Any ideas what went wrong : Oil Blackening.

[Armourkris]

First off, I'll get some pics up tomorrow, that will probably help.

So I went to oil blacken a helm I just finished, Figured I'd do it the way I did some spaulders a few years ago. I brought the helmet up to a satin finish, de-greased it and put it in a bbq. I set the heat to a point where the oil i used would smoke, but not burn, then proceeded to bake on coats of olive oil. worked great on my spaulders last time, but not so much on the helmet.

where the blackening did worked i got a nice glossy black, where it didn't the blackening crinkled up and flaked off. leaving bare metal behind.

Any ideas why this isn't working for me this time?

[Ironbadger]

Are the crinkled areas around the edge, or on the top of the skull?
My immediate guess- and I stress it is a guess- is uneven heating.

A second guess might be heat pooling inside the top of the skull? If the skull is the point where your crinkling occurred.

if the crinkling is in patches, randomly distributed- I got nothing.
Best guess then is some chemical residue contamination.


Pics may help.

-Badger-

First off, I'll get some pics up tomorrow, that will probably help.

So I went to oil blacken a helm I just finished, Figured I'd do it the way I did some spaulders a few years ago. I brought the helmet up to a satin finish, de-greased it and put it in a bbq. I set the heat to a point where the oil i used would smoke, but not burn, then proceeded to bake on coats of olive oil. worked great on my spaulders last time, but not so much on the helmet.

where the blackening did worked i got a nice glossy black, where it didn't the blackening crinkled up and flaked off. leaving bare metal behind.

Any ideas why this isn't working for me this time?

[AwP]

I'm going to agree with Badger. The crinkling sounds like overheating to me, and since you say it's only in spots, then the heating must be uneven. If it seems random, another possibility is that the thickness of the steel is uneven, which could lead to uneven heating from an even heat source.

[woodwose]

Get any finger prints on it between when you degreased it and when you cooked it?

[Armourkris]

blarg. My computer isn't wanting to see my camera for some reason.
But, the crinkling is mainly on the front half of the skull, but with smaller patches distributed randomly around the rest of the helm.
I'm just going to go get it powder coated. I mean, i was aiming for something less modern looking, but put side by side i cant actually see a difference between the oil blackening that worked, and semi gloss black powder.

[Halberds]

I would think the heat propagation through your helm was uneven.
A BBQ will not heat the top as well as the bottom.

That is why I use a flamethrower.