Update: AR*171268 (Oxy-acetylene vs Mig welding)

For me, one of the biggest conundrums involving the welding process is understanding the differences between Oxy-acetylene vs Mig welding. First and foremost, I have to admit that Mig welding is very easy to learn and just as easy to use. On the other hand, oxy-acetylene requires more understanding of the behavior of metal and does requires lots of practice. But, when one overcomes the challenges the ultimate reward is unparalleled.

Why oxy-acetylene? For one thing when used correctly it achieves optimum performance, durability, workability, and strength. Lets break this down further:

When working in an automotive setting where there are lots of panel welding and corrections required, the oxy-acetylene welding out performs any other method …….

Durability: oxy-acetylene welding when used correctly achieves maximum penetration and it allows for the weld to be fused into the panel achieving a virtually invisible finished product.

Workability: Another of the biggest benefits of oxy-acetylene is that the metal can be hand planished as the same time it is being welded in order to bring the panel to the desired shape.

Mig welding, on the other hand, is very easy to use and it is not hard to learn. It can work under many environmental conditions such as dirty surfaces.

It is the preferred choice of most body shops and metal shops across the nation.

Now the hard stuff: mig welding crystalizes the metal and the metal weld is not workable. It requires grinding which weakens the metal making the weld brittle.

Because mig welding makes a hard welding bid, the weld can not be hand planished or fused into the metal thus giving a very unattractive line that requires body filler to hide.

At our shop, we use a variety of welding equipment such as Mig, Tig, Spot and oxy-acetylene welding units and all of them have their proper applications for the intended job.

Hera are some oxy-acetylene samples:


The final step as seeing in this last photo note that there is no metal grinding of any sort. Just some hand planishing and light filling to highlight the working surface area highs and lows being worked.  This type of work can be completed with Mig or Tig but, the ultimate finish product will vary widely. The bottom line is, What is your tolerance for how much filler you want on your car?

This entry was posted in AR*171268, Metal Fabrication, Uncategorized. Bookmark the permalink.

10 Responses to Update: AR*171268 (Oxy-acetylene vs Mig welding)

  1. Tony Sigel says:


    Beautiful craftsmanship. It is great to be able to see this, though the group of four smaller pictures above is hard to see- is there a way they could be expandable when clicked on? I’d really like to know more about your use of gas welding and planishing, and would be interested in beginning to learn it. can you direct me to any books you;ve found useful? Perhaps you’d make and post a video of some of this work so we could see you in action?



    • aisllc says:

      Hello Tony, I will enlarge the photos for better viewing. I learn from watching a video from David Gardiner. He have a great video and I have seen it countless of time. I encourage you to purchase it and enjoy it http://www.metalshapingzone.com/
      I appreciate the feedback. Don’t forget to register so that you can receive regular updates on our work.



      • Tony Sigel says:

        Hi Lionel, I’ve been following your work for some time. I registered with your site, and just ordered the DVD you recommended, but I’d still love to see you at work on a 750 Alfa spider on video, explaining what you’re doing and why.



  2. Laurence Anderson says:

    Really spells out the craftsmanship differences, beautiful work!

  3. Brad B says:

    Hi Lionel,
    Do you have any sheet aluminum forming and welding planned? I’m aware Kent White and others prefer torch welding aluminum, rather than GTAW or MIG. I might mess around with the torch on aluminum scrap myself soon. I need cataract surgery first though, I cant see the puddle well enough under most conditions. I really enjoy your new blog!
    Best Regards, Brad

    • aisllc says:

      Hello Brad! Great hearing from you! I concur with Kent White and others about the preference for using torch as supposed to MIG or TIG. As I alluded earlier, there is time and place for the other two welding uses. For welding aluminum, the torch does a great job whenever you are able to reach and work the panel as well as there is easy access to clean the acid flux residues after the welding is completed. It is extremely critical that all surrounding near the welded area is thoroughly cleaned front and back. Also, make certain that you use the correct eye protection if you intend to weld aluminum using the oxy-acetylene equipment. You can buy the eye protection and aluminum welding lens from Kent White, I got mine from his website. I have not done any aluminum welding as of late but will do a demo video later. Regards, Lionel

  4. David Harrelson says:

    Thank you for your efforts to keep these great cars alive. I have several 101’s, and thought there was someone in your area making complete rockers and other parts for sale. Anyway, great work and a very nice set of photos.

    • aisllc says:

      Hello David, Thanks for the feedback. Regarding the metal fabrication panels in the area, that would be me. We are currently in the process of making additional sill kits for the 750 and 101 series spider. If you need some please feel free to contact me.

      KInd regards,


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.