cleaning castings in an acid bath

[Ozzie Seadoo]

Hi all,

I have just pulled apart my engine. The outside is corroded and needs to be cleaned up. I was going to use a steel brush and then briefly place each casting in an acid bath to get the corroded metal back to its original finish so that it can be repainted. Has anyone ever done this ( i am thinking of using Ammonium Persulphate whivh is used to burn printed circuit boards). The inside of the engine doesn't need machining and i am also thinking that an acid bath will not be a good idea for nicely machined surfaces???

Thanks.

[Technical Support]

Re: cleaning castings in an acid bath

There is never a need for such harsh treatment. A simply sandblasting takes care of paint.

[Ozzie Seadoo]

Re: cleaning castings in an acid bath

The paint is practically falling of-does sand blasting get rid of corrosion and restore the metal to its naturnal finish?

Thanks for your help:D

[Technical Support]

Re: cleaning castings in an acid bath

Yes.

[Ozzie Seadoo]

Re: cleaning castings in an acid bath

Thanks kindly for your help:emoticont

[chumbiwumba]

Re: cleaning castings in an acid bath

Sand blasting will work but is very agressive in its removal of material. I prefer glass bead blasting. It will rip right through paint and soft corrosion and will polish the metal.

Some castings on jet ski's are made of Pot metal which is a generic phrase for alloys of Zinc, Tin, Copper, Lead and Bismuth. Its basically a hard solder but can be eaten away very quickly by agressive sand blasting (learned from personal experience).

Harbor Freight sells the glass beads for $20 a jug (3 gallons). They sell the gon for another $20 and the bench top booth is $80 to $100. You can tell I hang out at Harbor Freight alot.

[Ozzie Seadoo]

Re: cleaning castings in an acid bath

Thanks for that, i will have a look around for someone that can do some glass bead blasting-much appreciated :emoticonc

[Ozzie Seadoo]

Re: cleaning castings in an acid bath

When cleaning the castings using Glass Bead Blasting, should i use some MDF or particle board to protect the insides of the engine, inside of cylinders, etc?

I don't need to get anything machined as the inside is in perfect condition-absolutely no scratching, etc.

Thanks.:)