1993 Cadillac Deville fender repair

pappy8

The front passenger side fender has a crack above the wheel well. The fender appears to be made of plastic. Can it be repaired? If so, how?

bigfur

itll be easier and probably cheaper.

swschrad

I would completely expect the fender liner (which once, long ago, in an age when metal behemoths roamed the earth and coal and vacuum tubes ruled commerce, was an inner fender also stamped of sheet steel but not painted pretty colors) to be a molded plastic sheet. easy to replace, fake popnuts probably hold it onto the (almost certainly steel) fender.

there is no good reason to try and repair a fender liner if they are availiable as service parts at the dealer, or unmunged in a junkyard. they're probably thick polyethylene or a blend, which doesn't glue real well.

if it's real holds-a-magnet steel, or nice form-molded epoxy fiberglas like a Corvette body, you could do a little bondo work.

but steel is most seriously unlikely to crack without application of liquid air or a collision. that alone suggests you have a plastic fender liner. order another Monday, and get your jackstands ready to hold the car up after you remove the wheel for access to put the new one in without bending it over enough to possibly crack it, too.

pappy8

The fender itself is plastic. I am not talking about the fender liner.

swschrad

it is either ABS composite resin or epoxy fiberglass. you could cut a little strip of fender someplace where nobody will see it (for instance, open the door, and slice a little ribbon off there with a sharp knife, a chunk like the narrow end of a toothpick about an inch long is plenty good enough.) get out of the wind and set it on fire, holding over a pile of sand or cat litter with a pliers. if you get nasty thick black smoke, it's ABS.

if you really want to fix this, cut a little narrow V out that completely contains the crack(s). use nasty heavy grit sandpaper on the back to rough up the back of the fender on either side and a little above the V you cut.

for epoxy fiberglass, now fill that with fiberglass body filler mixed with the appropriate amount of hardener, preferably with a little chunk of alcohol-cleaned fiberglass window screen behind as a reinforcing mat. the new stuff should rise a little above the V. sand as appropriate, prime, and paint.

for ABS, fiberglass filler may work... epoxy ribbon, a stiff nasty stuff you knead to a constant color and push in from behind like putty may also work nicely. epoxy ribbon may need to cure 24-36 hours before you shape and prime/paint.

if it's a real dinky hairline crack in ABS, using a soldering iron tip to melt the crack together, then sanding down the raised ridges and adding body filler, may get it.

the larger question is, are you REALLY sure you have seen and identified ALL the cracking? if not, this is your life's work, fixing today's added problem in the fender. that's why bigfur recommended a fender replacement.

incidentally, I'm quite surprised that caddy used plastic top body parts. I would be shocked white if they used ABS, which due to having more expansion and contraction than other body materials, leads to the larger panel gaps in Saturns (so they don't push together and warp on a hot day in the sun.)

bigfur

local bone yard. probably cheaper to get a new fender than to spend time trying to figure out fixing it. And that advice is coming from someone who used to do auto body for a living, its probably easier and less time consuming to just replace it.