MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - ? for the welders in the group


I'm thinking about getting a welder. I've done a little MIG welding & while the welds are strong, i've never liked how they look unless they're ground/filed smooth afer the fact --- something i've never been able to do effectively on a inside corner.

So, i'm thinking about TIG welding... does TIG enable you get the nice looking sort of weld? Does being able to do that take years of practice or is it something one can do reasonably well after several hours of practice? What other considerations do i need to think about before going this route?

Thanks in advance,
Rob
rficalora

Rob, I bought a TIG system last fall. I love it, but it does take some practice. I'm not very proficient in its use yet, but have already been able to produce some very nice looking welds. I spent a lot of time researching the various machines on the market here in the US and finally setteled on the Lincoln 185 unit. There are a couple of features it has that I think make learning to produce good looking welds easier for the beginner. It is slow in comparison to my MIG, so for larger pieces of 1/8" thickness or greater I will be using the MIG more, but have done quite a bit with 3/16" using the TIG just for practice. I finally started using it on my sheetmetal and am having better results than with the MIG and with less distortion than gas welding. One thing I found, MIG units using the CO/Argon gas mixture will weld through almost any remaining rust or paint, where the TIG requires very clean work pieces for best results. So far I have been able to weld in a patch panel and fill some holes with good results and very little distortion due to the heat. Just what I was looking for when I decided to make the investment. The additional ability to use it on aluminum made it worthwhile for my current MGA project.
Bill Young

Tig welding takes a lot more practice to get good results than MIG welding. With that said, some people just seem to have the knack for quickly acquiring this skill while others never really master it. Try gas welding some thin practice material using a mild steel filler rod. When you can get a feel for this and begin to produce nice freeze lines in your weld pool you can then practice making welds with minimal distortion and making the more difficult vertical welds and fillets. If you can weld in this manner, TIG welding will seem easier by comparison, without the heat distortion you'll get with gas welding. This way you judge your welding skill potential without committing to buying a TIG welder. A course in TIG welding will go a long ways in a short time if you have some gas welding experience. The biggest problems with TIG are the expense of the machine and the greater skill required to make nice welds. Because the heat is so much better contained with TIG welding, you can weld very thin materials with it without distortion. The problem for beginers is getting the rhythm down for adding the filler rod at the right time and for what length of time. With practice, you will eventually watch the weld pool and control it with one hand while the other hand instictively will add the right amounts of filler rod. It's kind of like driving a car for the first time and you spend lots of time making sure your car is centered in the lane and looking at your left front fender for a reference...then after some practice, you no longer think about what you're doing and are able to concentrate on more the more important aspects of driving. Bottom line- Practice, practice, practice!
I am also wondering why you are having such difficulty making inside fillet welds that look nice with the MIG...This should not be difficult to achieve. On sheetmetal you need to start at the top and weld in short bursts as you go down, allowing the weld puddle to freeze for just a fraction of a second before you blast the base of the last weld puddle. In this way, gravity will pull the weld bead down as you weld and with good welder settings to heat up and penetrate the base metal on both sides, you should get a nice smooth half round shape that requires no "doctoring" to make look nice.
My advice is buy the TIG if you can afford it and want the best looking welds you can make. Otherwise save yourself a ton of money and buy a nice little 135 amp MIG welder like the Hobart, Lincoln, or Miller. Don't think the MIG cannot be used to restore or build a car with good results. It definitely can.

FWIW
Scott
Scott Wooley

Rob, I just re-read your post and if I read it correctly the problem with inside corners is being able to grind or finish them because of clearance issues. Inside corners are also the most difficult to weld with either MIG or TIG because of the clearance problems with the torch tip which doesn't allow the same spacing from the pool as on other surfaces. There are special nozzles available for either type unit for close in work, so if you have a number of such joints to do it might be worth the investment which isn't much to get the narrow tips for those occasions.
Bill Young

Thanks guys... I think I'll try getting one of the tips suggested by Bill before investing in a TIG welder.
rficalora

I picked up a Lincoln 185 last year (impulse buy while filling my mig cylinder!) and I will attest to the fact that it takes a lot of practice to get good. I am not there yet. I started trying to use it on thin sheet metal and decided that that was not a good way to learn; it is not forgiving enough for a beginer. By the time you start having a good look at the puddle, it falls out the bottom. I then tried some 1/8" material and found that it gave me more time to play with the puddle and the filler rod "dab" technique. I am afraid that the tig has been gathering dust while my mig has been working quite hard lately.

Has anyone tried a tig welder for doing the plug welds on sheet metal panels?

Pete
Pete

Robert, great advice from all group members. I've been welding on projects for 30 years and trained on TIG while in the army during the VietNam era. Oxy-Acetylene is THE best way to learn TIG. The rigs are cheap and supplies are readily availble. After you've learned to master the the puddle in Oxy-Acetylene, the move to TIG is only a small step in technique but a great leap in control. While heat is the tool, control of heat is the real secret to great looking welds. A really clean weld surface should be the rule in any welding situation, but is a requirement when using TIG. The best of all experiences is welding a sheet metal panel with NO filler and almost NO distortion. cj
Chris J.

I have the Lincoln 185 tig unit and love it! I bought it primarily to custom build my own headers. Have you ever tried welding thin tubing with a mig? It looks crappy in my opinion. One of the problems with a mig on thin metal (if you're trying to run a continuous bead) is that a mig starts cold and runs and ends hot. To make a superior job with a mig, you need a unit with slope control which is only found in the high end units (expensive). The tigs heat is controlled with the pedal. I like the mig for heavier stuff where appearance is not as important and for tacking (you only need one hand). The advice to learn oxy-acetylene first worked for me. It made the tig easy after about 10-15 minutes practice.
Jack Morris

This thread was discussed between 18/01/2006 and 19/01/2006

MG MGB GT V8 Factory Originals Technical index

This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now