Author Topic: Reproducing factory pinch/spot weld marks  (Read 544 times)

Offline ninedrvr

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Reproducing factory pinch/spot weld marks
« on: June 15, 2017, 10:03:37 AM »
What are you guys doing to reproduce the pinch weld marks when a mig welder is used to plug weld panels together? I have done a search on this site as well as the web at large and only come up with one technique. The only post I found talked about grinding the welds smooth ant then laying down a couple of quick coats of high build primer, then using a pencil eraser to dab the primer to reproduce the original pinch weld marks.

Any other techniques?
« Last Edit: June 18, 2017, 04:07:26 PM by J_Speegle »

Offline caspian65

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Re: Reproducing factory pinch weld marks
« Reply #1 on: June 15, 2017, 11:26:02 AM »
Pencil eraser trick is about the only way to do it with mig welding.  Have you checked around with local body shops?  Some may have spot welders.  If you already have the rocker welded in, I can't imagine it costing very much to have someone with a spot welder go over it.  Although, it will take a hefty spot welder to do the thickness of the rockers.
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Offline JohnRB

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Re: Reproducing factory pinch weld marks
« Reply #2 on: June 15, 2017, 11:48:22 AM »
You can also use a pair of old wise grips. Grind one end round so it looks like a spot. Clamp it over where you want the spot, and hit it with a hammer. You might need to weld on a bracket or plate so you have a good place to hit it.

Yes, you might need to grind down the mig weld first!

After a google search I also found this;

http://www.boss302.com/smf/index.php?topic=57172.0

https://mods-n-hacks.gadgethacks.com/how-to/make-spot-welder-for-cheap-0140873/
« Last Edit: June 15, 2017, 11:52:59 AM by JohnRB »

Offline jwc66k

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Re: Reproducing factory pinch weld marks
« Reply #3 on: June 15, 2017, 12:59:07 PM »
There's an add on welding tip called a "stitch welder" that uses a carbon tip and low current from an arc welder. I think I got mine from Eastwood. I would not guarantee it's effectiveness to hold pinch welds, but you can "draw" a reproduction spot. I used it to weld in the replacement plate for a radio.
Jim
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Offline J_Speegle

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Re: Reproducing factory pinch/spot weld marks
« Reply #4 on: June 18, 2017, 04:26:46 PM »
Thought we had an older thread discussing this an showing a half dozen different home made tools to reproduce the look. Remember (often missed) that along with the weld there is normally (they will stand out if all the fake welds are smooth and straight in a row) the buckling and bending of the two panels that took place after the weld was applied and the worker jerked or tried to jerk the welder from that spot to the next

I did the pencil  eraser trick maybe 30 years ago but more recently use multiple depth locking pliers (Vise grips) where I've welded a post the diameter of a spot weld to one jaw and a female receiver (basically a larger holed nut) to the other jaw.   Squeeze, rotate multiple times and then twist and it provides a pretty nice reproduction of panels two panels thick.

 Three panels are a bit more difficult and if your doing rocker to floor pinch welds it depends on where the car was built and when since there are some other features that make the whole task difficult if not impossible IMHO to reproduce

A use fo the search feature here on the site would have turned up this prior thread


Best Way to replicate factory spot welds?  from 2013 http://www.concoursmustang.com/forum/index.php?topic=5772.msg32350#msg32350


The Boss thread about the same subject linked in that thread shows a number of home made or modified tools that might be useful ;)



« Last Edit: June 19, 2017, 02:39:33 AM by J_Speegle »
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Offline caspian65

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Re: Reproducing factory pinch/spot weld marks
« Reply #5 on: June 18, 2017, 07:12:40 PM »
Hey Jeff, have a pic of the pliers that you made? 
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Offline J_Speegle

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Re: Reproducing factory pinch/spot weld marks
« Reply #6 on: June 19, 2017, 02:34:52 AM »
Hey Jeff, have a pic of the pliers that you made?





« Last Edit: June 19, 2017, 02:38:45 AM by J_Speegle »
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Offline mtinkham

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Re: Reproducing factory pinch/spot weld marks
« Reply #7 on: June 19, 2017, 01:40:24 PM »
I have had good luck dimpling the panel with a hammer/punch/piece-o-wood prior to panel installation. Drilled panel plug-weld holes between the dimples.
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