Not the kind of problems you're probably thinking of.  I'm going for a rust finish on a project for a friend.  Living in Michigan, I've left it outside in the damp for several weeks.  A good start, but some areas aren't rusting.  I poled around on here and found a concoction of H2O2, salt and vinegar which sped the process along, but not fast enough in certain areas.  The areas that aren't rusting (tips of the horseshoes shown below) were parts of the horseshoe that were stamped with the brand name - I used torch welding rod (sorry don't have the brand or composition right now) to build up these areas.  I suspect that's the issue.  Any tips?

 

 

Try this. 

Wipe the whole sculpture with a rag.  After that, wash it detergent water to remove any oil or grease on its surface.. Then dry it. Now spot the non-rusted portions with undiluted vinegar. (its 5%, out of the bottle), Leave the salt and peroxide out of it.  Keep an eye on it while doing so. (it will rust quickly). When the rust is uniform you can darken the whole sculpture in a vinegar bath, if you wish to increase the rusting. If the reaction is slow warm the vinegar up, and then use it.

Vinegar is cheap and most super-markets sell it.

SLAG.

rod is probably the culprit, welded areas are usually happy to rust!  Can you find out what alloy it was?

 If you read up on an electrolysis tank, all you have to do is hook it up backwards. + or positive or red to rust...Find some rusty scrap to clean and use the project for the sacrificial electrode. You can move the rust from one part to another. Been there done that. Or I have had good luck with paint remover (zip strip)also.  And please don't take this as argumentative, but I thought you could use vinegar to de-rust...I've got some experimenting to do...               Dave 

You can: total immersion in vinegar derusts, surface application rusts due to the O2 being available 

 Thanks Thomas, makes sense now...still learning so that's a good thing....                        Dave 

Friends of mine who pretty much have a rust finish on all their work use brick cleaner to make things rust quickly. In hours in some cases.

What is the chemical ingredient list on the "brick cleaner" package. I suspect that it is hydrochloric acid. (= muriatic acod).

I am really curious.

Thanks in advance,

SLAG.

If you're electrolysis rusting pieces you can use a paint brush with the + clipped to it and paint rust where you want it. The same trick with the brush - and citrusclean will electro polish Stainless.

It's fun with electricity so be careful and use LOW amperage, PLEASE!

Frosty The Lucky.

Frosty, I assume you mean low voltage - or am I missing something here.

I am tryimg to squeeze in a lab-unit in my budget. They suppy a voltage between zero and 30V (which should be safe) and amperages between 0 and 3A.

There is a site somewhere that goes into detail and gives figures for mA/square inch etc.

Seems like most folks I know  use an auto battery charger as their power source as they are cheap and easy to find.

1 hour ago, ThomasPowers said:

Seems like most folks I know  use an auto battery charger as their power source as they are cheap and easy to find.

I use one for electrolytic etching, but I've been meaning to try it for rust.

 

Battery chargers work fine.  Just make sure it's the manual type.  The automatic chargers try to sense a battery-to-be-charged and don't play well with electrolysis.