Debate with myself over plastic filler vs metal on a classic car repair

So I'm working on a 1970 Chevelle that came in with a rusted out quarter panel, right near the wheel arch. Part of me thinks I should patch it with new metal, weld it in proper, spend the extra 10 hours of labor. But the other half of my brain is like, just use quality plastic filler and move on, the customer won't notice under the paint and it saves them $600. I went with the metal route this time, spent last Thursday cutting and shaping a replacement panel from a donor car. But now I'm second guessing - what if it warps under heat from the welds? What if the guy just wanted a cheap fix and I'm pricing him out of the job? Anyone else struggle with this choice on older cars? What do you usually pick when the budget is tight but the car deserves respect?

3 comments

3 Comments

nina1472mo ago

My buddy Dave did metal repair on a '68 Mustang once and the heat warped it so bad he had to cut the whole thing out again and start over. Took him twice as long and the customer was not happy about the extra bill.

gavin_reed2mo ago

Had the same thing happen on a '70 Charger quarter panel @nina147. What finally worked was using a wet rag on the surrounding metal and keeping the torch moving in tight circles instead of holding it in one spot. Also used a heat sink bar clamped right behind the weld area to pull heat away. Kept the warping down to almost nothing after that.

jana_ellis952d ago

Yeah I read somewhere that using a heat sink bar or even just a thick piece of copper behind the weld makes a huge difference. Copper pulls heat away way faster than steel so it stops the panel from getting all wavy. I also saw a guy on YouTube use a spray bottle with water and keep the area damp while he welded short little spots at a time. Said it keeps the metal from getting too hot in one spot and warping all to hell. That wet rag trick you mentioned sounds like the same idea just more controlled. I've heard guys argue that using water can make the metal brittle if you don't let it cool right but I think as long as you're not quenching it too fast it's fine. Definitely filing that tight circles tip away for later, seems like a low tech fix that actually works.