Welcome to the BugShop FAQ

The text following is part of a series of articles written by John S. Henry on the restoration and maintenance of air-cooled Volkswagens. While his experience is exclusively with the Beetle, many of the techniques can be applied to other models.

This text is copyrighted and duplication, re-distribution or publication is prohibited without consent of the author.

Article: General: Dealing with Rust
Last updated: 10/31/01

General: Dealing with Rust

Symptom: There are holes in your car in places where holes were not meant to be.


I have to preface this text with a disclaimer that these are my own thoughts, there are lots of other "Rust FAQ" texts on the web, most of which I generally agree with.  A lot of this article is aimed at doing the minimum to keep your car road worthy and safe if it has rust. It is not about restoration in the pure sense (see "Doing a #4 Restoration"). Before I had the resources that I have now and the '57 I always wanted with a lifetime to restore it, I had daily driver Beetles and limited resources. My approach to body work was dictated more by my available resources and the need to have a car to drive to work the next day than my skills and ambitions. And I think that a lot of VW owners are in that same category.

So before you jump in to any kind of rust repair, take the time to ask yourself: "What is it that I want to do and what are my resources and capabilities?". This article deals with that "basic need" body work. This is NOT a discussion on a years-long, total disassembly repair/restoration technique. This is "My VW is rusting away before my eyes, I need to drive it everyday, what can I do about it, NOW".


I live in Massachusetts, a state which pours literally tons of sand, salt and rocks on the roads every year so we can all develop our rust restoration techniques. And I will tell you that I have tendency to be a little fanatic about things (I have lots of those little storage drawer cabinets in my garage and most of my nuts and bolts are sorted by size, most of the drawers are labeled. All of the spray paint cans are in one place on the shelves and sand paper is stored in upright "file organizers".). Don't accuse me of giving "half ass" or "kludgy" advice here; thank me for offering some suggestions on some real life, low buck ways to keep your car on the road. But don't let me steer you away from the "right" way to do it either, if that is what you really want to do. DECIDE what you are going to do (ie.: methods 1 through 4 explained below)....and DO IT! I only have the skills that I have now because I am one of those people who 1) believe that I can do anything (in spite of the fact that I have proven that theory wrong once or twice) and 2) am WAY too cheap to pay anyone to do anything for me.

I have concluded that you HAVE to do one of four things to rust on your car:

  1. Ignore it and it will go away. It will, really. And it will take the rest of your car with it.

  3. STOP the rust. This is your only requirement. Use this approach and you could care less what the car looks like, painting the affected area is an afterthought, finding a paint color that matches the rest of your car is silly. WARNING: This approach could leave holes in your car into which could enter cold, water and small vermin.

  5. STOP the rust and repair the structural integrity of the car, if necessary. This means closing up the holes in "perforated" areas (Yeah, like who even thinks to do anything before you can poke a key through the bubbled paint) and often, if not always, involves replacing some metal. But you STILL DON'T REALLY CARE WHAT IT LOOKS LIKE.

  7. Remove and restore the rusted area to new condition. Yes, this is the "right" way, the method we would all like to be able to do, but it very often requires expensive things like sandblasters, shears, grinders, welders, compressors, paint guns, REAL auto paint and, almost always, a garage and lots of time and money. But you can go to the VW show with your car the next year.
Now remember these approaches. I will refer to them throughout this FAQ. Think of them as not so much a technique, but a mindset that guides your whole approach. You must DECIDE. You may find after you really "get into" your car that you go from a 2 to a 3 or 3 to a 4, but never backwards. Going backwards is chickening out, backing down, throwing in the towel, etc., and it far worse than just giving the car to reputable body shop and going home to count your money for the last time. And there is no substitute for a "#4", so if you (think you) can do it, DO IT!

Help in deciding what you are going to do....

So the first thing you must do is decide which of these approaches you are going to take. See, I know that while almost everyone would like to do that full, pan-off resto and be gleaming in the sun at next summer's VW show, the reality is, in most cases you just need to keep it on the road (this means that you can't cut it up so bad that you can't drive it to work the next morning) and really would like it to look like you are not ignoring the rust. So to guide you in making your choice, let me offer the BASIC tools, materials and skills that you would need to use the above 4 methods:

How to do it (well, sort of.......)

