tips for repairing dent in door
- Thread starter mbaird
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Riff Raff
Well-Known Member
It may be a little crude but, how about one of those suction cup dent remover thingies. I've used it a few times and works decent on dents with no creases. I've heard dry ice works too but haven't tried it.
Make the back side of the door thicker, add a couple layers of fiberglass mat with resin to stiffen it up.
Rustyfish
Member
When it oil cans, the metal is stretched. Usually you'd have to shrink the metal to eliminate that and the best, most effective way is with an oxy/acet torch but obviously this is not a paintless repair. Another option if you can find one, is an Electro-Magnetic Dent Removal System. They are very expensive though if you don't know someone who has one.
Can't hurt to try some heat with a hair dryer or paint gun, followed immediately by the dry ice. Never know, it might work and very cheap as long as you don't burn the paint with the heat gun.
Can't hurt to try some heat with a hair dryer or paint gun, followed immediately by the dry ice. Never know, it might work and very cheap as long as you don't burn the paint with the heat gun.
The whole chassis has been stripped so I am working with with bare metal.
I have two boards clamped on either side in an attempt to bring the memory back to the metal. I will apply some heat with a propane torch evenly accross the skin of the door.
I also considered tacking a metal bar inside the door skin as a reinforcement like the later models have. This is a 69 Swinger 340 car.... My 73 340 Sport had them from the factory... IIRC....
I have two boards clamped on either side in an attempt to bring the memory back to the metal. I will apply some heat with a propane torch evenly accross the skin of the door.
I also considered tacking a metal bar inside the door skin as a reinforcement like the later models have. This is a 69 Swinger 340 car.... My 73 340 Sport had them from the factory... IIRC....
Fiberglass and metal do not mix. Adding fiberglass to metal is hack repair 101, and a sure sign of substandard work. Always. There's a right way to do it, and that's not it.
Propane torch and a wet rag should work just fine. Heat it with the torch, cool it with the wet rag, should shrink it up pretty well. You don't need the metal red hot either, just hot. And you shouldn't need to heat the whole door skin, just the area of the dent. If done correctly you shouldn't need anything behind it. Easier said than done of course, there's definitely skill to shrinking the metal the right amount.
Rustyfish
Member
Good advice from 72, also more specifically you want to work from the outside of the dent to the center and I would do it like you are tightening lug nuts. Heat a spot, then quench with the wet rag and move to the outer opposite side etc and work your way in. Should work out fine.
breakstuff
Well-Known Member
I agree 100% I had a dent on the wifes car, front fender. Same thing and it popped right out
I offered a solution that will work.
The OP is asking a bodywork 101 question, so heat and a beginner normally end up with more damage.
It's the wrong way to do it.Period.
You'd be better off just slathering it in bondo. Yeah, still the wrong way to do it, but at least that way you're using a more standard practice even if it's in an amateur way.
Sorry, but fiberglass should not be used on metal. And that is bodywork 101. You don't fiberglass metal. And fiberglassing the back? So you can't figure out what happened with a magnet from the outside? Yeah sorry, that's shade tree, flip-job crap right there. If you have to conceal your "work" on the backside and cover it with interior panels you're doing it 100% wrong.
You're not going to convince me otherwise either. It doesn't matter if it would solve the problem. It's dirty pool. You're just screwing the car and the eventual next owner.
harrisonm
Well-Known Member
If a guy didn't have access to an acetylene torch, would a propane torch get it hot enough? I've been doing bodywork for years, and I guess I've been lucky enough to never come across a dent like that.
Absolutely, a propane torch will work just fine.
In some minor cases, a heavy duty heat gun might even be enough. The metal doesn't have to glow red hot or anything for the heat shrinking to work, especially if you cool it quickly.
adriver
Blazing Apostle
Hells bells.
It's a dent.
What harm can he do?
I've got a stack of doors I really should thin out.
Some have that crash reinforcement thing in them on the back side that looks like a guard rail
from the later 70s
Those suckers are heavy.
