At last figured out which wire speed/volts to use

[RobMsport]

After posting questions on someone else's thread -- sorry , I have played around with my secondhand MUREX 186c mig which I bought to use on 16 gauge CDS 25mm roundtube and arrived at the best settings for my machine on this stuff.
It has 6 power positions but position 2 on any wire speed setting was not producing a weld.Tried w.speed 2 which the panel intructions gave for 16 gauge -- no good . The wire speed has 6 settings too .
Finally after messing around on some cut off bits of 16 gauge , I got a decent weld (for me) on power setting 3 and w.speed 3.5 . It helped to have the gas at 20lpm and 10mm stick out for tight angled joins but just 5mm stick out around the tubes from above position. Having read very carefully on these forums and various youtube vid's , I also stopped drag welding to go forward but in short 20mm maximum welds then welded another position till it cooled .
Cleaning the shroud often and purging the gas line also helped as did some tig welding gloves for easy movement m making it possible to use the left hand to steady and control height . I'm really surprised that these power/w.speed settings worked as I assumed they'd be way too hot on 16 gauge roundtube.
My welds are too big at the moment but by looking into the tube I can see penetration's ok . Now I need to practice speed control and getting around the tube with one pass rather than going over the weld again to tidy it.
Thanks to all who gave the advice I put into practice

 

[pedrobedro]

From looking at your other thread I'd say you are getting there and need to pace yourself and steady the torch with your free hand. Just lean your thumb against the swan neck and you'll eliminate a lot of your wobbles. I do round tubes in 3 usually unless they are easy to get at with no change of position and 20lpm sounds a lot of gas, 10lpm or less should be enough although cylinder gauges are not that accurate and flow gauges give a more stable reading.

 

[RobMsport]

From looking at your other thread I'd say you are getting there and need to pace yourself and steady the torch with your free hand. Just lean your thumb against the swan neck and you'll eliminate a lot of your wobbles. I do round tubes in 3 usually unless they are easy to get at with no change of position and 20lpm sounds a lot of gas, 10lpm or less should be enough although cylinder gauges are not that accurate and flow gauges give a more stable reading.

Thanks pedrobedro , I did try the gas at 12 to 15 at first. The torch was just making a mess , sort of aero chocolate looking . Only problem I have now is not blowing holes which I can manage not doing provided I just do 20mm stints . If I was a better welder perhaps I could use less gas and move slower with less w.speed ??? It's coming anyway , at least enough to make a pair of 25mm x 1.6mm cds wishbones with inserts for rodends . Visually the welds are large so would like to be doing smaller flatter welds .
I'll see if I can figure out how to add photos then you'll see what I mean --- I didn't take any pic's till after I'd treated them with Bilthamber unfortunately so you can't see very clearly really.

 

[stuvy]

rob, just a thought as your welds are quite high. Turn the power down slightly or move your speed a little bit more.

The second thing i would do is weld a test piece and cut it in half to make sure you are getting good penetration.

What are the wishbones destined for?

 

[Lawnmowerboy]

Can't say I'd want to use them on anythin safety critical unless you were 100% sure of your welds.

 

[RobMsport]

rob, just a thought as your welds are quite high. Turn the power down slightly or move your speed a little bit more.

The second thing i would do is weld a test piece and cut it in half to make sure you are getting good penetration.

What are the wishbones destined for?

I bought this MIG because arc welding's so tricky on lightweight roundtube but none of my arc welds have ever broken.

They're are to go on a kit car weighing 600kgs . The previous wishbones I've made have been done with my 190amp arc welder and been on the car since 2005 (my car) and 2009 on a similar car for a friend. Mine is 231bhp , his 270bhp . I've competed in it since 2000 after building it then gradually modified various suspension parts in an effort to improve handling which it has acheived , winning me 4 championships plus other lesser awards over the years.
I hit a tree at one event in 2009 which wrecked the radiator , steering rack and body after the rodends bust which allowed the drivers side wheel to come out of the fibreglass wing. The wishbone itself just slightly kinked along the longest side where the wheel went on full lock BUT no welds were broken .
My car never goes on a public road so all it's stresses are at race pace .

 

[RobMsport]

Can't say I'd want to use them on anythin safety critical unless you were 100% sure of your welds.

H'mm , got me worried now , however the original wishbones supplied by the kit manufacturer cracked right around the edge of the outer wishbone weld on the drivers side and that was just going onto the rumble strip at GURSTON hillclimb without actually hitting anything --- although I did once the wishbone had bust !! Hence me starting to make my own suspension parts from that point , plus of course wanting a better set-up than poly bushes can give --- so I made them to take rodends

 

[stuvy]

nice fisher fury!

as i mentioned weld a test one up and section it to see the penetration.

Im only in wing and could pop over to show you what i mean if you wanted

 

[Lawnmowerboy]

Is it a rebadged yammy sigma out of a fiesta/puma?
those zetec's are wonderful engines, what is it the 1.6 or 1.7?

 

[RobMsport]

nice fisher fury!

as i mentioned weld a test one up and section it to see the penetration.

Im only in wing and could pop over to show you what i mean if you wanted

I could weld some scrap corner joints and cut that to check penetration BUT the wishbones already made cost me too much time , notching , welding and threaded inserts = cash to cut up
I was travelling only just fast enough to prevent blowing a hole and penetration could be seen peeping down the tubes with a torch . Not a pretty weld I know but like I say , I've driven on the others around Goodwood at 93 sec's for the standing start 2.4 miles.
You're welcome here anytime you fancy giving me some tuition , not sure if you can private message on here for the address or phone number ?

By the way , it's not a Fisher Fury ---- it's a Stylus , also designed by Jeremy Phillips but drastically modified by me suspension wise . He sold the rights to SSC in Wales but it's no longer manufactured .

 

[RobMsport]

those zetec's are wonderful engines, what is it the 1.6 or 1.7?

It's a 2lt Dunnell engine with sequential throttle bodies , big valves , race cams , pocketed pistons and all fully balanced , pushing out 231bhp and 185lbft .

 

[RobMsport]

Original factory w.bones

Look at these then and the design --- they came off a 400bhp car weighing 600kgs , hence my own design .