OK, I can't possibly tell you everything here. My real intent in writing this was just to give you some good ideas and tips that really focus on methods 2 and 3 above. #1 is easy, we see examples of this everywhere in the northeast, and #4 I have completed on my '57.  So let me give you the short version of #2 and #3 and then some basic tips.

Method #2 (remember, just STOP the rust, don't care what it looks like)

There are some great products out there that are able to neutralize rust and convert it to a black, inert substance which includes magnetite (Fe3O4, for you chem. majors). I used to use, and would still recommend, a product called "Extend" (made by Permatex). It is thick milky substance that you brush on to rust and it turns it black. It also comes in an "aerosol" but my experience has been that it doesn't work well from a spray can. The problem with the stuff in either form is that if there is no rust, it doesn't react, therefore doesn't protect whatever is underneath it, and doesn't adhere very well either (with no rust to react to). Take your typical "cancerous" bubbled area in a flat panel, perforated or not. The technique would be to expose all of the rusted metal by wire brushing, with a drill preferably, and then apply the white stuff. The problem is in the area where the rust stops and the good metal starts. If you used a wire brush, you invariably uncovered some unrusted bare metal at the "borders" of the rusted area. This white stuff will do nothing here. In fact soon after it dries it will peel off and expose the bare metal so new rust can form. So be aware. Paint the stuff liberally on where ever there is rust, just surface prep with a wire brush enough to get the loose stuff off and especially any bubbled paint. It will usually dry, turning form white to black in about a half hour. You can accelerate this process (which will be slower if it is cold) by warming it with a heat gun. I basically do this all the time now since I hate waiting for anything the "dry".

A superior product to the "white stuff" though, is Eastwood's "Corroless". I swear by it now and use it anywhere I would have used the white stuff. It is somewhat expensive (as is everything in their catalog) but it is superior because it converts rust like the white stuff AND acts as a primer/paint which doesn't need to be top coated if you don't want to. I paid $16 for my last pint, but I must admit that coverage is very good. At the time of this writing Eastwood's number was 1-800-345-1178 and they had a web page at http://www.eastwoodco.com.

Then there is the issue of covering the treated area. Well my rules about covering treated rust would be:

So what is this roof tar about? Use roof tar on the body if you really want to make a statement (see "A running example of all of the discussed techniques" below). I stumbled on this roof tar quite by accident with my first Beetle many years ago. I was looking for an inexpensive undercoating and I found this stuff at Sears called "Black Asphalt Fibered Roof Tar". I got a gallon can for about $7. (I have since purchased from Eastwood a "brush on" undercoating for $17 a quart and guess what? It looks, smells and applies just like that roof tar.) The idea is to apply the stuff anywhere you want to seal out water, sand, salt etc. You can apply it with a stiff brush, but be warned the stuff is very smelly and messy and depending on how thick you apply it, may take MONTHS to really dry. You can't apply it too thick because it will drip and sag for days. Several thin coats applied 2-3 days apart seems to be best. It is great for applying to irregular surfaces and, provided you have terminated the rust process underneath, it will insure that the rust does not come back. CLEAN THE SURFACE YOU ARE APPLYING THE TAR TO WITH SOLVENT FIRST. This is very important. It will adhere well to treated rust, bare metal and painted surfaces but only if you clean the surface first. I'm not talking about wiping it off with the palm of your hand or that rag that has been on the workbench since 1993. Use non-petroleum based solvent like lacquer thinner, methyl ethyl ketone (my favorite because it doesn't "eat paint" and I bought a bunch of cans at a warehouse store really cheap a few years ago, but I'm told that it is a known carcinogen), acetone (be careful with this stuff, it eats paint and plastic and may even erode the treated rust), prep-sol or any pre-paint solvent, or in a real pinch a 90% rubbing alcohol would be better than nothing.

For the tar I use an ordinary 2" nylon paint brush but first cut about half of the bristles length off at an angle to make it stiffer and give a "point" to push the stuff into corners. The trick is to "push" the stuff into cracks and crevices with the brush. Eventually (months) the stuff will semi dry to a gummy undercoating.

