Hi can anyone advise me what is the best techneque to do a downhand root weld on a single sided piece of 10mm steel plate as i am having a bit of trouble getting enough penetration.
A Butt weld should be no problem, on 10mm plate you would need to have some sort of edge preparation, you wouldnt get sufficient penetration if you just leave the edges square........you need to grind some preps on and have about a 1-2mm root face and about 2-3mm root gap then come verticle down in Dip transfer (1.0mm wire would be best) and the do a verticle up fill/cap.
Because its positional, it would be easier with a higher percentage Co2 Mix gas, such as Argoshield Universal or Heavy.......about (85% Ar 15% Co2 or 80% Ar 20% Co2)
Its a description of an arcing phase for Mig welding.......
You have 3......(But only 2 are really useable)
Dip Transfer
Intermediate/Mixed Arc
Spray Transfer
Dip Transfer, is the bottom arcing range, using low voltage range and low wire speed rates, its good for welding thin sheets and bridging gaps such as rooting etc. Wire touches plate and causes a short circuit, once this happen the wire breaks and detatches into the weld pool.
Spray Arc, High voltage range, high wire speed, spray arc, used for welding thicker sections, T-Fillets etc, no real use for root welding as power to high and pool too fluid.
Mixed, is when there is too much voltage to remain in the Dip transfer range but not enough to complete the transition into mixed arc. Its not very good for welding, as you have lots of spatter and an unstable arc.
I think papaS is welding 1G position, not 3G? If 1G (downhand) prepped as Matt's instructions, personally I would allow for at least a 2mm root face, 2.5-ish root gap, inclusive prepped angle of 60-70 degree. If solid wire, push, not pull method.
At 10mm thick, stringers all the way, root, fill runs and cap. Remember to keep the correct tilt angles, especially on root run, you need to make sure you fuse well in to each root edge, very important if you are cutting out coupons for root bend test?
And there the conumdrum Snowie, my interpretation may be wrong, just that when I am explaining for a weld to be welded on the flat, eg; corner joint, butt joint, I call it down hand weld, where as 3G, I would state, vertical up or vertical down, as I said, I could be very wrong, suppose papaS will be able to explain for the better?
Anyways, shower, hot water expansion pipe decided to burst, fortunately outside on the roof, been slipping n a sliding on the slates, and now very cold but sorted now
In the days before weld positions were denoted by codes, Downhand is flat, other positions, vertical up, vertical down, horizontal vertical, overhead etc,
confusing downhand and vertical down is a common occurrence, I guess the use of codes clarifies things especially for wps purposes, as long as you can remember them.