Cleaning Steel for MIG/TIG and subsequent painting.

[RoatanBill]

I was expecting to see this answered as a sticky somewhere, but couldn't find it.

I've tried numerous things to clean the really crappy steel I have access to on the island and all are EXTREMELY labor intensive. Some of the steel (from Guatemala) has a coating of grease on it. ALL the steel I get has at least a minor coating of rust on it. Some has what I term "rust barnacles" on it that a cup brush won't touch; I have to take a flap disk to these rust lumps to crack them open revealing a more powdery rust beneath them. I'm stuck with this metal unless I want to import from Miami and that gets very expensive.

I'm asking for suggestions on reducing my work load by using something other than the obvious angle grinder based approaches (cup brush, flap disk, sanding pad, etc) . I'm looking for some automation.

Are there DIY gadgets/machines/techniques to strip the crud from angle iron, square tubing, flat stock, etc that will do it a 20ft length of material at a time? I've seen videos that claim vinegar (acid) will eat the rust, but I don't have a 20ft trough to submerge lengths of material and then wait for who knows how long for results. I don't mind getting to bright shiny steel where a weld will go, but I also need the rest of the steel clean enough to prime and paint.

How are you folks cleaning dirty steel that doesn't involve elbow grease and wearing a dust mask while man handling an angle grinder?

[ronsii]

If you have lots of longer pieces just get some chain, shackles, and you favorite little vehicle....ute,quad, jeep etc.... and hook up five or six for a little outing on the beach or somewhere with rocky/sandy soil

[Louie1961]

Muriatic acid or vinegar. You could also look into electrolytic cleaning.

[RoatanBill]

Sooner or later one has to dispose of the residue from a chemical concoction. On an island, that would be called major pollution as there is no facility that can accept it.

Also, I'm talking about 20ft long sections that would require infrastructure in open air where people and animals might come in contact with it. The chemical route is unappealing for many reasons, not the least of which is personal safety and a responsibility towards the other island inhabitants.

[Louie1961]

I washing soda too controversial? https://www.instructables.com/id/Ele...val-aka-Magic/

[RoatanBill]

As a chemical/electrical treatment, it's OK.

However, the scale of such an operation for 20ft long pieces of steel just doesn't seem appropriate in a non industrial setting, which is my case.

[flushcut]

Sand blaster

[RoatanBill]

I've wondered about sandblasting/water blasting. How much metal does it remove when you start with 16 gauge? What type of media is best at what pressure and media to fluid (air/water) ratio?

I've got a 3500psi pressure washer but none of the other gadgetry for water blasting. Has anyone got real world experience using water blasting? I tried sand blasting using an under powered compressor and HF junk that didn't work too well and made a real mess, so I'd lean towards water blasting if someone has positive things to report.

[12V71]

For greasy stuff I use "Oil Eater" with an air siphon sprayer, then a hot water pressure wash on saw horses. Then it's easier to evaluate the rust problem. usually I just build then sandblast and paint after degreasing first.

[RoatanBill]

Tackit: There is no rental equipment on the island to speak of. I have to purchase anything I want to use and have it shipped in from Miami.

12V71: I never heard of "oil eater" or an "air siphon sprayer" but I'll check them out.

Build then blast - sounds reasonable. Doesn't the blasting degrease as well?

Do you have generic equipment recommendations - compressor stats, sand pot, media, etc?

[12V71]

Tackit: There is no rental equipment on the island to speak of. I have to purchase anything I want to use and have it shipped in from Miami.

12V71: I never heard of "oil eater" or an "air siphon sprayer" but I'll check them out.

Build then blast - sounds reasonable. Doesn't the blasting degrease as well?

Do you have generic equipment recommendations - compressor stats, sand pot, media, etc?

"Oil eater" is just a very strong detergent, I degrease, then build, if the rust is bad enough I have a sandblast contractor do it for me. He uses a "dustless" process that injects a small amount of water in the blast stream, believe it or not it wont leave rust behind. I have an Ingersoll Rand 185 CFM compressor and a 200# pot... Just don't like doing the blasting myself.

[Weldordie]

Doug Jackson at SV Seeker, apparently, had satisfactory results when using a sandblasting attachment to his pressure washer, .

[RoatanBill]

Weldordie: I think I'll get the necessary equipment for my 3500PSI washer to try this.

The only "sand" on the island isn't sand at all - beach sand - which is useless since it's soft limestone particles. I'll have to import some media.