Hot Rolled vs Pickled & Oiled for Offset Smoker Build

[phoenixsmoke]

Hi All,

I'm thinking of building an offset smoker and wanted to see if anyone has any knowledge if the mill scale on hot rolled steel would be detrimental in an offset smoker if it was not removed. I've done some research and it seems like it would be a time consuming and difficult process to remove mill scale from the inside of a rolled pipe. Do you think it's okay to leave the mill scale or should I remove it? I'm having a hard time finding pickled & rolled stock. Thanks in advance.

 

[Casebrew]

The scale on the hot rolled is a blue oxide, similar to gun blue. It is protective. An unless you have hemochromotosis, iron is not harmful. Though a spot of rust will kill a batch of beer. Besides, a layer of smoke will protect it all, both ways.

Cast iron would be best. Or a brick smoker?

 

[phoenixsmoke]

The scale on the hot rolled is a blue oxide, similar to gun blue. It is protective. An unless you have hemochromotosis, iron is not harmful. Though a spot of rust will kill a batch of beer. Besides, a layer of smoke will protect it all, both ways.

Cast iron would be best. Or a brick smoker?

I'm mainly concerned of the scale flaking off at some point and getting into the food. At the very least it would not be pleasant and on the other end are the health concerns as you mentioned with hemochromatosis (I have friends with this condition) and other things.

Unfortunately, for an offset smoker, cast iron and brick are not options for me. Thanks for weighing in.

 

[kmmamm]

Mill scale is difficult to remove mechanically, but it is no match for acid. I use a dipping tank to soak large pieces rotating them to sure all of the surface has at least a 3-6 hour soak. I use muriatic acid which can be purchased at any pool supply location or big box. If you do not have a suitable dipping tank, a cheap 6’ diameter kiddie pool will work just as well. You don’t have to use an extremely high acid concentration, 2-3 gallons per 75-100 gallons of water will do the trick. Never locate the acid bath indoors , keep it as far away from things that can rust as practical….the acid vapors will travel in the wind. Always wear long sleeved gloves approved for working with acids. Facial and eye protection are also mandator. Keep the acid tank covered when not in use. Once the piece has soaked, rinse the scale off with fresh water. It may be necessary to hit the scale with a nylon pool brush while soaking. Once all of the scale is off, I rinse the piece thoroughly with clean tap water then immediately dry it with a lp weed burner. Unless you live in an oven, expect the steel to rapidly grow a light patina of surface rust, which can easily be removed mechanically prior to paint. Once you are done with the acid water, it can be neutralized with plain old baking soda (available in 10 lb bags at Sam’s Club) and then simply dumped onto the ground…keep in mind there will be a temporary rust stain wherever you dump it.

 

[phoenixsmoke]

Mill scale is difficult to remove mechanically, but it is no match for acid. I use a dipping tank to soak large pieces rotating them to sure all of the surface has at least a 3-6 hour soak. I use muriatic acid which can be purchased at any pool supply location or big box. If you do not have a suitable dipping tank, a cheap 6’ diameter kiddie pool will work just as well. You don’t have to use an extremely high acid concentration, 2-3 gallons per 75-100 gallons of water will do the trick. Never locate the acid bath indoors , keep it as far away from things that can rust as practical….the acid vapors will travel in the wind. Always wear long sleeved gloves approved for working with acids. Facial and eye protection are also mandator. Keep the acid tank covered when not in use. Once the piece has soaked, rinse the scale off with fresh water. It may be necessary to hit the scale with a nylon pool brush while soaking. Once all of the scale is off, I rinse the piece thoroughly with clean tap water then immediately dry it with a lp weed burner. Unless you live in an oven, expect the steel to rapidly grow a light patina of surface rust, which can easily be removed mechanically prior to paint. Once you are done with the acid water, it can be neutralized with plain old baking soda (available in 10 lb bags at Sam’s Club) and then simply dumped onto the ground…keep in mind there will be a temporary rust stain wherever you dump it.

Thanks for the tips. After doing some research I'm probably going to skip removing the mill scale except for inside the cooking chamber and I think I've found a way to do that using diluted muriatic acid.