Motorsport Fabrication Fundamentals: Step 4: Welding
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Step 4: Welding
12.38
| 00:00 | - Before we begin the welding process, we obviously need to decide on the welding method and for this, we've chosen MIG. |
| 00:06 | Although there's no reason you couldn't use TIG instead if you wanted. |
| 00:10 | It's just going to take a lot longer to weld up all of your parts. |
| 00:13 | Generally, for workshop fit out items like this, we prefer MIG welding as it saves a lot of time and still gives great looking results. |
| 00:21 | For the best results, it's always advisable to perform a few test welds to dial in your settings for the welder. |
| 00:27 | To do this, we've just prepared a couple of sections of off cut material and chamfered them the same way as the actual parts for our bench. |
| 00:35 | This gives us the opportunity to adjust the welder so that we're getting good penetration into the base material which will provide for a strong weld. |
| 00:42 | One of the key elements to consider during the welding process is ensuring that the frame for the bench top is flat and square. |
| 00:50 | This should go without saying but it's actually a deceptively tricky process since the welding process tends to make the parts move around as the weld progresses. |
| 00:59 | The surface that you set up your job on will also have a major effect on the flatness of your finished product, so working on a rough or uneven surface is going to ensure poor results. |
| 01:09 | We're using our steel work bench which we know is perfectly flat and it's large enough to support the entire frame. |
| 01:17 | We can start by laying out the components and getting them roughly into position. |
| 01:21 | We can now use a square to help us square up each corner. |
| 01:25 | This should get us close but we're still not going to likely get a perfect result by just relying on the square. |
| 01:32 | A tip here when squaring up parts like this, is to use a tape measure and measure the diagonal length between opposing corners. |
| 01:39 | The measurements of each diagonal should be identical if the frame is truly square. |
| 01:44 | When we're happy the frame is square, we can cut off any excess wire from the MIG hand piece and tack the outside corners together. |
| 01:52 | This needs to be done carefully as the heat from the welding can result in the parts pulling and moving which will then affect how square the parts remain. |
| 02:01 | This requires us to recheck the frame after all four corners are tacked and we may need to make some minor adjustments if the parts have moved. |
| 02:09 | With the frame tacked and the frame still square, we can repeat the process and tack the inside corners. |
| 02:14 | Again, we need to recheck the frame for squareness after this process. |
| 02:19 | Since the frame is still only tacked, any adjustments should be easy to make with some light taps with a hammer. |
| 02:25 | Now we can clamp the frame to the workbench and fully weld the top surface of each corner. |
| 02:30 | Next we release the clamp and we can fully weld the outside corners before flipping the frame over and welding the other side. |
| 02:37 | The weld that will be on the top surface of the table needs to be linished flat so that the table top will sit against the frame properly. |
| 02:45 | This can be achieved using an angle grinder with a flap disc fitted. |
| 02:49 | We don't want to fully weld the inside corners of this frame as the table legs are going to locate here and a weld bead would make it impossible for the legs to sit flush against the top frame. |
| 03:01 | Now we can move on and weld up the legs for the table. |
| 03:03 | We're going to use the tabletop frame as a jig while we weld in the lower supports to the legs. |
| 03:09 | This will help ensure that everything fits as expected as well as remaining square and true. |
| 03:15 | We can start by clamping the legs to the frame using G clamps. |
| 03:18 | We're now going to lay a section of offcut material on the workbench and this is going to act as a packer. |
| 03:25 | This will set the height of the lower support off the ground, remembering that we're actually working on the bottom of the legs at the moment not the top. |
| 03:33 | With our support in place, this can be then tack welded in two locations. |
| 03:37 | We repeat this process on the other side of the table before adding the third lower support that runs from one side of the table to the other. |
| 03:45 | Before tacking we want to make sure that the support is flush with the face of the legs and this can be achieved using our square or even just an offcut of scrap material. |
| 03:54 | Now we can remove the legs from the table, flip it over and reposition the legs into the top of the frame. |
| 04:01 | We can hold the legs in place using G clamps before tack welding them to the top frame. |
