Type of aluminum to use in a sewage plant

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I have been contacted by the local sewage dept to replace some covers at the plant that are rusted out steel.  The sewer gasses really corrode steel so they want to use aluminum.  The most aluminum work I've done is on trailers & dump trucks.  Most of them are 6061 I think.  Would 6061 be resistant to the sewer gasses?  If so I've been looking for a reason to get a whole sheet of 6061.Miller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools
Reply:they use alot of chemicals in sewer treatment plants, I would make sure there wont be a chemical reaction to the aluminum...Of all the things I lost I miss my mind the most...I know just enough about everything to be dangerous......You cant cure stupid..only kill it...
Reply:For communal plants we use EN AW 5754 (AlMg3/54S) or EN-AW 5052 (AlMg2,5/57S) for clearing bridges (main beam), stairs and hatch covers.EN-AW 5050 (AlMgSi0.5/50S) extruded for handrails (horizontals) and EN-AW 5754 for the verticals and mountingplates.In sewage environment Stainless will eat rapidly through Aluminium due to electrochemical corrosion, especially when H2S is around. So isolate well or even better, avoid contact between the two.
Reply:Originally Posted by ElGuapoFor communal plants we use EN AW 5754 (AlMg3/54S) or EN-AW 5052 (AlMg2,5/57S) for clearing bridges (main beam), stairs and hatch covers.EN-AW 5050 (AlMgSi0.5/50S) extruded for handrails (horizontals) and EN-AW 5754 for the verticals and mountingplates.In sewage environment Stainless will eat rapidly through Aluminium due to electrochemical corrosion, especially when H2S is around. So isolate well or even better, avoid contact between the two.
Reply:Thanks for the help guys.  These are the areas that need to be replaced.  There are 2" deep channel in the concrete that they slide gates into to block flow to do maintenance.  The gates are aluminum, but they are only in temporarily.  I have to check what material the channels are.  They looked like either aluminum or galvanised but might be stainless.  If I use stainless what would be best. Attached ImagesMiller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools
Reply:316L would be best but I hope you are not doing it from 2" thick. 304 would probably last long enough and is much cheaper. You could use 1/2" and add 1 1/2" legs underneath.Those look very much like the project I did from 304.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:The slide channel is 2" into concrete but only 1/2" wide.  If I use aluminum I was planning on using 1/4".  It don't need to be real tight, just stay in place.Miller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools
Reply:If the guides are galvanized steel, would the use of stainless cause the guides to corrode faster?Miller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools
Reply:Originally Posted by osweldIf the guides are galvanized steel, would the use of stainless cause the guides to corrode faster?
Reply:316304SteelZincAluminiumMagnesiumGalvanic order. Keep 'em together as close as possible in a wet and conducting (salt, acid) environment.
Reply:Originally Posted by ElGuapo316304SteelZincAluminiumMagnesiumGalvanic order. Keep 'em together as close as possible in a wet and conducting (salt, acid) environment.
Reply:You can use any crappy aluminum. It will feel right at home.   I believe Bird Poop Arc Welding is the correct procedure for that location using a HF flux core 110v welder...Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Can't their engineer spec it in the job documents?
Reply:Do your homework before you give your quote....I welded up a large stainless tank a while back just to find out it was an ACID tank and I used 308 filler....I had to grind it out and use 316 I wasn't real happy about that but it was my fault for not asking    Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by B_CDo your homework before you give your quote....I welded up a large stainless tank a while back just to find out it was an ACID tank and I used 308 filler....I had to grind it out and use 316 I wasn't real happy about that but it was my fault for not asking
Reply:I've worked at waste water plants for for 15 years now. Is this municipal or industrial sewage. like most have said. Make sure to find out exactly what is in the channel. If it is a chemical (usually sodium hypochorite.....chlorine) mixed with the treated wastewater, gonna want stainless..  The blue motor with yellow plate looks like a muffin monster or mechanical grinder/comminutor. So this may be the influent or even a pumping station.. That is the good stuff. As far as the grating goes we have switched over to the synthetic type. some kind of resin. this way we could use stainless or aluminum for brackets and plates depending on where we were. just make sure two different types of metal don't touch.. We have lots of old aluminum slide plates so we used aluminum in lots of places that were dry.  Stainless in area that would be submerged.
Reply:It is the inlet pump station for a municipal sewage treatment plant.  I found out the guides are some kind of composite, not metal.  I will be using 5052 aluminum, couldn't find any stainless near this area.  I got the job & my quote was $50 under what they has budgeted so they didn't get other bids.  Also the plant is less than 2 miles from my shop.Miller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools
Reply:This is the drawing I did of it. Attached ImagesMiller XMT 304 cc/cvMiller 12RC w/ 15ft Tweco #4 GunMiller 30A SpoolgunCustom Thermal Arc TA 10/270 Generator "Thermal Star"Smith oxy/acet-propane with weld, cut & rosebud tipsAnd of course grinders, chop saws, hand tools