Announcement

Collapse
No announcement yet.

Load question for the engineers....

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Load question for the engineers....

    I'm trying to set up a "light weight" welding table in my shop, since I have absolutely zero floor space left available for a traditional bench/table.

    I had a hair brained idea that I could mount a steel plate on the front of my wooden workbench that I built (heavy duty, 14 foot long) and have it hang straight down in front of the bench on hinges. Then just pivot the plate up and stick a couple of legs under the front of it when I want to use it as a table.

    I found some hinges to use (McMaster # 1852A61) but I'm not sure how many I would need to use in order to support the back side of the table? The 1/4" steel plate I picked up is 2 ft X 5 ft long, and weighs in at 106 lbs.

    What say you?
    Last edited by Highpower; 05-26-2010, 01:21 AM.

  • #2
    Oops, your link doesn't go to any particular hinge. You'll need to give us the MMC catalog number.

    It sounds like you're going to have the long edge of the plate attached to the table with two feet sticking down or out. That's going to block access to a lot of stuff under the bench when it's down. Also, the welding table won't be far enough away to keep MIG spatter or grinding grit from getting on the stuff that's on the bench.

    Can you post a picture or a sketch of your shop layout? That'll guarantee you'll get some good suggestions from the many ingenious members of the forum.
    Any products mentioned in my posts have been endorsed by their manufacturer.

    Comment


    • #3
      I don't know if the weight of the added wing is the only consideration. I would think that standard door hinges would be enough to hold it, perhaps a set of three as you would use for a heavy door.

      BUT, I would think that a welding table would be used for some heavy items which may be ten or twenty or even more times as heavy as the table. So that would change the equation by a lot. Also, you will probably want to hammer on something on it sooner or later. Again, that changes the equation. You may want to consider some very heavy hinges or perhaps the legs should be both at the front and at the back of this added wing.
      Paul A.

      Make it fit.
      You can't win and there is a penalty for trying!

      Comment


      • #4
        Correct. Long edge of the plate will be attached to the front of the bench with 2 ft hanging down. Blocking the lower shelf part of the workbench will actually be a benefit for me, as I store some items there that I would prefer to be out of sight anyway.

        There won't be a lot of splatter to be concerned with as this will mainly serve as a small TIG welding table. Even so, I figured I could always throw a welding blanket over whatever might be sitting on the bench top behind the plate.

        As far as my shop layout is concerned - just imagine 50 lbs of stuff crammed into a 20 lb box. That pretty much sums it up.

        The heavy duty hinges are rated at 150 pounds (per pair) but actually I think the idea of adding a couple more legs to the back side as well makes more sense than relying on multiple hinges alone. Just have to put in 4 sockets for the legs instead of 2.
        Hmmmm....

        Comment


        • #5
          You could have a hinge and swivel at one end of the plate where it attaches to the bench. The other end would have a hinge that can easily be detached from the bench.

          To use the welding table, you'd lift it up from the stored position, and attach two legs. If you needed more working room or access from the back side, you could put a third leg under the detachable hinge, and swing the table out from the bench. That would leave one corner attached to the bench for stability, and you could put a leg there to keep from overloading the hinge/swivel.
          Any products mentioned in my posts have been endorsed by their manufacturer.

          Comment


          • #6
            Why do you need a bench and a welding table?
            why not just put the steel ontop of the bench and work on that.
            If you work on something delicate or needing a clean surface, keep some 3/16" thick 'door skins' around to cover a small area of the table needed.

            If you do put a steel plate ontop of wood, while my brother tryed his VERY HARDEST to set my dang table on fire by welding at 120A ontop beween two parts and buckleing the sheet metal ontop of the table and scoring the wood due to heating and did not succeed, a second small 1/4" plate is great for shielding the table from excessive heat during welds beween parts on the table.

