Thread: removing rust/scale

I just made this welding table. I am wondering what is the best way to remove the rust/scale on the top surface apart from using wire brush and angle grinder?

Thanks,
Trong

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Assuming you don't want to dunk the table into anything so you can do a chelating (no loss of metal) rust removal conversion like then I'd go the wire brush and angle grinder.

Hi Jackaroo,
If it is a welding table it will hardly require a pristine surface. What do expect to do on the table? Depending where you live and how corrosive the local atmosphere is it is going to rust. How close to the ocean are you in Victoria?

Another way to remove the surface rust could be to scrape it with a wide bladed paint scraper. Given off course that the surface has not got spatter all over it YET?

Dust the loose stuff off and coat it with phosphoric acid. Wipe that down with a bit of metho on a cloth and coat it with a smear of lanolin oil- theres heaps of different brands.

The lanolin oil will keep the table relatively clear of rust but you will have to refinish occasionally.

Other than than please tell us why you need to avoid the A/G and wire brush.

Grahame

I'd get the belt sander out, probably start with something like a 60 Grit belt then go over it again with a 100/120 belt.
Depending on how motivated i was feeling at this point I may put a 240 pad on the orbital and give it a going over with that.

If you persisted through to the point of using a 240 on the orbital it would be a very neat looking top at this point.

If you are truly a glutton for punishment, put a medium scotchbrite on the orbital.. It'll look sexy as, but you probably wont want to weld anything on it then

Hi Trong, Guys,

I agree with Grahame, I don't see any point in cleaning it up either ! The first time you use it to weld on it will get splatter on it.

It will, but if its clean when you start you can earth the work through the table top

Thank you everyone,

@BobL, it is about 130kg and 1200mm for the length so rust conversion might not be an option.

Hi Grahame. I am quite far away from the coast so saltwater won't be an issue. I was wondering if cleaner surface will give better earth through the table top especially for TIG welding? I was planning to mount a copper block underneath and use that to connect with the earth clamp from the welder and thinking maybe exposing the surface will better.


Regards,
Trong

I didnt clean mine...that will come in time....it will get cleaner the more I use it was my theory...grinding away splatter etc

Originally Posted by jackaroo

I just made this welding table. I am wondering what is the best way to remove the rust/scale on the top surface apart from using wire brush and angle grinder?

Thanks,
Trong

I'd use stripping disks - or flap disks - whatever you have. Make it clean for a good electrical contact and don't add any gunk to preserve it because it'll just contaminate a weld.

Jack

I didn't bother to anything to my top except cut out a opening in the top for my removable vice

Weldbench1.JPG
Weldbench2.JPG

Originally Posted by jackaroo

Thank you everyone,

@BobL, it is about 130kg and 1200mm for the length so rust conversion might not be an option.

Hi Grahame. I am quite far away from the coast so saltwater won't be an issue. I was wondering if cleaner surface will give better earth through the table top especially for TIG welding? I was planning to mount a copper block underneath and use that to connect with the earth clamp from the welder and thinking maybe exposing the surface will better.


Regards,
Trong

Hi Trong,

I'm not a welder though I have done some quite recently along with some instruction !

The company that helped me had several welding work areas, the one that I used did have a steel table, the steel table top was connected to one side of the welding machine but also had a separate cable and clamp, a bit like a crabs claw, to connect directly to the workpiece. I did ask why it was like this and was told that you not only couldn't rely on a good earth to your work but occasionally the workpiece would get welded to the table from a secondary contact. A separate earth connection prevents that by providing a better path for the welding current.

I agree with Baron J 100%.

Just earth straight to the work and make sure there is a shiny cleaned spot under the clamp contact surface to ensure a good earth.

Leave the rust on there and the surface will be less inclined to have spatter to stick to it.

If you mark out using french chalk== boilermakers chalk the rust contrasts well.

Grahame

Thank you for the idea Baron. I actually have 1 spare earth cable about 1.5m long, that will be perfect for that. I could mount that to the table from underneath through the copper.

20210520_205837.jpg

Here’s a picture of mine, this was from when I was shimming it when I built it, I cleaned it with the orbital fitted with a medium scotchbrite and WD40.
I clean it and oil it on a regular basis because monkey like shiny (and on the odd instance where I have customers come to see mock ups or in progress, it just looks like I take a bit more pride... no laughing from anyone that’s seen the inside of my bomb testing area, I mean workshop recently).

I have a lead that I bolt to a spare fixture hole in the table top to earth it, and I also have a length of braid that put under the same bolt to drape over odd shaped (mostly circular) things if I can’t get a decent connection. I do clamp direct to the work if I have bigger stuff and am running the machine close to full noise. I only use a TIG or Gas these days (I say that but I can’t remember the last time I used the gas for anything other than heating to bend) and a lot of the stuff is smaller and doesn’t really lend itself to having a 300A Clamp attached to it. But you do you, like with most things, there’s one purist way to do it, and a million others that will work just as adequately and are more convenient at the time..

Most of the stuff I weld is small so I rarely weld small work pieces directly on my table.
Instead I either weld with part of the work held in the vice or I have a mini table that I hold in the vice and weld stuff clamped on top of that.
I have essential tremor (very shaky hands) so I usually weld with half length rods plus welding on a smaller/higher table means less bending over.

The mini table is a piece of 200 x 200 x 6 mm plate with a piece of 25 x 25 SHS welded to the underside and that is held in the vice jaws.
The other slightly larger table/plate on the bench with round stubs attached is one of my bending jig.
The lamp is a LED spot for extra lighting.
Weldbench3.JPG

Being small, a clamp or two easily holds things near the edges of the mini table
This minitable also collects most of the spatter and I don't hesitate to weld things to it for support.
Every now and then I get a thin kerf cutting wheel and cut any protrusions off it , followed by a 36 grit flap wheel and take the mini table back to scratch .
It's probably more like 5.5 mm thick these days.