Need advice on steel size..

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So after 2 plus years on display this piece has sold.. I need to make a pedestal for it to pick it up about 3 feet. Something like this..This piece is about 1100 pounds and is 10 feet in diameter. Was thinking of using 1/4 inch steel, The base of the sculpture is 25 inches by 32 inches by 1/2 inch thick.. Was thinking the bottom of the pedestal will be about 32 by 40 by 36 inches tall. A solid base plate with 4, 1/2 inch holes for anchors. The top of the pedestal will have a opening to allow for reaching down to the inside of the bottom to insert and tighten the anchorsbefore placing the sculpture on top of the pedestal.  Four studs to match the holes in the sculpture base to meet the four holes for nilock nuts to hold the sculpture to the base. Probably will add two cross braces out of 1/4 inch to help stiffen the four walls.. Everything mig welded together and powder coated to match. Only get one chance on this one so thought I would ask for advice from the forum...????From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:I think 1/4" is major overkill.My name's not Jim....
Reply:1/8th inch with more cross bracing?It will be on the sidewalk in front of a museum in Penn.    So snow and rain will be for sure....Need to people proof it.....From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:10 ga. would be plenty for the side walls, maybe 1/4" for top and bottom plates. Stiffeners may help keep the side walls from bowing in but would not be necessary for strength.The biggest issue if it is outdoors is wind load. You need to make sure the sculpture will stay attached to the base, and the base to the ground, if a big gust of wind hits it.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Kevin, I know why it took time to sell. The damned things bent!I know you're a welder, but have you considered concrete? I'd use four pieces of MDF board, four 2 x 4s. The two ends would be oversized leaving something to attach the 2x4s. inside I would rip a small piece of wood triangle to chamfer the concrete corners. Concrete will look good under paint when you are dead and your art is worth ten times what it is now.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:.....Last edited by Bosco99; 03-03-2015 at 10:53 PM.
Reply:I would use the 1/4" for the sides and 1/2" for the top and bottom . You could cut the top plate out of the center of the bottom plate. I would also use non shrink grout under the bottom base plate. Set the anchor bolts with enough exposed thread to use a leveling nut , washer, plate, washer, nut and jam nut plus an inch or 2 for leveling.
Reply:.....Last edited by Bosco99; 03-03-2015 at 11:07 PM.
Reply:Bosco99,,Lolololo!From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:1/4 " would be fine, though 1/2" on top to drill and tap for bolts would be more betterer.
Reply:Kevin,1/4" sounds like overkill, on the other hand you probably want to overbuild - a few extra dollars in steel to provide insurance against a silly liability claim for a failed pedestal seems like an easy choice.  This is one of those cases where overbuilding isn't going to hurt and wont even cost much more.  How confident are you of the mating connections on the art piece - I'd make sure you aren't building an invincible pedestal and relying on mounting connections that are insufficient.I really enjoy seeing your art and the videos on youtube.  Kudos to you for being willing to share your experience with everyone.Hobart LX235Victor 250 Oxy-Acetylene Rig (welding and cutting)Bobcat 773F-350, 1999, 4x4, 16' 10K# trailerOutdoor Wood Burner - 10 cords/year
Reply:1/4" is my vote, it's overkill, but it will turn out nice and flat and smooth, and plenty strong, don't bother with cross bracing, just weld up the edges and done.Ian TannerKawasaki KX450 and many other fine tools
Reply:Hey Kevin, put some spokes in that thing and mount it on an axle and you'll have a giant whirly-gig. GraysOrnamentalIron.com
Reply:Kevin-10' high x 1100# in public venue--implies having engineered design and signoff.The pedestal is one thing, the foundation and actual, supervised installation is another. You haven't mentioned what the foundation is.Wind load is a factor, people jacking around on it is as well.Blackbird
Reply:Originally Posted by dave powelsonKevin-10' high x 1100# in public venue--implies having engineered design and signoff.The pedestal is one thing, the foundation and actual, supervised installation is another. You haven't mentioned what the foundation is.Wind load is a factor, people jacking around on it is as well.