            Protip: Devise a way to connect the ground clamp from your welder to the table, It makes welding small/ackward parts MUCH easyer when it just grounds through the table insted of trying to clamp a ground onto a part.
            And usally just laying on the table is good enough connection to prevent arcing/marks on the work and table.. sometimes heats up however.
            Just a 1/2" bolt welded somewhere on the table works wonders for my weld subplate (My 'welding' table is actualy painted 18guage over wood. Pathetic I know! but works... Just havent gotten around to buying better when I have this junky old table I reperposed...
            Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

            Comment


            • #7
              It doesn't sound like a good idea to me. If you place a horizontal surface in front of your work bench like that within a few milleseconds it will have so much stuff on it that you will never be able to lower it again. Then the regular bench will be unreachable which means it will never be possible to use it again.

              About the only way that I see this working is to make the new extension hinge UP. That way when you are done using it for the moment you can clean it by lifting it up with an overhead chain fall to dump the contents on the regular bench and hide it all at the same time. The stuff under the bench will begin to look pretty good and if you just spray it all with flat black it won't really show that much.
              Free software for calculating bolt circles and similar: Click Here

              Comment


              • #8
                Are you going to get the flatness you require if you support the 1/4 plate on each edge? It sounds like it would sag under weight, or twist if your legs are not even. If you weld stiffening ribs on to it you may also bow it.

                106# is really nothing to be concerned with.

                Ideally you also want your table level so that you can use level protractors to set angles.

                Sorry but it sounds like a PITA. Do you need 5' long or is that just because of your bench size? I'd lean to making a more dedicated bench area.

                Comment


                • #9
                  I know you asked for engineers, but are getting over-engineers. Sorry, but I'm one of them as well. I would look in McMaster for a piano hinge (or two) to span the entire length of the plate. It will stay a lot flatter and will be much stronger (a hundred pounds ain't much to worry about, but the weight of the project and the inevitable hammering will increase the "load"). Piano hinges can be had in a miriad of sizes. Go big.

                  $000,000,000.02
                  Mark

                  Comment


                  • #10
                    knees

                    Originally posted by Highpower
                    and have it hang straight down in front of the bench on hinges.
                    Wheres your knees go? Not your knee mills, I mean your legs. At my bench I'm picturing your steel plate would intersect my thighs about 4 inches up from the knee. Either that or I'd end up mighty bow-legged after a couple hours.

                    I think you'd gain a lot more by building shelves under the bench than a "garage door" that blocks the underside of the bench. That's where I keep my "second tier" shop equipment, and big grungy stuff like coiled air hoses. I suppose storing air hoses underneath a welding table wouldn't be so great of an idea...

                    Replace your main bench with steel. Then, in the event you really need to work on wood (I'm guessing, when woodworking and you don't want rust stains? Maybe when finishing?) then you buy a nice small fancy plywood sheet from home depot and absolutely cover the bottom of it with magnets, like enough to need a crowbar to peel it off the table. Or you could drill/tap/screw mount a temporary wood table on the bench.

                    How does the sawdust and paint solvents and stuff from woodworking mix with the sparks and hammers and stuff from welding?

                    Another idea, don't hinge the top, screw/dowel/whatever it into the edge of the top of the workbench. Then store the sheet behind the bench when not using it. Yes I know you said its 106 pounds, but, its going to awkward no matter what... (edited to say, excellent excuse to buy an engine hoist)

                    I always though it would be cool build/buy a flat bed trailer and beef up the trailer floor to act as a giant mobile welding bench. Two for the price of one, kind of. Not so good in the rain and snow, I suppose.

                    Comment


                    • #11
                      An Alternative

                      Originally posted by Black_Moons
                      Why do you need a bench and a welding table?
                      why not just put the steel ontop of the bench and work on that.
                      If you work on something delicate or needing a clean surface, keep some 3/16" thick 'door skins' around to cover a small area of the table needed.

                      If you do put a steel plate ontop of wood, while my brother tryed his VERY HARDEST to set my dang table on fire by welding at 120A ontop beween two parts and buckleing the sheet metal ontop of the table and scoring the wood due to heating and did not succeed, a second small 1/4" plate is great for shielding the table from excessive heat during welds beween parts on the table.

