against the drift on course(cruise).

Any information or reference related to these properties would be highly appreciated.

Thank you inadvance

Ü.Başak GÜLEKEN
Metalugical Engineer

I'm not aware of any hard data on the friction and impact resistance.

I can say from experience that the majority of ship hulls that are metal sprayed are sprayed with aluminium. If you arc spray, you will generally acheive a higher bond strength than with flame spray.

This is not a scientific test but I suggest you find some TSC coatings and hit them as hard as you can with a large ball ended hammer. There is unlikely to be significant damage as the coatings are very durable and have some ductility so you do not get 'chipping' of the coating. On a slightly more scientific note, you could run a metal sprayed sample through a paint impact test rig and check out the results.

You can spray rough coatings if desired for friction surfaces or smoother coatings if desired. Tyically, a TSC coating would have a similar roughness to 120 grit sandpaper (I could start quoting Ra figures etc but we all know what sandpaper feels like). However, coatings in the marine environment are nearly always sealed and/or painted and/or have anti-fouling applied over the top so I would not think that drag would be much of an issue in the finished boat.

Hi basakglkn

Can't add much more than Stuart above. If you haven't seen this thread, it might be worth a look anti-slip-coating

Arc spray is good for achieving different roughness profiles. As Stuart said the hull may be coated with anti-fouling coating which will smooth out texture. Else where coating texture can be controlled by arc spray parameters (atomising air pressure, air caps etc.)

Thanks for the information.

These answers support my assumptions.

But here is another question: Why Metallize if you are going to use an antifouling over it I know that Zn has similar properties like an antifouling paint, zebra mussles can not survive on Zn metallized concrete e.g. dam gates.. but all the examles I have come accros about ship hulls are either inonel(for wear resistance i assume) or Al with 2-3 layers of epoxy on top. Why is this than

R.S.: I have checked thetread about anti-slip already. It is also valuable info

Sorry - not an expert on anti-fouling but I believe that the two coatings are designed to do different things.

The aluminium is a corrosion protection coating. It is normally sealed with a thin (by thin, I mean runny, not thick) sealer to prevent ingress of water through the porosity that is inherant in metal spray coatings. The sealer coat needs to penetrate the porosity and does not need to have a dry film thickness. The 2-3 top coats are normally for decoration as people don't want to have a grey/white alumium boat.

The anti-fouling coat is then put on as just that and has no corrosion protection properties.