Been too long since I posted! Got busy with work and travel. Then there is the new roof on the house. Thats a story that is even more twisted and frustrating than restoring 104006!
Oh well. No resto photos to put up today. But some general comments on welding equipment. I've noticed that this is a common theme on 356 Talk, so I'd like to share my experiences.
I started with a very inexpensive MIG. 110v, 70/90 amp. Bought from Home Depot nearly 20 years ago. Believe it or not, it was not too bad. I could weld sheet metal together, perhaps a little crudely, but satisfactorily for the occasional job I did. Lots of grinding and finish work was always required. This is what I started in on 104006 with.
Doing a 356 will really improve your welding skills in a hurry. Early on, I realized that the little Home Depot machine was inconsistent. The weld would start poor, get nice for a few seconds, then get poor again. Why? Initially the weld wasn't properly shielded. So, I made a little modification to the welder. A switch was added on the panle that allowed me to start the gas flow manually. I'd flick it on a second or two before starting the weld. May seem dumb, but it really made the welds much nicer when starting. Also bought a narrower tip, which helped focus flow on the work. The welds still got crappy later on. spotty and splotchy. A little more investigation revealed that the motor controlling the wire feed received its power from the general transformer. As the weld and machine heated up, power to the drive motor was changing. The wire feed rate was inconsistent. A separate power supply was installed for the wire feed motor, resulting in two AC plugs to stick in the will for my MIG. Sounds goofy I know, but the little Home Depot MIG really worked pretty smooth after these two modifications. I think I still have less than $300 in this machine. technique changed too. I only use the high heat setting, use the smallest wire I can get locally (0.023), and weld only in relatively short bursts. Get good penetration and nice smooth welds now on 18-22ga metal. No hard "worms", no hairy "bristles", much less grinding and finishing than I once did.
Early on with 104006 I wondered about spot welding. Seemed like a great idea. Its how our cars were originally assembled. Was in harbor freight one day, and they had this 220v pinch-type spot welder on sale. Bought it. Really cool. Worked great, made great welds......the first few dozen or so anyway. Then I pulled the trigger and nothing happened. Set it on the floor, under the car. There was a sharp electrical sizzle, a wisp of smoke and......the darn thing burst into flames! Dragged it out from under the car by the cord and watched it blaze away. A few days later I took it apart. Made in some former Soviet province (not China!). The transformer was held in place by two wooden pegs, which appeared to be hand-whittled twigs! So much for harbor freight. You get what you pay for.
I stopped in at the local welders supply house to but a Miller spot welder. No 220 units in stock, but he had a nice used 120v unit. Bought it. Worked OK. Used it a lot, but always a little unhappy. Needed more current. The lower voltage put too much heat into the tongs, which tended to reduce the welding current and required lengthy cool down periods.
One day I stumbled across a website for HTP Welding (
www.usaweld.com). They had an incredibly cool looking spot welder. $3500+, way too expensive for me. They did have an interesting looking 220V handheld unit for much less, about $600. I bought one. Its a gem! Makes beautiful and strong welds. Consistently. Every time. Triggers automatically as the tongs clamp, for a specified time. Clever little indicator to set the clamping pressure. They have a nice array of tongs too, for different situations. Made in Italy. I assume there are no hand-whittled pegs inside it, though judging by some of the coachwork I've seen on Ferraris, maybe I shouldn't be so certain! In any case, an excellent tool, well worth the price for anyone working on 356's.
Another spot welder! In between the Miller and the HTP welder, I acquired a Lenco machine. Heard about this from a 356Talk respondent. A single-sided spot induction welder. Quite expensive new. Found several used ones on EBay. Finally found an oldie but goodie for $175. Shipping cost me another $80. These are interesting devices. Tricky to use, but when all is right, make an excellent weld, working from one side of the panel only. I have found that tip cleanliness and shape are critical, as is good contact between the panels. The Lenco machine is VERY powerful, and will instantly vaporize a hole if the upper panel is not in solid contact with the lower. Also I found that clamping one lead to the work, and using the other trigger lead to just make one weld at a time gives better, if somewhat slower, results. Noted Justin Rio's comments about using a Lenco machine to duplicate the appearance of factory spot welds after plug welding. It will certainly do this well, but when used with care it can make welds just as strong as resistance welds. BTW, I have spent, and still occasionally do spend, a fair amount of time trying to break spot welds I've made. Gives a good feel for what is working and what is not.
Gas welding! My friend Lloyd was watching me working a tight and awkward spot one day with the MIG. He said I should be using a torch. I said that's crazy, no one uses torches these days, and besides, it takes years of experience. He said that was bunk. He went down the road, brought his back, and in a few minutes cleanly melted the inside corner together that I had been trying to get with the MIG. Smooth, clean, no mess. Looked like the factory had done it! I bought a gas torch. A small one, per Lloyds advice. Then he started teaching me to use it. He is good with it, I'm not. But, practice, practice, practice. Burned a lot of hair and skin. Set a few things on fire. It became kind of fun. Coaxing metal to melt and flow together is neat. Furthermore, being able to see it happen with a gas torch (no matter how dark the lens, you can't really see what is happening inside an electrical arc) makes you a better welder with other machines. After a while I got pretty comfortable with it. Not skilled by any means, but comfortable. There are so many places on a 356 that cannot be done any other way than with a gas torch. Flying in the face of conventional wisdom, if I could only have one welding tool, I can see that the gas torch would be the one to have.
Evolution to the TIG. One day I got an urge. Why not try a TIG? Went to Lloyd again. He has one and is quite good with it (he built a replica Lotus 7 from a pile of tubing and aluminum sheet). He said keep learning with the gas torch if I wanted to go with a TIG. I did. One day I went on line to that usaweld website. Spur-of-the-moment decided to order a machine. Expensive. Over $2000! Yikes! But it arrived and I started playing with it. Very interesting. A lot to know. A lot to juggle. TIG welding seems to require you have 3 (or mor) hands. It is very much like having an electric version of a gas torch. Still not very good with it. But I like it! VERY clean welds, when all goes right. You can stick a couple of pieces of sheet together with barely a ripple along the seam. Or you can burn right through them and make a mess. I'm at the stage now where its beautiful 50% of the time, a mess the other 50%. Have now used it for much of the battery box of 89379. I can see in the future I will be using it more and more. Must keep practicing, and starting to think I need to find some aluminum to weld.
So thats the summary of my amateur welding world, and the evolution that has accompanied my work on 104006. Probably of no great interest to most of you out there. I just like to write about my experiences for my own mental well being. I don't expect to ever be a skilled welder, but I have gotten to the point of being comfortable welding. I find that ALL these machines have their place and usefulness for a 356 project. I still pull out the el-cheapo, much modified, home depot MIG for certain jobs. But, if I could only have one, it would be the gas torch.
Maybe next week I'll find some more metalwork photos to post.
DG
Like you I'm just a hobbiest welder. I'll consider myself a real pro when I'm qualified to weld-on bungs for tanker cars that carry Chlorine gas and such like my buddy Warren does.
