Time for an overhaul of my 1.9 '98 BMW Z3 Individual

[IainP]

Loving where this thread is going (as someone fascinated by welding but never done it)

Then if you use Instagram, you’ll like this then

http://instagr.am/p/C3j1HhKvyXD/ View: https://www.instagram.com/p/C3j1HhKvyXD/?igsh=aTRyZXlqcGc5dGN2


150,000 + of us are watching this young woman and muttering “Holy F***”.

 

[DrWong]

Wow, can understand the reaction. She’s not a beginner though, right?? Hahaha

 

[DrWong]

@Matt Barnes would be interested in how much you’ve spent on welding stuff thus far to get to this point, if you wouldn’t mind sharing the big ticket items.?

 

[Matt Barnes]

@Matt Barnes would be interested in how much you’ve spent on welding stuff thus far to get to this point, if you wouldn’t mind sharing the big ticket items.?

to be honest mate, the welder was about 150 quid, helmet about 30 quid... @IainP very kindly sent me some steel pieces, which I still use. new spool of wire about 20 quid....I went flux core as it doesn't involve a gas tank...so for about 200 quid you can get setup...if you want a posher welder you can always try Marketplace for a second hand one..I bought two 500mm x 500mm 2mm sheets for 40 quid which will hopefully lasted me a while...the only thing you'd regularly need to add is spools of wire..

 

[Matt Barnes]

Then if you use Instagram, you’ll like this then

http://instagr.am/p/C3j1HhKvyXD/ View: https://www.instagram.com/p/C3j1HhKvyXD/?igsh=aTRyZXlqcGc5dGN2


150,000 + of us are watching this young woman and muttering “Holy F***”.

well that's another Instagram account followed !

 

[DrWong]

to be honest mate, the welder was about 150 quid, helmet about 30 quid... @IainP very kindly sent me some steel pieces, which I still use. new spool of wire about 20 quid....I went flux core as it doesn't involve a gas tank...so for about 200 quid you can get setup...if you want a posher welder you can always try Marketplace for a second hand one..I bought two 500mm x 500mm 2mm sheets for 40 quid which will hopefully lasted me a while...the only thing you'd regularly need to add is spools of wire..

Relatively small investment for potentially a lifetime of fun then I reckon haha

 

[Matt Barnes]

Relatively small investment for potentially a lifetime of fun then I reckon haha

I've bought hundreds.of pounds worth on tools and products since starting this project. Luckily my wife isn't on this forum...if she was..
it's a tenner..

 

[IainP]

Relatively small investment for potentially a lifetime of fun then I reckon haha

A welder is probably the best investment I’ve made. Fixed, or made, all sorts of stuff, car, house, garden, even fixed a container for the local youth football team.

Flux core isn’t as neat as gas mig, and takes a little more practice to get going (imo), but a gas mig will set you back £500 min including a bottle. People will quote you less, but I’ve been doing it long enough to know they’re talking b*******s. Practice with either is essential, but lots of evening classes are available to learn the basics. YouTube wasn’t available when I started, I scrapped cars I could easily fix now, it’s just time and patience. Really, that’s it, outer bolt on panels are replaceable. Underlying bits that need welded can be done in sections if necessary.

Lots of the cheaper gas migs have inconsistent wire feeds, fixing them is a pain. Been there. Cheap wire rusts, which tears the plastic liner, steel liners are expensive, though canny folk just use steel curtain liner for a couple of quid.
Available cheap s/h, if you have to fix the wire feed and overhaul, or even replace, the torch, it’s no longer so cheap.

There’s also a sequence to turn the gas regulator on/off. Reg’s are Lifed at 5 years. Use the wrong sequence cracks the diaphragm, means you can’t set the flow rate accurately, leaks away your expensive gas. £45 for a replacement. Worse, you get interrupted as I did on Sunday and forgot to turn the bottle off, went to use it yesterday to find it empty. Thankfully it had little in it, full it’s £90. Small bottles aren’t worth it, best to get the biggest you can. Then you need space to store it.
You can’t have a pit with gas, argon is heavy, odourless, colourless and displaces CO2, so you can collapse and die with absolutely no warning. Or accidentally kill your pets. Seriously.

Starting again I would probably go gasless, I’m teaching both my lads and teaching myself tig, but my mig has a flux option I’ve never used I’ll try at some point. Needs some parts for that, my Portamig is set for 5 and 15kg reels, not the little 1kg flux reels.

 

[Matt Barnes]

A welder is probably the best investment I’ve made. Fixed, or made, all sorts of stuff, car, house, garden, even fixed a container for the local youth football team.

Flux core isn’t as neat as gas mig, and takes a little more practice to get going (imo), but a gas mig will set you back £500 min including a bottle. People will quote you less, but I’ve been doing it long enough to know they’re talking b*******s. Practice with either is essential, but lots of evening classes are available to learn the basics. YouTube wasn’t available when I started, I scrapped cars I could easily fix now, it’s just time and patience. Really, that’s it, outer bolt on panels are replaceable. Underlying bits that need welded can be done in sections if necessary.

Lots of the cheaper gas migs have inconsistent wire feeds, fixing them is a pain. Been there. Cheap wire rusts, which tears the plastic liner, steel liners are expensive, though canny folk just use steel curtain liner for a couple of quid.
Available cheap s/h, if you have to fix the wire feed and overhaul, or even replace, the torch, it’s no longer so cheap.

There’s also a sequence to turn the gas regulator on/off. Reg’s are Lifed at 5 years. Use the wrong sequence cracks the diaphragm, means you can’t set the flow rate accurately, leaks away your expensive gas. £45 for a replacement. Worse, you get interrupted as I did on Sunday and forgot to turn the bottle off, went to use it yesterday to find it empty. Thankfully it had little in it, full it’s £90. Small bottles aren’t worth it, best to get the biggest you can. Then you need space to store it.
You can’t have a pit with gas, argon is heavy, odourless, colourless and displaces CO2, so you can collapse and die with absolutely no warning. Or accidentally kill your pets. Seriously.

Starting again I would probably go gasless, I’m teaching both my lads and teaching myself tig, but my mig has a flux option I’ve never used I’ll try at some point. Needs some parts for that, my Portamig is set for 5 and 15kg reels, not the little 1kg flux reels.

great write up Iain!...absolutely the reasons I went flux core...they're cheap (by comparison) you can take it anywhere, relatively small, so easy to store. I don't have the world's largest garage as most have seen. I can't even lay out a fully assembled rear axle in one piece inside..so no chance of a large gas bottle. I'm learning/hearing flux core is trickier, messier and not designed for thin gauge metal...but it's all I know so I take that as a plus. This weekend I might practice some plug welding using a copper heat sink...but my priority is fitting that sodding ABS controller to the Peugeot after I drill out it's mini versions of the bolts of doom

 

[IainP]

My first Mig was a BOC, 130 amp, awful thing, the wire feed was plastic, unreliable and inconsistent. Not what you want when trying to learn. Modified it. Second mig a decade later turned out to be almost the same machine rebranded, (once I took it apart!). I modified the feed considerably, upgraded the torch, steel liner, brass cogs, couple other things, gas solenoid I think, Anyway, it was still rubbish.
At that point I was still trying to run beads “because that’s how it’s supposed to be done”. Loads of distortion, + waiting on the thermal cutout to reset because the duty cycle was rubbish.
My lad got his first Mini age 15, needed Everything welded. I’d asked on a welding forum for recommendations, advised to up the budget a bit and go for a Tecarc Portamig, British built to order. Spec’d down to 15amps minimum. Introduced to pulse welding, on a second, off a second. Not the “correct” way to do it, but little distortion, less holes, much more consistent welds and duty cycle is days.
It’s practice, practice, practice.
There are so many variables, earth quality, current, wire speed, torch angle, travel speed, on time. That’s before you even consider the thickness of metal, or type of weld.
Torch angle, travel speed, and pattern if it’s thick, or angled, can be practiced with the torch off. Moving consistent amounts and patterns with gloves on is probably one of the hardest things to do. There are vids of people taping sharpies to the torch and trying blindfold, bit extreme, but reducing variables gives you less to think about.
I mostly use Tig gloves, they’re much thinner, better feel, I only use thick gloves making something thick. You shouldn’t be touching anything hot anyway, gloves don’t last long if you do.
Oh and setting your helmet up. Strike an arc on a thick piece of steel and adjust the shade with one hand until you can see clearly what he arc is doing, move the puddle about and adjust up/down to get the sweet spot. Note, or mark, the setting. And always keep spare batteries if it’s not solar.
A weld cap stops arc burns to your head!

