Rust

i4Marc

i4Marc

Joined
Oct 19, 2011
Messages
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I just cut the top off a gas cylinder to use as a quench tube for my longer blades. The inside of the cylinder is solid but pretty rusty. After scuffing and wiping the interior clean, what can I use to effectively stop the rust that's left? Do I need to grind the whole interior back to bright clean steel or will chemical treatments work?
 
Ospho, sold at Sherwin Williams, and auto parts stores. You don't have to clean to bright metal, just remove the loose rust. Follow the instructions on the bottle.
 
PHosphoric acid, the ingredient in Ospho, works great. You'll find it under many different names, just in case you can't find "Ospho"

In the past, the most well known brand name was "Naval Jelly"
 
Good suggestion John and zaph1. I always have a bottle of Naval Jelly in the shop. Been using it for years. Mainly for small items, tools, and what not, but it can be applied to larger items as well. It works great, but I'd imagine you will need at least a couple of bottles for your application i4Marc. I buy it at my local Lowe's.

IMAG0163.jpg
 
Maybe Im missing something then, if hes using it as a quench tank, it will be filled with oil correct, does it need to be down to bare metal? He should just be able to knock the rust off, maybe throw some sand inside and roll it around a bit and then fill. The oil will stop any further corrosion. Or am I off it?
 
Thanks for the suggestions gentlemen. Here is a further explanation of my thinking. I currently have my Parks 50 in a clean 6 gallon metal pail. The oil level in that pail is a bit too shallow for the longer blades I'm quenching due to the diameter of the container. That's why I'm using the cylinder which has a smaller diameter and will allow the same volume of oil to be deeper. I am transferring the oil from the pail to the cylinder for the quench but will be returning it to the pail for storage later because it is a cleaner container, has a lid and a more stable footprint. I would like to remove as much rust as possible from the inside of the cylinder so I don't contaminate my "clean" container with any more foreign matter than I have to. I'm probably over thinking it.
 
You are probably going to have decarb popping off the blades you quench so stuff in the oil is inevitable

However I would not be able to leave the rust in there either, and I would likely put a 6" coarse grit flapper wheel on the end of a threaded rod and grind it down to the shine using my drill press or a hand drill ;0)

EDIT

Make sure your drill press is on low speed a long unbalanced rod will get wicked out of control in a big hurry
 
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I get where you are going with that but like John says.. you are going to get gunk in there anyway. Take it down enough that you arent worried about it and then when transferring back to your clean container, use a cover filter to keep out the crap.
 
Just brush/wipe the loose stuff off the walls and rinse out the cylinder. Let it dry and pour in the oil. Be sure to make a cap of some sort to keep water, dirt, and critters out of the oil. The rust and any scale from quenching is not a problem, as they are insoluble in oil. Every so often ( 1-2 times a year for most folks) pour the contents of the tank through a screen strainer basket to remove the crud that will fill the bottom. This is really an issue if you do a lot of clay coated quenches on long blades.
 
At this point I have it cleaned up with wire brush wheels in my power drill. Then I vacuumed out the dust and wiped down the interior with a rag and WD-40. I picked up a couple bottles of Naval Jelly but I think it's ok for now. I still need to weld on some rebar handles and find or make a lid.
 
That's a good link John, thanks. Unfortunately most of those caps are full inch sizes. The OD of my tank is 8.5"
 
looks like this one will fit, had to scroll down to the nominal pipe size chart, It has an id of 8.63" with a minimum of 7.70"

QC-108 8.63 7.70 9.11 8" PL - 8" CI - 8" Copper - 8" ST - 8" SS - 6" West Coast Clay
 
Looks like they carry them at Home Depot. I'll swing by and check it out. Thanks.
 
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