Ally sump welding quote......

[baz-r]

Originally Posted by AshG

you will only need about 120-130amps to tig that up. i could do it for you if you can wait a few weeks for me to get my work load down a bit. that is an hours work max including making the plugs

maybe if its preheated my zetec sump i welded at 140-180a 20% cleaning but my tig is fixed freq @ 75Hz (i think)

ac tig settings are quiet simple and you have to bare in mind the propertys of ally it melts at a lower temp but conducts heat realy well and forms an oxide layer on the serface in air but if yor weld pool runs out of all oxygen you get a thing called arc flutter (moving the arc will help)

Amps = total power you will need a loads more than dc on steel and also (effected by ballance) the work piece soaks up heat real well on ally so you are loosing power via heat conduction and reversed current
ballance or +/- = this is the amount of ratio between welding (normal) and inverted (cleaning) curent. this is also a % of heat direction too much cleaning and it burns out your tungsten not enough and you will have poor penitration and poor weld pool formation.
another effect this has is it changes the width of the weld pool so more cleaning makes it shallow and wide less deep and narrow.
Freq/Hz = most low end units are fixed but now more common. this will effect the depth/width of the weld pool mainly.

remeber everyone personalises thair own way of setup but a few basics will need to be applyed

high pureity argon is a must (99%) at 10Lpm,large cup , clean area to be welded (avoid grinding or steel contamination) i find stainless wire brushes are good and red scotchbright pads just befor welding, blunt point on a sutable tungsten (i use gold ones for eveything) 2.4 or 3.2 (bigger than dc per amp),
if you have foot control use it its ideal for AC as as everything heats up you can reduce your amps
start with 25-30% cleaning/ballance (showen in all sorts of ways)
60-100Hz freq
pulse off, up and down slope are not too importent
1 sec pre and 2 post gas
2.4mm 4043 filler for most cast allys 5356 for sheet

hope that helps

[AshG]

Originally Posted by baz-r

maybe if its preheated my zetec sump i welded at 140-180a 20% cleaning but my tig is fixed freq @ 75Hz (i think)

crumbs thats a lot of current for that. what welder are you using its not a Chinese one is it?

on the sump for my saab engine it was 4mm thick cast and it welded up lovely using around 90-100 amps, can never know exactly as i just give it more pedal if i need it. cast ali is always a strange thing to weld some times it melts like butter and other times it is a pain to get heat into, just depends on the composition.

[RAYLEE29]

Hi, do you actually need to weld the plugs in? you could make the plugs with o ring grooves and a tight clearance fit and use a bolt and washer to hold in or make them top hatted and bolt in.
no welding also means no distortion no grit blasting no chemical cleaning etc
just a plain simple engineering solution.
Ray

[baz-r]

thats the settings for pritty much any make or model of tig i would be using ash as long as its square wave form even more for sine wave old tigs.
dont want to be there all day welding the thing or trying to make it hot

but yes its defo not made on this side of the world but not even the big names are made anywhere near europe thease days (trust me i have been inside them)
unless your spending real big money or realy know what your buying (ewm would be my choice btw)
i just need somthing that works and does my hobby bits not worth spending more than my build and i dont have 3ph so cheap s/h ac/dc tigs are like flying pigs
god i see sets selling more s/h on ebad than i sold new a couple years ago!

[AshG]

mine is a cemont ac/dc inverter made in italy. but as you said lovely bit of kit the size of a sewing machine with options galore but new they cost more than the car lol.

[Eternal]

Wow thanks for all the advice guys! Started clearing space in the garage and will try and do some test bits on offcuts and see how that goes. If i turn out to be totaly crap will get it sent off to mikemph! Yet again thanks a load guys its really great to have the community support.

[baz-r]

Originally Posted by AshG

mine is a cemont ac/dc inverter made in italy. but as you said lovely bit of kit the size of a sewing machine with options galore but new they cost more than the car lol.

150a one? cemont are simmular as saf/oerlikon made in france units citotig i think it was called
and yes i do think thay cost more than some builds ash
one bit of advise keep the matalic dust well away when it gets in all tigs with hf seem to go wrong for some reason
whip off the cover and blow it out every once in a while (make sure its been off for a while big caps inside and thay bite)