 

[Matt Barnes]

My first Mig was a BOC, 130 amp, awful thing, the wire feed was plastic, unreliable and inconsistent. Not what you want when trying to learn. Modified it. Second mig a decade later turned out to be almost the same machine rebranded, (once I took it apart!). I modified the feed considerably, upgraded the torch, steel liner, brass cogs, couple other things, gas solenoid I think, Anyway, it was still rubbish.
At that point I was still trying to run beads “because that’s how it’s supposed to be done”. Loads of distortion, + waiting on the thermal cutout to reset because the duty cycle was rubbish.
My lad got his first Mini age 15, needed Everything welded. I’d asked on a welding forum for recommendations, advised to up the budget a bit and go for a Tecarc Portamig, British built to order. Spec’d down to 15amps minimum. Introduced to pulse welding, on a second, off a second. Not the “correct” way to do it, but little distortion, less holes, much more consistent welds and duty cycle is days.
It’s practice, practice, practice.
There are so many variables, earth quality, current, wire speed, torch angle, travel speed, on time. That’s before you even consider the thickness of metal, or type of weld.
Torch angle, travel speed, and pattern if it’s thick, or angled, can be practiced with the torch off. Moving consistent amounts and patterns with gloves on is probably one of the hardest things to do. There are vids of people taping sharpies to the torch and trying blindfold, bit extreme, but reducing variables gives you less to think about.
I mostly use Tig gloves, they’re much thinner, better feel, I only use thick gloves making something thick. You shouldn’t be touching anything hot anyway, gloves don’t last long if you do.
Oh and setting your helmet up. Strike an arc on a thick piece of steel and adjust the shade with one hand until you can see clearly what he arc is doing, move the puddle about and adjust up/down to get the sweet spot. Note, or mark, the setting. And always keep spare batteries if it’s not solar.
A weld cap stops arc burns to your head!

M eyes are bad enough without adding arc eye to the list, so I probably overdo it on the shade, as when I pull the trigger I can't see the metal at all. So I need to fettle the shade knob a bit. I've heard that the arc from a flux core is more intense than from MIG but as I've never used a MIG I don't know. Must say I do really enjoy it, even though you think you're doing the same thing on another piece of metal but end up blowing holes in it...and it could be something small like a bit of grease, enough to make a difference. I've found welding charts don't really help as every piece of metal is different..They're good for a ball park, but don't account for how rough or dirty the metal is, only the thickness, so there's no one setting for say 2mm or 1.5 mm....I'll be out there again this weekend... promised my Wife it'll be back on the road by Spring....though I didn't say which one

 

[IainP]

The lower the amps the lighter the shade.
My helmets go from 9 to 13, I only use 9 for really low stuff, most bodywork is between 10-11. Above 3-4mm I’m up to shade 12, never used higher than that.
I’m short sighted and the helmets sit on my nose, can’t wear glasses so I’m right up close to what I weld. I probably should buy a magnification lense for the inside but I’ve just never bothered.

 

[Matt Barnes]

The lower the amps the lighter the shade.
My helmets go from 9 to 13, I only use 9 for really low stuff, most bodywork is between 10-11. Above 3-4mm I’m up to shade 12, never used higher than that.
I’m short sighted and the helmets sit on my nose, can’t wear glasses so I’m right up close to what I weld. I probably should buy a magnification lense for the inside but I’ve just never bothered.

I'm short sighted, so I wear contact lenses for distance, but my near sight is going as well so I also wear reading glasses when up close.... so between the piece and my eyeballs is a welding helmet, reading glasses and contact lenses

 

[Matt Barnes]

Today I decided to have another welding session?..... are you sitting comfortably ?.... then I'll begin.....

