Rustaway or OSPHO to treat rust

[rommar]

I have a problem with heavy rust parts on a barge and there was wandering which product i may be using to treat rust : rustaway or ospho. Anyone in this field have experience with these product please advice.

R

 

[berkshire]

Both of these are materials that contain Phosphoric acid, they work by converting the rust into iron phosphate.
You are better off if you remove most of the loose rust on your barge, before you use Phosphoric acid, that way you will not, have a problem with unreacted rust flaking off after you have completed your paint job.
Do not forget that the iron phosphate coating is water soluble and must be painted over.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[rommar]

Thanks BE so I can use both of these products. Our planning is to sandblast all paint and rust , do a MPI test and thisckness test and treated with either ospho or rustaway. Is this correct?
What are the standards for marine coating in salt environment ?

Please advice.

 

[TomDOT]

Depends how long you want it to last. My standard for cleaning is SSPC SP-10 or SP-5 and a good coating system, none of this rust treatment stuff.

 

[berkshire]

If this is for a marine environment, you will be better off, sand blasting to white or grey, then using a clear penetrating epoxy, folllowed by an epoxy mid coat, then an epoxy or urethane top coat of your choice.
I have cast iron keels painted this way that are still good after 17 years.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor