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Welding questions
woodster - 4/3/14 at 11:07 PM

After many hours of scraping the mini shell of old underseal and getting back to bare metal the time has come to bite the bullet and start replacing the rusty bits with some new metal, my questions are which welder do i get, I know MIGs the one to have, do I go gas or gasless, the metal on the minis mainly 0.9 a bit like tissue paper so I guess I won't need anything big and whilst we,re talking metal where can I get 0.9 thick pieces from ? Motor factors ? I'll need to make some repair pieces ....... I've never welded before, I've been told its easy to blow holes in the thin body panels

[Edited on 4/3/14 by woodster]


Wheels244 - 4/3/14 at 11:28 PM

Go for a gas mig with 0.6 wire.
If you want to come round I'll give you a few lessons with mine.

Rob


Peteff - 5/3/14 at 12:01 AM

Get some 18g 1.2mm sheet to make your repair panels with, it will be easy enough to work and thick enough to weld. Motor factors or metal suppliers will carry stock. Whereabouts are you ? someone local will know a supplier or have links for you.


r1_pete - 5/3/14 at 07:47 AM

If you get a machine that will take gasless wire too, you will find it helps if you are welding upside down, as you need to really crank the gasflow up to get a proper shield, a spool of gasless wire will save on gas.


FASTdan - 5/3/14 at 07:53 AM

Its not so much about 'not needing anything big' but more ensuring the welder you do get can be turned down low enough to reliably weld body panels. So whilst it might seem that a low power cheap welder will be ok this is often not the case as you don't get the control.

Don't get me wrong - you can do car bodywork with a cheap MIG, but its hard work. I went for years with a £150 MIG welding up my XR2, but its only since having bought a decent set I realise how much easier it would have been had I had this kit from the start!

I can't recall amp requirements as its ages since I did any bodywork welding but I am sure someone will be along who can advise shortly.


Slimy38 - 5/3/14 at 08:12 AM

quote:
Originally posted by FASTdan
Its not so much about 'not needing anything big' but more ensuring the welder you do get can be turned down low enough to reliably weld body panels. So whilst it might seem that a low power cheap welder will be ok this is often not the case as you don't get the control.


Absolutely. Logic would dictate that you could get away with using a 90 amp welder because it won't need much power, but the small welders don't have much of a range. If you go for a bigger one they usually have better options to turn them down.

I wouldn't go to a motor factors to get metal, go straight to the source and look for a metal supplier, it will be much cheaper. Start here for some guidance on where to go;

http://www.mig-welding.co.uk/metal-suppliers.htm


femster87 - 5/3/14 at 08:39 AM

I am doing up a MG midget, I got the rtech I-MIG 180. With a range of between 30-180amps. I find it quite easy to use and I only had half a day welding training. Not the cheapest but also not crazy expensive.

Also, I get my metal from a sheet metal fabrication yard close to work, pay £5 each time I pop in for some offcut sheets.

[Edited on 5/3/14 by femster87]


NigeEss - 5/3/14 at 09:16 AM

Most steel stockholders should either carry or easily get hold of 0.9mm.

I buy (mostly) from B+M Steel, who have branches up and down the country, at around £50 for an 2440x1220 sheet. Buy
two and the price drops considerably.

I'd say 1.2 is too thick for general repairs, good for floor and structural areas but a PITA to shape into body repairs.
0.9mm is much better.


pewe - 5/3/14 at 09:50 AM

If you intend welding underneath the car it's worth buying not only proper welding gloves but also some gauntlets to protect your fore-arms.
These can be found at most welding suppliers and only cost a few quid.
Reason for suggesting is that molten metal and bare skin don't mix - ask me how I know.....
Oh and make sure you have a decent welder's mask.
It makes my flesh creep every time you see so-called professionals welding without a mask.
Welder's eye can be seriously damaging to your vision!
There are some good tutorials on here
BOL.
Cheers, Pewe10


FASTdan - 5/3/14 at 09:54 AM

quote:
Originally posted by femster87
I got the rtech I-MIG 180. With a range of between 30-180amps. I find it quite easy to use and I only had half a day welding training. Not the cheapest but also not crazy expensive.


[Edited on 5/3/14 by femster87]


Same here, the only bodywork I have done with it was rear arch panels into a puma and I was highly impressed with it. Allowed fairly much continuous welding on the thin outer skin. Very nice machine for the money.


geoff shep - 5/3/14 at 10:53 AM

There's one for sale on here and he's got a separate ad for an auto darkening helmet (which helped transform my welding from poor to almost acceptable!)

http://www.locostbuilders.co.uk/forum/34/viewthread.php?tid=189275#


RedAvon - 5/3/14 at 11:30 AM

I found this a fascinating link with some really good advice, I'm even making one of the bench top folders.

Hope this helps.

Regards

Ian

http://www.locostbuilders.co.uk/viewthread.php?tid=187398


FuryRebuild - 5/3/14 at 12:26 PM

I'm going out on a limb here and saying look at TIG as well.

It takes time to build technique, but you can get great 'stack of dimes' results. It's a slower process, so you get much more controllability and is the right way to go when welding thick to thin (e.g. 1.5mm to 5mm). It does mean you have your options open for more structural work later on.