I went through the process as if it were on the car... Identifying the area to be cut out and welded...

chopped out the area with the angle grinder cutting disk back to good metal

and as before masked and marked up the piece for cutting out (oh the spots above are me practice voltage settings

laid out on cardboard and used scissors to cut out the shape

checked with the "car" to ensure a good fit, it was slightly over size which was good....and I can then file down the piece of metal as needed.

Cut out the piece and trial fitted it.

Have to say these flap wheels are excellent for shaping the metal and getting the material down to the line

I STILL have gaps !... which becomes important later !.... you can guess already can't you !

start tacking the piece in and all looking good !

continue round and then I start blowing holes again in the corners, probably due to the gaps.. this is it ground down, but what's hidden is revealed later !

I'm still having trouble seeing what I'm doing.... plus if I turn on my LED light.. my helmet darkens !! so literally can't see anything with the light on !

this is evident if you look at the backside, see all the places where I've missed !

and if I hold a light behind it, you see it doesn't pass muster.... I had to stop in the end as I had run out of expletives for one afternoon !!

I might have some really thick underseal though

so my takeaways from today, you REALLY do need to get the patch almost watertight, any gaps are going to blow, and I need to sit down with my helmet on different settings, I went to 9 but as soon as I started welding it was like looking at the sun.... so went back up to 12...

but.... technique is getting there even if the end result isn't yet !

 

[DrWong]

Welding experts and trainees - could flux core be used to repair/patch in new steel for the outer sills? Or is that like, a really really bad idea hahaha
I mean, a £150 welder is cheaper than a new pair of sills, right.?

 

[Matt Barnes]

Welding experts and trainees - could flux core be used to repair/patch in new steel for the outer sills? Or is that like, a really really bad idea hahaha
I mean, a £150 welder is cheaper than a new pair of sills, right.?

I've no choice mate...I'm flux coring the hell out of my sills!

 

[IainP]

You need to turn the wire speed up when there are gaps Matt, you need the excess wire to fill the gap. Start the arc on one side and drag it across, pause and end. Effectively you’re creating a little bridge, or a series of them. Fig 1 Once they’re cool, turn the speed down slightly and weld across the edge of the bridge. If you have a copper, (or aluminium, though I’ve never used Ali myself) block that helps stop the weld pool slumping, you may need to up the current a smidge depends on the machine.
Fig2

Hope that makes sense, I’ll try and do a demo piece on Wednesday, my son has the mig up at where his Mini is stored.

 

[IainP]

Welding experts and trainees - could flux core be used to repair/patch in new steel for the outer sills? Or is that like, a really really bad idea hahaha
I mean, a £150 welder is cheaper than a new pair of sills, right.?

My pair of sills cost £245, so yeah!
Thinner metal is easier to warp, but it’s also going to take less heat to melt and it’s easier to planish, basically smack it with a hammer to stretch it. Welding it causes the tacks to shrink, if the fitment is really tight it’s immediately obvious when it shrinks. The edges will buckle or lift. At that point, stop, grind the tacks flush, smack them with a hammer and dolly ideally, but a hammer and chunk of metal works. Keep going until the edges are level again. Tack and repeat.
You can speed up the process by cooling the tacks with compressed air, even a damp rag.

 

[DrWong]

So my impression is it’s not a totally ridiculous idea to flux core thin metal. In which case, I’m quite tempted to have a punt on my sills

 

[Matt Barnes]

You need to turn the wire speed up when there are gaps Matt, you need the excess wire to fill the gap. Start the arc on one side and drag it across, pause and end. Effectively you’re creating a little bridge, or a series of them. Fig 1 Once they’re cool, turn the speed down slightly and weld across the edge of the bridge. If you have a copper, (or aluminium, though I’ve never used Ali myself) block that helps stop the weld pool slumping, you may need to up the current a smidge depends on the machine.
Fig2
View attachment 291987
Hope that makes sense, I’ll try and do a demo piece on Wednesday, my son has the mig up at where his Mini is stored.

aaaaah cheers Iain... I had the wire speed and voltage as low as they went, ironically as I didn't want to blow through ! ... I'll have a crack next weekend.. I'm definitely getting less blow through than I used to get, so I'm getting there (I tell myself !)