Ironhead Posted January 11, 2021 Share Posted January 11, 2021 (edited) I had similar issues as I learned how to weld on mine. The copper backing works great, but in some places isn't really an option. What worked for me was to go pretty hot on the weld, but do it EXTREMELY quickly, like just a split second weld. The short duration helps prevent blowing through and keeps the weld from stacking too high (more to grind off), but the high heat setting still gives good fusion. Like you said, once you have a few solid tacks, it's easy to keep adding more to them. It is also critical IMHO to have a slight gap (1/16" or less) between the two panels being welded. Otherwise, once the weld is ground flat, you will have countless pinholes to be filled. Some recommend TIG for thin sheet metal, but I tried TIG and it was a disaster for me. It is by nature a slower process, and I found controlling the heat to be a nightmare. Edited January 11, 2021 by Ironhead Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted January 11, 2021 Share Posted January 11, 2021 4 minutes ago, Ironhead said: I had similar issues as I learned how to weld on mine. The copper backing works great, but in some places isn't really an option. What worked for me was to go pretty hot on the weld, but do it EXTREMELY quickly, like just a split second weld. The short duration helps prevent blowing through and keeps the weld from stacking too high (more to grind off), but the high heat setting still gives good fusion. Like you said, once you have a few solid tacks, it's easy to keep adding more to them. It is also critical IMHO to have a slight gap (1/16" or less) between the two panels being welded. Otherwise, once the weld is ground flat, you will have countless pinholes to be filled. Some recommend TIG for thin sheet metal, but I tried TIG and it was a disaster for me. It is by nature a slower process, and I found controlling the heat to be a nightmare. I completely agree.’I had to learn both of those lessons over lots of trial and error. I just did my floor pans with more success. I still have more to grind off than I’d like, but the two metals had dissimilar thicknesses so I felt more comfortable removing material with a flap wheel than trying to minimize the extra wire. I have only been welding for 4 months. IMG_5233.MOV Quote Link to comment Share on other sites More sharing options...
rossman Posted January 12, 2021 Author Share Posted January 12, 2021 It's good to know that I'm not alone, suffering thru this job! Actually, I kind of like doing it though. It's almost like I enjoy working on it and talking about working on it more than driving it. I never thought about it too much but along the lines of quick, hot spot welds, I tend use .030 MIG wire instead of the thinner stuff. It seems almost counter-intuitive to use the thicker wire for such thin metal - but it works for me. Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted January 12, 2021 Share Posted January 12, 2021 5 hours ago, rossman said: It's good to know that I'm not alone, suffering thru this job! Actually, I kind of like doing it though. It's almost like I enjoy working on it and talking about working on it more than driving it. I never thought about it too much but along the lines of quick, hot spot welds, I tend use .030 MIG wire instead of the thinner stuff. It seems almost counter-intuitive to use the thicker wire for such thin metal - but it works for me. It is satisfying, I agree. The tough part is when you “peel back the onion” and realize you have months of work before she will be back on the road 😂. That might just be me though. The thing with rust is when you go looking for it, you usually find much more than you thought you had. Kinda like roaches 🤷🏽♂️ Quote Link to comment Share on other sites More sharing options...
grannyknot Posted January 12, 2021 Share Posted January 12, 2021 11 hours ago, rossman said: It's good to know that I'm not alone, suffering thru this job! Actually, I kind of like doing it though. It's almost like I enjoy working on it and talking about working on it more than driving it. I never thought about it too much but along the lines of quick, hot spot welds, I tend use .030 MIG wire instead of the thinner stuff. It seems almost counter-intuitive to use the thicker wire for such thin metal - but it works for me. You might want to buy yourself a small roll of Silicon/Bronze Mig wire and try it out, it's about the same cost as regular Mig wire these days but brazes at much lower temp than steel wire so there is less chance of warping. It grinds so easily that it is not a big deal if all of your welds are big and globby For sheet metal it is about all I use anymore, I have never brazed anything thicker than 18ga with the Sil/Brz but when testing it the parent metal always breaks first not the weld. You can use standard 75%Arg/25%CO2 but 100%Argon gives you better results, the technique is a little different from steel wire Mig but it is not too difficult to pick it up, on butt joints it likes an air gap the same width as the thickness of the sheet metal you are joining. Your progress looks good. Quote Link to comment Share on other sites More sharing options...
