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View Full Version : Metal Passivator source in BC, or at least Canada?



mickeyf
03-23-2012, 03:26 PM
I'm ready to try my luck at Electrolytic rust removal. (http://www.oldengine.org/members/orrin/rustdemo.htm) However, at least some of the parts will not be painted afterwards and need to be left bare. I'm not having any joy finding a source for the suggested passivators (Jasco Metal Prep, Ospho) or anything like them. The local paint stores give me a blank stare.

I know there are at least half a dozen people on this board who are in BC - have any of you tried this and/or know of a source for this stuff? Ideally on Vancouver Island, but at least on this side of the Border? (Although I suspect it couldn't go through the mail even from a Canadian source.)

Thanks!

ecortech
03-23-2012, 03:36 PM
I have purchased Evapo-rust at Canadian tire recently, it was in the automotive section with the body repair items. Any decent automotive store should have a metal prep of some kind. I didn't look in the paint section but Canadian Tire should have something. Home hardware also has Evapo-rust and a number of other products.

Ed

mickeyf
03-23-2012, 03:51 PM
My closest Home Hardware gave me blank stares also, but then I was describing the process rather than offering them a brand name. I'll check Evapo-rust out. Thanks! I don't know this stuff. Did you/have you actually used this product in this way?

Evan
03-23-2012, 09:50 PM
Go to the local greenhouse supplier and buy straight 80% phosphoric acid. About $20 for a litre which will make up about 4 to 5 litres when diluted to working strength. Sometimes sold as "pH-Down".

mickeyf
03-23-2012, 11:20 PM
Thanks Evan, Black_Moons has suggested this. The article I referenced said clearly DON'T try to use straight phosphoric acid, it will do more harm than good. The author says he's tried it and knows what he's talking about. I'm conservative enough to take his advice since I have no experience of my own on this.

I did check out Evapo-rust and several other Canadian tire products, and it appears that they are not really what I'm looking for, but an alternative method of rust removal, rather than a way to stabilize the surface of the metal after the rust has been removed.

My research continues.

wtrueman
03-23-2012, 11:33 PM
Also: try google rust removal forum. The electrolytic process is easy and works great. Flood with plenty of water after and prime early. Good luck, wayne.

LKeithR
03-23-2012, 11:36 PM
Have you tried any of the plating shops in Victoria? We've had stuff cleaned and passivated over here so you might find something in your neck of the woods. Also, places that do SS work will sometimes have chemicals for passivating...

Evan
03-24-2012, 01:29 AM
Phosphoric acid may be used with no additives other than a very small amount of liquid soap (a drop or two). This results in an iron phosphate conversion coating. Before using on the production part the phosphoric acid solution should be "conditioned" by dissolving iron in it. Some steel wool works well. This provides a supply of iron ions to produce the iron phosphate coating without destroying the surface finish of the product. It works just fine. The part must be completely degreased. Then it is treated in the solution which should be warm to promote a rapid reaction. When the part darkens it is removed and rinsed in boiling water. The water need to be low in dissolved minerals, preferably deionized.

This provides a low grade of protection sufficient to prevent flash rusting in a humid atmosphere. It is not sufficient protection to prevent rusting in outdoor use. It provides an excellent paint base.

cameron
03-24-2012, 09:21 AM
Flyte rust remover is phosphoric acid based, and is supposed to leave a zinc phosphate coating. Will provide some protection for indoor use, but IMO should get the same oil or wax treatment you use for steel or iron tools and equipment.

Available at Busy Bee, I don't know if you have them in Victoria.

Dave Cameron

ecortech
03-24-2012, 11:09 AM
I did check out Evapo-rust and several other Canadian tire products, and it appears that they are not really what I'm looking for, but an alternative method of rust removal, rather than a way to stabilize the surface of the metal after the rust has been removed.

My research continues.[/QUOTE]

Quote taken from article you referenced in op

Passivation

If you donít immediately prime and paint, the passivation process is something you should do after abrasive blasting, anyhow. So, itís not any more work to do it as suggested, here.

