Aiuto elettrolisi!!!

[xrasex]

Ragazzi aiuto sulle portiere del mio ninety stanno apparendo delle fioriture dovute all'elettrolisi, ho provato a scrostare la vernice, e sotto ho trovato polvere bianca. Come posso fare? esiste un prodotto? non posso smontare mezza macchina per isolare i metalli! Help me please!

[philip]

ehh..quando è gia' in stato avanzato...piu' che carteggiare,dare un nuovo fondo e vernice. se non vuoi smontare niente, magari,( per quel che costa), spruzzi nelle fughe tra telaietto porte e lamiere alu un po' di prodotto ceroso, ev. prima converti ruggine se c'è gia' ruggine...e cosi' tiri la'. Ciao Philip

[philip]

Se ti arrangi un po' con l'inglese ho trovato questa pagina interessante..... le uniche soluzioni le vedi sotto ""Prevention or Remedial Actions"": Galvanic corrosion can occur when dissimilar metals are electrically connected in the presence of an electrolyte (i.e. conductive solution, e.g. salted water). Galvanic attack can be uniform in nature or localised at the junction between the alloys depending on service conditions. In such a process, one of the metals acts as cathode where oxygen is reduced and the second metal acts as anode that suffers corrosion (oxidation). To predict the risk of corrosion and determine which metal will corrode in a given electrolyte, metals/alloys are classified following the corrosion potential (natural potential) they develop in contact with this electrolyte. The following table gives those potentials for some typical alloys/metals in contact with aerated seawater. Dissolution potentials in aerated sea water at 25°C Alloys E corr(mV % SCE*) Graphite + 200 Stainless Steel - 100 Brass and copper - 350 Low-alloy steel - 600 Low-alloy steel and cast iron - 600 Aluminium alloys - 750 Zinc - 1000 Magnesium - 1600 * Saturated Calomel Electrode This metal classification stays valid for many types of solutions. As a consequence, aluminium will corrode when contacted with stainless or normal steel (commonly used in road transport), or copper (sometimes). On contrary, aluminium will be protected in contact with zinc that corrodes preferentially. In most cases (except in frequent contact with chloride solutions), the combination "aluminium/steel" only generates a detrimental effect on the aesthetic appearance of the aluminium structure but not on the mechanical properties of the assembly. Indeed, aluminium corrosion in contact with common steel is very slow. This is why connections with steel chassis are usually made using steel fasteners. Without suitable precautions, the combination "aluminium/stainless steel" should be avoided taking into account the big difference of corrosion potential of both metals. However, aluminium alloy components are often assembled using stainless steel bolts. It is than important to remember that stainless steels have surfaces that can be passivated and this inhibits or eliminates galvanic corrosion. In case of frequent immersion or wetting (e.g. inside tanks), aluminium and other metals should be isolated from one another to prevent aluminium corrosion (elastomer gasket or special coating). Possible origins of galvanic corrosion: 1. Steel bolts or rivets on aluminium plates 2. Aluminium body (tipper or tank) on a steel chassis 3. Stainless steel bolts or rivets on aluminium plates 4. Aluminium body (tipper or tank) on a stainless steel chassis 5. Bolted assembly inside a tank used to carry aqueous solutions 6. Multi-aluminium-alloy components (condenser, radiators, coolers, welded or brazed assembly) Possible effects near the bimetallic contacts 1 & 2 Less aesthetical appearance (white precipitate of aluminium oxide) 3 to 6 Significant decrease of the thickness of aluminium components Prevention or Remedial Actions 1 to 5 Insulate dissimilar materials (see figure) 3 & 4 Use stainless steel with passivated surfaces 5. Use special coating 6. Good corrosion design (choice of right combination of aluminium alloys) Attention: if the insulation is not properly done, galvanic corrosion will often be combined with crevice corrosion. Ciao Philip

[xrasex]

grazie mille! mi sa che dovro' mettermi al lavoro a cercare dove si innesca,il fot....o processo e isolare il tutto.

[baldazar]

Ciao XRASEX se usi la funzione cerca e vai su carrozzeria e digiti ruggine ti apparira una discussione di poco tempo fa,con qualche indicazione per il tuo caso............. a presto ...........

[xrasex]

Grazie Baldazar vado subito!