Reply:Definitely needs overkill.  A good 30 to 50 mph gust would definitely put a large torque at the base.  An idiot doing some stupid stunt on a skateboard could probably do some damage.  Plate is cheap. Squashing people isnt.Multimatic 200Ellis 1800Haberle S225 9" cold sawMM 300;  Spoolmate 30A w/ WC-24TB 302GDynasty 280 DX Tigrunner
Reply:Kevin ... I really enjoy your you tube channel ... Two things1.) What is it?2.) Hey Kevin What are u doing!!! I just love the way your wife (I assume wife) just happens to walk in with the camera and ask that question!!! As if she doesn't know!! Great job ...Located In SE OklahomaLincoln Mig 135Hobart Ironman 230 Mig5x10 CNC Table with DTHC & FTHypertherm PM65 on the tableMiller Bobcatwww.caneyagequipment.com
Reply:I know you're a welder, but have you considered concrete? I'd use four pieces of MDF board, four 2 x 4s. The two ends would be oversized leaving something to attach the 2x4s. inside I would rip a small piece of wood triangle to chamfer the concrete corners. Concrete will look good under paint when you are dead and your art is worth ten times what it is now. I agree with the concrete only because I'm a concrete contractor self employed for over 35 yrs. You could even get fancy and sandblast it or chemically exposed the aggregate. That way it would look good AND be maintenance free.Crete
Reply:Congratulations on selling the piece! Sounds like a nice high profile installation. I agree with some of the above, Wind load, therefore tensile strength, is really your biggest concern. It only weighs 1100 lbs so it won't take much steel to hold it up but the sail area is big. Crete may be right, Concrete with some J type anchor bolts? I think you want some long, large diameter(3/4"at least) anchors for this. Best of luck! I will look for it if I get down that way.www.facebook.com/gstreetworksLincoln Power Mig 210 Miller Maxstar 150Lincoln Idealarc 250/250 G Street Works LLC
Reply:Nice piece Kevin, great sale, good patience; as far as installation I think you, MJD and walker are barking up the right tree.  Just make sure that pedestal is fasten down!Some kind of Big Blue constant current welding machineAnother smaller yet, Blue machine (it's got wire in it)
Reply:Id have a structure hold it then skin it with something thin. Anchor it down good or deep so there's not a 10ft mobius rolling down the street in a storm.Welding/Fab Pics: www.UtahWeld.com
Reply:I look at it as similar to a sign structure. You have to determine square foot and center height mass and wind load. You may be looking at 3-4 yards of concrete , 4-5 'deep for a foundation. Most engineers could figure this out. You need a pretty substantial plate and sides to the metal base to prevent buckling and folding up in a high wind.
Reply:Wind shear, side loads, ,,, so many things to think about!They are planning on installing this one the sidewalk next to the building.This pad is supposed to be poured to 10 inches deep with rebar.I have used 1/2 anchors with epoxy for things like this in the past.Was figuring 4 four inch by 1/2 about 2 inches in from all four corners. Maybe I should make the base bigger by 12 inches?Make the base 38 by 46?Thoughts? ?From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:My vote would be make it bigger, and overkill. 1/4" , and 1/2"  at the top and bottom.Good luck, and love this sculpture!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:Is frost an issue? A plywood template to match the bolt pattern is generally used to set J bolts in the concrete. A 10" pad seems very skimpy. Usually on something like a sign or lightpole the foundation is a few feet in the ground since the soil helps with the overturning factor. The smallest anchor I would consider is 3/4" diameter. I would check with someone who can run wind load calculations on this.Originally Posted by kevinacaronWind shear, side loads, ,,, so many things to think about!They are planning on installing this one the sidewalk next to the building.This pad is supposed to be poured to 10 inches deep with rebar.I have used 1/2 anchors with epoxy for things like this in the past.Was figuring 4 four inch by 1/2 about 2 inches in from all four corners. Maybe I should make the base bigger by 12 inches?Make the base 38 by 46?Thoughts? ?
Reply:Originally Posted by JD1Sounds like a real engineer ought to analyze and make a recommendation. It's not like it's installed in someone's backyard 100' from their house. I wouldn't be at ease with anything less if it were my install. I'd think you'd want solid data before risking it.
Reply:.......Last edited by Bosco99; 03-05-2015 at 01:07 PM.
