Post-electrolysis drying question

[fever87]

Ok, so I've cleaned various iron pieces with electrolisys (and some with apple cider vinegar (both with varying degrees of success)) but here is where I have an issue. I've rinsed the pieces and then baked them in the oven on low for about an hour before I can apply Briwax. The problem is that in the oven they "flash" rust. How do you stop that??

Some pieces that rust like that clean up easily with a wire brush but some I have just set aside until I can find an answer. Thanks for any input!

 

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[fever87]

So, by they lack of input from Tnet regulars I have concluded that either:
a) I am the only one with this issue
b) no one has a solution to this problem
c) folks know, but its a trade secret

 

[sosa961]

I'm having the same issue.. Maybe someone will help us out. I have used Distilled White Vinegar to get major rust off my iron relics with a lot of success.. wash them off with water, put them in the oven and they get that light coat of rust.

Should I be putting on the anti-rust solution before the oven??

 

[pa plateau hiker]

I tried the vinegar method several times after reading about it on this site. The iron ALWAYS flash rusted and I stopped using vinegar after that. I continue to use electrolysis and the iron doesn't flash rust. I think using the oven is a waste of energy. I dry with a propane torch, it only takes several minutes. You have to remove the fine powdery residue before sealing with a preservative after the iron cools down.

 

[Rick (Nova Scotia)]

I've not had that problem, didn't even use an oven or any other heat. It is possible you didn't leave in the vinegar long enough ? to remove all or most of rust in first place. It does take time and patience, depending on how heavy the rust was.

 

[Davers]

I have experienced Certain pieces Flash rusting & others Not , I suppose it depends on the Piece.

BTW . Tho ACV Does work , "I" dislike the blackish grey that most relics come out looking. Also their Texture.

 

[Curious The George]

. The problem is that in the oven they "flash" rust. How do you stop that??

Some pieces that rust like that clean up easily with a wire brush but some I have just set aside until I can find an answer. Thanks for any input!

I would find a product with phosphoric acid in it. Naval Jelly is one but I'd find one that was more liquid than that. I'm headed to a Tractor Supply in a little while and will find it there and post later what they call it.

Phosphoric acid converts iron oxide, rust, to ferric phosphate. Ferric phosphate doesn't continue to bloom like rust does.

I'd take the object out of the oven and pour or even spray phosphoric acid on it while still hot. It will flash off instantly and don't breath in the steam. I'd keep hitting it with the PA as it cools to make sure you get the chemical conversion.

I used to have a friend that was an art blacksmith. He took his work right off the anvil and threw it in a tub of PA before it had a chance to develop any kind of rust bloom.

Rust is like a mushroom. It lives underground and what you see is the blooms of the roots. PA will penetrate the pores of the iron and convert the roots of the rust to a substance that doesn't react to oxygen. What is happening is that right out of the oven you have stripped all the oils and waxes off the iron there is nothing keeping the oxygen from combining with the iron molecules and it does it quickly.

After you treat with PA then put what ever coating, wax, varnish or what have you on the piece and it will hold up for a very long time. After the PA drys that is.

The archaeologists with the NC Dept. of Archives and History use a Rust-olem clear product and submerge the iron object in it till no bubbles rise to the surface, 10-15 min. or so, as their standard iron preservation solution.

And don't forget Phosphoric Acid is an acid, take care with hand and eye protection when using and don't inhale the steam coming off a hot piece of iron.

I am currently electrolizing an object I found yesterday and will be doing exactly what I describe above to preserve it. I'll post about the find in the "Just Found" section next.

 

[Curious The George]

I bought a quart spray bottle of "Rust Kutter" at Tractor Supply yesterday afternoon. Kind of pricey and I think there may be a better solution.