| 04:06 | Once we're happy with everything here, we can fully weld the seams where the legs meet the top frame. |
| 04:12 | We also need to weld in a centre brace to the top frame. |
| 04:15 | Using our tape measure we can correctly locate it before tacking it and then welding it in place. |
| 04:21 | With everything tacked, we can now flip the table over on our workbench and work our way around, fully welding all of the seams that we've tacked. |
| 04:29 | It might sound silly but it's a good idea when you're finished to just double check you haven't missed any seams. |
| 04:34 | With so many seams requiring welding it's easy to miss one or two, particularly when you need to constantly relocate the frame to allow easy access for welding. |
| 04:44 | Now we can prepare the foot plates. |
| 04:47 | These require an M20 nut to be welded to them to accept our adjustable feet. |
| 04:51 | The nuts that we're using have a plating applied which makes them a little difficult to weld so we're going to use the linisher first to remove this coating where the nuts will be welded. |
| 05:01 | Now we can clamp the nut to the plate, ensuring the alignment with the hole is correct before welding. |
| 05:08 | These nuts don't need to be fully welded the whole way around and welding alternate faces of the hex will provide more than enough strength. |
| 05:15 | We can now drop the plate into location on the legs of the bench. |
| 05:19 | As you can see, we've purposefully made the plate a little smaller than the outside dimension of the leg and this provides a nice chamfer for our weld. |
| 05:27 | After tacking each corner, the plate can be fully welded to the leg and this is repeated on the remaining three legs. |
| 05:34 | Now we can move onto the frame for our welder. |
| 05:37 | We're using a magnetic clamp here to help locate our components at a 90° angle and support them as they're tacked. |
| 05:44 | To help ensure the parts don't move during welding, we can use G clamps and clamp them to the work bench before fully welding the outside edge. |
| 05:52 | As with our tabletop, it's a good idea to check the parts remain square and adjust as necessary before welding the remaining faces. |
| 05:59 | With the welding completed, we can linish the weld beads using our angle grinder. |
| 06:03 | We can now get the two parts of the welder frame located onto the rest of the table for welding. |
| 06:09 | We've used a pair of G clamps to help hold the frame in position while the location is confirmed. |
| 06:15 | We can also make sure the frame is square to the table legs using a square. |
| 06:19 | We've temporarily clamped an off cut to the frame to help ensure that it's aligned flush with the table leg when it's tacked into location. |
| 06:27 | With these two parts of the frame welded in place, we can add a horizontal bar. |
| 06:31 | To help with aligning this with the other two parts of the frame, we've clamped an off cut of flat plate to the underside of the frame so that the horizontal bar can simply sit on top while it's welded in place. |
| 06:43 | This process is repeated on the other side of the frame and then the remaining joins can be filly welded. |
| 06:49 | We can now go ahead and weld up the box section that will hold our filler rod. |
| 06:53 | We've cut the open ends of these at a 45° angle which will help avoid collecting dust as well as making them easier to access. |
| 07:01 | We simply want to ensure that these pieces are properly aligned and then a short weld at each end can be applied on the top and bottom. |
| 07:08 | There's no need here to fully weld the entire length. |
| 07:11 | With the individual tubes welded together we can then align and weld the plate to the back of them. |
| 07:17 | With the filler rod holder complete, we can now flip the table over and get it into location using a 150 mm ruler to ensure it's aligned central with the TIG support frame. |
| 07:27 | Next we need to build a pair of hooks for our cables. |
| 07:31 | We're making these out of some 40 x 5 mm steel strap and these will need a 90° bend in them. |
| 07:38 | We've started by making a mark 100 mm from the end of the strap and then marking a bend line across the strap at 90° using our square. |
| 07:46 | The 5 mm thick material is too thick to bend nicely in our sheet metal bender so we're using a home made press break tool that works in conjunction with a hydraulic press. |
| 07:57 | You could make something similar or you could choose to simply bend the strap in a vice with a hammer or alternatively cut and weld the two pieces together at the desired 90° angle. |
| 08:08 | Next we can mark the desired location on the table leg and weld the two pieces of strap in place. |
| 08:14 | It's best to start by tacking each end before confirming and adjusting the angle of the strap as required. |