Reply:Lay it flat and name it Mobius Died."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Take a look at gas station signs.They use 1 inch bolts.I was pumping gas and noticed the steel post the held the light and CO2 system had a very nice weld.Just above the weld the post was rusting thru on all four sides.I watch your videos on Youtube, good stuff.I follow my dads example and build every thing stronger than it has to be.
Reply:Have a structural engineer coming next week to take a look at what I am doing...Both the pedestal and the concrete pad..You guys got me second guessing myself now....From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:Great! Would you mind posting his recommendation? I'm very curious.
Reply:Originally Posted by kevinacaronHave a structural engineer coming next week to take a look at what I am doing...Both the pedestal and the concrete pad..You guys got me second guessing myself now....
Reply:So this is the word from the Engineer. Pedestal:                1. Use ½” steel plate.  Weld all sides. Concrete Foundation/Slab:Use 6’-0” x 6’-0” x 6” thick concrete slab (minimum 2,500 psi concrete strength) with (5) #4 reinforcement each direction with 3” clearance from bottom of slab Connections:                This can be up for discussion. 1. There are two ways to connect the pedestal to the concrete (weld it to an embed plate or use anchor bolts.) 2. On the drawing it appears the holes on the bottom of the pedestal are located directly below the holes on the top of the pedestal.  Please confirm. 3. If you provide anchor bolts at the pedestal base can someone reach into the pedestal to easily tighten the anchor bolt nuts?  Please confirm.4. It was mentioned all the holes are 5/8” diameter.  Are they exactly 5/8” diameter or are they considered a standard 5/8” diameter hole meaning the hole is actually 5/8” plus 1/8” = ¾” diameter total.  If the holes are exactly 5/8” diameter it is recommended to use ½” diameter anchor bolts and bolts for the bottom and top of the pedestal respectively.5. For an anchor bolt connection at the bottom of the pedestal to the concrete slab it is recommended to use (4) ½” diameter Hilti Hex Head ASTM F1554 G anchor bolts with 4-3/4” minimum embedment into the concrete.  Provide a washer and nut and tighten snug-tight. 6.  For the pedestal connection at the top it is recommended to use (4) ½” diameter hex head ASTM 325 F1852 bolts with washer and nut.  You could tack weld the bolt head inside the pedestal with the threads extending upward for an easy connection.So I am going with the 1/2 inch plate for the whole pedestal..    Now the questions is        Mig   or Stick?If Stick which rod do you all suggest?Have a can of 7018 sitting there so I was leaning that way...From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200
Reply:why wouldn't you overkill?
Reply:Wow. Very interesting. Good to get it official. Could you post photos when it's installed?  I'm not expert enough to comment on Mig/Stick. I'd guess stick but others are far more qualified to comment than I.I saw a pic yesterday of a piece my sister did in art school. It was sort of horizontal and steel, looked to be maybe 15 - 20 feet long, 3 foot dia at the widest, hollow and she had to hire riggers to move it to the art gallery installation. Well, the riggers screwed up. The put their big canvas straps around it to crane it up but because it was hollow and where they put their straps, the weight of the piece crushed a section of the side in.She had a very quick and volatile temper, so I imagine the air was completely blue around there for some time. Hopefully you'll have better riggers than she had.
Reply:7018 has a 62000-74000 pound minimum yield strength, a 27-37% elongation, and 74000 - 88000 min tensile strength. Should be forever welded.HF 98233 Stick/TigHF  95136 PlasmaEastwood TIG200Eastwood MIG250Damn, I cut it twice already and it's still too short!
Reply:Originally Posted by tigmaniac7018 has a 62000-74000 pound minimum yield strength, a 27-37% elongation, and 74000 - 88000 min tensile strength. Should be forever welded.
Reply:If it's mild steel 7018 would be as strong or stronger than anything else. Also no problems if it's welded outside.
Reply:Thanks guys!! Off to the steel yard on Monday and get my butt to work.   This thing has to be on site by end of April...     May get to drive it there myself....   All depends on cost of shipping versus doing it on my own...From the desk of Kevin CaronTrying to be the best me I can!www.kevincaron.comAHP Alpha Tig 200x MillerMatic 251Miller Syncrowave 200