DEGREASER AND ALUMINIUM ?

[kingfishercam]

Hi guys and girls , just wondering if anyone can help me. Im wanting to clean up my tinny which has some thick grease and grime on the hull , Is it safe to use degreaser on the aluminium??????????? thanks.cam.

[tareeterror]

It will not hurt it, use degreaser, then just rinse well with fresh water.

[pjbink]

It might help if you could tell us the chemical make up of the degreaser (it might be some sort of caustic). Aluminium is a very reactive metal so I would be careful.

[pjbink]

Further to my last comment aluminium reacts strongly with caustic:

Reaction of aluminium metal and alkali.

Sodium aluminate is also formed by the action of sodium hydroxide on elemental aluminium. The reaction is highly exothermic once established and is accompanied by the rapid evolution of hydrogen gas. The reaction is sometimes written as:

2Al + 2NaOH + 2H2O → 2NaAlO2 + 3H2

however the species produced in solution is likely to contain the [Al(OH)4]− ion or perhaps the [Al(H2O)2(OH)4]−.[5]

This reaction has been proposed as a potential source of fuel for hydrogen powered cars.

[macmac]

Rusting on galvanised steel

Package instruction

Further to my last comment aluminium reacts strongly with caustic:

Reaction of aluminium metal and alkali.

Sodium aluminate is also formed by the action of sodium hydroxide on elemental aluminium. The reaction is highly exothermic once established and is accompanied by the rapid evolution of hydrogen gas. The reaction is sometimes written as:

2Al + 2NaOH + 2H2O → 2NaAlO2 + 3H2

however the species produced in solution is likely to contain the [Al(OH)4]− ion or perhaps the [Al(H2O)2(OH)4]−.[5]

This reaction has been proposed as a potential source of fuel for hydrogen powered cars.

Hi Billfisher,

Sounds like u are as expert as chemist. Can u help me on this galvanic corrosion problem?

Recently, I changed the rubbing strip on my trailer using steel rivets. The rivet grip the rubber abd the galvanised steel component of the trailer. However, within 2 weeks the steel rivets totally corroded but i really carefully selected the right rivet to use as recommended by the package instruction. The brand of rivets is Zenith and bought them from Bunnings. So which rivet ahould i use? Steel, aluminium or stainless?

Pls be noted that I always flush my trailer with tap water after finish my boating session.

Edited November 1, 2011 by macmac

[pjbink]

Rusting on galvanised steel

Package instruction

Hi Billfisher,

Sounds like u are as expert as chemist. Can u help me on this galvanic corrosion problem?

Recently, I changed the rubbing strip on my trailer using steel rivets. The rivet grip the rubber abd the galvanised steel component of the trailer. However, within 2 weeks the steel rivets totally corroded but i really carefully selected the right rivet to use as recommended by the package instruction. The brand of rivets is Zenith and bought them from Bunnings. So which rivet ahould i use? Steel, aluminium or stainless?

Pls be noted that I always flush my trailer with tap water after finish my boating session.

It looks like your steel rivets wouldn't have had much in the way of corrosion protection (ie protective coating). Aluminium won't fare too well in contact with the steel of the trailer (galvanic corrosion). Stainless screws or rivets will last forever but are expensive. Most trailers use galvanised steel screws or rivets for that purpose. These can tend to rust, albeit slowly. You can always give them a spray with lanolin or another rust preventer every now and then.

[macmac]

It looks like your steel rivets wouldn't have had much in the way of corrosion protection (ie protective coating). Aluminium won't fare too well in contact with the steel of the trailer (galvanic corrosion). Stainless screws or rivets will last forever but are expensive. Most trailers use galvanised steel screws or rivets for that purpose. These can tend to rust, albeit slowly. You can always give them a spray with lanolin or another rust preventer every now and then.

Thanx for advice. but as what I know there are no galvanised rivet in the market (actually not sure but definitely not available from Bunnings). If use screw, will there any problem in future by hole widening?

Cheers, Phil

[tareeterror]

A small pack of stainless rivets are under $10, and always handy to have spares at home anyway.

[tuffy]

Purchase aluminium rivets with ally head AND ally shaft - available at Toolfix ( I think) at West Ryde/Ermington, Hope St).

Available in a vast range of sizes and not expensive.

Tuffy