Help with tig on ac

[oceanobsession]

Hello again everyone. when tig welding on ac i get a smooth purring sound
when the tungstone is about 8mm from the aluminium that im welding. this
also gives me a wandering arc when i put the tungstone closer i loose the
smooth purring sound for an irratic purring sound but my arc is more stable.
it would seem to me that the tungstone is supposed to be about 3mm from
the aluminium with the smooth purring sound. does my machine need adjustment i have had a look for some type of points adjutment also had
both sides of my machine whilst arcing up to look for a blue type light but
i cant see one there is a pot adjutment on a pc board maybe this is my
trouble i have bought some new rods today and my butt welding is improving
but my fillet welding is poor ive tried everything and believe that it is my
machine out of adjustment with the fillet weld it does seem harder to get a
controlled flow if i were to get the 3mm distence with the smooth purring
sound i feel that i could control the weld pool better any opinions very
welcome my machine has only post gas so maybe the pot needs adjusment
on the pc board i might have a go tomorrow cheers ocean

 

[oceanobsession]

fillet weld

fillet weld

 

[oceanobsession]

second fillet weld

second weld

 

[runnach]

Hi Oceans, now joy seeking out hf contactor..........Hmmmmmmmmmm, they are normally situated in a prominent position for ease of access for general maintenance. I assume you do not have the original owners manual?

As for pot adjustment, I wouldn't be dabbling with this till you speak to a qualified plant engineer. What I can do, but will have to wait till next week, is to call our engineer for further advice re; position of hf contactors.

Re Fillet welds: have you added more stick out to tungsten, if not do this and see how it goes.

Re different noise: if the arc is stable, this is more important than differing noise levels.

Cheers...........

 

[oceanobsession]

Re help with tig on ac

There is 3 plastic relays on the pcb board all of them seem to have contacts
but there is no way of adjusting them or removing them come as part of the
board. i have had another go today with a fillet weld you can get both sides
melting dip in the rod but you cannot seem to get that puddle to move much
so you dip in again it continues like this but you end up with a weld that
doesent have much definition cheers ocean

 

[oceanobsession]

Re help with tig on ac

The contactor that you have circled might be adjustable but i thought that
would cause the hf not to work at all or am i missing somthing ive looked at
the miller manual about adjuting spark gaps but when energised dont they
come together and stay tightly togeather cheers ocean

 

[Kiwi K]

be very casrefull if fiddling with machine internalscould do irrepairable damage,wait until you/somebody on your behalf has a word with welder engineer

 

[oceanobsession]

Re help with tig on ac

Im not messing until i know what im doing

 

[runnach]

The contactor that you have circled might be adjustable but i thought that
would cause the hf not to work at all or am i missing somthing ive looked at
the miller manual about adjuting spark gaps but when energised dont they
come together and stay tightly togeather cheers ocean

Hi Ocean, what I circled was a guess on what may be the HF position within your plant? I have always known them as HF contactors, not to be mistaken by electrical contactors, which of course do make contact when operated.

When a plant arcs up, HF kicks in and jumps across the pre-set contactor/s. Gap between contactor may vary from manufacturer to manufacturer, as I mentioned in a previous post, BOC ADR 375 HF gap is 10 thou. Ajustment (if nessessary) is done normaly by slackening off hex grub screws. Links below explains, scroll down to "AC power source".

http://www.twi.co.uk/content/jk17.html

Good your not messing, also good to have a look around inside, helps with learning and location of parts.



Cheers............

 

[oceanobsession]

Re help with tig on ac

Ihave just been informed that the reason for my weld being dull in appearence
and lacking definition is because im welding it on a 1200x600 x8mm plate im
told that if i weld it of the steel table things will be better im also told to clean the rods and aluminium with scotchbrite i suppose the steel is drawing the heat out of the aluminium fast causing the dull apperance also stopping
the weld puddle from flowing being only hot where the tungstone is pointing
im all clean and ready for my first drink of the night so ill try again tomorrow
i will buy some 2.5 zirc tungstones cause ive only got 1.6 grey type thanks
for all your help cheers oceanobsession hey runnach im diving st kilda in
july 2009 also into diving

 

[runnach]

Process of elimination eh Oceans!! Lifting off bench will make a difference of course, see how it goes and report back.

Nice one with St Kilda, never been, not enough wrecks for my liking, but flora and fauna are close to the best you will find around uk waters! I have a mate based at Kyle who gets choppered out there when torpedoes are being tested oot, lucky man.

Have you viewed our vids? Scotlands Wrecks The Western Isles, Red Sea ect.....oops I digress...........no Iolaire streaming, havta check it out tomorrow

Cheers.........