Recent content by coreng

My mistake : I missed the word "anode" !!!

Hard to say without zoomed pics. What do you mean by eroding "normally" ? Because from the corrosionist point of view, normally is nil.

Oceoprotec is now supported by Mader. http://www.mader-group.com/UK/

Anode or not anode? Anodes are not a guess and intended to deliver only needed quantity of protective current. No more (over-protection), no less (under-protection). Quantity of current, depending on nature of protected equipments, are well known now and depends upon several factors... If your...

Why should it be a problem? Anodes depletion occurs only if there is a demand for protective current. Only a potential measurement of protected metals will tell you if your system is safe and everything OK with it. Otherwise, it's just a guess. And this is a strong recommendation issued by main...

Corrosion of propeller due to electrolysis is due to an outgoing electric current that can easily be checked through potential measurement vs Ag/AgCl electrode. This will tell also efficiency of anodes. Shift in various configurations measurements will indicate a stray current. Though not common...

Rotting of wood is effectively due to overprotection. Cathodic protection guidelines should be closely followed, in particular, electro-chemical potential of protected items should be kept closely within wood hulls usual protective limits (much higher and tighter than steel).

Best naval practice to surely appreciate anode's efficiency/consumption and identify harmful stray currents (these go out an attacked immersed metal right into the water) remains equipment 's electro-chemical potential measurement through dedicated electrode. Corrosion might occurs if value are...

I know it's far from England but, even if it's a small concern and only the beginning : "Some EU authorities have raised concern over copper compounds used in antifouling paints used in pleasure craft, leading to restrictions and/or bans of copper-based anti-fouling paints in Sweden and the...

Of course anodes are useless out of water. Though it is not unusual to bolt anodes with stainless, on aluminium, you should better use (cheaper!) galvanized mild steel bolts. I don't know for Duralac but a paste like Tef-Gel is not an electrical isolator : it just prevents formation of a...

Of course anodisation will be lost. Why not consider re-anodising? It is quite inexpensive especially if you can't paint. Should you do so, marine work needs AA25 british standard grade.

Due to probable ban of copper based antifoulings in the next years, several experimentations have been conducted on big ships, especially within US Navy. You will find a commercial/technical notice for recreationnal boats from Hempel here ...

And as a matter of fact, no manufacturer developped a different seal technonology. Guess why...

The job of an anode is to lower the potential of the protected metals by delivering a very small quantity of current (about 20 mA/m²) during a scheduled period of time. So far, amps and volts are linked by Ohm's law. Current recommended naval practice is then to measure potential of immersed...

A common cause for crazing defect of marine paints is a high film thickness. Remedy is then a thinner coat of paint, a slower drying solvent and attention paid to the drying conditions.