rossman Posted January 31, 2021 Author Share Posted January 31, 2021 (edited) Thanks grannyknot! I'll have to try that out. Progress has been slow the last few weeks. I got bogged down trying to decide how to repair the right curved section behind the tail light fascia where the top of the quarter panel and hatch come together. I was debating custom sheet metal vs. welding in the existing pieces I had on hand. I went with the existing pieces and I think it turned out pretty good. luckily it's a place that will be hidden for the most part so nobody but me will know it's there if it looks like crap after painting. This area was pieced together from 3 different sections. two pieces from this car and one from the 280z donor. I took it really slow to minimize warping and avoid blowing holes in the thin sheet metal. The next step will be to match cut and weld up the top part where it's currently overlapping - resulting in a butt-weld. Followed by grinding flat the welds and spot welding the dozens of remaining pin holes. I also welded up most of the 280z donor where I match-cut it to the existing sheet metal. Again, I took it very slow and moved around from one area to another to minimize warping. Thanks for looking! Edited January 31, 2021 by rossman Quote Link to comment Share on other sites More sharing options...
rossman Posted February 20, 2021 Author Share Posted February 20, 2021 Here is a little preview of something I've been working on in my spare time. It's still in work. The geometry is close but the mounting needs to be figured out. It's just sitting there in these pictures so the alignment is off. Quote Link to comment Share on other sites More sharing options...
walkerbk Posted February 20, 2021 Share Posted February 20, 2021 Please tell me that is 3d printed... looks awesome Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted February 20, 2021 Share Posted February 20, 2021 (edited) @rossman Here is a tip, but first my qualification. Started welding 5 months ago. Made many mistakes: going too fast and warping thin sheet, blowing holes, lots of pin-holes, proud welds that need a ton of grinding. First thing I learned is the welder DOES matter, and I now know why. A Lincoln Electric 140 (for example) is what I have now. It either feeds the wire at a consistent speed, or 100% stops (temporarily). This means when you hit a hidden spot of rust, or your arch is losing a solid circuit, the wire keeps traction in the machine or worse, bind. The gun may push back on you, but the wire will still feed. You get fewer holes, and the puddle is flatter when welding on super thin or shit base metal. Other thing i learned the hard way, turn UP the wire speed on thin wire (0.025). like, way up. I'm at 6.5/10 on fire feed on 2/4 power. probably be 2/3 that wire speed if i was running 0.030 wire. If you are getting a consistent frying sound without pulses or hissing, its probably spot on. Then try to turn DOWN the wire speed as much as you can just before you get the hissing. Welding with a consistent snapping arch at the lowest speed you can gives you a nice flat puddle, but still feeds enough to prevent the wire from prematurely melting on the tip. Turning up the speed from this point only serves to give you a prouder weld, and more grinding. The breakthrough for me was turning UP the heat. I now weld 20 gauge on 2/4 vs. 1/4 power. It takes LOTS of practice not to burn through. The huge payoff is no holes! the puddles flow out, fill cracks, and the back-side of the weld shows the puddle made it 100% through the base metal. I rarely ever need to go back and fill pinholes anymore. I still get burn-through in spots, but as you get better you also get better at filing them in. I can now fill 1/4"+ gaps in 20-gauge entirely with a Mig, the the metal deposited does not exceed the thickness of say... 14 gauge. Not ideal because you are burning gas and wire, but sure beats cutting a custom sliver. Yes it needs to be ground flush, but with a flap-wheel its quick work and looks like there was no gap to start with. il post some pictures as an example if it helps. To be clear, i am NOT a great welder or a professional. No formal training, just hours an hours or trial and error. I thought this might give you the confidence to experiment and see what works for me. I feel like im finally getting my stride. Edited February 20, 2021 by AydinZ71 Quote Link to comment Share on other sites More sharing options...
rossman Posted February 20, 2021 Author Share Posted February 20, 2021 7 hours ago, walkerbk said: Please tell me that is 3d printed... looks awesome Yes it's 3d printed out of PLA on my new Anycubic Chiron printer. I want to print the final version out of ABS but I'll need to build an enclosure for it first and fine tune the printer for abs. I'm new to printing on inexpensive printers which need lots of setup and fiddling with the settings to dial them in. I'm spoiled at work by Stratasys printers that just work right out of the box. Quote Link to comment Share on other sites More sharing options...
rossman Posted February 20, 2021 Author Share Posted February 20, 2021 Thanks @AydinZ71! From one novice welder to another, I truly appreciate the you taking the time to share your experience. Quote Link to comment Share on other sites More sharing options...
rossman Posted February 23, 2021 Author Share Posted February 23, 2021 I decided to bite the bullet and purchase a new gearbox for the car. It's only money, right? Quote Link to comment Share on other sites More sharing options...
