Hi all.

At some point a car coolant received a dosage of some aluminium powder 'supposed' to do some good.

 

Which way would you suggest to backwash the radiator in order to remove any obstruction caused by such powder ?

 

Would detergent, or borax, a solvent, or gasoline or something else work better without harming the aluminium cored radiator which is healthy but assumed semiobstructed ?

So, you have aluminum powder inside an aluminum radiator?

Get a mild acid and wash it through a couple of times. Vinegar, extremely dilute HCl or H2SO4, etc. These will release gases, which might make pressure an issue (feel free to correct me, because I am absolutely clueless about what goes on inside a car). You want it to be strong enough to dissolve the powder, but not enough to start eating your radiator (which is semi-protected by an oxide layer of aluminum anyway).

The aluminium radiator is protected by its oxide layer as well. Unless the alloy resists corrosion better than the powder - you'd need to know which alloy both are... - any acid would corrode both, at (very) different speeds which are impossible to predict.

 

The necessary amount of strong acid is BIG. It's amazing how much concentrated acid it takes to dissolve a bit of aluminium. I did it previously with FeCl3 (50kg for <1kg) which acts faster than a normal acid and had to complete it with much additional HCl.

 

Other liquids like gasoline or detergents will help strictly nothing.

 

Well, I believe you have to open the circuit and clean it mechanically...

Thanks, gentlemen.

 

The intention was a chemical to promote dislodging, not dissolving the stuck aluminium dust inside as it would risk the core material too...

 

Well, will try some miscellaneous household mild products and simultaneously attach some mechanical vibration during backwash, as there is no access to mechanical cleaning.

If there is a "Do not use such !!" opinion, let me know.

 

Otherwise, I will end at the radiator store for a new one.

Many solvents and tensides are bad for seal joints.