Brick cleaner on out-drives?

[alt]

I use brick cleaner to clean crud off my stainless props and they come up amazing. No scrubbing, just rub with a paint brush and everything disappears (growth).

But what about the aluminium out-drive / transom shield?

It comes in a plastic bottle so I imagine it wouldn't fizzle away the aluminium, but thought i'd ask here before I even think about it.

 

[[2068]]

Brick cleaner will do a fantastic job of dissolving your outdrive for you.

 

[alt]

To be fair don't think it was brick cleaner that did that

But if the consensus is that it'll do damage i'll steer well clear... out with the scrubbing pad it is

 

[Nick_H]

This may answer your question

Hydrochloric Acid Reacting With Aluminum - https://www.youtube.com/watch?v=LaaORZ0ofCY

 

[maby]

Be very careful with any cleaning product on aluminium unless it is specifically designedfor that purpose - it is a very reactive metal once you get through the very thin layer of surface oxide!

 

[alt]

This may answer your question

Hydrochloric Acid Reacting With Aluminum - https://www.youtube.com/watch?v=LaaORZ0ofCY

CHRIST!
Thank you for that, so glad I asked.

The answer is 'NO' then

 

[maby]

CHRIST!
Thank you for that, so glad I asked.

The answer is 'NO' then

Might be worth looking in Halfords at alloy wheel cleaners - they are primarily aluminium and a specialist cleaner used according to the instructions should be safe.

 

[[2068]]

CHRIST!
The answer is 'NO' then

A bit of white vinegar and a green plastic pan scourer works for me.
Softens up the barnacles, and the outdrive keeps it's original shape.

 

[alt]

I'm actually on fresh water so only slime but there are still little crustations on the inner side of the shield from years ago when she was on salt water for a year. I refuse to powerhose in there hence why they're still there

 

[alt]

A bit of white vinegar and a green plastic pan scourer works for me.
Softens up the barnacles, and the outdrive keeps it's original shape.

Thanks. I'm on phone so accidentally deleted my other post. I will follow this advice

 

[A_8]

As long as you dont have any open metal surfaces you should be fine, the paint etc will keep the acid of the metal.

 

[alt]

As long as you dont have any open metal surfaces you should be fine, the paint etc will keep the acid of the metal.

The paint is all good, but i'm not going to tempt fate. I am not in a rush so happy to spray vinegar on it over the coming week.

 

[maby]

The thing to remember with any cleaner used on aluminium is to control the duration of the exposure and make sure it is fully washed off after use. In that rather spectacular video that was posted above, the aluminium foil was in the acid for quite a long time before the violent reaction started. The metal is normally covered with a very thin layer of oxide which is very unreactive and which protects the metal underneath it. Aluminium is a highly reactive metal and even something quite mild like vinegar will attack it once the oxide layer is breached. The alloy wheel cleaners that you get from shops like Halfords are quite acidic and come with strong warnings to leave in contact with the metal for a defined period of time, then rinse off very thoroughly afterwards.

 

[Momac]

I used Bar Keepers friend Power spray - which has oxalic acid in it.
It helped soften and clean hard limescale off the outdrive and trim tabs . Still needed some physical effort but perhaps that's not a bad thing.

 

[A_8]

The paint is all good, but i'm not going to tempt fate. I am not in a rush so happy to spray vinegar on it over the coming week.

You will notice if it starts eating the metal and if so rinse it off, not much worse then having it exposed to saltwater for a bit longer.

 

[alt]

You will notice if it starts eating the metal and if so rinse it off, not much worse then having it exposed to saltwater for a bit longer.

Understood. I think i'm still going to err on the side of caution though... i'll try vinegar first (the out-drive is painted and bit of antifoul still on it) and see how I get on with that.

Has anyone actually used brick cleaner on their out-drive? Any first hand experience?

 

[GrahamHR]

I've used hydrochloric acid to clean my outdrives/ props even when there's some paint damage, for 16 years; I dilute 35% stuff down to around 8-9%. Alloy wheel cleaners are also around the same concentration with a token level of detergent. Just rinse it off when it's done it's job.

The word "acid" seems to cause some sort of collective hysteria here without taking concentration into account. The video is aluminium foil ( =thin, soon consumed once the protective oxide layer is gone) in 25% hydrochloric acid. Brick cleaner is around 8-10%..

Quiz for the scaremongers, dig out your old chemistry books;

How much hydrogen chloride ( the active part of hydrochloric acid) would be required to dissolve a complete outdrive casing, weighing, what, around 15kg ?

How much to consume 1mm of such a complete outdrive casing?

Clue; quite a lot !

 

[gjgm]

If you have antifouling on the drives then just scrubbing with a kitchen scourer alone should be enough to remove most things as you will remove much of the antifouling too..and hence the slime.
Barnacles might need some scraping with a suitable decorating scraper. I don't think you need to use any chemicals to get back to a good base for next antifouling.
If power washing hasn't removed most of the barnacles then cautious use of a power chisel will get rid of them!