Mill Scale

[Ram48]

What do you use to strip the mill scale from steel before welding?
I use the black or red open weave surfacing discs but was wondering if there is a better (read cleaner, faster) way to strip it.

[geezer]

I used to use an old 8 inch B&D body grinder, heavy ugly thing and then one day it walked out of the shop. Now I use those puny 41/2 jobs with a hard disc. They are handy but the old B&D was my favorite.

[Robert s]

I use my sand blaster but all the parts I make ether get painted or powder coated. This gives me a head start on the final cleanup.

[welderdude]

Unless I'm TIG welding something, I weld over it. When I do need to clean it off, I use one of those Zirconia flap wheels. They are expensive compared to a regular grinding disk, but they work very nicely.

[wruehl]

I usually only worry about the weld area and clean that with a blending disk or hard wheel, whichever is closer. Then let the powder coater sand blast it when he does his thing.

[everlastsupport]

4 1/2 inch grinders with ether flap wheel or grinding disc. Which ever one I grab first. I only do the welding area thought, groove or taper as needed.

Then when time for the prime/paint, the rest of the work happens. Normally try to pass that to someone else.

[Mikeymetal]

The last sentence in Mike R.'s response sounds like the ticket But really, I just started using the 4-1/2 and 7 inch flap discs. I use 40 grit or 36 if I can find them. They really get the scale cleared out better then a hard disc.

4 1/2 inch grinders with ether flap wheel or grinding disc. Which ever one I grab first. I only do the welding area thought, groove or taper as needed.

Then when time for the prime/paint, the rest of the work happens. Normally try to pass that to someone else.

[Robert s]

I usually only worry about the weld area and clean that with a blending disk or hard wheel, whichever is closer. Then let the powder coater sand blast it when he does his thing.

I wish I could just send it out to get a coat of powder shot on it but the only shop that does it here sucks!!!

So I built my own booth and oven so I can do it all in house. Then when it sucks I know just who to yell at. This is why you have kids that grow up to work with dad. ( built in scape goat )

[ScratchStart]

Sait 36 grit flap disc, if it has to be more clean or smooth I'll use an 80 or 120 grit. if it has to be powder coated I blast it with my NT sand blaster, but it takes forever! looks great tho.

what are you using for an oven? I have a little jet hot coating kit, never used it cause it seemed like a pain in the @$$. but now you got me thinking about my wifes electric oven... maybe she needs a new one, so I can have the old one....

[kenwhite]

I also use a flap disc, but I clean both the welding and ground connection areas - without a good ground, the welds can become very inconsistant...

[everlastsupport]

I wish I could just send it out to get a coat of powder shot on it but the only shop that does it here sucks!!!

So I built my own booth and oven so I can do it all in house. Then when it sucks I know just who to yell at. This is why you have kids that grow up to work with dad. ( built in scape goat )

I have three sons and they all weld, paint, etc.. Two like the powder coat, but small things (small oven). Unlike you and Ray with the big booths, I have a very large toaster oven for that stuff.

[everlastsupport]

I also use a flap disc, but I clean both the welding and ground connection areas - without a good ground, the welds can become very inconsistant...

Can't count the times I have gotten everything ready to weld, and went to hook the clamp on and mumbled to myself dang-it.

[Salty]

I use a HF pneumatic angled die grinder with the 3" cut off wheel. Its light, easy to maneuver and you can grind a small bevel with it if you like.

[jojobead]

grind wheel hard or flap disk.I run cnc oxy table. russin metal can be hard to clean or any metal thats been on boat for long time.good to run 6010 for first bead if stick welding we call it farmers rod ,can cook out some of the crap.then use 7018

[jojobead]

have used phosphoric acid to clean weld for painting.

[Oxide00]

Flap discs work great for me. Or if I am in a pinch a stiff wire wheel will work.

[dgarnier]

the flap disk works good on everything except 1"x1" steel tube...not sure way but I round off the corners before I get the middle clean.

[Steve]

I use a flapper disk also. What is nice about them is that they seem to last way longer than a standard sanding disk. They cut much better through the mill scale and they seem to hold the ability to sand longer. More expensive than the sanding disk, but I was going through sanding disks at a fairly high rate. Now I have noticed with the flapper disks, it has cut back to very rarely having to get a new disk.

[revkev6]

I use a flapper disk also. What is nice about them is that they seem to last way longer than a standard sanding disk. They cut much better through the mill scale and they seem to hold the ability to sand longer. More expensive than the sanding disk, but I was going through sanding disks at a fairly high rate. Now I have noticed with the flapper disks, it has cut back to very rarely having to get a new disk.

the best thing about the flapper disks above and beyond the performance is that they do not add as much heat to the material. if you are working lighter gauge sheet metal you have less chance to warp it.