Allow me to diverge and mention sandblasting. While I consider this a "#4 class" technique, if you have access to it, by all means use it. I have a 3 1/2 hp compressor and a "blast out of a bucket" blasting gun that you can get for about $25. I use "Black Beauty" (silicon carbide, "black sand") blasting abrasive that I can buy locally for $9 for a 100 lb. bag! (Eastwood sells it- 50lbs for $80 plus shipping, go figure). It is spectacular for those flat body panel, no perforation "cancers". My only caution would be that blasting might remove so much rust that the white stuff might not work. Blasting and Corroless is a true #4 technique for non-outer body panels, used on the outer body is a #3 technique (I'm getting pretty anal about this #1, #4 stuff, huh?)

You might also consider using a sandblasting shop. The one I used to do my '57 body charged $75 and hour for sandblasting services but they had some serious equipment and could do a lot in an hour. Rims, for example, were about $10 a piece, a Beetle hood, both sides, was about $35.

So there are my New England tested tricks for STOPPING rust. Just remember:

Method #3 (remember, STOP rust, repair/restore the structural integrity, still don't care much what it looks like)

Go read "Method #2" if you haven't already, because #3 is just some metal work after you treat the rust as you do in #2 but before you cover the treated area. While I chuckle when I see a car on the road with bondo applied with a garden trowel to the rear quarters, I have to give guy credit for at least trying. I know so many people that will just watch their car waste (rust) away, day after day, and do nothing, sort of like putting sour milk back in the refrigerator and hoping "it might be better tomorrow".

So #3 is really about putting back metal that rust has taken away and restoring the structural integrity of the car. It is not about using bondo, glazing compounds, leads, primers and paints. That is all #4 stuff. While I now routinely use inexpensive wire welders, in the interest of fairness I will not mention them as part of a #3 solution since I did not mention welding as a resource needed to do a #3. But let me just say that if you have access to a .024" MIG welder, you can do #3-like repairs (replace metal, restore integrity but don't car what it looks like) and I would definitely recommend it over the fastening methods below.

Tools You Need

We can all be cheap when it comes to buying tools. About 7 years ago when I easily snapped a flea market quality 1/2" breaker bar trying to loosen lug nuts, I decided I had had enough, and vowed only to buy top quality tools from then on. I prefer Sears Craftsman tools because, as we all know, they will unquestionably stand behind them. Home Depot now sells a brand called "Husky" that is good and very affordable (and also has a lifetime guarantee too, I think) You need a good quality pair of tin snips. Ones that will cut up to 18 gauge metal. I bought a pair at Sears for about $12, if I remember correctly, about 5 years ago. I have beat the coating off the handles with a rubber mallet trying to cut "thick" metal and they still work great. Also a set of titanium drill bits are key. Lots of times you cannot exert immense pressure on a piece of sheet metal you are drilling and a good sharp bit will save the day. You can get a good 1/16"- 1/4" set for around $15, I like the titanium "bullet" tipped ones best. And of course the wire brush and drill are key. You should also seriously consider getting 4" grinder. Harbor Freight sells one for around $20 that is a very good value. These will take down metal very fast. For a picture of this tool, see Page 1 of the "#4 Restoration techniques.

Here's a trick that I did not mention in the text for #2 above. When using wire brushes on a reversible drill, reverse the drill often (every 10 minutes of use or so). This prevents the bristles from getting bent over too much and also makes the brush much more effective. The tips of the bristles will develop angled surfaces quickly based on the rotation of the brushing. When you first reverse the drill you will notice a much better "cutting" of the bristles on the metal.


