hydrochloric acid - an issues with using it for rust removal?

admin

I believe denizens of the US prefer to call it Muriatic acid.Scored myself 3x  3m lengths of 150mm C section and a 3m length of 15cm x 1cm plate for 30 bucks, reckon the C section is the perfect thing to cut in half then weld together for a heavy duty bench top. Make a nice 1.5m x 0.9m bench.Only problem is the old boy I got them from had left them out in his yard for about 3 years after becoming to ill to use them. They are well rusted and pitted, so I figured using hydrochloric acid to remove the rust would be the go. But after reading various threads here with people talking about using low hydrogen rods etc for better weld results, I thought that perhaps bathing steel in hydrochloric acid  (HCL obviously being hydrogen based) might not be the best thing to do if I want to go and weld it later on.But then I thought it is only going to be a welding bench so would it matter anyway?, is it an issue, would it matter for the intended use - what do people reckon?
Reply:Just neutralize the acid with a base like baking soda when your done.  Generally hydrogen is only a problem in electroplated parts, not parts cleaned in an acid bath.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Grind, bevel, weld. You should be just fine. If you do use the acid, give it a good rinse and you're good to go.
Reply:Don't use it in doors or everything will be covered with rust
Reply:Don't even store it indoors.
Reply:And an acid rated respirator and goggles are a must!!!From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:A citric acid bath would be less hazardous.
Reply:cheers fella's. Got mask, gloves etc lined up.Job will be done  outside on an area where the weeds are the only things growing. Got a 10 litre bottle of epsom salts left over from the wife's above ground pool supplies which should be good to wash it down with afterwards.G-son Hydrochloric is like a buck a litre here, other acids start about 20 bucks a litre. I'm to cheap to use Citric
Reply:Using epsom salts (Magnesium Sulfate) to neutralize Hydrochloric Acid isn't what this chemist would call a "best practice;" use baking soda (sodium bicarbonate) in water if you can (unless you can measure the pH of the waste in that case use sodium hydroxide in water).Honestly, you'd be better off using something like naval jelly, which contains phosphoric acid and will be easier to neutralize.  Since it is a semi-solid it would be much easier to handle as well.Outrunning my headlights since '81.
Reply:I'd wire wheel it, fast and no chemicals. If you really want to clean it up after that you can use a rust converter (phosphoric acid) that will turn the rust to a phosphate coating that you can paint over.
Reply:Originally Posted by jackdawg... hydrochloric acid  (HCL obviously being hydrogen based) ...
Reply:cheers OkieDave
Reply:Originally Posted by OkieDaveAll acids have one or more free hydrogen atoms (well, hydronium ions: H+); that's what makes them acids.  Bases have free hydroxide ions (OH-); when the two meet, they become water (H2O); that's neutralization.Some acids are stronger than others (HCl being one of the strong ones), and can vary in concentration (which is not the same as strength).In any event, as long as you neutralize it properly (baking soda is great because it bubbles; when the bubbling stops, it's pretty close to neutral), you should be fine.