What thickness for fab table top?

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A couple years ago I bought a very heavy duty table to use a as my primary fab table. the top is 36" by 64". Its made entirely out of 3" channel and is mounted on 10" industrial steel casters. I scored it for about what one caster costs new. It is however in need of a new top. The current top is something around 3/32" or 1/8" and it is severely washboarded to the point where it cant really be used for layout. Luckily its only tack welded from the underside so removal shouldn't be too terribly difficult (angle grinder). I'm wondering how heavy a piece of plate I should buy for my new top. I'm thinking somewhere between 1/4" and 1/2" but specifically what that I'm not sure. My one other thought is that I'm thinking of getting something heavy enough that I could get a piece 36" x 72" and let the excess hang over one side. This would be so I could cut a sizeable rectangular hole out of the overhang for doing fully supported cutting like my dads uncle has in his shop. But his table top is something like 1" or 1-1/4" (hes a professional fabricator). Id like to hear your guys opinions, as well as any other ideas like my cutting hole that I could do to make this thing as functional as possible.Hobart Stickmate LX AC/DC buzzboxLincoln SP-100 MIGMid-size O/A setup with heating tips and cutterJet 5"x6" Horizontal/Vertical BandsawAtlas 15" drill press
Reply:Originally Posted by thebobcatkid86. . .My one other thought is that I'm thinking of getting something heavy enough that I could get a piece 36" x 72" and let the excess hang over one side. This would be so I could cut a sizeable rectangular hole out of the overhang for doing fully supported cutting. . .
Reply:I agree, 3/4" at least. Thats what I have on my 4' square table  (6" overhang all around) and I wouldn't want any less.Cut an MGB and widened 11" C4 Corvette suspension and LT1 Chevrolet power & 6 spd. Pictures here:Part 1http://forum.britishv8.org/read.php?13,7581Part 2http://forum.britishv8.org/read.php?13,22422
Reply:Wow, 3/4... that's pretty heavy, and you say at least, so would a full 1" be better? I guess in this business its hard to have too heavy. If I were to scrap the overhang idea, could I go for something lighter, like 3/8 or 1/2? Conversely, is an overhang something I'm going to wish I had if I don't? And if I do have overhang would it be good to have it on more than one side? Say on one long and one short side? or all the way around? and how much? I don't weld/fab professionally, at least not yet, but I do enjoy the stuff that Ive done. Even though its really just a hobby for now I want to make sure that every piece of equipment that I own is as useful, versatile, and durable as it can be. I have access to a plasma cutter from a friend of mine, which is what I was planning on using to modify the overhang portion however its maximum severance capacity is 1/2". Though too, my steel supply is also a job shop so I suppose I can have them modify it for me, as Im not very proficient with my cutting torch and I want it to look fairly professional. I don't know if there's a name for the hole near the end of the table but you guys know what I'm referring to right? Is it a good thing to have? My one other issue may be actually getting this piece out of my truck and onto the table frame. My "crane" as it were, is a very small skidsteer which has a book lifting cap. of 750 lbs. Short distance, on flat concrete, I can probably lift a little more than that but even so, whatever I buy especially if I go a full 1", its probably gonna be close.Any particular alloy to ask about? or is normal A36 sturdy enough?Hobart Stickmate LX AC/DC buzzboxLincoln SP-100 MIGMid-size O/A setup with heating tips and cutterJet 5"x6" Horizontal/Vertical BandsawAtlas 15" drill press
Reply:I agree thicker is better. My 2'x4' top is 3/4" and I can move/ load it in the truck by myself with a bit of work.As far as the overhang, I'd go as deep as the clamps you have will go. That lets you clamp to any egde you want as far in as the clamp will reach. My buddies bench someone in the past chopped the top so it would fit tight to a wall. Now in the middle of the room, there's no overhang on one long side, so you can not clamp to that edge..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Ihave a piece of catwalk grating, the kind made of flatbar on edge, mounted flush w/ table top to use for a cutting surface.                   MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:One more vote for "thicker is better"I would get the thickest plate you can safely handle, if you go too thin, you have to put something under it to keep it flat, especially with the overhang you are considering.Yup
Reply:i have 48x48" 1/2" thick...but i only weld paper clips, thumb tacks, razor blades, coke cans and aluminum foil.  yes, i'm being sarcastic what are you guys welding that you need tops so thick?is the extra thickness for heat dissipation? extra thickness keeps the top flat?  to what point is there a point of less return?  sure, a 3 inch thick top dissipate heat real nice and keeps itself flat, im sure much nicer then 1/2 inch top, but if you're going 3 inch thick already, why not get 3 3/4?  I've seen some amazing (pro) fab work done (not by me) on a half inch thick top.  but that's just me though.