In the absence of welders, I recommend 1/8" aluminum rivets for fastening in the new metal. They are cheap, easy to work with, low profile and won't rust out. You can get a rivet gun for around $12, or borrow one. If you are not familiar with rivets, the basic principle is that you drill a 1/8" hole through both pieces of metal you are fastening. A rivet is a cylindrical piece of aluminum with a "pan" head on one end. A steel pin passes through the rivet and has a bulbed end on the side opposite the rivet head. The rivet gun grasps the steel pin from the head side. The "headless" end of the rivet, pressed up against the bulbed end of the pin is inserted into the holes in the two panels. The rivet gun, when the handles are squeezed, pulls the bulbed end of the pin through the exposed rivet cylinder on the other side of the gun and panels such that the rivet deforms and "squashes" against the inner panel. When the deformation is against the inner panel and the handles on the gun a squeezed further, the pin, just below the bulbed end and inside the rivet cylinder breaks off, releasing all but a tiny piece of the pin that is still inside the rivet cylinder. (whew!, trying to describe the simplest things with words is tough, go buy a box of rivets, look at them, and this will all make sense)

The rivets I described are called blind "pop" rivets. Blind, because you don't need to have access to the other side of the panels you are fastening, and "pop" because the pins break off once the rivet has supplied sufficient pressure to the panels. I would recommend riveting every 2" along the edges of panels, closer on irregular panels and at all corners. Make sure that the head of the rivet is on the outside of the car, this makes covering/sealing the repair easier. The technique for replacing metal is pretty basic:

  1. Cut out all of the heavily rusted area. The "edges" of your hole can be surface rusted but should be full thickness as you will be fastening the new metal to this area.
  2. You may be inclined to try to cut out one big square hole. But don't cut out more than you need. It is much easier to work with smaller, irregular shaped pieces than one big one.
  3. Cut your "patch" metal about one half an inch bigger than the hole you are covering. You want to minimize the overlap but provide a solid fastening area.

The Bad News You Don't Want to Hear: RBR (really bad rust)

There is a saying that "any car is restorable". I believe this. I also believe that given the right amount of resources and money, the Titanic could be salvaged and "restored" into a really neat amusement park ride. In writing all this stuff about rust, I began to realize that I might want to warn the reader about "bad" rust. I call it "bad" or "doomsday" rust because when you have this kind there is no easy way out. You can't do a #2 or #3 on it. Your rust has eaten up multiple panels of the car and the bolts or whatever holds them together. It may very well have weakened the structure of the car and often may make the car UNSAFE to drive. ONLY A #4 WILL FIX "BAD" RUST and it almost always requires taking your car apart a lot more than you can possibly do in a long weekend; and it usually costs lots of money and requires lots of #4 type tools and skills. I know that you didn't want to hear that, but we have to be honest about this.

In my experiences, I have run in to "bad" rust in 3 locations on the Beetle, and while yes, I sometimes did apply some #3 techniques to it, I knew I was only buying some time. And this doesn't mean that these are the only locations for "bad" rust, but these are by far the most common. (if you are looking at a Beetle to buy and it has this kind of rust, keep walking)

Let talk some more about heater channels

I get asked all of the time about replacing heater channels. Is it worth it? How hard is it? Where can I go to have it done? While I have never personally done it myself, I feel confident in presenting the following list of

 8 Reasons Why Heater Channel Replacement May Not be as Easy as You Might Think:

  1. It takes a very long time. To do it properly, it requires you to drill out literally hundreds of spot welds which connect the channel to the other panels of the car.
  2. You run the risk of messing up the door opening dimensions and having doors that never close right again, especially if you try to replace the channels while the body is off the pan.
  3. If the channels are badly rotted, chances are good that some of the panels that attach to the channels are rotted in those locations too (most notably, the lower A-pillars)
  4. The generally available replacement heater channels are not correct for many of the older model VWs. While the vendor may say they "fit" (and they do) the heater outlet is in the wrong place.
  5. Eventually, new heater channels will rust out again, especially if the car is driven in harsh conditions. The inside of the replacement channel is usually not coated with anything more than primer and welding them in will make them even more prone to rusting (hot metal burns paint off)
  6. With every day that passes, there are fewer shops/mechanics/bodymen who can do this and do it right.
  7. The heater channel is not a simply body "panel", it is an important structural component that provides lateral rigidity to the body and floor pans.
  8. It is not trivial, in fact is in not even just "difficult". (see below)

Boy, I bet you feel better now, huh? Don't misunderstand me. I'm not trying to discourage anyone from doing this. I am just trying to let you know that this is not trivial. Many people ask if they should do it like it is like replacing a floor pan. It is not, I assure you. To do it right requires skill, patience and time. Any one of those things may make up for some short comings in the other. What I mean by this is if you are a novice bodyman and have all of the time, patience and ambition in the world, go for it.

