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what does the muriatic acid do?

Posted: Sun Apr 30, 2017 4:49 pm
by Hillbilly Stills
Im fairly new to this so don't be to hard on me. Am I understanding that the acid will help with dross removal? I use Stainless, CR, and copper.
Thanks for any information.

Re: what does the muriatic acid do?

Posted: Sun Apr 30, 2017 5:15 pm
by acourtjester
it works fine on CR but not stainless, I think it eats Copper, use a 50/50 ratio and soak for a few hours. Clean very good so rust does not start.
Use a plastic tub to soak parts, many different sizes (home depot has mud mixing tubs 2 sizes) Tracker supply has a larger on for about $80 animal water tub.

Re: what does the muriatic acid do?

Posted: Sun Apr 30, 2017 7:55 pm
by Gamelord
Muriatic acid eats a lot of the dross off of your parts, it also removes all mill scale, just soak and then rinse off. I have left 14ga parts in over a 24 hour period with no issues to the metal but nearly all dross is gone. It will also round off the sharp edges a little.

Re: what does the muriatic acid do?

Posted: Sun Apr 30, 2017 10:02 pm
by little blue choo
Gamelord wrote:Muriatic acid eats a lot of the dross off of your parts, it also removes all mill scale, just soak and then rinse off. I have left 14ga parts in over a 24 hour period with no issues to the metal but nearly all dross is gone. It will also round off the sharp edges a little.
I have let 16 & 14 gauge soak for over a week and no issues.

Rick

Re: what does the muriatic acid do?

Posted: Mon Jun 05, 2017 2:09 pm
by Hillbilly Stills
Thanks guys.. just mixed up some and have parts soaking

Re: what does the muriatic acid do?

Posted: Tue Jun 06, 2017 8:16 am
by michmetalman
It can be pretty pricey. If your anywhere near a Menards check it out there. I got some for $2.87 a gallon a few weeks ago.

Re: what does the muriatic acid do?

Posted: Fri Oct 13, 2017 5:40 pm
by Jwagnon89
So how'd it go? Im also new and looking for the most efficient way to remove slag.

Re: what does the muriatic acid do?

Posted: Mon Apr 30, 2018 11:51 am
by DMoneyAllstar
little blue choo wrote:
Gamelord wrote:Muriatic acid eats a lot of the dross off of your parts, it also removes all mill scale, just soak and then rinse off. I have left 14ga parts in over a 24 hour period with no issues to the metal but nearly all dross is gone. It will also round off the sharp edges a little.
I have let 16 & 14 gauge soak for over a week and no issues.

Rick
I have noticed random pitting and every-now-&-then some staining when I leave my 14/16ga artwork piece in for more than 2-3 days. I use plastic tubs and 50/50 or stronger mix.

If you stack parts on top of one another and leave in for more than ~12hr, the acid may etch a shadow of mating parts onto one another. If you're grinding, it will go away. But light sanding won't take it away.

Every now and then I get a copper-colored plating effect on edges of pieces. I have no idea where this comes from. Grind or sand blast takes care of it.

On very fine details that are perhaps only 0.10" thick, longer term soaks in acid may eat the dross and the small feature. You may find that more of your fine feature was dross than actual solid steel. All depends.

I neutralize with baking soda & water mix in a tub. Tub works better than a spray-bottle. With spray bottle, I'll later finish & clear-coat my parts and get a couple small spots with an orange haze. It's not rust -- it's reacting muriatic acid. Submerging the part in the tub of neutralizer guarantees all of the acid is gone without any rogue drops or spots.

**Muriatic acid is a dangerous liquid with a dangerous vapor. It needs to be handled properly with proper precautions & PPE. Try to keep it outside if you can, as it will flash-rust anything ferrous in your shop / barn / garage and to keep the fumes downwind.**

Re: what does the muriatic acid do?

Posted: Mon Apr 30, 2018 2:21 pm
by steel 35
Magic :lol:

Re: what does the muriatic acid do?

Posted: Tue May 01, 2018 11:08 pm
by CGT80
Even 4-5 hours is too long for my 16 ga parts. They get pitting that is no good when it comes to easily putting a finish on them. 2 hours is better. Very fine details can be damaged by the acid, but if there aren't extremely fine sections, it does a great job of smoothing the edges and removing the dross and mill scale. Even when some dross remains, it comes off easier after soaking. When in a hurry, I will skip acid and just use surfacing discs.

I have read that acid can cause hydrogen embrittlement when you go to weld parts, so it might be better to skip it for something that needs a structural weld.

Re: what does the muriatic acid do?

Posted: Fri Jun 22, 2018 9:51 am
by FallMtnWorkshop
I have never used this stuff, what kind of safety precautions do you guys use? Someone mentioned the fumes and doing it outside if possible but how bad is it with skin contact?

Re: what does the muriatic acid do?

Posted: Fri Jun 22, 2018 10:28 am
by SegoMan DeSigns
What skin? LoL

Keep the hose handy and wear plastic gloves and PPE (apron, visor & respirator). Like posted above baking / laundry soda will neutralize..

Re: what does the muriatic acid do?

Posted: Wed Jun 27, 2018 10:18 am
by DMoneyAllstar
SegoMan DeSigns wrote:What skin? LoL

Keep the hose handy and wear plastic gloves and PPE (apron, visor & respirator). Like posted above baking / laundry soda will neutralize..
Yep, spend $50 on Amazon and get some PPE. I look like Walter White from Breaking Bad when I'm ethcing parts, lol. God only knows hat my neighbors are thinking, but thankfully they're 400+ feet away. :lol:

I got into rushing some etched parts this past weekend and was using "old" baking soda + water mix that had tinted orange (iron). And go figure, after rinsing, drying, sanding and clear-coating...I had a couple of those pesky orange hue spots show up. I had to media blast, sand and clear those couple pieces again. Stupid lazy me. Water and baking soda are dirt cheap.

I agree...not all parts need etched. If I'm using a grinder finish/texture, there's no need to etch. But if I'm doing a sanded / smooth finish, the results are very clean and consistent with etch pieces. Also if the dross got nasty for whatever reason (rare, but happens), I'll let it soak in acid for a little bit and the stuff comes off with almost -0- effort.

Etch / soak time also depends on your concentration. I've got a "15min-to-1hr" tub (mostly muriatic acid right from the bottle) and an "overnight" tub (50-50 water & muriatic acid).