I have to make welds to attach the 14 gauge steel to the top of my COE bed. There are three welds that concern me. One is right down the center of the bed and then two along both sides. I have steel framework under the weld area in the center, but not along the sides. Is there any way to minimize wapring that may cause the bed to bow? Should I weld the entire edge or just short sections? Should I just plug weld it?
You could just s***ch weld it, or weld it doing short sections like you say. 14 gauge shouldn't distort much if any by s***ch welding a little at a time and alternating sections.
Am I better off with a wire welder or tig? I am conserned that over 14 feet of length, that the bed will try to warp downwards, especailly in the center.
To s***ch it, do I start at one end and work across, in the middle and go both directions or at each end back to the middle?
To s***ch, just run a bead only about 3/8 long. You can start at an end or the middle. The idea is that the area you weld has time to cool before you weld next to it. Take your time and keep the panel cool. Weld one at the middle, then one at a far end. Then do the other end. Now go back and fill in the middle of all the gaps. eventually, the entire panel will be welded solid. One great trick is blast the weld with an air chuck as soon as you weld it. You can watch the metal shrink, and lose any heat the weld made. Also, if you can, weld steel on the inside. You may not have to grind as much, and the thicker you leave a weld, the stronger it will be!
If you've ever watched an upholsterer do a T-bucket, their progress tacking the matl is similar. I'd start in the center and tack, then move outward in the six directions. You could clamp the ends and keep checking to see if things are moving as you s***ch.
weld some angle steel between your x members along your outside rail which will give you a straight line to land your bed on.you can then plug weld the bed to this angle and x members. Personally I would glue the bed down. there are some amazing glues now used in the transport industry that are as strong as welds and NO distortion. Not sure if you guys have it in the States but we use Sikaflex check out the bed I have built for my COE here http://rides.webshots.com/album/573567191xiTfam I will be glueing my bed onto the bed frame Cheers Willy
I would tack all corners, and occasionally in the middle also. When im welding sheet metal i jump around not start on one end and move out, or start in middle...
Are you talking about welding the floor to the tubing? If so, I'd do what KIWIWILLY said. I'd glue it in place with 3M Panel Boding adhesive, and weld three or four tacks (1/2 " long) down the center and both outer rails. Amazing stuff, and it also seals the bed floor the the framework so there will never be any rust issues in the future. Nice work on the bed, by the way. Read this. http://3mcollision.com/products/fillers-and-glaze/smc-repair/3m-panel-bonding-adhesive-08116.html
I like the glue idea (never thought of that) and the angle on the edge idea (I did think of that). It makes sence. Can I prime everything prior to gluing and not have sandwiched areas of bare metal between the bed top and the supports, or do I need to glue to bare metal?
3m makes a glue "panel bond". I would use it on the floor and s***ch weld the corners for good measure. If you use the 3m stuff, the floor and the tubing have to be bare metal, no primer. I would squeeze the glue on the tubing but use a small brush to cover the contact area that the floor will touch. A 2 inch roller would probably be faster though. The only draw back is the special 2 part gun that you will need. If you have a buddy that works in a body shop that would be a plus! we use this stuff all the time hope this helps. Chris
S***ch weld with short and spaced s***ches ALWAYS MADE IN THE SAME DIRECTION. Start with a tack at each end, progress to a few more tacks between. Then make a bead around 1/2" to 3/4" long heading to one end or side of the seam. Let it cool some. Jump over halfway, same. Other end, same. Back to first bead, same short bead. ALWAYS MAKE SHORT WELDS AND LET COOL. ALWAYS MAKE YOUR WELDS IN THE SAME DIRECTION OF MOVEMENT. NEVER COMPLETE A LONG SEAM WITH SHORT WELDS AND COOLING IF YOU HAVEN'T DONE THE SAME AS OTHER PANELS INVOLVED. I did learn a little bit from changing to welding sheetmetal compared to heavier metal changed to tubing and treated for driveshaft building.
Just another suggestion. My bed is entirely bolted together,floor, front and side panels and stake pockets and rear roll pan. Made it real easy to ***emble, remove for prep and paint,etc.
Bolting is more forgiving to the metal in this cir***stance. Seam sealers are readily availible if needed. If it is to be the deck of a flatbed of a truck to have a pretty painted deck, the deck cannot be welded to the structure because of differences in metal expansion from enviroment.
S***ch and use a copper backer...a s****. Or take a hunk of copper tube from a plumbing store and cut it open and flatten it out. the weld won't stick to copper and will pull heat......shove it behind the welding area...it will also help trap the shield gas to protect the metal....
try clamping a length of rectangular tubing on top of your decking, about an inch inboard of the outer welds, to hold it down flush..... This also will act as a heat sink of sorts while s***ching the welds
A coupe other views of the bed. There is a seam right down the middle that has tubing underneath it along the entire length. The sides do not have supports except where the cross supports are tied into the side rails. I also have thicker plates for the ends with keyholes cut into them for chains.
Bed looks great. Love the curved side rails and the lower panels are very nicel. Another thing you could drill a number of equaly spaced 1/4"- 5/16" holes in the floor pieces to line up with the tubing and rosette weld it. Maybe use a weldable primer between the two. What are your plans on finishing the bed floor ?
I've had customers do it both ways. If you use a panel bonder cleanliness is essential. Use a solvent designed for this use. If you weld it we use a Heat Sink Putty. It draws away the heat and is resuable for a couple of applications. We get ours from Cronotron Welding online. The stuff is amazing. We have to use it on the late model cars because the metal is so thin and is not steel but a mixture of recycled metals. Just stick the putty next to the seam and s***ch weld. By the time you come back it cool and ready for the next weld. Dan
My biggest worry is that running 14 feet of weld down the center of the bed, even in short s***ched welds, will cause shrinkage and then cause the bed surface to bow and warp up. First time i ever boxed a frame, it warped something terrible. I have thought of the rosette weld idea too and that seems simple and smart, but I wonder if they can also shrink and cause issues with the metal gapping to the structure below, between the welds. If that happens, will I have rattleing? The glue idea seems good too, but how to lay two 14 foot long sheets of steel in place that weights a ton, by myself, with wet adhesive and a tight fit...yikes! ahhhhhh!!!!! I can't make up my mind. Oh, heck with it, I'll just use 15,000 pop rivets..(kidding) As for finish, I plan on running rubber pyramid design mats on each side where the tires go (about 20 inches wide - pyramid is the pattern used on model A fords). I plan on painting the middle with stripes and graphics similar to old surf boards. So, if I weld it down the center, I will need to grind and finish the weld smooth.
I have thought of welding from underneath too...I have structure underneath and can easily run a bunch of short 1 inch long welds to the decking. But if I do that, will those welds shrink and cause problems?
Where I messed up is running one seam down the middle. If I had run two seams, one on each side with a wide section of metal in the middle, the seams would have been hidden under the mats. Too late for that now. Skidmarks, you are right, I will plan my welds and live with a nice pattern of uniform welds.
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