                      Protip: Devise a way to connect the ground clamp from your welder to the table, It makes welding small/ackward parts MUCH easyer when it just grounds through the table insted of trying to clamp a ground onto a part.
                      And usally just laying on the table is good enough connection to prevent arcing/marks on the work and table.. sometimes heats up however.
                      Just a 1/2" bolt welded somewhere on the table works wonders for my weld subplate (My 'welding' table is actualy painted 18guage over wood. Pathetic I know! but works... Just havent gotten around to buying better when I have this junky old table I reperposed...
                      If there is concern about charring the wood table top, why not put a piece or two of 1/2" cement board (used as under-layment for ceramic floor tile.) between the steel plate and the wooden table top. This will provide sufficent insulation and the table top will be be safe.
                      Bill

                      Being ROAD KILL on the Information Super Highway and Electronically Challenged really SUCKS!!

                      Every problem can be solved through the proper application of explosives, duct tape, teflon, WD-40, or any combo of the aforementioned items.

                      Comment


                      • #12
                        Evan, you know me all too well....
                        I haven't seen the work bench top in years, there is so much "stuff" piled on it. I need to be able to lower the welding table so whatever is on it will fall to the floor, because there is no place for it to go on the bench if I raised the table.

                        Horizontal storage space is non-existent in my little cracker box basement. I have a single path to walk around the perimeter of my "shop". The rest of the floor space is FULL. I've been working on tossing everything I can to make more room, but I've got so little space to begin with.

                        106# is really nothing to be concerned with.
                        It is when you aren't a spring chicken any more, and have to raise and hold that 106# with one hand - and install legs underneath with the other, by yourself. No room for any over head hoist either. (7 foot to the overhead floor joists.) I have to duck under the heating & A/C duct work as it is.

                        Mark, I did look at piano hinges at McMaster. But the heaviest one they had (6 ft.) only has a 1/8" hinge pin. Too light for my tastes.

                        I also thought I would make a square tube frame to tack underneath the plate for support and to attach the leg "sockets" to, but is sounds like that is a bad idea also for fear of warping the plate?

                        Comment


                        • #13
                          personally, I HATE stuff like that which "easily tilts out of the way when finished"....... AS IF I was ever doing just ONE thing..... and could clean and polish the shop when that was done.

                          But, assuming you pursue the unreachable, your question related actually to the load.....

                          I would not worry too much about the hinges. Several door hinges will be fine. Anything you would put on that table will be sufficiently well supported by them. if you can find the type that is NOT just formed metal, so much the better.

                          The 0.25" or so hinge pins will support more than you want to put on it. The stamped metal plates will probably bend before the hinge pins shear, and with several thick hinges even that will be at an absurd load.

                          Your problem will be attaching the hinges to the existing bench, The attachment is the weak point. Ordinary screws up into the bottom are a no-go, so thru bolting with carriage bolts is probably a good plan.
                          1601

                          Keep eye on ball.
                          Hashim Khan

                          Comment


                          • #14
                            Welding in the basement isn't such a good idea. Welding makes a LOT of smoke. Do you have a plan to deal with that?
                            Free software for calculating bolt circles and similar: Click Here

                            Comment


                            • #15
                              Well I ordered 3 of these and will take my chances.


                              Yes, the plan is to bolt the hinges to the front of the existing work bench frame (4x4). The top of the work bench overhangs the frame by a couple of inches, so the hinges and steel plate will hang below and behind the bench top edge.

                              Ventilation is provided by an adjustable speed, dual cage range hood that is mounted over the opposite end of the workbench and is vented to the outside. That is where I do my bullet casting, and the hood has worked just as well for my MIG welding in the past. I haven't yet set off the smoke detector down there, so hopefully that will continue to hold up.

                              I can control the direction of cross flow needed as well by opening different windows on the side wall or the opposite wall from the bench location.

                              Thank you for pointing that out though Evan, since it is a valid concern.

                              Comment

                              Working...
                              X