welding

[mojobaby]

I'm not a very good welder, with just a few hours on small projects with a neighbours arc welder. Nearly destroyed some garden furniture!!

Now I've discovered a hole in the floor near my accelerator. I didn't even know that it was rusty and I was really surprised that the metal is so thin.

I'm really keen to fix it myself and my choices are to either rivet a plate over the top, or to cut out the rusty area and weld a plate onto the floor.

With such thin metal, I suppose arc welding is out? Did a bit of internet research and I think that most people use MIG welding.

Is this an expensive outlay and also something that I could teach myself? I'll obviously practise on some metal first before I tackle the job. It's about time I started welding but I want to make sure that I buy the correct equipment.
Any advice for a beginner?

 

[Cornish4]

Hi mojobaby, it's not a good idea to rivet a patch in the floor, welding is the only way. You should be able to buy a DIY mig welder for maybe a little over €100, this is just a guess as they are around £100 over here through mail-order. These generally use a small bottle of shielding gas, which don't last long, but long enough for you to do your repair. Mig welding is dead easy, you just have to make sure you have good solid metal to weld to which is rust free. Once you get your confidence there will be no stopping you. Happy welding, regards Brian.

 

[iMacThere4iAm]

I have no welding experience at all but I'm looking into getting a cheap MIG welder and practising on something easy before I attack my floor pan.
The previous owners bolted a great big patch in the same place as your rust and I want to replace it with a proper job.

 

[malcolm]

There is some info and tutorials on http://www.mig-welding.co.uk/

MIG is the answer for car bodywork. I would try to avoid the really cheap ones as they can be quite difficult to use. Something second hand maybe.

 

[mojobaby]

@Cornish4, thanks Brian, should I be looking at any particular size mig welder? They're measured in Amps, I think.

In one of the Youtube videos that I watched I think someone said between 135 and 150 Amps. Also what thickness wire do I need?

Going to look tomorrow-not to buy just yet, just to look and get prices. I just hope "Mig" is "Mig" in French as well

 

[Cornish4]

Hi there, yes somewhere between 135 and 150 amps would be fine, and wire size of 0.6 mm is about right for thin sheet metal. Good point from Malcolm, all I can say is spend as much as you can afford, and if you can find a good quality second hand one so much the better. I think "MIG" is pretty much a universal term for this type of welder.

 

[orsome]

mig welding eq

Hi Mojaby, i think one option is to get a rental MIG welding equipment fom a local company which rents building equipment.

That's what i did, they change gas/wire according to consumption.

What you should chevk what kind of electric plug you have available in your garage/house, is it a normal lightning current(16 amps fuse) or do you even have power current/power point avalable.

Current mneed for old/rustuy car welding with thin plate is not high.
Main problems will be plate thichness, new plate used should be 1.0...1,25mm thick that your work would be easier for newbeginner.Don't beging with car, just learn wih two waste plates to get them together, without burning holes everywhere.

If you then would not geel confident with welding yourself, there is always a possibility to prefabricate only plates to be welded(and of course take rust off basic material) for your welder, by this mean you save a lot of his valuable time.

Rusty Renault 4 seem to have most thinnest plate thicknesses among cars i have welded.

Good luck !

 

[herbacious_harley_37]

Renault 5 Mk1's also have very thin floorpans. My second R5 Mk1 which was an X reg GTL automatic that I had between Nov '89-August '90 developed a problem where rain was getting into the driver's side and accumulating in the driver's footwell I think perhaps it was the rubber door seal either being mis-aligned or failing at one or more points. It didn't take long for a small rusty area in the floor to develop!

 

[mojobaby]

the hole in my floor is exactly where my heel goes at the base of the accelerator. Oddly enough its quite comfortable resting my foot in it.

The shop that I went to this morning only had one mig welder and the price was 300Euro. Then I checked on ebay and found new welders from 81Euro up to 170Euro.

Some of them are marked" mig/mag inverter" Is an inverter still a welding machine? They also have gasless mig welders. That sounds more convenient! Is the gas better?

Thanks for the help!

 

[Cornish4]

I'm not sure what a mig/mag inverter is, and I've heard that the gasless type are not the best in practice. The motor body repair industry always use professional gas mig welders, so they should know what's best for the job. It's a case of you get what you pay for.

 

[malcolm]

MAG is the correct term for MIG but MIG is more commonly used. Avoid MMA welders as they are arc welders and will blow a hole in the R4.

Any can be inverters. They use complicated electronics instead of transformers. Cheap inverters are imported from China normally through Germany. Very high risk they won't work long enough to make a patch.

Transformer MIGs are available from 200 euros. The cheap ones are very difficult to use mostly because the output is very unsteady. Mine cost 800 euros and is lovely. It's normally a waste paying less than 300.

Shielding gas particularly argon - CO2 mix is much easier for thin metal. You will be able to see what youu are doing, it can run colder, and allows discontinuous welds.

Have a look at the forum on mig-welding.co.uk for what people recommend in your area.