The 95' Disco I just bought looks good but has two rust areas. The areas are under the observation windows and at the bottom of the support between the front and rear doors. Are these common and do you have any tips to have these repaired?

 

Depending on how bad the rust is will determine the appropriate action. If the sheetmetal is rusty but appears to be structurally sound you'll want to give it the "screwdriver test" where you give it a moderatelly harsh stab with a screwdriver and see if you punch through. This "test" scares the hell out of alot of people, but fact of the matter is, if you are able to punch a hole through easily, then you have complete rot-out and it's going to get worse unless you address it. Hopefully you kind of have an idea in your mind of what I'm talking about. You don't want to strike the panel so hard with the screwdriver that you stretch the metal and leave an indentation...you're just trying to find out whether or not the metal is solid or not.

IF you aren't able to punch a hole, GREAT. This means that it's mainly superficial rust and it's going to be much easier to repair and get a handle on. The correct way of handling this would be to use a handheld grinder or sander and remove all of the paint and the rust of the surrounding area. You can treat the metal with "metal etch" / phosphoric acid / naval jelly. This treatment will make the rust inert. Next you'd hit the area with a very slight coat of body filler. EVERCOAT makes OUTSTANDING body fillers (Rage Xtreme or Metal 2 Metal).

Following the directions on the body filler, you'd hit the area with a cheese grater to get most of the filler worked down, then wait for it to dry up. Luckily the Disco's are pretty boxy so sanding should be a breeze. You want to block sand the area down, beginning with a medium grit and working up to a high-grit so the area you just treated blends naturally with the surrounding paint. You need to use your hand as a guide because we're talking about at fraction of an inch in height of depth. If you used quality filler and followed the instructions, you shouldn't have pinholes. If you end up with pinholes you'll need to use a glazing putty to fill them in...again, follow the directions on that. Mask off the area(s) and hit it with some dark primer and sand to see your highs and lows. Continue until you are satisfiedthat you've gotten all of the highs out and you do not have any noticeable low spots. Prime again...

That's as far as I can take you on that...the final part is really left to a body shop unless you want to try your hand at painting.

If you've got serious rot-out
You're going to want to grind the paint off of the surrounding area to see how wide-spread the rot is. Once you're satisfied that the rot out is confined to a particular area, you're going to want to draw an imaginary box around that area and cut it out using a handheld cutoff tool. It could also probably be done using tin-snips but I don't really recommend this because you're going to stretch the metal to hell in the process and trying to finish the area is going to be very difficult. Once you have cut out the rotted area, you are going to need to locate some sheetmetal, either from the local steel shop or from a donar vehicle. If the area that is rotted out has some type of contour or body design, you're probably going to be best off trying to locate a salvaged Disco I and cut that area out of the body. You're going to need to be very precise in cutting out a replacement panel exactly the size that you removed. If you used a handheld grinder, there is probably a 1/16 gap built into the measurement because of the thickness of the cutoff wheel.

Now is the fun part. You're going to want to get some intergrip panel clamps from EastwoodCo. If you used a cutoff tool to cut out the replacement panel you might want to planish the edges of the new metal. The heat from the cutoff tool can shrink the metal and by taking a smooth-faced hammer and a flat surface, you hammer just the surrounding edge of the panel to bring it back to where it should be. Don't over do it, otherwise your replacement panel is going to be too big to fit! If you measured nicely, you can continue to planish to tighten up the gap even further. You want to grind both the existing body and the replacement panel edges at an angle so that you end up with a "V" when they are butted together. This will allow for a nice place for the spot welds to sit and a proud bead can be planished down to perfection.

Once you get the new panel clamped in place, you're going to need to weld it, or have someone else weld it. This is really best done using a TIG welding machine operated by someone who knows what they are doing. It can also be done using a mig welder set on low heat or even a jewelers-like oxy/acet torch. I've actually had some great success using the jewelers torch, but it's not easy! Regardless of which method you use, you want to do short "blips" and work around the area. Remember...too much heat in one spot is going to cause shrinkage and distortion. By keeping the temperature low and by working around the panel, you are keeping the heat to a minimum.

Once it's welded all the way around, you want to put a dolly on the backside and planish the welds down flush with the panel. Some grinding may be necessary depending on how nicely the welds were done. If you over-planish the area, you are going to want a shrinking disk to tighten the metal back up. This is basically just a stainless steel disk that you mount on a grinder that spins and creates hit through friction WITHOUT removing metal like a regular abrasive disk would. A prominent metal shaper named Wray Schelin sells these, PM me for contact details.

The correct method for finishing the metal is to get a magic marker and color the entire area with it, then sand lightly. This will show you and high and low spots. Once you are satisfied, you apply the body filler using the above directions.

edit: superficial rust isn't really that big of a deal unless you don't take care of it immediately. Complete rot-out is a problem and the only true way of taking care of it is by replacing the rusted-out metal. I'm sure there are people here who would just as well throw some fiberglass and fiberglass reinforced filler over the area and call it done...but the approach you take all depends on how long you want the repair to last. Body filler and fiberglass will expand and contract differently in heat and cold than the underlying metal, which will cause the "repair" to fail. If you plan on keeping the vehicle for a long time and do cheap and easy repair on it and have it painted...that region will eventually fail leaving you back making a post about rust.

 

Thanks. I have the problem kind under the windows. This looks a bit beyond my weekend warrior status at the moment. Probably best to find a professional for around the so called alpine windows.

 

I had a spot of rust under the alpine window on the passenger side and thought it'd be easy to fix surface rust. I had to take out the head liner (hard) and take out the window (easy). I found lots of rust when I took the sander to it along the bottom of the window which was hidden by the window rubber. I had to MIG weld in new metal and had to go down past the contour below the window. The metal was so thin there (after taking off the rust) that I kept blowing through with the welder so I had to cut it out and weld in new metal. I'm not an ace at body work so it took me 3-4 hours of welding and sanding to get it smooth. Painful but sure looks nice when finished.

If you aren't handy with a welder - take the body shop advice.

Good luck,
Marv

 

Hi,

Just stumbled upon this thread but I'm in exactly the same boat as mburnett, my rear and alpine windows have some serious rust around them and I'm sure are going to require welding/new metal.

I'd be interested to see any pics that anyone might have of such work - I'm handy with a MIG welder and am hoping to do the work using MIG & CO2/argon mix - and lots of patience. Not sure when but hopefully can squeeze it in before the winter.

Thanks.

George