Friday, 21 September 2007

Fireflex Installation (Bay)

Apparently old VW engines have a tendency to catch fire!

I don't know if there's something about the design that makes them more prone to this than other vehicles or whether it's just an age thing. Whatever the reason, regular checks to make sure that the fuel lines are in good condition and carrying an extinguisher should be considered mandatory. I've already been doing both since day one, however today I took things a stage further and fitted an automatic extinguisher into the engine compartment of my Bay.

Automatic extinguishers consist of a pressurised bottle of gas, foam, or powder to which is attached a length of 'hose'. In a nutshell, you clip the hose around the engine bay and, in the event of a fire, the hose ruptures spraying the contents of the bottle all over the fire.

There are a number of decisions to be made before you buy:

1. Gas, foam or powder.

2. 0.5kg or 1.0kg bottle.

3. Horizontal or Vertical mounting for the bottle.

I initially purchased a 0.5kg upright gas bottle from VW Heritage but after seeing it for real I decided to use that one in my Bug (where I can easily mount it to the firewall) and bought a horizontal version for my Bay. In both cases I went for the 0.5kg bottle because I've been assured that it's plenty for use in the confines of the engine compartment in a Bug or a Bay. I went for gas because I liked the idea that there would be no additional clean up required as a result of it being activated. We discussed this on where some folks suggested that foam would also be a relatively easy clean up and less prone to dissipation. Their argument was that gas would disperse after putting out the fire which could then reignite. The counter argument is that the vehicle would have stopped by then and although there may still be fuel present, the source of ignition would have been removed (the heat of the engine is insufficient to cause petrol vapour to auto-ignite - it needs a spark).

Having made my choice the next job was to fit it. As I said, I originally purchased a vertical bottle but although there is plenty of space in the Bay's engine compartment there are not many suitable vertical mounting points. On the other hand there are plenty or opportunites for horizontal mounting, including the roof of the compartment.

The roof is covered with hardboard, which has holes in it, and glass fibre insulation behind above that. The hardboard is fixed to an arrangement of beams which support the metal floor of the luggage compartment above.

Now I have seen bays with the hardboard and glass fibre removed and although I don't like the idea of hardboard in the engine bay, I figure that it's been doing it's job of keeping noise and heat out of the interior for the last 36 years so why remove it now?

My reason for mentioning it at all is that I figured that one of the beams to which the hardboard is attached would make a good mounting for the extinguisher bottle. You can tell where the beams are by looking at the fixing points for the hardboard and if you look at the floor of the luggage area you'll also see where they are spot welded.

The image below shows the roof of my engine compartment with a pencil line drawn between two of the fixings in preparation for drilling holes for the extinguisher bracket.

Holes were drilled and self tapping screws used to fix the bracket in place. Then, after clipping the cylinder in place and tightening the large cable tie (supplied) I moved on to the job of fixing the hose.

I'm not the first person to write on the web about installing one of these things and if you look around you'll find that everybody, and I do mean EVERYBODY, who has ever done so says that there are not enough cable ties supplied with the kit. Why the manufacturer has not taken notice and put a few more into the kit I can't imagine. I can't accept that doubling the number included would seriously affect their profitability however, forewarned is forearmed: get some more cable ties because you will need them.

As far as the installation in my Bay was concerned that hardboard ceiling with it's pattern of holes was a blessing because it gave me loads of places to attach the ties without having to drill holes or attach sticky pads. Given that I'd made sure I had extra ties available it was no big deal when I decided that some were in the wrong place. I also made a point of attaching them loosely at first so I could slide the hose around until I was completely happy with the layout. As you can see from the final picture I spiralled the hose over the engine i.e. around the area where a fire is most likely to break out.

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