Reply:Originally Posted by mla2ofusIhave a piece of catwalk grating, the kind made of flatbar on edge, mounted flush w/ table top to use for a cutting surface.                   Mike
Reply:Originally Posted by oxy moroni have 48x48" 1/2" thick...but i only weld paper clips, thumb tacks, razor blades, coke cans and aluminum foil.  yes, i'm being sarcastic what are you guys welding that you need tops so thick?is the extra thickness for heat dissipation? extra thickness keeps the top flat?  to what point is there a point of less return?  sure, a 3 inch thick top dissipate heat real nice and keeps itself flat, im sure much nicer then 1/2 inch top, but if you're going 3 inch thick already, why not get 3 3/4?  I've seen some amazing (pro) fab work done (not by me) on a half inch thick top.  but that's just me though.
Reply:Well I went out the garage this afternoon and after remeasuring the frame of the table I find it is in actuality 36" x 55". Memory got the best of me... and Im only 22  haha. Anyway, most of my clamps that I own are 6" or less throat but I do have a few 8 inchers.  After listening carefully I have decided that a 48" x 72" top, 1" thick is what I would ultimately like to have. Centered, this allows for 6" overhang on the long sides and about 8" on the short sides. And besides being heavy enough to do anything I could ever imagine, that also gives me enough mass to drill and tap bolts on the edge to mount a piece of catwalk for a cutting surface... just a thought.Burnit - you mentioned yours was heat treated, stress relieved and blanchard ground. My steel supplier that I was planning on buying from, they are a job shop but their website doesnt mention anything about those processes. Would it be in my best interest to find a supplier, or possibly another facility with those capabilities? and how much would those cost for a piece of steel that size? Also is A36 mild steel adequate, or is there possibly some other alloy that I might look into?I read another thread on here about table tops, and one reply was saying dont not under any circumstances, weld it to the frame. He was sayin even 1" will distort, the suggestion being to drill and tap the underside to bolt to the frame. I was planning on using a few 2" long fillets, probably with 1/8 6011, from the frame to the top, which is what is on there now. Should I be worried? Would a different rod be less likely to cause problems? or should I drill and tap? Id hate to spend all that money and time and effort just end up with a not flat table. According to a steel supply calculator that I found, its around 980 lbs. Now I just have to call the steel yard around the corner and get a quote.Hobart Stickmate LX AC/DC buzzboxLincoln SP-100 MIGMid-size O/A setup with heating tips and cutterJet 5"x6" Horizontal/Vertical BandsawAtlas 15" drill press
Reply:Check the price on a full 4' x8' sheet while you are at it. Often the price can go up if you don't get a full sheet. I'm frequently amazed that I can get the full sheet at almost and in one or two case less than a short sheet. The weight on 1" will probably still make it pricey, but if it's not too bad you can have a small table also, just for beating and so on if you want..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:So, dredging up an old thread here, had put this project on the back burner for awhile. Finally called the fabricator/supplier around the corner from me, and quoted me $550 for 3/4" and $680 for 1", 4'x6'. You guys have said time and time again that heavier is better. Currently, Im debating whether my Bobcat 453 is enough to lift this piece into place or if I should spend a little more and take the table to them have them set the plate with their crane and tack it on. Book lifting spec on the loader is 700lbs.Hobart Stickmate LX AC/DC buzzboxLincoln SP-100 MIGMid-size O/A setup with heating tips and cutterJet 5"x6" Horizontal/Vertical BandsawAtlas 15" drill press
Reply:a 4' x 6' piece of 1" plate weighs 816 lbs, 3/4" is 612 lbs. I have a 4' x 4' table with a 3/4" top and the top alone weighs just over 400 lbs. One thing I did was to bolt the top to the table frame from below. I drilled and tapped holes in the plate and set it on 1/4" thick rubber pads then bolted from underneath. This did 2 things: one it didn't warp the top by welding and two, it took a lot of the ringing out of the steel of you are pounding on it.Cut an MGB and widened 11" C4 Corvette suspension and LT1 Chevrolet power & 6 spd. Pictures here:Part 1http://forum.britishv8.org/read.php?13,7581Part 2http://forum.britishv8.org/read.php?13,22422
Reply:I just talked to the shop around the corner, the guy said hed sell me 4' x 6' 1/2" for $250. My main concern is the rigidity when clamping to what will be overhangs of 6" on the long sides and 8" on the short sides. How much more of a potential for bending is there over 3/4"? When Id called this same place 3 or so months ago I got a phone quote of $550 for the same in 3/4" What do you guys think? Am I being too picky?Hobart Stickmate LX AC/DC buzzboxLincoln SP-100 MIGMid-size O/A setup with heating tips and cutterJet 5"x6" Horizontal/Vertical BandsawAtlas 15" drill press
Reply:Personally, I think you're way over thinking this whole thing.  I used to work at a decent sized, very successful welding shop and all their tables were 1/4" except 1 that we had for HUGE excavator buckets and forks and stuff.  it was 4 or 6" thick and flat and all that crap, but it wasn't Blanchard ground.  that's just overkill.  Anyway - 99.9% of everything we did was on the thinner tables, and they worked JUST FINE. Look at it this way - if you're welding on your garage floor, ANYTHING will be better.  a little planning goes a long ways - but the diff between 1/2 and 3/4 is quite minimal.  If it were me - I'd just go with what was the most readily available.  if you bend an edge - you're a metal fabricator, heat it up, bend it back, and add some gussets so it don't happen again.  time is money - if you're spending extra time on jobs welding them on the floor while you plan the perfect table that will never break or need modification, you're wasting money.  if all else fails, you can always sell the table you build on CL and build a new one - cuz it probably ain't going to be perfect on the 1st try.Millermatic 135Syncrowave 250
Reply:If you are going to weld and cut on it ,dont even consider blanchard grinding the thing.First time you stick some slag to the table,all that accuracy is gone.If you want a one inch top but can only come up with half inch plate? Double up! Weld  a half inch plate to the legs then bolt the second plate to the first.When the top plate is fubar,you still have a good foundation and less cost to replace the thinner top plate.tractor,loader.dozer,backhoe,and all the tools to keep em movin
Reply:i have tables built from 3/8, 1/2 ,5/8  and 1". Thicker is always better.  I just got a quote from a grinding shop in Alabama- 4'X8'x 1" ground flat on one side and milled square on all four edges- just a hair under $1500.00. Thats delivered to Nashville too. This table will be for tig work and furniture building. I like the top to be heavy enough you dont have to weld it down. If you mount the top on top of threaded adjusters you can tune it in very quickly. People often warp their tops by welding too much.
Reply:I just found this on Craigs List. Its 72" X 36" X 1 1/8" thick. I'm going to go take a look at it tomorrow evening to make sure its flat and square. He wants $300 for it. Price seems reasonable compared to what you guys have been quoted. I was wanting to build a 48" X 72" bench, but beggars cant be choosers. What do you guys think for the price? I'm going to try to get it for $250.Millermatic 251Spectrum 300 PlasmaEverlast PowerTig 250EXEverlast PowerCool W300Harris / Victor OACraftsman 13 Speed Drill PressProTools Air/Hydraulic Bender48" BrakeCompressor, Notchers, Grinders, etc.