If you donít passivate, youíll notice some red rust forming soon after you are done. This is what happens: Some of the rust was converted back to pure iron, but it is in the form of very fine particles. This fine iron ďdustĒ will almost immediately re-rust. The passivation process removes the last traces of rust and prevents re-rusting.

So you are actually removing rust


Most any of the products that are called rust removers, and leave the surface ready for paint, will do the job. Whatever process they use to leave the surface ready for paint, also prevents rust from reforming. (ie it passivates)
Evapo-Rust will work fine just spray it on, wet the surface completely, let it dry.
Home hardware also has another product Surf-Pro Rust Remover it is phosphoric acid based, will do the job.

Don't get hung up on what the product is called if it leaves the surface ready for paint, it will most likely do what you want.

Ed

Black_Moons
03-24-2012, 11:19 AM
Whats wrong with just coating the metal with oil?

Yes, you will have to remove it all before using the metal. But then you should be cleaning all the oil/dirt/etc off before painting anyway.

mickeyf
03-24-2012, 11:55 AM
Thanks all for all the leads, suggestions and background info.

Part of what' s hanging me up is that no one here has actually said "I have personally used fill_in_name_of_product_or_process and it has worked fine."

I guess I'd like to hear first hand that something works, rather than be the one to boldly go where other home shop machinists have gone before, but have then had to turn around and come back.

The original article, and at least one other source I saw indicated that plain phosphoric acid (for example) did *not* work fine.

Black_moons, some of this is plate that I'm hoping to use for the surface of a welding table, so I want it to be bare, oil free, and conductive. Perhaps I'm expecting too much in this particular case. Or maybe light surface rust doesn't matter here - I don't have the experience to know. What is the nature of the surface of expensive straight from the steel mill plate that is used by people who aren't scrounging, recycling pack rats? Since it doesn't rust significantly unless out in the weather, I presume it is passivated (pickled), although probably by an industrial process I'm not about to duplicate.

All my other parts will be painted so should be no problem.

Evan
03-24-2012, 02:03 PM
Part of what' s hanging me up is that no one here has actually said "I have personally used fill_in_name_of_product_or_process and it has worked fine."

I use it all the time.

http://ixian.ca/pics9/phdown.jpg

It works about as well as cold bluing if you oil it.


The original article, and at least one other source I saw indicated that plain phosphoric acid (for example) did *not* work fine.


It depends on what you are expecting. If you are looking for a long lasting durable finish, then no, it will not meet that expectation. If you want to keep a welding table from rusting, then it will do just fine. BTW, a little oil will make no difference to electrical contact. Mill plate just has the from the mill hot rolled oxide finish. It is very durable.

lynnl
03-24-2012, 02:50 PM
I don't know what the ultimate goal is, but I've used Rustoleum Rust Reformer for small items. It leaves a sort of blackish gray surface which holds up pretty well.

http://www.google.com/search?sourceid=navclient&aq=1&oq=rustoleum+rust+reformer&ie=UTF-8&rlz=1T4GGIE_enUS393US393&q=rustoleum+rust+reformer&gs_upl=0l0l0l5031lllllllllll0&aqi=g5

mickeyf
03-24-2012, 11:34 PM
I use it all the time.

Thanks Evan - that's the confidence inspiring thing I was hoping to hear. I suppose then I can just mix up a batch of home-brew along the lines of:

1 gallon of Phosphoric Acid
2 drops of liquid soap
1 heaping teaspoon of steel wool (or perhaps some of those filings from the 4x6 bandsaw I'm always sweeping up)

Let stand for a while (a day maybe?) to allow the steel wool to dissolve, store in an appropriate (?) container, and use as directed.

I'll try it.

Evan
03-25-2012, 12:51 AM
The stuff I show is 80% acid. You can tell just by handling it if it is the real thing because the density is about 50% higher than water at that percentage and it feels heavy.

Mix it down to 20% for use.