Spot-welding prep on new AMD panels with EDP coating

Discussion in 'Body Restoration' started by lapedr, Feb 12, 2018.

  1. Rustbucket350

    Rustbucket350 Veteran Member

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    Somebody asked me why I removed the EDP before priming once and I told them exactly what you said. A lot of them do have surface rust under there. Just because it's new doesn't mean somebody didn't rub their oily fingers everywhere while it sat waiting to be coated. Plus, it's more to keep the panel from rusting on the warehouse shelf than on your vehicle.

    I usually strip the area to be welded to bare metal. You can weld through the EDP but it starts to bubble. On something I want to last I'll prime the back with a real 2 part epoxy or urethane. It'll burn when welded but not as bad as "weld through primers" which aren't even waterproof so the rattle cans are basically useless in my opinion.
     
    Last edited: Feb 24, 2018
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  2. Shizzle

    Shizzle Veteran Member

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    I tried using Eastwood’s weld thru primer, the welds never held where ever it was sprayed.
     
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  3. NeoNeuro

    NeoNeuro Veteran Member

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    I've tried several brands of weld thru. None of them worked the way I expected. They basically flaked off 2-3 inches away from the weld when they cooled down. Didn't really work any better than a regular primer in that regard.
     
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  4. thesalboy

    thesalboy Veteran Member

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    I agree most "weld-thru" primer is not effective. But I've had good results using UPOL WELD#2 Cooper (UP0768). I always buy it from a pro paint supply store in person. I've heard stories that the copper can solidify at the bottom of the can with age. Wear a respirator when spraying it.
     
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  5. lapedr

    lapedr Veteran Member Gold Member

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    So glad I asked this question
     
  6. giggity

    giggity Veteran Member

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    I contacted AMD and they claim the coating doesnt need to be stripped completely, I have been googling this for about an hour, and there is no proof that there is any issues leaving the coating...
     
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  7. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    When I did my fender patch using the new AMD fender as a donor I didn’t find any rust under the bracing and it had 100 % coverage of the EDP. It passed the lacquer rag test but I still ground it away from the weld area
     
  8. badazz81z28

    badazz81z28 Veteran Member

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    If you are that meticulous...yeah strip the panel completely. Heck have it dipped...honestly I don’t see leaving it coated will cause future issues. Definitely strip where you plan to weld
     
  9. xten

    xten Veteran Member

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    It's no wonder new cars rust. Planned obsolescence. Take any hinge off any new car and see what you find. Bare metal. Not even any E-coat under hinges. Now they want us to cavity wax inside brand new OE parts. I am a firm believer in cavity wax. Watched a time lapse vid of it defying gravity. It creeps. Welding is going to burn off anything you spray prior to welding. Nothing you can do about that aspect of welding. Actually, welding is the worst thing you can do for the inner structure of a car. Only thing you can do is try to protect the internal structure after welding is done. And cavity wax and epoxy are the best that I know of.
     
  10. hubedobeedo

    hubedobeedo 3rd times a charm

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    welding is the start of oxidation alot of these reply's are spot on. manufacturers did not make them to keep.why do you think there are continual model changes. love my 2nd gen.3rd times a charm
     
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