Just joined? Please introduce yourself.
Results 1 to 6 of 6

Thread: Hammer 'n dolly guidance needed

  1. #1
    Registered Member
    Join Date
    Aug 2015

    Member #:2643
    Location
    Tampa, FL
    Posts
    428

    Hammer 'n dolly guidance needed

    Over the weekend, I welded in this patch panel. Overall, it came out decent for a beginner, but the horizontal seam is puckered in some, due to shrinkage. I'm a novice at auto sheet metal replacement and a newbie at hammer 'n dolly. Can I alleviate the puckering via hammer n dolly, and if so, which side do I need to be hammering on? Also, what type of hammer and dolly should I use? I removed the quarter window tracks, but space is still limited to swing a hammer on the inside.


  2. #2
    Registered Member
    Join Date
    Aug 2013

    Member #:1806
    Posts
    414
    Its hard to tell by the picture, but it doesn't look too bad. Put a dolly on the inside that closely matches the contour of the panel, and put some firm pressure on it as you strike it on the out side with a body hammer. Think of it as the dolly is trying to push the metal out, and the hammer taps directly on the dolly are stretching the metal, and that allows the metal to move out.

    I would practice some to get the hang of blindly hitting the dolly, everytime you miss the dolly it isn't stretching and its possible that something else could be happening, depending on where the hammer lands. Sometimes its necessary to cut away some of the inner metal to get good access. Something might be made to hold the dolly for better access sometimes, but its more difficult to keep the pressure on it when its on a stick, and its much easier to tell where the dolly is when its in your hand.

  3. #3
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    4,671
    Lee T gave you some good advice.

    Use a flat or nearly flat face hammer and a nearly flat dolly. When the hammer hits "on dolly" you are stretching the metal, which is what you want to do when planishing a weld. There are situations where you want to hammer "off dolly" which won't stretch the metal but can be used to level a damaged area. (Not a weld.)

    As Lee said you can cut part of the inner quarter away temporarily for dolly access.

    You want to grind the weld prior to planishing. At least to 90% then finish up as you go.

  4. #4
    Registered Member
    Join Date
    Aug 2013

    Member #:1806
    Posts
    414
    Yes, grind most of the weld off first. If you use a cut off wheel, be careful not to undercut.
    Rick, I'm sure you are not suggesting this, but I just had to show what could be out there. I bought my first body hammer from Sears in the mid to late 1960s, and I don't know if these are still sold by anyone of not. You can see that it didn't get much use, and that was because it did more damage than it fixed. When I finally bought another hammer (1979), I felt like superman---The right tools do make a difference. Try to imagine hitting the metal perfectly
    flat, every time.


  5. #5
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    4,671
    You are so right on the details of just about any hammer or dolly.

    You usually don't want absolute flat, but nearly so with a slight crown.

    The Harbor Freight and other Chinese imports are pretty bad - worse than the old time Craftsman example because the flat stuff usually isn't flat. Or it's only finished nicely over 80% of the face. Or whatever the problem, one set usually has samples of all possible problems.

    At least that old Craftsman could be fixed, except the rookie doesn't know it needs it, and someone who does probably knows because he now owns something better.

    There's several good sources for hammers and dollies, but personally I like the Martin stuff. Eastwood sells them, as do many others.

    Martin does have a dolly with an absolute flat surface, but I wouldn't use it on a weld. It does have it's uses, mostly in fabrication.
    Last edited by Rick_L; 05-08-2017 at 06:14 PM.

  6. #6
    Registered Member
    Join Date
    Aug 2015

    Member #:2643
    Location
    Tampa, FL
    Posts
    428
    Lee and Rick, thanks for the great advice! I appreciate it!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •