Cleaning Steel?

[Hedgehog]

This is a relevant question for most anybody working with new rolled steel. There must be an easier way to clean the coating off raw rolled steel than using a flap wheel to clean it off for a quality weld. Most any advice would be appreciated.

 

[Lumpy Grits]

Is this the 'scale' rust coating or?

LG

 

[HackFabrication]

Is this the 'scale' rust coating or?

I'm going to assume he's talking about mill scale that would be present on hot rolled steel. Most cold rolled steel will only have surface rust or trace lube from processing.

If it's hot rolled steel, and depending on the size of the piece, I either run it through the sandblast cabinet, or get the angle grinder out.

 

[Hedgehog]

Yes it's the hot rolled steel scale. I was hoping there would be some sort of chemical method for removal. This stuff even resists cleaning with an angle grinders flap wheel. It can be done but it's tedious and now that the job is done darned near impossible to do. I've more or less completed an 8274 Winch plate (highly modified H-F plate), now for the finishing. Maybe I'll send it to the powder coater. They will sand blast it before coating, but it's pricey process.

 

[HackFabrication]

Yes it's the hot rolled steel scale. I was hoping there would be some sort of chemical method for removal.

Muriatic acid will strip it. But it's a nasty and somewhat dangerous process. I'm done a number of small pieces with it, but the larger ones are a different story.

Best to get it blasted. I use a medium grit aluminum oxide in my cabinet.

 

[Lumpy Grits]

Do you have a 'jitter-bug' type sander like what is used in body work?
I have had good luck with them in removing that dang scale for welding etc.
LG

 

[IOPort51]

Muriatic acid will strip it. But it's a nasty and somewhat dangerous process. I'm done a number of small pieces with it, but the larger ones are a different story.

Best to get it blasted. I use a medium grit aluminum oxide in my cabinet.

Muriatic will turn it white but not remove it. I fail to see the problem, are you making bad welds? Hot rolled is what hot rolled is.

 

[Hedgehog]

On various shows they mention that the slag has to be removed for clean welds, especially for MIG welding where things need to be clean. The edges are easy enough to clean before welding. It's the over all flat area's that are no fun. Then there can be issues in painting. It's also bad for a forging process like forge or hammer welding. A while ago there was a show called "Big Giant Swords". In one of the episodes he used some sort of a process where he made a shallow container, laid his metal in it and added a chemical (not acid, it could have been vinegar) that over time lifted or loosened the slag to be wire brushed off. Unfortunately I can not remember what he used.

I recently gave my sand blaster to a friend. It was given to m and I ran out of room to store it in the garage. There is a company that sand blasted my roll bar so I think I'll be using them. Part of the advantage of sand blasting is to clean tight areas for I can't get to.

 

[IOPort51]

there is a difference between slag and mill scale. SMAW stick welds and flux cored wire should be brushed between passes for best results to remove slag. I use a brush on a 4" grinder. GSMA Welds with gas shielded hard wire will be more affected by oil or paint, anything that contaminated the gas shield and air movement that blows the shield away, Do not try to mig weld in front of a fan.

Forge welding is a completely different proposition and it is a rather slim chance you will have need of it.

My powder coater blasts everything before paint and the rino coat would need something in the 30 grit flex disk range

I hope this is of some help to you.

 

[Hedgehog]

All information is helpfull. Forge welding, I've been thinking about building a forge. Blacksmithing has always fascinated me. So, the question on removing scale is multi faceted.

A wire wheel on my grinder is a must. Unfortunately I can't always get into the tight spaces, even with a hand held brush. No fans in my work area.

 

[IOPort51]

All information is helpfull. Forge welding, I've been thinking about building a forge. Blacksmithing has always fascinated me. So, the question on removing scale is multi faceted.

A wire wheel on my grinder is a must. Unfortunately I can't always get into the tight spaces, even with a hand held brush. No fans in my work area.

blacksmithing is , for a fact, very cool. I suggest you contact your local blacksmith assn. or perhaps check out the Artist blacksmith assn. , ABANA, to help you get started. A whole new world will be opened to you.

 

[Hedgehog]

Good idea. My supervisor is does some blacksmithing I have always found it fascinating. I do worry about the noise and my neighbors. They have been tolerant of my CJ work and welding, but I'm not so sure about beating on metal. Then there is the price of a good anvil OMG! Every farm had at least one when I was growing up. Like finding treasure I guess. $700 at least and far more can easily be spent on an anvil. We had a coal forge that just sat around. What we didn't know we had back then. My forge would be gas, not coal.

 

[jpeck71]

One of the smiths on Forged in Fire (History Channel) used a coal forge in a cast iron skillet and his air source was a blow dryer taped to a pipe nipple that fit into a hole drilled in the skillet. I couldn't believe it! The skillet wasn't big enough to make a sword in so he found a metal satellite dish and wedged the skillet in it so he could have a bigger pile of coal.

I've also been curious about it but would only be interested in doing it once just so I could experience it. I can see myself building a skillet forge but I don't know where I'd get an anvil. I certainly don't want to spend $700 on one and I would only be interested in making a knife.

 

[Hedgehog]

Yeah, I saw that show. Coal forging is a difficult messy process. A propane forge is surprisingly easy to build, most anything can be used. Its popular to use small propane tanks lined with one kind of insulation or another. Brick, batting, even concrete will work. The nozzles are easy to build or buy. For less than $50 you can have a usable forge ,,,,, sure it is easy to spend a lot more than that.

Like the show not specifically for the items being forged, but for a look at the little things like equipment and methods being used. My friend makes most anything other than knives or weapons. He likes to make snakes and lizards out of old rasps and files or leaves or any one of a bunch of forged wall art. Me, I'd make knives and a sword would be cool.

If you are only doing a little forging a decent anvil can be made from a piece of rail road rail. Heavy iron like that can be used for any number of uses where pounding on stuff id necessary, even for little stuff like punching metal to drill holes. Most every week I find myself wishing that I had an anvil.

 

[IOPort51]

getting a gas forge above 2100 deg., welding temperature, is a bit of a trick but a coal forge does it easily. Coal is more fun but gas does not give you black boogers.:laugh:

Go to a local hammer in and I bet you will find someone that gives seminars. couple hundred and a weekend meet some nice people and have a lot of fun. find out if it is something you want to get into.

Short section of rail road track makes pretty good first anvil. My first forge was a brake drum with brick dirt in it and an old Kirby vacuum cleaner with a rheostat.

coolest thing about smithing is making square holes.

 

[Hedgehog]

There is a guy up North in Camp Verde that gives a great work shop on forging. My friend attended it a year or so ago and came away with great things to say about it. It was pricey though well worth it.

 

[Peanut Butter]

getting a gas forge above 2100 deg., welding temperature, is a bit of a trick but a coal forge does it easily. Coal is more fun but gas does not give you black boogers.:laugh:

Go to a local hammer in and I bet you will find someone that gives seminars. couple hundred and a weekend meet some nice people and have a lot of fun. find out if it is something you want to get into.

Short section of rail road track makes pretty good first anvil. My first forge was a brake drum with brick dirt in it and an old Kirby vacuum cleaner with a rheostat.

coolest thing about smithing is making square holes.

Anything you haven't done, IO? Wholly Cow, I need to come spend a couple weeks with you. Do you take on Interns?