Cutting out the rust on a 72 Challenger • The Dodge Challenger Message Board

by **RedRaven** » 27 Mar 2008 20:27

So guys I got a hold my 72 on sat and Ive noticed some cancer around the roof and the quater panels, the car still has paint on it so to save on money I want to strip the paint myself any suggestions as to what method I should use??

by **Eddie** » 27 Mar 2008 21:18

Hey Wayne! A fast way to remove paint is chemically. Methyln Chloride comes to mind, but it is very nasty due to the fumes. I wore 'MOP4' military gasmask and rubber gloves,(you dont want to breathe this stuff), and it comes off very easily, another way is to use a Porter Cable type of machine sander to remove it. it takes much more time but no fumes. POR-15 makes a paint remover that works very well, or you could buy some chemical remover from your paint and body store.

by **RedRaven** » 27 Mar 2008 21:21

I hope you aint been drinkin or sunbathing in that stuff Eddie!!! :lol:

Any ideas about the rust, is it best to cut it out and replace or lead it??

by **Eddie** » 27 Mar 2008 21:24

Bodywork is not my expertise Wayne. I bet Dave or Ian would know!! :thumbsup:

No not drinking that nasty stuff. Not anymore! :s024:

by **dave-r** » 28 Mar 2008 9:47

If the rust is surface only just wire brush it and treat it with a chemical rust converter.

If it goes right through to a hole you have to cut it out back to clean bare metal and weld new metal in.
You cannot weld rusted metal so you have to cut right back to the good stuff.

by **RedRaven** » 28 Mar 2008 11:36

Yes Dave there are a couple of through spots alright, whats the solution and where do you get the correct gauge metal??

by **dave-r** » 28 Mar 2008 12:14

You might have a metal stockist near you. Actually if you have a B&Q store you can get 100cmx50cm steel about the same thickness.

I have used cut-out panels from other cars in the past to make patches. Like old doors and bonnets from cars where I have had to replace these bits but kept the old.

To weld it you need to cut out the rusted area and make a bit to fit. If the area is curved you need to form the steel to the same shape. You also need a MIG welder on its lowest setting for bodywork. You have to tack the new bit in place first and then weld small sections of the join at a time. Cooling the steel between each bit of welding. Otherwise the panel will buckle and distort with the heat.

It is a dirty and time consuming job.

by **Chris** » 28 Mar 2008 14:38

I stripped my whole car using my dewalt 4.5" grinder with the rubber backing pad and 80 grit discs. as long as you keep it moving and dont stay in one spot too long because it can get hot with those high rpm's.

by **dave-r** » 28 Mar 2008 14:47

Hard work though eh?

I mate did his like that and i was tired just watching him. :lol:

by **Chris** » 28 Mar 2008 15:05

Yes, I think i still have blue paint in my nose.

by **Eddie** » 28 Mar 2008 15:10

Chris wrote:Yes, I think i still have blue paint in my nose.

Careful breathing that stuff Chris. The older enamels contain lead.

by **Chris** » 28 Mar 2008 15:17

Thats probably good advice Eddie . When I started i only used a cheap particle mask but its worth spending the $25 on the mask with the replacable cartridges.

by **Eddie** » 28 Mar 2008 15:23

Chris wrote:Thats probably good advice Eddie . When I started i only used a cheap particle mask but its worth spending the $25 on the mask with the replacable cartridges.