| 08:21 | Once we're happy with the location, the straps can be fully welded. |
| 08:24 | Now we can assemble the bottle mount and we'll start by fitting the back support. |
| 08:28 | Once we've marked the location of this, we can use a pair of magnetic supports to hold it in place while it's tacked. |
| 08:35 | Once it's tacked in place, we remove the magnets and fully weld the joints. |
| 08:39 | With this horizontal support in place we can locate and fit the vertical support. |
| 08:44 | We can use a scrap piece of offcut material at the base of this vertical strap to achieve the same offset that it has at the top and a G clamp is being used to clamp it to the horizontal support. |
| 08:56 | Now it's a case of assembling and welding the lower bottle mount and we can use our magnetic squares to hold these parts in place while they're welded. |
| 09:04 | We can then mark the location on the table and weld it into location. |
| 09:09 | This is the perfect time to test fit our gas bottle and make sure that everything is going to work as we expect. |
| 09:15 | We'll need a way of securing the top of the bottle which we're going to do with a fabric strap. |
| 09:20 | And this requires a couple of slots to be cut into a section of steel strap. |
| 09:25 | With the slot locations marked out and centre punched, we can then drill the holes using our drill press. |
| 09:31 | With the holes drilled out, we still have a section of steel in between and we can simply remove this using a file. |
| 09:37 | Using a flat file next we can now work the slot into our desired shape as well as adding a chamfer to the edge. |
| 09:45 | Alternatively you could achieve the same result by using a die grinder instead. |
| 09:49 | With the slots cut, we can test fit our fabric strap to ensure a good fit. |
| 09:54 | Before welding it in place, we're going to add a couple of slight bends to the strap so that it better follows the contour of our gas bottle. |
| 10:02 | We also took the opportunity to radius the corners on our linisher for a more professional look. |
| 10:08 | The finished strap can now be clamped to the vertical support, squared up and welded in place before a final test fit of the gas bottle and strap is made. |
| 10:17 | Now we can make the alloy tray that the welder will sit on and this is being cut from a flat sheet using a jig saw. |
| 10:24 | Due to the way our frame is designed we will need to relieve this alloy sheet to clear the frame and we can mark this out and cut it using the jig saw again. |
| 10:32 | The finished cut on the alloy sheet will be slightly rough so we can clean this up and remove any burrs using a flat file. |
| 10:38 | We're going to be bolting this plate to the frame using counter sunk cap screws so the locations for these need to be marked out and drilled. |
| 10:47 | Once the alloy sheet is drilled it can be deburred and then counter sunk so that the head of the cap screw doesn't protrude from the surface. |
| 10:55 | The frame will then need to be tacked to suit the M6 thread that we've selected. |
| 10:59 | Once complete, the protective film can then be removed and the sheet bolted in place. |
| 11:04 | Next up we can weld our caster wheel mounts to the frame. |
| 11:08 | We're using a single mount at the welder end to allow for a swivelling caster and two fixed casters at the bottle end. |
| 11:15 | These simply need to be located to suit then they can be clamped in place and welded. |
| 11:20 | We can now install our adjustable feet into location as well as the casters which we're securing with cap screws and nyloc nuts. |
| 11:27 | Lastly we can secure the top to our bench, starting by moving it into location and aligning it carefully. |
| 11:34 | We can then use our adjustable square to mark the location for our fasteners. |
| 11:39 | These can be centre punched and drilled. |
| 11:41 | Again, we're using counter sunk head cap screws, this time in M8 so that the top surface will be flush and we need to carefully counter sink the bench top to the correct depth. |
| 11:52 | Now we can move on and tap the holes in the top rails of our bench frame before completing a final assembly of the bench and adding our gas bottle, welder, earth strap and filler rods. |
| 12:03 | If we want to make the bench easy to move we can simply raise the feet so that the casters contact the ground. |
| 12:09 | And finally, we can test out our hard work by laying down some welds for the first time. |
| 12:14 | Once last consideration is protecting the finished bench since the raw steel finish will corrode over time. |
| 12:21 | We've chosen to have the frame of our table powder coated black however there's nothing wrong with simply applying a coat of spray paint instead. |
| 12:29 | It is important that the actual bench top is left raw however for conductivity to the work piece. |