There are some websites on my links page that show pictures of heater channel replacement.

But very quickly, what is the heater channel? Well, it is a hollow, multi-walled "tube" that runs from just in front of the rear torsion tube ends all the way along the lower edge of the sides of the car to the bulkhead where the master cylinder is bolted. It is a key structural component of the car. It houses a hollow tube that carries heat (yeah, right) up to the front floor vents. It is the front floor vents, it is the door "sill", it is the thing that the running boards bolt to. It is all of these things.

(Left side shown)

And all too often people ask "Should I have it done?" before they ask "Can I have it done?". Heater channel replacement is not like having your house painted by someone. You won't find anyone listed in the yellow pages under "Heater Channel Replacement". They guy who you would want to have replace your heater channels would be an old VW bodyman who cared about your car, quoted you flat rate for the job and took as long as he wanted to do it. Yes, many of the skills needed are common "body shop" skills, but some are not. Someone with a basic "chisel, patch and weld" technique, who is most interested in getting your car out so he can get the next one in, might get the job done but will look like crap, diminish the value of your car and you may have structural problems down the road.

If you seriously want to assess this job, first go find out what a replacement channel looks like. You usually can see them at the larger shows and many good catalogs, even Hot VWs ads, have pretty good photos/drawings. They usually run $130-$150 a piece. Once you see what one looks like, you will have a better idea about how it fits into your car, and what is involved in putting it in. Pull up the front footwell and rocker panel carpet, remove the rear quarter panel(s) and rear seat bottom. Remove your running boards (if they are still attached). You will now be able to see just about as much of your existing channels as possible. Examine them front to back and you will see how many different places that they are welded to other panels in the car. They are welded to the back upper floor where it rolls down toward the seat back, the lower edge of the rear quarters, the bottom of the B-pillar, the bottom of the A-pillar (hinge facing edge and inside the footwell area), the front quarter behind the front wheels and to the bulkhead cross member.

The old channel must be carefully cut away in all these places and there must be good metal present to weld the new one in. "Filled hole" MIG spot welds are best and closest to the original assembly. MIG butt and stitch welds may also be used but will definitely not look "factory". In any case, extensive welding is required. The job can be done with the body on the car. It is a bit more difficult working around the pan (unless it (they) is being replaced too) but it does help keep the door opening square.

As I said in the "buying" article, I wouldn't "walk" on a '51 for $1000 because the rear running board area was rusted through, but don't just lump wholly rotted channels into the same aggravation factor as a hole in the pan or a dented fender. Heater channel repair is major commitment.

Your options if you have "bad" rust

If I were in law school, I would tell that you have just one option- stop driving the car, for fear of some kid throwing some roof tar over a gaping hole in his front pan and then suing me when his front end flops off when he hits a pothole doing 75 mph. I do believe that you should evaluate your entire situation and let safety be your FIRST criteria.

"Bad" rust in the rear quarter panel area, as I have described it, has little effect on the structural rigidity of the car. But a #2 or #3 approach to rust in these areas will, at the most, buy you a little time. Some cutting, some patchwork with sheetmetal, some sheetmetal screws, wire brushing and lots of roof tar bought me a couple years in my "salt beater" '68; but all the while I knew this car needed major transplant surgery or was on it's deathbed. No matter what you do, aside from a full heater channel replacement (aka: "a #4"), will effectively stop the rust inside the rear heater channel.

You can buy replacement front end (bulkhead) panels or maybe find a clean new pan at a wrecking yard, but again, this is #4 territory.

