[justmic]

Hey forum,
Novice/newby hobbyist welder needing a bit of advice to get me going. I've set out to learn how to weld my own intercooler pipe joins on my car. I'm having some heat control issues I believe that someone might be able to help with.
Machine - lincoln powercraft 200m, torch is the supplied item with the push button
- number 7 cup
- WL15 lanthanated 1.6mm electrode, acute angle (haven't got any tooling available to grind it accurately)
- argon gas flow ~10cfm (could be to low?)
The parts I'm welding are aluminum tube 1.5mm thickness (Aussie, so please excuse the metric references). Ive just made the switch from 5356 1.6mm filler rod to 5356 2.4mm filler rod off the advice of a friend and can only seem to pool a blob of filler up on some practice piece joins. I was concentrating the torch on the blob to sink it in to the join but then was running into issues of the tube heating up very quickly and blowing the tight join open. I'm able to successfully tac the joins in numerous places around the tube prior to starting the bead.
On the practice off cuts (roughly 40mm-50mm length tube pieces) I have been starting with 50amps/110hz/ -2 ac balance. The amps are on the low side, but Ive been concentrating on torch position so its not too low and not too far away and heating up the filler blob until it sinks in.
Ive played around with the amps up to 70amps and it either turns into a blobby mess and sits a good few mm's up outside of the join, or its burning the join right open and turning into a royal mess.
Would this all come down to me holding the torch too close to the practice piece at higher amps?
Or, not heating up the piece enough at the lower amps causing the thicker filler to just blob and build up on itself? Im always watching the cleaning action on both sides of the join and dabbing into it when its shiny and the frosting outside the arc is showing. I'm cleaning with acetone and beveling the outside edges slightly.
Just wondering if Ive roughly got the machine settings correct for what I'm trying to achieve:
AC Sine wave, pulse is off, trigger 2T, pre flow 1.5s, pre current 13a, no up slope, 2s down slope, post current 15a, post flow 2.5s

Bit of a long one, thanks in advance
Mick.

[justmic]

Anyone?

[cj737]

What you’re describing is often the result of too low amperage for getting a puddle on the base material. With thicker filler than the base, you’ll struggle to get a good weld.

Filler is used to chill the puddle, not to be heated into the base material. Turn your amps up, get the puddle going first, then add filler (switch back to smaller filler) until you control the width of the bead, the puddle sags into the joint, and then move forward.

Maintaining the proper arc length is critical and a good torch angle. Maybe a bit more gas flow, and usually about 1 second of post flow for every 10 amps. 1.5 of preflow is good.

[tweake]

Hey forum,
Novice/newby hobbyist welder needing a bit of advice to get me going. I've set out to learn how to weld my own intercooler pipe joins on my car. I'm having some heat control issues I believe that someone might be able to help with.
Machine - lincoln powercraft 200m, torch is the supplied item with the push button
- number 7 cup
- WL15 lanthanated 1.6mm electrode, acute angle (haven't got any tooling available to grind it accurately)
- argon gas flow ~10cfm (could be to low?)
I have been starting with 50amps/110hz/ -2 ac balance.
AC Sine wave, pulse is off, trigger 2T, pre flow 1.5s, pre current 13a, no up slope, 2s down slope, post current 15a, post flow 2.5s

Bit of a long one, thanks in advance
Mick.

hi ya mate across the ditch. sorry this forum seams to hide a lot of the first posts.

as mentioned low amps is the common problem. if amps are low then travel speed suffers and the part overheats and turns to crap. keep the heat up and travel faster and strangely enough it keeps the part cooler.
also i would use a 2.4mm electrode with a blunt grind, and use a no5 cup, tho 7 is not bad.
no idea on -2 balance. typically aim for about 30% cleaning action ie positive.
i also would increase your post flow time to keep the tungsten clean. the cleaning action heats the tungsten a lot more than normal so it needs longer time to cool down before the gas turns off.
if you can a pedal helps a lot with aluminium.
for amps, you want it to melt into a puddle within a few seconds. if it takes longer your amps are to low.

hope that helps

i don't think the filler size is such a big deal. having it a bit bigger helps with the chill. melt, then chill.

[justmic]

Thanks legends, I'll sort out some more scrap pipe pieces and try again with higher amps and practice on moving quicker once that puddle starts off the torch . Might muck around with both fillers and see what I find suits better.
The pre current of 13a and post current of 15a, is that alright for me to continue on what I'm trying to do?

In terms of the AC balance from the manual, the range is -5 to +5 I haven't been able to track down a document stating what % represents the shown number, hazard a guess Id say 0 setting = 50% cleaning action?

AC Balance
Is only available in AC welding mode. Adjust the balance as a percentage between the
forward and reverse current cycles when welding in AC output mode. The reverse part of
the AC cycle gives the ‘cleaning’ effect on the weld material, while the forward cycle melts
the weld material. Neutral setting is 0. Increased reverse cycle bias will give greater
cleaning effect, less weld penetration and more heat in the torch tungsten, which gives the
disadvantage of reducing the output current that can be used for a given tungsten size, to prevent the tungsten overheating. Increased forward cycle bias will give the opposite
effect, less cleaning effect, greater weld penetration and less heat in the tungsten


Thanks

[Jack Ryan]

In terms of the AC balance from the manual, the range is -5 to +5 I haven't been able to track down a document stating what % represents the shown number, hazard a guess Id say 0 setting = 50% cleaning action?

I don't know the Lincoln Powercraft 200m but I doubt the balance is 50% +/- 5%. A 10% range of balance seems too small to me and 50% EP seems pretty useless, leave alone 55%.

Unimig also give a vague description of their balance control. in some places they say it is +/- 5% and in other places +/- 10%. Nowhere does it say what the basis is.

From measurements (not mine), it was established that 0% meant a balance of 40% EP and the adjustment was +/- 10%. In other words, the balance could be adjusted from 50% (40% + 10%) to 30% (40% - 10%) EP.

Your balance control would be based on a similar value. You could ask Lincoln or measure it - the salesman is unlikely to know.

Jack

[tweake]

In terms of the AC balance from the manual, the range is -5 to +5 I haven't been able to track down a document stating what % represents the shown number, hazard a guess Id say 0 setting = 50% cleaning action?

i would guess you want it set at -4 to -3. if tungsten goes super hot and melts then try it +4 to +3. positive side will be the one that heats the hell out of the tungsten.

[justmic]

Legends, thanks guys. Been caught up a bit with a crazy work schedule of late. But will definitely give your suggestions a go in the coming days.

cheers