Have you been looking all over the Web for that elusive page on how to replace heater channels? Well, look no further, you have found the right place! This article will walk you through the procedure from beginning to end, so you will have no trouble at all doing it yourself. Many people seem to be in the dark about heater channel replacement because none of the published repair guides have any info about the procedure. Well, let me tell you, I am here to fix that.
Here on the left is what most people start out withtheir Volkswagen project. Don't be intimidated, it is good clean fun, replacing these babies.
First off, are you replacing for structure alone, or are you doing it with heat? There's no difference aside from the price of channels ("No heat" is half the price of normal heat channels). To do a thorough job do a "full body off" and get that puppy up on saw horses about 36" + or - (close) off the ground, make sure you take your time-support it better than good cause you'll be crawling back and forth underneath to perform this procedure. The picture at left is a "worst case" but in Wisconsin as a bugger you see the good in the dead... heat channels are in reality VW's only outer support off the pans.
Second, tools you need. A 4 1/2" grinder with several packs of wheels (both, thick and thin), a welder, a small chisel and a good hammer. Two pairs of thick welding gloves (one for you and one for your assistant). Last but never forgotten safetygoggles (you want to see this after you're done.
Third, time and patience. If you're on this page you either can't afford to have someone do it or you fancy yourself an up and coming VW surgeon (well if you've done the body off what's two days or a week off the body matter!) This is a huge undertaking for an amateur, but within your realm if you love your new bug as much as I think you do.
Take some measurements while you're in the patient planning mode. Bolt holes on the old channels, if they exist. In the worst case, the edges of the channels across the inside of the car. Anything you can do now so that when you cut them out and replace them (one at a time) you'll have a reference and be able to say close enough. The closer you get these puppies in the install the better you'll feel when you set the car on the pan again. Usually the Brazilian repair pieces; channels, panels, etc. are off but I'm talking esthetics here (you'll have to fill and engineer on the fly, but you've come this far so your ready for that, right?)
Forth, unless you're a dynamo take a break this is huge... You're about to raise the dead. Bugs that would have been on the heap are on the road because of this procedure.
Fifth, get a mask or bandana when you start cutting. Otherwise you'll taste it. Very important: Keep the doors of the Bug closed, or else you risk major door alignment problems if you don't heed my warnings here. The channel has major tie in points; up at the fire wall in front (bigger bolts go into the channel here), the front door pillar (there's a tube inside for you heaters), the rear door pillar (more detailed section, lots of angles), and the back of the rear Quarters (these usually don't line up and need a little finessing). What your looking to do is to remove the old channel but grind daintily around these areas, these are your tie ins were you will be re-attaching the new channels (VW spot welded at the factory). Once you get most of the old channel out, a chisel and hammer cleans up the tie ins (after light grinding they glow). I am hoping you see these areas thru photos and as you gut this back you'll see what I'm talking about. You've gutted back the channel, now get out your reference measurements and turn around and look at the other channel you haven't removed yet (you're doing them one at a time!). Your main object here is to get the new channel into position and tack weld where you can, just get it to stay put so you can do some magic repair. When I did mine I had to reconstruct each tie in point and overlay a patch (see photos). The bottom of the channel should be close to the other one if it's there. Otherwise use the new one as your new reference. You don't want to end up with a lopsided bug so pay attention to any reference you can - You Are The Sculpture!
Sixth, take a break (but if your break impairs your skills of concentration or makes you a hazard to yourself with tools, call it a day). Hopefully your looking at a tacked in channel, enough to hold together or a completed side. Even if it's tacked in technically your half done, that's great!Now, move to the other side when you're convinced the first one is secure. Once both sides are gutted and the new ones are tacked in, you can either reinforce tie ins and bond (the slacker method, not recommended but hey it's your car) or you can be a VW sculptor and use steel and that grinder and patch in all areas that are tacked. Take your time.
Finally, clean up with wire brush, sandpaper, what ever your prefer, and prime those puppies. Now it looks like factory, or at least as your first heat channel repair, better than the old ones for sure.