New Heater Channel

VW Beetle Restoration Project, Oct-2014

The chassis & floor were tidied up just enough to be used as the main reference for the new heater channel. I took a whole load of new measurements – A to A post, B to B post, A to B post each side & distance between heater channel bottom flange bottom of brace bars. This would help align the new heater channel and also make sure the door aperture dimensions were maintained. 

The plan to fit the new channel was:

  • Cut the old heater channel out
  • Trial fit new heater channel & prepare weld areas
  • Bolt heater channel to the floor, lower body onto floor & align
  • Tack weld heater channel into position
  • Raise body, roll chassis out of the way & finish welding

Was planning to do this in the one day – what is it they say about plans?

Started by wire brushing the lower rear quarter behind the running board to find the spot welds and found some rust damage. What a surprise! Also found 10mm of filler covering an old repair:

No option but to cut this out:

Just as well I did – there was a lot of rot under the filler along the bottom edge. I’m not against using filler but the surface it attaches to must be sound otherwise moisture will get in and the filler will quickly crack & deteriorate.

Still, no need to unpick the spot welds!

There was no need to unpick the spot welds at the front inner wing either as I knew this was just a cover panel over the rotten original inner wing and I was pretty sure it had mostly disintegrated. So I set about cutting out the heater channel from the bottom of the A & B posts. The heater channel didn’t put up much of a fight and came out pretty easily:

Front inner wing:

10 minutes later:

There was no less that four layers of metal, each “repair” just tacked on top of the old:

With most of the ragged edges cleaned up and some new metal welded to the bottom of the A & B posts, it was time to trial fit the new heater channel. It was bolted to the floor with a couple of bolts and checked for alignment with all the other bolt holes. Then the body was lowered back on to the chassis:

Inserting the two rear body to suspension bolts helped align the body to chassis accurately:

The front flange of the heater channel aligned to the front of the front bulkhead and all of the other bolts holes (e.g. rear bulkhead) all lined up. The rear flange aligned with the rear bulkhead and the height of the channel (bottom flange to bottom of brace bar) was correct:

The new metal at the A post needed a little trimming to set the height correctly. The door aperture (outer) was still at 950mm, so the heater channel was ready to weld into place.

Before welding the HC in place, I thought it would be better to fit the tube that carries hot air to the demister first as it looks like a difficult job to fit it later. However, we couldn’t find one on the VW Heritage site and I didn’t want to be held back. So I improvised using a spare vacuum cleaner tube that I had lying around. It’s from a Dyson!

With everything checked and double-checked – bolt holes aligned, door aperture correct, vertical alignment OK, etc, and with the heater channel bolted to the floor and the body resting on the chassis, it was time to weld it in for good:

Now I have something solid to build to, I can fit repair sections to the front inner wing and lower rear quarter.

Whilst preparing the heater channel prior to fitting, I cut off the flange at the end of the heater tube and welded up the seam. This gives us the option of fitting, say, a silicone joiner to a custom stainless steel tube instead of the standard parts: