The ultimate antifoul?

[domlee]

How about this for a pub argument? I was reading about a procedure for 'hot metal spraying' a crankshaft to build up wear marks, then the crankshaft was reground to the original profile etc. What about 'hot metal spraying' a hull with liquid copper to a thickness of 1 or 2 mm? All you would need would be the heat source, a big compressor and the copper (copper is very cheap at the moment). The initial layer would fuse with the GRP of the hull (possibly with a thermo-reacting epoxy/plastic layer to aid ahhesion of initial copper layer) The copper coat would last for at least 30 years, no problem- no recoating and no lift outs! I think the idea has merits, any thoughts?

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[claudio]

I think the melting point of copper may be a little higher than the combustion point of GRP /forums/images/icons/smile.gif

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[BrendanS]

I think the existing products to put copper layer with self adhesive film probably more practical on most grp boats.

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[domlee]

Yes, I was thinking along the same lines which is why I suggested a 'Thermo reactive' layer. (This must be a chemist's dream). The thermo reactive layer would have three functions - it could - at the same time- bond to the GRP, insulate the hull from the heat of the melted copper and finally provide a suitable surface on which the copper could bond...

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[domlee]

I looked at this technology and thought it was both very good and convoluted. It was very labour intensive and therefore high cost. If a repaint job of a hull were to be accomplished using the methods of bonding paint to a hull by using an adhesive ( which I understand is the chemical process of paint adherance anyway) by using thin strips of paint, covering a small area at a time then the cost of repainting the hull would far outweigh the cost of the procedure. I am simply suggesting using technology from other areas of industry in an alternative application. The fiscal rewards would be immense - for the developer, the applicator (DIY using hired equipment) and the end user.

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[BrendanS]

If you can get it to work, I agree, great stuff.

Problematic though. Spraying liquid metal is not an easy task.

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[domlee]

The melting point of copper is higher than grp but the point of contact between the two materials can be controlled e.g. the temperature of the GRP or the insulating layer between the liquid metal ( which I understand to be a fine mist ). The disipation of heat could be easily controled.

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[supermalc]

I still have little experience of boats, antifoul etc. However if a GRP boat covered with a copper skin is the solution, how about building a thin copper boat, then reinforcing with GRP on the inside. A mould could be metal sprayed with copper far easier, than a GRP hull I would have thought.

<hr width=100% size=1>Malcolm. Just trying to be helpful.

 

[charles_reed]

When I first bought my boat

it had something very similar. Scott Bader "Copperclad" a gel coat heavily impregnated with metallic copper granules.

The theory was fine, every so often you abraded the surface with wet&dry to restore the uncombined copper and keep the surface nice and smooth.

In practice I found the biannual rubdown excessively tedious, the antifouling effect inadequate and thankfully returned to abrading antifoulings (admittedly TBT).

As a result of these experiences I view with some scepticism the claims made for various "copper-rich" antifoulings and despite re-assurances by those who should know (because they sell them), certain communications in this and other BBs suggest I might be right in my attitude. In fairness these complaints appear to have had more to do with commercial practices than product performance.

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[charles_reed]

Technical problem

Melting point of most Cu alloys around 900C, flash point of polyester about 375C.

Always the problem with non-engineers, they miss the obvious.

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[charles_reed]

If you could

work out how to do it you'd be £ss in.

525C difference?

Fusion energy made simple.

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[charles_reed]

Keep at it

you may be about to make the technological breakthrough which several research teams have been working at for about the last 20 years.

I'm sure you'd at least deserve an hon DSc from one of the more prestigious universities, if not a Nobel prize.

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[Talbot]

IIRC, wooden warships were copper clad for two reasons. The most important was to stop the terredo worm boring into the hull and eventually sinking the ship. The side benefit was that the copper "delayed" the fouling of the hull. It did not prevent it completely as ships still had to careen every so often. This practice finished when wooden walls gave way to metal. Copper and iron/steel not being the best of partners underwater! /forums/images/icons/smile.gif Thus the introduction of paint based antifoulings.

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[Talbot]

IIRC, wooden warships were copper clad for two reasons. The most important was to stop the terredo worm boring into the hull and eventually sinking the ship. The side benefit was that the copper "delayed" the fouling of the hull. It did not prevent it completely as ships still had to careen every so often. This practice finished when wooden walls gave way to metal. Copper and iron/steel not being the best of partners underwater! /forums/images/icons/smile.gif Thus the introduction of paint based antifoulings.

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[mickshep]

When I bought my first proper boat she was painted with a very dark brown antifouling, wish I knew what it was because even after some 10 years on the hard there was no fouling at all

<hr width=100% size=1>"Just because I'm paranoid doesn't mean they're not out to get me."

 

[Talbot]

Bet it was a commercial grade designed for ships with all the bits in it that we non-commercial types are not allowed to use cause of the impact on the environment. /forums/images/icons/smile.gif

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[starboard]

Many forms of copper treatment exist today under various trade names. They mainly consist of copper particles mixed into an epoxy coating system. This is then applied as you would an epoxy coating and hey presto. I have seen boats with this at my own marina and it seems to work well. I understand every season you give a lite rub down with abrasive to expose more copper for the coming season. I believe the manufactures talk of a 30 year life with the benefit also of an epoxy coating!

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[ships_parrot]

Re: Technical problem

In actual fact it is possible for liquids to enter a 'supercooled' state where they drop below their melting point , but remain liquid, if the environment is clean enough. It happens a lot in clouds, which is why aircraft have anti-icing (bleeds off the compressor in the case of many with jet engines) stuff.
It's concievable that you might be able to do this with copper, though I don't know if you could in practice.

Also, there's no need to be mean to us non engineers...

For what it's worth I'll be using low tech antifoul this year..


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[tcm]

Re: Technical problem

oh bugger! I was looking forward to the photos of expensively torching a boat in the name of advancing the frontiers of science!

Are you sure you're an engineer? Surely, if you are, you won't pass up the chance of a fun experiment to prove you're right?



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[BrendanS]

Apart from the copper impregnated coating systems, there are also copper foil solutions which you stick to the hull.

Both foil and coating systems typically claim 10 to 15 year life expectancy. If anyone is claiming 30 years, then they are not typical.

<hr width=100% size=1>There is no such thing as "fun for the whole family."