T90 Case Rusted, Best Removal Method

Gents, I ordered NOS t90 case from Walcks, and its covered in rust. Whats the best steps for removal?
Bucket of diesel and scrub, vinegar, or what?
Thanks,
JT

 

sandblaster?

 

Really just depends on how bad the rust is and what kind of resources you have available. Put up a pic so we can see what you're talking about. Do you have a tank large enough to submerge the whole thing (or half of it)?

 

Its really just surface rust, but its inside and out.

 

Yes, I have a bucket i can submerge it in. It seems like I could use toilet bowl cleaner and water, but I might be dreaming that.

 

If it's just on the surface I would consider brushing on a coating on naval jelly, rinsing it off, and calling it good. Cast iron is very porous so most acidic solutions will seep in and cause problems. If you have the materials to go with electrolysis, that would also work. I don't have much experience with it, but evaporust could be an option.

 

"The Works" toilet bowl cleaner works great. I have used it to clean out rusty gas tanks and they came our clean shiny metal.

Put it into one of those plastic storage container tubs. Pour in a couple bottles of "The Works" and fill it up with enough water to cover it. Let is soak and slosh it around a bit every hour or so. After 3 - 4 hours dump it and rinse it very well with water. Then blow it off with an air hose, dry it well with some heat, then spray it with oil.

If you are single you can put it in the oven to heat it, if not I recommend a different method.

 

I've had excellent results with evapo rust. Non caustic and reusable.

 

There are rust convertors (Naval Jelly) and rust removers. The usual rust remover is an organic acid, like acetic or oxalic acid. Not sure what the reaction is, but it combines with the iron oxide on the iron surface, making iron acetate or iron oxalate, I presume. I think plain vinegar would take a long time to remove much rust. Old time two-part radiator flush used oxalic acid to dissolve the rust in radiators. These products are gone, but you can buy oxalic acid as "wood bleach" and dissolve it in water. Possible that's the active ingredient in the toilet bowl cleaner suggested above. You could also use a product like CLR which contains other organic acids (lactic acid, apparently targeting calcium scale, and gluconic acid, apparently targeting rust stains).

 

Oxalic acid would be a good choice, I forgot about that one. I would avoid CLR and the toilet cleaner though as they a primarily dilute hydrochloric acid and will be more reactive with the base metal.

 

The radiator flush cans were a top half of oxalic acid for the flush, and bottom half of sodium carbonate to neutralize the acid. If you go with some kind of acid, neutralization would be a prudent step. Sodium carbonate is available cheaply as "washing soda" - look at the hardware store. It's an old time laundry additive. Its detergent properties probably benefit the radiator flushing process. Bicarbonate (baking soda) might be ok too, but it was not what they provided with the radiator flush.

 

If I use "the works," do i need to neutralize it with anything other than water?

 

Yes, being as it is essentially hydrochloric acid with disinfectants. Washing soda (as mentioned by timgr) is probably the safest and easiest route. Baking soda does work as well, just takes a decent amount of it. The only one you wouldn't have to worry about neutralizing would be along the lines of evaporust, which is a chelating agent as opposed to a typical acid.

 

Washing soda and a battery charger also known as electrolysis. Removes rust to clean metal does not damage anything else. All that’s needed is a peace of sacrificial metal, battery charger and a piece of wire to suspend the case in a 5 gallon bucket. Works great even on heavy rust!

 

You paid for a NOS case that you would assume to be rust free. Send it back and make them deal with sending you one that is what you ordered. I can send you an old on for the price of shipping, but you want a NOS one. This is nonsense.

 

I respect Chris's opinion, but I think his prescription here overstates the situation. NOS is new, but does not say perfectly preserved to me. Of course the condition of the parts will depend on how and where it was stored between when it was new and now. The buyer has some responsibility here. If the buyer (the OP) did not ask or specify the condition, then it just needs to be actual NOS. No question there. Surface rust won't change the utility of the part. If you want to make an issue of this, I expect Walck's will take the part back. However, I believe some (not excessive) surface rust won't affect the utility of the part, though it may offend your aesthetic sense.