It's a dent.
What harm can he do?
I've got a stack of doors I really should thin out.
Some have that crash reinforcement thing in them on the back side that looks like a guard rail
from the later 70s
Those suckers are heavy.
You can buy map gas for propane torch tip, it heats alot hotter
Fiberglass is actually an isolater against corrosion, it is common practice to use it when two dissimilar metals are used together in the aircraft industry.
Fiberglass and metal together will cause no corrosion.
You are the first person that has ever said to me that metal and fiberglass do not mix.
Not to stir it up further, but lots of modern cars have a fiberglass mat glued into high stress areas such as trunk lids and hoods where they know people will be putting pressure on them.
Seems to me that the door is already disassembled, why not just fixed it with the traditional hammer and dolly method? Work the high area first to releave the metal stress and then start bringing up the low. I don't know much about heating and cooling method, but I'm pretty sure if the dent is large enough that it put an "eyebrow" in the metal, all the heat in the world won't help until that metal has been tapped down.
Seems to me that the door is already disassembled, why not just fixed it with the traditional hammer and dolly method? Work the high area first to releave the metal stress and then start bringing up the low. I don't know much about heating and cooling method, but I'm pretty sure if the dent is large enough that it put an "eyebrow" in the metal, all the heat in the world won't help until that metal has been tapped down.
GeorgeH
Well-Known Member
Like said above when it oil cans in there will be a high spot around it. Find that high spot/crown, eyebrow as it was called, I usually mark with a sharpie so I don't lose it. Hold the panel out and tap the high spot around the low spot. It usually doesn't take much to put tension back in the panel. I use a pick hammer with a sharpened point and I strike towards the oil can to move metal that way. Just taps, no need to frail it. Hard for me to say without looking at it but heat shrinking with a torch can really move some metal and I wouldn't approach an oil can that wants to stay low with it. If i shrink it's usually with a stud gun and shrinking tip. A lot more controlled. The effects of shrinking can be hard to undo if things don't move as anticipated.
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Rap a bunch of ice in a dish cloth. Take a heat gun, heat just the dented area. Get it really hot. Take the heat gun off & really fast put the ice on it. Might take a few times. Ive had one come out the first try & then ive had ones that took a few times. Another way- if you know some one with a stud gun. Put a stud in the middle of the dent. As you pull on the stud take a body hammer & tap on the outside of the dent.
GeorgeH
Well-Known Member
They are adhesive pads used for sound deadening so the car doesn't sound like tin can when you close it. A lot different then using resin to bond fiberglass to metal. The problem comes from different expansion rates of 2 different materials on the same panel. Applying resin and glass to metal doesn't usually last very long.
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GeorgeH
Well-Known Member
They use it to make boats too, and on top of a substrate that absorbs resin it makes for a nice tight bond. Resin has 0 strength by itself and on top of metal there is very little mechanical bond. There's nowhere for that boundary layer of resin to go to. Now if you were talking about the adhesives and epoxies that are used along with mechanical fastening of some means, either welding or riveting it would make more sense. An encapsulated fiberglass structure over a frame ok, but as a sealer on metal I don't see it.
RichB
CherryCuda65
When I watched an old body man do it, he heated around the edge of the dent, getting it just barely red hot with a lower oxygen flame acy torch which anneals the steel allowing it to relax. If you can get a dolly behind the dent, tap the edges of the dent while its still hot with a flat body hammer & dolly until it's nice and flat.
GeorgeH
Well-Known Member
Getting the metal hot and hammering "on" dolly will stretch the metal further and cause it to rise. Heat the circumference of the dent cherry hot? First, as the panel heats it will swell. No telling where that will end up after it cools. Might have a 4ftx 3ft warped mess to fix after that. In 30+ years have never seen anything like that.
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RichB
CherryCuda65
That's true about hammering on it. I said tap on it to help flatten it back. And not in cherry hot condition.
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