Newbie question

[ger1979]

Hi all.
I have a classic car which will need some work in the future.
In our area its so hard to get a welder and if you can the prices are crazy.
So ive bought myself a little mig welder, nothing fancy as it may only be used once in a blue moon.
I've gone for an SIP Weldmate 120A.
It can use gas or be used with the flux cored wire that comes with it.
I've been doing some reading and it seems that gasless welding isn't the best for car panels.
Im looking now at using Argon mix, 95/5 along with 0.6 wire and tips.
Flow rate apparently should be set around 5LPM-10LPM.
Regarding the gas i have a few options but have decided against the small 900cc disposables items.
Local supplier can supply 2L or 10L cylinders.
2L is £23.65 for gas plus £25 bottle deposit,
10L is £46.82 for gas with a £55 bottle deposit.
Twice the price but 5 times the amount of gas, 2000l compressed compared to 400l.
If my flow is 5LPM using the 2L cylinder I'd get roughly 80 mins weld time according to my maths, does that sound right???
Obviously the 10L makes more sense but the welder is only for use as and when I need it so I think 10L may last forever.
Am I best off getting the 10L then forgetting about it for ages or just getting a 2L and then a refill as and when needed?
Any advice Is gratefully welcome
Thanks

 

[tigdlo]

Depends how much welding you have to do and how much learning/practicing you need to do before tackling jobs on a car, my advice you be to look for Adams gas, SGS gases and Hobbyweld distributors nearest to you, compare the cost based on bottle sizes and fill pressures and get a 20L bottle. 2L is a big waste of time and money.

If my flow is 5LPM using the 2L cylinder I'd get roughly 80 mins weld time according to my maths, does that sound right???

Probably not in reality, bottle volume and pressure is good to compare different options but IMO there are too many variables to accurately calculate weld time which itself isn't really predictable, every classic car weld job is bigger than can be seen if you want to do the job properly.

Im looking now at using Argon mix, 95/5 along with 0.6 wire and tips.

This is my setup for up to 1.5mm, above that I like to sway to 0.8mm wire with the same gas. 0.6mm wire can be frustrating if the wire feed setup isn't spot on as the wire can buckle just after the feed roller.

In our area its so hard to get a welder and if you can the prices are crazy.

The prices probably reflect the skill, time and experience required to do the job and live life with the current cost of living, I don't know many welders running their businesses from the Cayman Islands......

 

[BrokenBiker]

Gasles isn't ideal, it's slower than straight mig, needs more clean up before paint etc...

That said, I did a lot of car repairs on sills and suspension mounts with a 100amp gasless only mig before I got a proper mig. It's all about technique and accepting that it's not necessarily going to be pretty

 

[Misterg]

Hi, and welcome.

Whereabouts (roughly) are you?

I think flow rate will be more like 15 LPM for MIG, but I think your maths is right otherwise (provided both cylinders are filled to 200 bar).

Presumably you get the deposit back, so just on gas prices (assuming 15 LPM):

2L is £0.89 / minute of welding and 26 minutes per cylinder
10L is £0.35 / minute of welding and about 2 1/4 hours per cylinder.

I know which one I'd go for, but shop around a bit. (Also factor in the time / fuel / frustration of needing to change cylinders - it's unlikely the gas will run out just as you finish a job.)

 

[steveo3002]

what amount of work does the car need ?

mine needed a couple of plates the size of a postcard , i got by with disposables and carried on for years , for the odd small bit once a year theyre ok , but yeah if you need days of welding forget them

 

[ger1979]

Thanks for the replies
Its just something I want to get into for future use, as in keeping on top of things.
The cars sound ATM but in years to come it'll need work.
Which wire would you all recommend then 0.8 or 0.6 for car stuff, maybe a bit of panel work and say sill work?
Is it actually worth me setting it up gasless and seeing how I get on, using scrap pieces of good metal or just go straight onto gas?
The car is a classic mini and we rebuilt it 18 years ago. One A panel has got a bubble, where rain water has sat behind the panel. I did clean it back last year and there was a tiny hole, say 2mm round, and the metal around it was sound, so I put in a bit of jb weld, primes and painted as a temp job but when the weather is better I want to remove the bodge, clean the whole A panel back then prep, prime and spray it.
Plan is to use a drill and drill a hole like 6mm so the rusted bit is gone, then either put a little plate behind and tack it from the front, or to fill the hole with weld then obviously grind back for all the paint prep.
Would gasless be ok for that kind of work?

 

[ger1979]

Gasles isn't ideal, it's slower than straight mig, needs more clean up before paint etc...

That said, I did a lot of car repairs on sills and suspension mounts with a 100amp gasless only mig before I got a proper mig. It's all about technique and accepting that it's not necessarily going to be pretty

That's good feedback. Im not bothered about it looking pretty as it would be ground back, seam sealed, primed and prepped etc.
Is gasless OK for say putting in a small plate to a car panel or is it likely to blow through?
I read that argon mix burns cooler

 

[ger1979]

Hi, and welcome.

Whereabouts (roughly) are you?

I think flow rate will be more like 15 LPM for MIG, but I think your maths is right otherwise (provided both cylinders are filled to 200 bar).

Presumably you get the deposit back, so just on gas prices (assuming 15 LPM):

2L is £0.89 / minute of welding and 26 minutes per cylinder
10L is £0.35 / minute of welding and about 2 1/4 hours per cylinder.

I know which one I'd go for, but shop around a bit. (Also factor in the time / fuel / frustration of needing to change cylinders - it's unlikely the gas will run out just as you finish a job.)

