EASY MILL-SCALE & DROSS REMOVAL

Share tips and tricks regarding cut cutting, material handling, metal finishing, marketing, or anything you find helpful.
Post Reply
User avatar
steelfx
4 Star Elite Contributing Member
4 Star Elite Contributing Member
Posts: 768
Joined: Sat Oct 10, 2009 12:09 am
Location: St. George, Utah
Contact:

EASY MILL-SCALE & DROSS REMOVAL

Post by steelfx »

Hi Everyone!
I'd like to post an excerpt from my eBook, 'STEEL PATINAS & FINISHES' which can be found here http://plasmaspider.com/shop/steelfx.html
And, a Brand New alternative to Muriatic Acid for Mill-Scale Removal: GRIME GIT'R?
Thanks!
Bill :D
steelfxpatinas.com_eBook-excerpt1.jpg
steelfxpatinas.com_eBook-excerpt2.jpg
MILL-SCALE REMOVAL_hot-rolled-steel_steelfxpatinas.com.jpg
mill-scale-removal_steelfxpatinas_grime_gitter(tm).jpg

You currently do not have access to download this file.
To gain download access for DXF, SVG & other files Click Here

adbuch
6 Star Elite Contributing Member
6 Star Elite Contributing Member
Posts: 8936
Joined: Thu Sep 21, 2017 5:22 pm
Location: Tucson, Arizona
Contact:

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by adbuch »

Bill - thanks for sharing! This is great information to have available for future reference.
David
Danj4164
1 Star Member
1 Star Member
Posts: 11
Joined: Tue Aug 16, 2022 8:29 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Danj4164 »

Bill,
Will this work on galvanized material to help remove the dross, I paint the signs I make with it anyway so no concern about any damage to the galvanized coating. I have a bunch of free material that I am using for things right now, mainly just want to make sure I don't create a toxic brew LOL.

Thanks,
Dan
sonbakler
3 Star Member
3 Star Member
Posts: 362
Joined: Fri Apr 15, 2011 3:47 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by sonbakler »

I notice Bill has not been very active, I have heard he has some health related issues unfortunately. I expect that you could use this technique on galvanized steel with normal safety precautions when working with this acid.
Plasma-art
2.5 Star Member
2.5 Star Member
Posts: 166
Joined: Mon Sep 12, 2022 9:29 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Plasma-art »

It also removes the zinc off of it and sometimes reacts pretty violently to zinc so be aware.
I have used it for removing the galvanizing off of chains in a 50/50 mix.
Danj4164
1 Star Member
1 Star Member
Posts: 11
Joined: Tue Aug 16, 2022 8:29 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Danj4164 »

Thanks guys for the responses, I will give it a try and report back with the results.
User avatar
Joe Jones
5 Star Elite Contributing Member
5 Star Elite Contributing Member
Posts: 3192
Joined: Sat Oct 11, 2014 2:33 pm
Location: Franklin, KY., USA
Contact:

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Joe Jones »

I went a different route for mill scale removal.

On the recommendation of a trusted friend, I bought two of these industrial diamond cup brushes and a powerful variable speed grinder to achieve the low (1,000 - 2,800) RPMs required for these brushes to work as designed.

Joe

http://www.toolfetch.com/Pferd-84349-4- ... PERFECT-MI

http://www.toolfetch.com/Pferd-84348-4- ... CT-MILL-SC



Franklin, KY., USA
Samson 510 & 4x4
6” Z Rail Lift Kit for PlasmaCam
CreatBot D600 PRO 3D Printer
16 Lasers
FREE DesignEdge Training!

It is more fun when it isn't necessary!
Danj4164
1 Star Member
1 Star Member
Posts: 11
Joined: Tue Aug 16, 2022 8:29 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Danj4164 »

Morning guys,
Just wanted to share the results from using the 50/50 muriatic acid and water mix on galvanized steel. It did bubble and fizz when I first put the steel in the mixture but after leaving it in for 24hrs the steel was clean and the dross mostly blew off when drying the pieces with compressed air.
There was some dross remaining by easily scraped off with a putty knife.

Thanks,
Dan
sonbakler
3 Star Member
3 Star Member
Posts: 362
Joined: Fri Apr 15, 2011 3:47 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by sonbakler »

Thanks for reporting back on the galvanized Dan, good to know. This stuff is dangerous no matter what but if you do it safely it is hands down the best method of cleaning and dross removal if you can wait overnight :Like :Like
Retro
2.5 Star Member
2.5 Star Member
Posts: 123
Joined: Sun Sep 09, 2018 3:34 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Retro »

Im curious about the percentage of the muriatic acid. Here in germany i can buy a 31 % acid. Like this:https://www.ebay.de/itm/325241957978?ha ... BMhrW9qI5h

Does it make sense to still use a 50/50 mix?
cuttinparts
3 Star Member
3 Star Member
Posts: 375
Joined: Tue Sep 30, 2008 3:40 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by cuttinparts »

I am not sure to be honest. I would suggest trying a small amount of 50/50 mix in a small plastic sandwich container or something, leave a small part in overnight and if the dross and scale is not gone in the morning try 75/25 and find the balance that works well for the acid your using.
finyuk2005
1 Star Member
1 Star Member
Posts: 15
Joined: Mon May 30, 2022 8:50 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by finyuk2005 »

whats the best to neutralize the acid before painting? or do you just wash off with water?
Im guessing it flash rusts pretty quick after?
User avatar
Joe Jones
5 Star Elite Contributing Member
5 Star Elite Contributing Member
Posts: 3192
Joined: Sat Oct 11, 2014 2:33 pm
Location: Franklin, KY., USA
Contact:

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Joe Jones »

Rinse it with water. Dry it QUICKLY. (Heat gun, propane torch, Acetylene Torch, etc.) Prime it IMMEDIATELY.