Zetsaz Posted February 23, 2021 Share Posted February 23, 2021 New CD009? Quote Link to comment Share on other sites More sharing options...
rossman Posted February 23, 2021 Author Share Posted February 23, 2021 It's a new 1998+ RS5R30A z32 gearbox. The ones with improved synchros. The one I have installed now is Japanese export, supposedly with less than 30K miles but it's been crunching 1-2 and 4-5 gears since I got it. I figured I'd grab an new one before they're gone. Going with the CD009 would cost more than this one, plus I don't really feel the need for another gear. Quote Link to comment Share on other sites More sharing options...
Zetsaz Posted February 24, 2021 Share Posted February 24, 2021 18 hours ago, rossman said: It's a new 1998+ RS5R30A z32 gearbox. The ones with improved synchros. The one I have installed now is Japanese export, supposedly with less than 30K miles but it's been crunching 1-2 and 4-5 gears since I got it. I figured I'd grab an new one before they're gone. Going with the CD009 would cost more than this one, plus I don't really feel the need for another gear. The extra gear doesn't get you more than your current trans either. I'm pretty sure it has a shorter first but it's 6th is nearly the same as your fifth. Very tight gearing. I've considered it, but it's huge and I'm not sure would work great with my 3.9 rear. I know some are running that, but most have agreed that 1st in particular is just way too short, especially if you have a turbo. Quote Link to comment Share on other sites More sharing options...
rossman Posted February 24, 2021 Author Share Posted February 24, 2021 You are correct. The CD009 has a 3.78 first gear vs. 3.21 for the RS5R30A. I have a 3.7 diff which is the same as the z32. For me, the gearing is good, no real complaints. Regarding weight, yah, it's heavy, weighing in at around 150 lbs (2x stock 4spd) but it fit in the tunnel of my 240z with no mods required - at least that I recall, and I'm reusing the existing transmission mounts. Quote Link to comment Share on other sites More sharing options...
rossman Posted April 12, 2021 Author Share Posted April 12, 2021 (edited) Did a little work on the s30 this weekend. Between family, work, and cycling (in that order), there is very little time left for the cars - including helping my son with his s130 project car. Anyway... I welded/tacked on the right side corner piece. I am thinking more and more of going with the 280z donor piece even though it's full of holes and a few dings here and there. The aftermarket panel just needs to much fiddling to get right. Here it is clamped in place. I still need to make the left and right lip that holds the hatch seal. I also temporarily mounted the tail lights and rear tail light surround to check alignment. I had never noticed but the surround top lip was previously installed incorrectly, with the lip under instead of on top of the hatch panel. The tail lights are just sitting in there, not mounted yet. Edited April 12, 2021 by rossman Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted April 12, 2021 Share Posted April 12, 2021 @rossman nice work! I completely rebuilt my rear hatch slam panel as well. Had to build the underside support, since you have now noticed it is several sheets of thin metal spot welded with lap joints. Pain right!? Quote Link to comment Share on other sites More sharing options...
rossman Posted April 12, 2021 Author Share Posted April 12, 2021 5 hours ago, AydinZ71 said: @rossman nice work! I completely rebuilt my rear hatch slam panel as well. Had to build the underside support, since you have now noticed it is several sheets of thin metal spot welded with lap joints. Pain right!? Yes it is a pain in the butt. There is not a straight part in the assembly, including the seal interface - the hatch is actually curved higher in the center than on the sides. Quote Link to comment Share on other sites More sharing options...
rossman Posted April 19, 2021 Author Share Posted April 19, 2021 Here are a few pictures of the work I did this past weekend. Making slow and steady progress. I forgot to take a picture of the ground down spot welds before test fitting the top plate. I'll get it next time. I flip-flopped on the top plate. I think I am going to use the new panel. While it doesn't match perfectly and definitely has it's flaws it's cleaner than the 280z one and doesn't have any rust on it. The 280z one would need to be patched up. Anybody have experience bonding the top panel with 3M Panel Bond? Here is the patch panel cut to shape fit up. Panel clamped... Spot welded Test fit the top plate after grinding down the spot welds. It's just sitting there, not lined up properly. I had to spend considerable time re-shaping the replacement panel...lets just say it was a little...off. Quote Link to comment Share on other sites More sharing options...
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