Metal Sandwich anyone?

Not too much to report and no pictures in this blog.   I’ve spent a fair bit of time poking about in the garage and in a fit of pique, chopped out the left-hand floor and sill – and the right-hand floor.  There have been past repairs to the rear of the floors, metal has been added above and I think below to what was there originally. This is causing me a bit of a problem… I’ll have to do something with the surplus metal or the floors won’t sit properly on the sills, they are currently about 5 ml higher than the small lip on the sill, which I assume is there for them to sit on.  Or, I could lower the sill a bit and extend the A and B posts – I’d rather not though, I’ll probably end up with a massive gap under the doors through which the elements will find their way in, my feet will get cold and misery will ensue.

Cutting the sills out with the floors is not recommended as things will start moving about, although I only did this on one side, so hopefully only half of the things will move about.  I still have all the bracing bits in place (thanks to Pete) so any twisting and misalignment will be minimal.

I really need to get committed to welding all the new panels in.  The only practical way to do this is to punch a series of small holes in one panels’ edge, clamp it to another panel and then to fill the hole with weld from the MIG welder, thereby glueing the 2 bits together. I must make a start on this soon or I will never finish the restoration. 

What is a Mig Welder I hear you ask?  MIG stands for Metal Inert Gas and the welder bit of it is a box which, creates an electric arc which is hot enough to melt metal.  The clever bit is that the ‘torch’ feeds out the wire, the gas comes out round the outside of the wire, shields the arc and stops oxygen getting to the hot bit.  If there’s no oxygen, the metal will not burn, it will just melt.   The idea is that you press the trigger on the torch, the thin wire fed from a spool in the welder gets close to the steel you are welding to, the arc is struck, the wire melts, the heat melts the metal being welded, the gas shields the arc.  Job’s a good ‘un.  

The gas is a mixture of CO2 and Argon.  There’s a weird thing going on in the welding world which means you can buy gas but you can never own your own cylinder, so you have to rent one.  The rented cylinder is replaced with another when you get the gas refilled.  You can rent the same cylinder for a number of years, paying the fee each year but never needing to have it refilled. Refills are free, so you could have any number of cylinders replaced during the same period.   Weird isn’t it?  Actually, you can own your own cylinder but nobody will refill it for you, nor will they exchange it.  If you happen to own a C02 cylinder which came from a pub and you attempt to get it refilled or exchanged, you will be refused and then asked a lot of awkward questions, which you might not want to answer – ask me how I know.

It’s relatively easy and forgiving of you are welding metal which is 3 ml thick or has inherent stability, like a box section.  However, a Citroen 2CV is made of thin floppy steel, less than 1mm thick.  Unless it’s new, it’s going to be even thinner and rusty and you can’t weld rusty sheet steel with a MIG. It will just burn holes in the panel, spit and spatter and generally have the look and strength of Pidgeon poo.  This is why cars are put together using a spot welder. A spot welder has 2 prongs, which when clamped either side of 2 thin bits of metal, strikes an arc, creates a ‘spot’ of melted metal, which joins the panels together.  You don’t need gas with a spot welder, it’s quick, neat and all together a good thing.  They are hugely expensive and I don’t have one.

There are some things to watch out for when MIG welding.  Don’t forget to turn on the gas, or run out of it.  Do not try and weld galvanised steel – poisonous fumes will be given off and you will become ill.  Do not turn up the power on the welder, it will turn into a crude, hot metal spitting, cutting tool.  Do not weld without a mask.  You will get ‘arc eye’ which by all accounts is very painful.  Do not touch the job before it has had a chance to cool off, no matter how tempted you are to stroke your finger along the perfectly created weld because this will also hurt very much.  When you are welding properly, you will be rewarded with a lovely crackling sound, like bacon frying over a high heat, welds will be a continuous river of molten metal or perfect spot welds which will not pop apart overnight or as soon as you turn your back.

Welding is one of those things that one becomes very good at by doing a lot of it.  Unfortunately, I do not want to spend all my time honing my welding skills, so will probably never be very good at it.  I will aim for adequate. 

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