So your options are:

  1. Say good bye. Sell the car "for parts", part it out, call Jack Kervorkian, but give it a "dignified death". (nobody ever insures Beetles enough to make a staged "accident" worthwhile anyway)
  2. Jump into a #4. Bite the bullet. If you can afford to do without the car for 2 months to 8 years (like, buy another one), you have a bottomless supply of cash, two cousins that own body shops and are unmarried- go for it!
  3. Use #2 and #3 as appropriate and safe, and then be kind to your car. Shift it gently, never rev it above 3000 rpm, take it to a counselor, treat it to a "premium" gas every once in a while, tell it that you really don't mind the oil stains on the driveway and that it is nothing to be embarrassed about. In general, baby the car until it's last breath.

A running example of all of the discussed techniques (light reading) ....

Something happened to me when I got married (well, a lot of things happened actually). I had just finished as much of a restoration as I could afford on my '67 and got it a $700 paint job, when I decided it was too nice to drive in the winter anymore. A couple other things influenced this too:

  1. I moved out of a 2 room apartment into a rented house with a 2 car garage
  2. I had a good friend who, for as long as I had known him, had sworn by having a "good" car and "salt" car which he drove in the winter. (problem was, he got so anal about the "good car", an '84 black GTI he bought new, that he just quit driving it, stored it under cover in the garage and drove his salt cars year round)
  3. My brother, who continuously dabbled in every hobby known to man, was fading from a 1 year stint with Beetles and drifting into boating.
I bought (stole) his '68 from him with a new mail order front end, brandy new engine and Prelude seats taken from a wrecked Honda with 1000 mi on the odometer, for $800, and it became my salt car.

I mention this because this car truly became the embodiment of method #2 above. Visualize this car: I stripped off all of the body molding from this baby blue Beetle because some rust was starting to form around the holes, treated the rust and then went around with silicone in a caulking gun to fill the holes, leaving little silicone "Hershey's kisses" on the hood that stayed there for 4 years. I took off the running boards and riveted new sheetmetal over treated rustout on the rear quarters and then applied a coat of roof tar from underneath to about 8" up on the quarters. I used extra wide foam weather stripping between the hood and body (see the "heating your Beetle" article) that stuck out all around. I had some trouble with the ignition switch so I just wired a switch on the dash and a push-button underneath so no key was needed. This car was a true "salt beater".

One of its many duties was to deliver the trash bag to the end of my driveway on Friday mornings when the garbage truck came by. My driveway is 150 ft. long. I would toss the Hefty bag full of trash up on the roof of this car in the garage and then back down the driveway slowly picking up speed. Just before the road at the end, I would cut the wheel slightly and hit the brakes hard. I got pretty good, I could usually deposit the bag right at the curb edge. I remember looking forward to Friday mornings before work.

It was a car that made a statement. People in the Lexus's and Jags did a double take and aborted the merge next to me in the city; people in the parking lots avoided brushing up against it and mothers yelled to their curious kids "get away from that thing"; a shopping cart in a good empty space at the grocery store made my day and curbs and median strips were just minor inconveniences (although my rear camber compensator mysteriously disappeared after some "curb climbing", I never found it). I kept the interior meticulously clean, but the closest the exterior ever got to a car wash was some overspray from when I washed our Jetta next to it on the driveway.

I used a hot glue gun in December to glue a string of 12 volt Christmas tree lights to the drip rails (maybe you saw me?). I drove it in a caravan to the Manassas VW show one memorial day weekend. At rest stop a guy's teenage girlfriend and I were talking, she asked, "So, what color are you going to paint it?" I faked insult and said matter-of-factly, "it IS painted". I always thought that there should be a new class at the VW shows: "Best use of body fillers and miscellaneous adhesives" I used this car and a length of rope to tow home the engineless, brakefluidless, one-emergengy-brake-cable-working '57 Beetle I restored (that's a real exciting story in itself, see the My '57 Beetle Restoration- page). In fact, we had to DRAG the '57 out of the barn it had been sitting in for 6 years as all 4 hubs were frozen and had to be beaten into agreeing to roll. I used this car as what in southern sections of the US is referred to as a "stump puller", to rip unwanted shrubbery from the front of my house. I carried so much pressure treated wood on the top when I built my deck and porch, on a homemade roof rack, that I cracked 2 body-to-pan mounts. I miss that car. But I drove it 4 years and 80K mi before I sold it for $500. That's VW value to me.

Copyright© 1998; John S. Henry

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