Guest 240hybrid Posted January 28, 2003 Share Posted January 28, 2003 What gauge is the sheet metal on a 73 240. Im about to start my body work and it requires the cutting a replacing of some small areas of rust. Also, I've heard that its better to go with a heavier gauge that what is stock for patch work, is there any truth in this? thanks Chase Quote Link to comment Share on other sites More sharing options...
Guest freakypainter Posted January 29, 2003 Share Posted January 29, 2003 it is my experience to patch with the same guage of metal that the car is made. when u start welding a heavier guage to a lighter guage you will often burn through the lighter as it takes more heat to properly penetrate the heavier. I dont know the exact guage for the car, i think it depends on application (heavier in the floors, lighter in quarters etc) hope that helps, good luck. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted January 29, 2003 Share Posted January 29, 2003 Yeah I figured that heavier gauge for patchwork was just a crock...I'll look through my manuals again. I think it says the gauge of metals in service manuals, havent been able to find it. I only have a service manual for a 77 280 and a haynes for 240/260's. The gauge of sheetmetal on the 280 is heavier than that of a 240 is it not? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 29, 2003 Share Posted January 29, 2003 Replacing the floor pans on my 240z with 20 gauge, and it looks to be the exact same gauge as Datsun used. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted January 29, 2003 Share Posted January 29, 2003 I figured it was somewhere around that gauge. I think it was 19 gauge for the 280 if I remember correctly. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted January 29, 2003 Share Posted January 29, 2003 Actually, I prefer to use a heavier gauge for the patch piece because it allows me to use a slightly hotter arc and allow the molten steel to flow very gently onto the peice being repaired. That way the heat of the molten steel is 'welding' the piece being repaired and not the arc from the welder. Just my 2c..... Tim Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 29, 2003 Share Posted January 29, 2003 Agree with Tim on riding that thicker piece of sheet metal and momentarily dipping onto that thinner gauge for a deposit. I also like a fabricated flange to frame the sheet metal rather butt weld the edges together. Takes a good adjustable mig welder to join thin sheet metal together with out burning thru. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted January 30, 2003 Share Posted January 30, 2003 Good info to know....I was wondering if that heavier gauge deal was true, heard it from a small body shop up the road. My father has a flanging tool that he picked up a while back. Figured I'd use it to make it alittle easier to patch some of these areas. I'll give your techniques a try, I'll practice on scraps first. I alway like to hear a few opinions before I tackle something were skill is needed. Thanks guys Chase Quote Link to comment Share on other sites More sharing options...
Guest freakypainter Posted January 30, 2003 Share Posted January 30, 2003 I prefer to cut a patch the exact same size and shape as the hole im trying to fix and butt weld it . granted it takes alot of practice but it makes for a nicer job and after you grind the weld down you dont have to do as much mudwork, but everybody has their own way. pracice on some scrap and do what works for you. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted January 30, 2003 Share Posted January 30, 2003 yeah Im worrying about warpage too. I've done work on a door a while back and the warpage drove me up the wall. I figure some warping will occur, but intend to just tack them in place and using a copper plate on the backside and a moist rag on top to remove some heat quickly after tacking...will the quick removal of heat with a wet rag cause any affects that are unwanted?? Like cause the metal to rise or sink make it more of a hell to work with, or should I only use the copper plate to pull heat from the area?? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted January 30, 2003 Share Posted January 30, 2003 In all the patching work I've done (and there has been A BUNCH on my V8 project car), I have had almost ZERO warpage, by tacking at opposite sides and laying a damp rag on the weld right afterwards. While this isn't necessarily a good practice for welding (tends to make the weld brittle), for body panels that have very little stress or structural needs, it's not a problem. Tim Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted January 30, 2003 Share Posted January 30, 2003 I didnt think that a moist rag would hurt it in any way, but I figured I'd ask to make sure. Thanks Chase Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted January 31, 2003 Share Posted January 31, 2003 All of the books I am reading say to have a hammer and dolly at the ready, weld an inch or two, then immediately hammer the weld flat. In the books they do this and with one or two passes with the grinder have a weld that doesn't need any bondo. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted January 31, 2003 Share Posted January 31, 2003 Yeah I have a couple metal working hammers and dollies too....I dont plan not to have the right tools. lol thats a good though though, I'll test that out on a few practice pieces and see if I cant get descent at it and use that tech. I wouldn't mind not doing as much filler/smoothing of the surface I patch. All of you are filling me full of good ideas and techniques, I'll see which one Im satisfies me and looks the best. Chase Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted February 1, 2003 Share Posted February 1, 2003 Tim240 you got it right....thats one the areas Im patching in. I agree, I dont see a brittle weld cracking on such areas that dont take that much tension. Theres not that much twist/pressure put on the sheetmetal there I wouldnt think. All of the areas Im doing patching on arent very sturctural parts such as frame rails and such, Areas Im patching in are....lower part of fenders, rocker, lower part doors, and fender lips. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted February 1, 2003 Share Posted February 1, 2003 Naw I wasnt gonna use a wet rag then hammer the welds flush...end up makein a mess out of the area. I ment after welding and hammering then try to remove the heat with a rag. Air hose idea seems plausible. Nobody ever did say what the exact gauge of sheetmetal is on a 73 240 though, dependin on which methods work best for me. Will test them out this weekend. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted February 1, 2003 Share Posted February 1, 2003 RacerX, I did allude to the fact that cooling the weld too quickly will effect the integrity of said weld, but do you concur that, for a body panel patch, say at the lower rear part of the front fenders where the Z tends to rust out, where there are no issues of structural strength required that the point is basically moot? Or am I missing something? I defer to your expert opinion: Tim Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted February 2, 2003 Share Posted February 2, 2003 I plan on using a mig and tacking the patches into place as to not warp the hell out of the area being repaired. I've had some experience with warpage from heat and will avoid using alot of heat as any cost. I would gas weld but am more experienced with mig welding and dont want all that heat that comes with gas welding. Quote Link to comment Share on other sites More sharing options...
Guest jdllaugh Posted February 2, 2003 Share Posted February 2, 2003 I'm no expert and haven't done any of this yet, but on body patch panels, such as repairing rustout around the fenders, I will use bonding glues. I understand from what I've read and talking with body/fender guys the new bonding agents work great for non-structural areas and do away with concerns about warping. Make the patch slightly larger than the hole your repairing, bevel the edges of the patch, and glue into place. I'm mig welding the floors and rails. Still have to be careful not to cause warping, but any cosmetic flaws will be hidden from view. I'm using 16 gauge for the floors and overlapping. I've practiced lap-welding the 16 gauge to the thin, rusty floor material I cut out of the car. With the right settings, it was a breeze. Quote Link to comment Share on other sites More sharing options...
Guest 240hybrid Posted February 2, 2003 Share Posted February 2, 2003 16 for the floorpans....I got some floor pans from MSA I'll be installing soon too and was think at least 18 if I have to patch some areas that the floorpans dont cover, which Im sure I'll have to do. for the fenders and rockers Im thinking 20 gauge sheetmetal. Went to home depot and looked at some today, but they didnt have any 20 and from looking at 18 and 22 looks like thats what I want for my patch work of fenders and rockers etc. I'll compare floorpans and fender sheetmetal to what Im buying before I weld it in too. Still have yet to decide if to go with same gauge for patches or slighly heavier, still experimenting. Thnks for all the recommendations guys, guess next thing is to get out there and do the work once I decide my method of destruction . Chase Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.