Reply:I do most of my welding on a table that's only 1/8" thick.  I have a smaller table that's got a 3/8" top.  For when I'm pounding and shaping, I have a bench with a 1" thick top.  If you're starting out, I think mot krig is right -- use whatever you've got handy and don't waste a lot of time worrying about it.  I also agree with 1-800miner that grinding it perfectly flat is wasted on the same surface you're doing a lot of welding on.  You want to be able to weld stuff to the table, sometimes, and then break it loose with a grinder.  It won't stay pretty for very long.Jack OlsenMy garage website
Reply:Im bumping this to say that I did finally get a top for my table. After talkin to the guy in charge at the fab shop around the corner, he sold me a piece of half inch - 52in x 73in - for what he said was just over cost at $200. Im happy, works great, and as my dad was so fond of saying after a major purchase... "Now we can finally be somebody" hahaHobart Stickmate LX AC/DC buzzboxLincoln SP-100 MIGMid-size O/A setup with heating tips and cutterJet 5"x6" Horizontal/Vertical BandsawAtlas 15" drill press
Reply:My first table was 1/8" thick, I was happy to have a steel top I could ground small parts to or tack them if necessary.  Sure beat working off the floor with the ground lead falling off the workpiece all the time.Next was a 1/2" thick table I bought used from a retired welder.  It is great.Now I have a 1" thick table, no real advantages from the 1/2" table for the work I do, looks impressive though."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:Just picked this up Friday.  26" x 41" x 1" thk w/ 2" radius corners.  305 lbs.  Paid $200.  This will be the top to a combo fab table / tool chest I'm building.  It'll have a pattern of 35 1/2-13 holes so I can use my milling machine step clamps.I'm not sure what the steel supplier (Cyclone Steel, Houston) used to cut it...think is was a CNC plasma table...whatever, the thing is damn near perfect square, dimensions are spot on, and the cut is absolutely smooth!  Now I'm wondering if he would have cut the holes for me as well.  Next time I'll be sure to ask.Make no mistake, this thing is heavy.  I ended up buying a 1 ton engine hoist to lift it onto the milling machine to drill / tap the holes.  Tried elevating it on rails and pipe rollers but I chickened out....sudden attack of common sense I think....doesn't happen to me very often.I'm thinking of having it Blanchard ground.  There's a shop here that'll do it for about $60 but from what I'm reading on this forum it might end up being a waste of money.  I laid a carpenters level across it and measured about .020 gap so it's seems pretty flat from the get go.  But those ground tables look so cool..... Attached ImagesMiller 211 w/ spool gunMiller Dynasty 200DXLongevity 60i IGBT plasmaO/A w/ crappy chinese torch/gaugesSouth Bend 10K latheGrizzly 4029 10x54 millGrizzly 7x12 hor bandsawangle grnders, bench grnder, bench belt sndr7.5 hp 80gal cmprsor
Reply:That defiantly looks like it was cut with a CNC torch. Plasma is not commonly used on that thick of steel. I would have to say I would not go less than 3/4. I have worked on tables (including today) and its a huge PITA for keeping projects flat. Starting out, 1/2 will get you buy. Anything more serious, go 3/4 or 1". I have never seen anything less than 3/8? 1/4 would be brutal.Torching holes in thick plate is not always pretty. I find the holes can get ob longed and not very straight (Kerf). Larger holes 2" and over turn out nicer as you can start in the middle and work your way out. The plate takes a while to preheat to get a good piercing. Best to drill holes to start the cut. So I think you went with a better option by drilling your own holes.Bobcat kid... congrats on the table. Should work out for you quite well for ya.Last edited by oxygen454; 01-11-2011 at 12:56 AM.
Reply:its like anything the bigger the betterThe thicker the better, ribs on the backside are good, dog holes and a vice mount are good too. 1/2" is min, 3/4" or 1" is better as well as a nice sturdy frame, don't forget jacking bolts to level it off. Overbuild it now and you wont be wishing later.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:I'm building a work deck for the back of my mobile rig.  It'll be 3/8" plate to keep the cost and weight down.  Either steel prices have skyrocketed since this thread started, or steel is much cheaper in other parts of the country.  The quotes I have for 4'x8'x1/2" is $430 and for 3/8" thick is $325.  That's new steel, not reclaimed.Anyway, my real point in posting is that with a little planning and some c-channel, square tube or angle iron, you can make a 'thin' sheet of steel much stiffer without adding all that cost and weight.I'll be welding up the frame for my truckbed work top this weekend.  I'll post photos in the thread I started to show what I'm talking about.Lincoln publishes a really good reference book on design of weldments that shows how to build lightweight, but very rigid structures from welded steel.  It's less than $20, and even if all the math is greek to you, the pictures and drawings in the book do a good job of illustrating the concepts.Yes, welding on the steel plate will require a lot of clamping, and maybe pre-stressing the plate to counter distortion.  But I think the effort to do this is worth the savings in cost and weight.Just my $0.02.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:I made a lot of money off mine and its just 3/16".  If I was building another it will be 3/8".  The Craig list one sounds great!