Joe
Franklin, KY., USA
Samson 510 & 4x4
6” Z Rail Lift Kit for PlasmaCam
CreatBot D600 PRO 3D Printer
16 Lasers
FREE DesignEdge Training!

It is more fun when it isn't necessary!
adbuch
6 Star Elite Contributing Member
6 Star Elite Contributing Member
Posts: 8936
Joined: Thu Sep 21, 2017 5:22 pm
Location: Tucson, Arizona
Contact:

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by adbuch »

finyuk2005 wrote: Sat Nov 19, 2022 2:16 pm whats the best to neutralize the acid before painting? or do you just wash off with water?
Im guessing it flash rusts pretty quick after?
Some us a baking soda/water mix to neutralize the acid. Then just rinse off with water.
David
User avatar
acourtjester
6 Star Elite Contributing Member
6 Star Elite Contributing Member
Posts: 7870
Joined: Sat Jun 02, 2012 6:04 pm
Location: Pensacola, Fla

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by acourtjester »

I have had great results with the pool muriatic acid at 50% with water and overnight soak. Then scrub with Bristle brush in water and washing soda, then clear water and blow dry.
DIY 4X4 Plasma/Router Table
Hypertherm PM65 Machine Torch
Drag Knife and Scribe
Miller Mig welder
13" metal lathe
Small Mill
Everlast PowerTig 255 EXT
rock4xfab
2.5 Star Member
2.5 Star Member
Posts: 101
Joined: Wed Aug 18, 2010 11:07 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by rock4xfab »

Pure White Vinegar cuts though millscale also and it wont flash rust all your other bare metal parts.
aicomp
2.5 Star Elite Contributing Member
2.5 Star Elite Contributing Member
Posts: 233
Joined: Wed Feb 02, 2011 5:15 pm
Location: Santa Anna Texas
Contact:

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by aicomp »

I use white vinegar. It is cheap and doesn't destroy any metal outside the tank. Works as well for me as acid did.
Just my $.02
http://www.PenningtonFab.com
Torchmate 3 with Accumove 3
Hypertherm 1250
Hypertherm 85
Hypertherm 380
Lincoln V205T Tig
Lincoln wirematic 250
Eastwood 175 with Spoolgun
Eastwood 135 Mig
plasmanewbie
5 Star Elite Contributing Member
5 Star Elite Contributing Member
Posts: 2636
Joined: Thu Jul 24, 2008 11:15 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by plasmanewbie »

I will have to give a try. Would be much safer than a big tub of acid and I could store it indoors as well. Appreciate the tip :Like
Gogo
2 Star Member
2 Star Member
Posts: 51
Joined: Fri Nov 04, 2022 11:02 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Gogo »

So I use this method but what am I supposed to do now that it is freezing outside. I am very worried about the corrosive fumes inside. My shop is wood heated. I don't think the vinegar will work on the dross.
User avatar
acourtjester
6 Star Elite Contributing Member
6 Star Elite Contributing Member
Posts: 7870
Joined: Sat Jun 02, 2012 6:04 pm
Location: Pensacola, Fla

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by acourtjester »

Have you looked into a heating element attached to the bottom of the tub, just a low temp one would hold it from freezing.
DIY 4X4 Plasma/Router Table
Hypertherm PM65 Machine Torch
Drag Knife and Scribe
Miller Mig welder
13" metal lathe
Small Mill
Everlast PowerTig 255 EXT
Gogo
2 Star Member
2 Star Member
Posts: 51
Joined: Fri Nov 04, 2022 11:02 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Gogo »

that's a good idea. i have a large tub i could put over it as well. all plastic. thanks.
PlasmaDon
2 Star Member
2 Star Member
Posts: 67
Joined: Wed Nov 15, 2023 6:44 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by PlasmaDon »

Buy P&O material next time ?
Gogo
2 Star Member
2 Star Member
Posts: 51
Joined: Fri Nov 04, 2022 11:02 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by Gogo »

i just did. 😀
sean_cj7
1/2 Star Member
1/2 Star Member
Posts: 9
Joined: Sat Oct 04, 2014 4:47 pm

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by sean_cj7 »

i live in the northeast and in the last 2 years never has the acid bath froze. I have a dedicated outside shed for my acid bath, while we haven't had the coldest winters in recent years, the bucket of water i store in the shed to rinse small parts has froze solid. Once i'm done with my xmas rush of signs I'll take a few minutes and do a write up of what my set up looks like. Its very trashy, but serves its purpose.
sonbakler
3 Star Member
3 Star Member
Posts: 362
Joined: Fri Apr 15, 2011 3:47 am

Re: EASY MILL-SCALE & DROSS REMOVAL

Post by sonbakler »

sean_cj7 wrote: Thu Dec 14, 2023 6:37 am i live in the northeast and in the last 2 years never has the acid bath froze. I have a dedicated outside shed for my acid bath, while we haven't had the coldest winters in recent years, the bucket of water i store in the shed to rinse small parts has froze solid. Once i'm done with my xmas rush of signs I'll take a few minutes and do a write up of what my set up looks like. Its very trashy, but serves its purpose.
Hey Sean, good to know, thanks. What is your acid/water mixing ratio?
Post Reply

Return to “Tech Tips From Other Members”