Yeah, I spoke with my neighbor who does autobody work and thats what he told me. Particularly older vintage cars&trucks that used to use lead based paint. I guess the lead helped the paint flow better? I hate body work never took to it. It's an art form in my opinion. I stripped the paint off my R/T's underbelly before handing it over to the pro's and wore my gas mask doing it. :biggrin:

by **RedRaven** » 28 Mar 2008 17:14

Here we go lads as promised the photos, one of my mate mark looking very guilty!!! :mrgreen:

by **Chris** » 28 Mar 2008 19:10

I had the underbody sand blasted along with the engine compartment and around the windows, he would do anywhere that there wasnt open areas of sheetmetal that could warp. These are the areas i did with the grinder. He charged me 600 cash. Apparently you can have the whole car done if they have a soda blaster (baking soda) . Nobody around my area did this.That panel behind the rear window was shot on mine too and i just replaced it. You can get those for under $100. But you will need that welder,I bought a used wire feed welder, I think its 90 amps but like Dave said keep it low and spot weld everything dont try a continuous stitch. goodluck.

by **ianandjess** » 28 Mar 2008 23:25

gday wayne that rust will definately need to be cut out & replaced i prefer to use zinc aneal sheetmetal its cheap & easy to get should be readily available over there to i would use 0.8 gauge as you will need to make some tricky shapes there also if you find you cant get the right shape i.e. it keeps twisting the wrong way when you try a compound bend then just make the patch in a couple of sections & join them once youve tacked it on it save a lot of time & aggravation heres an example hope this helps
mig welders are cheap nowdays i bought mine new for $500 its a gmc 150 amp does the trick nicely for panel work but i wouldnt want to do any heavy duty welding with it also i find that gasless wire is not as good as using gas when spot welding , gasless seems to need a bit more heat to get the flux working propely
i didnt take a photo of the patch when it was finished but once it was ground & tidied up it came out quite good it was a lot easier than dicking around with the twisted piece of crap that some clown had stuffed up before
cheers ian

by **RedRaven** » 30 Mar 2008 21:53

Any body heard of nitro mortis?

by **RedRaven** » 30 Mar 2008 21:56

Any body heard of nitro mors? Found this any comments?

by **dave-r** » 31 Mar 2008 8:37

I have used it on my new (used) grille and also things like the k-frame. Works well but don't get in on your skin or God forbid in your eyes.

by **dave-r** » 31 Mar 2008 8:40

The bits along the edge of the front and rear window area. Just cut out small sections at a time to repair that. If you cut out the whole lot you can have problems with things getting out of shape.

by **RedRaven** » 31 Mar 2008 9:57

dave-r wrote:The bits along the edge of the front and rear window area. Just cut out small sections at a time to repair that. If you cut out the whole lot you can have problems with things getting out of shape.

Yes I see what you mean, so if I stick to small sections at a time it will reduce major warping!!??

by **dave-r** » 31 Mar 2008 10:35

Some of the panels are sometimes in a pre-stressed state from when they were pressed and originally welded.
Sometimes when you cut away a whole section you hear a loud "pop" and a panel is suddenly not quite the same shape any more.

Also when welding small areas it cuts down on the risk of major warping as you say.

by **RedRaven** » 31 Mar 2008 10:59

dave-r wrote: risk of major warping as you say.

So more of this = more of this!! :lol:

by **dave-r** » 01 Apr 2008 20:29

I found this one photo from when I repaired the bottom edge of my front and rear screens.

by **RedRaven** » 01 Apr 2008 21:19

That looks nice compaired to mine!! :tears:

by **dave-r** » 02 Apr 2008 8:00

That will teach you to look for rust before you buy!

by **Moparman1972** » 03 Apr 2008 0:59

Boy, I thought New England musclecars had it bad! That's some serious rust there. Glad you're restoring it, some would call that a lost cause unfortunately.

by **RedRaven** » 08 Jun 2008 20:54

Guys I was looking at some sites that have new 1/4 panels and an entire new roof, wold this be a cheaper and more straight forward option than trying to welding and chop etc?!!

by **dave-r** » 09 Jun 2008 15:35

It depends on how good the guy doing the bodywork is Wayne.

But new sheet metal will probably be the best option in most cases.

by **RedRaven** » 10 Jun 2008 7:21

With new panels and a new roof will this make the work a lot smoother and straight forward Dave, I mean would it be less time and money spent on paying a guy to do the body work because its new metal.