Downsides are that you need argon, not CO2 (more expensive) and a decent set, don't go cheap.

Take a gander through http://www.mig-welding.co.uk/forum/ This is a great place, and they have some excellent training videos. Watch that lot and it will help you make a decision.

With either technique, it boils down to
1) how well you prep the part for welding
2) how much time you spend practicing
3) how good your welder is - cheap welders have wire feed problems, or in TIG case, tend to wear and break.
4) what the duty cycle is that you need - odd 1" stiches will be fine at the lower end - continuous seams on 4mm steel on the other will require a much more manly welder
5) if you can live with the results of gasless mig - it tends to not be as neat
6) there is NOOOOOO number six.

good luck
M


DIY Si - 5/3/14 at 02:06 PM

TIG is a good process, but would I suggest it for an old, manky body shell? Not unless you have a serious cleaning fetish. Good TIG needs very clean metal, and with old steel that can be very time consuming. MIG is much more forgiving but is more limited in scope. It's also a much quicker process so often prevents you getting fed up with welding all day long when you want to be making more obvious progress.

As always though, man maths says you need both, just in case.


motorcycle_mayhem - 5/3/14 at 02:25 PM

I have a 1990's SIP Autoplus 100, an old, 'low power' by the standards of most armchair enthusiasts, but extremely capable. Seriously expensive in it's day, but it'll weld compromised steel all day. Fan cooled, very sensitive controls, 6 power settings, lovely piece of kit for what you want to do. It's been heroic.

I purchased a Migatronic 5000MX to replace the Autoplus, simply because it could take a 4m eurotorch without problems. I still go back to the Autoplus though!

So, there you go, that's my recommendation. Something of quality, good stable arc and wire feed. with less attention to the power.

Avoid TIG. You really don't want to go there with an old Mini. I have enough issues welding new chassis material with TIG, not the least is the time it takes and the heat it puts into the job. Don't go gasless on the MIG, don't.


britishtrident - 5/3/14 at 04:06 PM

With SIPs young will spend more time fiddling with the welder than fixing the car.

With a BL Mini almost very patch panel you will ever need is available ready made.

Also a "spot" puddle welding nozzle for your Mig is handy.

For puddle welds clamping a strip of stainless steel plate behind the lower half of the parts to be joined produces nice neat round puddle spot.

[Edited on 5/3/14 by britishtrident]


woodster - 5/3/14 at 09:27 PM

Thanks fellas as always great helpful replies , I've called a favour in and borrowed a mig set from a hire shop, I've spent some serious money there over the last couple of years , I'm currently working with 3 German engineers and 3 Hungarian welders and bless them they've offered to give me some lessons , they've been fitting stainless pipe work In a factory I'm working on, using TIG, they've got another 10 weeks here so they should have plenty of time to show me the ropes .......... Thanks again and when I work out how I'll put some pictures of the mini on


Peteff - 6/3/14 at 09:53 AM

quote:
Originally posted by FuryRebuild
I'm going out on a limb here and saying look at TIG as well.


For car body repairs you will be covering them in gobbo and paint then carpet so your stack of dimes will not be visible plus the consumables cost a lot more and you need a year to learn to use the machine upside down and vertical. Stick with the mig idea. If you use 0.9 steel make sure you don't have any gaps or you will be chasing the edge of the plate trying to make it join to the parent metal. 1.2 is perfectly workable with basic hand tools, a bit of angle and a vice to bend it and will cut easily with a pair of aviation snips from Machine Mart or somewhere cheaper. I've been doing this for 40+ years and like to make the job as easy as possible I have a tig and a kemmpi mig and I know which comes out when a car needs welding.


FuryRebuild - 6/3/14 at 10:57 AM

this is weird because I'm doing the opposite of starting a religious war between MIG and TIG.

I agree with all the comments about TIG probably isn't be right for 'an old manky body shell' - MIG will get you going straight away. It will take a lot more time to TIG panels in place rather than a quick run along with MIG. I went for TIG because I was making a lot of adjustments structurally to my body shell and wanted it to be a weld *I* trusted, and I wanted it to be the best technique I could learn and look good. I'm fickle.

Since learning to weld, I've been frightened by some of the work I've seen. Supposedly structural welds where you can blatently see that most of the MIG filler is sat on top of the weld and penetration is poor. For me, TIG meant I could be far more sure I had good penetration.

I also use the current charts on the mig-welding.co.uk forum I mentioned earlier. If you have a welder that is reasonably accurate, their current charts are brilliant - they list the settings by material, thickness and joint type. Just dial it in and go.

Good luck - there's nothing quite as satisfying as knowing you've got the weld right and you can trust your life to it.

[Edited on 6/3/14 by FuryRebuild]


woodster - 16/3/14 at 10:27 PM

Had a couple of lessons with MIG welding and found it not to difficult I guess I just need to practice a lot , any way the question is with body panel repairs do I over lap or butt joint ? I've googled and with the minis panels being so thin people seem to say over lap and weld both edges, do I then clean the weld up and paint ? ....... Any help would be greatly appreciated