Wow, when you work out those maths yes the 2L is crazy money.

 

[BrokenBiker]

That's good feedback. Im not bothered about it looking pretty as it would be ground back, seam sealed, primed and prepped etc.
Is gasless OK for say putting in a small plate to a car panel or is it likely to blow through?
I read that argon mix burns cooler

Normal mig does burn cooler. I have a synergic mug and when set to gasless on the same settings as normal mig the wire is a lot faster...that said, you are going to end up running a series of overlapping racks anyway so you just need to adjust your technique to suit the gasless

 

[ger1979]

Normal mig does burn cooler. I have a synergic mug and when set to gasless on the same settings as normal mig the wire is a lot faster...that said, you are going to end up running a series of overlapping racks anyway so you just need to adjust your technique to suit the gasless

Ok. The welder has everything ready to go gasless, worth me trying that first before getting gas do you think? I was reading that gasless is smokey, fumey etc.
What about pub gas or is that a waste of time

 

[ger1979]

What about using pub gas, CO2 or is that rubbish as I can get that easily.
Is Co2 better than gasless?

 

[Nick DV]

Ok. The welder has everything ready to go gasless, worth me trying that first before getting gas do you think? I was reading that gasless is smokey, fumey etc.
What about pub gas or is that a waste of time

Hi & welcome I wouldn't use gasless or CO2, but that's me. Try here https://www.sgsgases.co.uk/product-...o2-argon-cylinders/10l-5-co2-argon-cylinders/

 

[BrokenBiker]

Ok. The welder has everything ready to go gasless, worth me trying that first before getting gas do you think? I was reading that gasless is smokey, fumey etc.
What about pub gas or is that a waste of time

Gasless is a slightly different technique in as much as you pull the weld, mig can be pulled or pushed.

Gasless is as dirty as stick welding, similar process really. You will have slag to chip off and will need a good wire brush to clean up the residue as well.

It will work, I've welded land rovers, haha, fairs, transits and hilux's with gasless as well as heavier stuff like gates, brackets, shelves, welding benches etc.

I like the saying, if your only tool is a hammer, every job is a nail...you make it work

 

[ger1979]

Gasless is a slightly different technique in as much as you pull the weld, mig can be pulled or pushed.

Gasless is as dirty as stick welding, similar process really. You will have slag to chip off and will need a good wire brush to clean up the residue as well.

It will work, I've welded land rovers, haha, fairs, transits and hilux's with gasless as well as heavier stuff like gates, brackets, shelves, welding benches etc.

I like the saying, if your only tool is a hammer, every job is a nail...you make it work

Ok I get you.
Have you ever welded with CO2?
If all welds were going to be visible id obviously want them to look good, but all my stuff will need grinding back, filling, priming and paint after so as long as the weld is good the aesthetics aren't to big a concern.
More of a concern is im new and dont want to be blowing holes in the panels.
Also 0.6 or 0.8 for the type of stuff I want to do?
Thank you

 

[BrokenBiker]

Ok I get you.
Have you ever welded with CO2?
If all welds were going to be visible id obviously want them to look good, but all my stuff will need grinding back, filling, priming and paint after so as long as the weld is good the aesthetics aren't to big a concern.
More of a concern is im new and dont want to be blowing holes in the panels.
Also 0.6 or 0.8 for the type of stuff I want to do?
Thank you

Yeah I used co2 for a while with a 160 amp inverter, wasn't a huge fan of it compared to 5% Ar/Co2.

Also worth noting at this point that it is incredibly easy to make a mig weld look good but get no penetration. Not as much of an issue on car panels, but still something to consider. Gasless penetrates better, but you have to be more careful with welding pattern to keep distortion down

 

[Misterg]

More of a concern is im new and dont want to be blowing holes in the panels.

You need to practice on something similar first then - scrap panels, or something (preferably with a bit of rust). You need to blow a few holes to get an idea of how far you can push things.

What about using pub gas, CO2 or is that rubbish as I can get that easily.

Pub gas (**100%CO2**) is OK, but the argon mix is much nicer to use and gives neater welds (IME). If I had nothing else, I'd use it. Pub gas will need a different regulator to the Argon/CO2

Also 0.6 or 0.8 for the type of stuff I want to do?

Doesn't make much difference (IMHO). I used to use 0.6 and pub gas, currently using 0.8 and Argon/5% CO2 (on bodywork). The gas makes a huge difference, wire size you don't really notice.

If you already have tips/rollers, etc. for one size, I'd get some wire to match.

My 2p.

Roughly where in Wales are you?

 

[BrokenBiker]

I use 0.8 wire with 5% argon mix. I tried 0.6 a while back, didn't really notice much difference.

If you are anywhere near Newport I don't mind coming along for an hour or so of a Saturday morning when my Mrs is off work to give you a few pointers if needed. I'm away mon-fri day for the foreseeable but every other Saturday my Mrs takes the baby out in the morning so have some free time

 

[Cobbler]

Just spotted this discussion, so I’ll add my 10 pence worth. I prefer to use 0.8 for everything. It feeds better as its stiffer so doesn’t try to snake or bird’s nest as it’s pushed, also on thicker stuff using higher powered settings the wire speed will be slower than 0.6, therefore more controllable. This is just my take on it, others may feel differently about it.

 

[Nick DV]

Have a look here if you're fixing car panels

 

[ger1979]

Have a look here if you're fixing car panels

Awesome video that. Very grateful you put that up.
Amazed to see that he says he uses CO2.
I think a lot of it comes down to personal preference.