Advice/opinions on penetration.

[bigbadbugga]

Hope I have got this in the right section, please move it if not

I need some opinions please.

I am at the point on my subaru/vw project where I need to be welding bracing and new brackets to the chassis. Most of the steel I will be using is 3mm thick, comprising of RHS and flat bar.

My welder is a clarke 105 turbo (the blue one), I've bought a new reel of 0.8mm wire and tips and had a go at laying some beads on an offcut.

Most of the beads seem to lay on top with a high profile, but after a bit of fiddling with settings I managed two beads that look ok.

set on 2-max, wire feed at 5, gas is CO2 (no flow guage but good flow)

I sectioned the welds on my bandsaw and cleaned up the saw marks...

I suspect my welder is a bit short on power for the job, am I right?

If so, would I be ok tacking everything together using it until I get a more powerful machine?

Is there anything I can do to improve the penetration?

thanks in advance

 

[andy82]

with Power full....I would maybe turn the wire speed down so that you dont have it building up similar to the pic.

It may work better when joining the box section to have a chamfer on each of the edges.

 

[shenion]

Laying beads on top will take a considerable amount of heat.

Try welding two pieces together with a small gap like 1mm. Then you can judge better. If that is not enough then grind the joint to a V to reduce the amount of metal to suck heat out.

 

[bigbadbugga]

with Power full....I would maybe turn the wire speed down so that you dont have it building up similar to the pic.

It may work better when joining the box section to have a chamfer on each of the edges.

I tried turning down the feed but it just started burning back and pausing, with the wire speed at 5 (actually a fraction under (4.75 ish)) I get the best weld pool, I tried with different torch speeds too and the two beads shown are the best I/my welder can do.

Laying beads on top will take a considerable amount of heat.

Try welding two pieces together with a small gap like 1mm. Then you can judge better. If that is not enough then grind the joint to a V to reduce the amount of metal to suck heat out.

I will try it again with a gap and chamfer a bit later, I'm sure it will penetrate better.

The reason I feel I need penetration into the type of sample I have shown is that I will need to weld some of that type of material at 90 degrees to another piece (like making a letter 'T'), and therefore will not be able to chamfer the cross piece of the 'T'

Also, for some reason I seem to get slightly better results welding this material with 0.6mm wire, I always thought the thicker wire was meant to be better for thicker steel, that is why I put the 0.8mm on for this exersize.

I'll do some samples with 0.6mm later to compare.

thanx for the input so far

 

[bigbadbugga]

ok, done some more....

Joined two pieces of 50x25x3 RHS.

wire size 0.8mm, full power, wire feed at 5 (fraction under to be exact)

then I turned it over and loaded some 0.6mm wire and tip.

the first bead is with wire speed at 5, second bead (top) wire speed at 6.5

then I cut through the sample..

top is the 0.6mm with feed at 6.5
bottom is 0.8mm with feed at 5

I tested the short offcut to destruction, it took around 20 big hits with a lump hammer.

I'm thinking I will be ok tacking everything up, but will be better borrowing my mates big 250A mig (or saving for a portamig if the wife will let me)

opinions?

 

[hotrodder]

Yep, you need a bigger welder , no penetration to speak of and barely and fusion. Will likely be worse with a proper fillet weld too.

No point with those welds but an acid etch will highlight the welds fusion zone. It's not the correct reagent (nital) but battery acid will produce a weak result, section and polish the weld as you did here before adding a drop of acid. Have a cup of tea or a beer and then rinse. I did this a while ago to try and demonstrate but getting a clear photo didn't work to well so i didn't bother. Just highlighted the fusion zone which helps some but it's clearest if you save the pics and scroll between 'em. Probably would have got a clearer result if i'd polished it properly and not used acid from a dead battery



A bit more work but a better test than the BFH, a nick break test is very useful too

 

[wallopadonkey]

i welded some 3mm 50 x 30mm box the other day and on the 185 portamig and it used .8mm wire with wire feed of 5.5 and power setting 10 of 12
i am sure it is a damn site more than a 105 can kick out (it barely penetrated the other side but it did though!) i hit it with a hammer a few times and it didnt break.
i don't know how to measure output but i figured it is about 150/160 amps?
hth dave

 

[Wozzaaah]

Sorry BBB, as the others have said, if that's the best your machine can do on full power then your machine just isn't up to it
Looking at how your test piece failed, the weld beads broke almost cleanly from the RHS leaving the metal underneath virtually untouched, this shows that it was a very weak weld.
You can see that the short bead towards the back of the left piece is just sat on top too.

Treat yourself to something with at least 130A, ideally 150A or above if you can.

 

[shenion]

130A will still struggle, My Clare 130EN would do a decent weld, but not full penetration on 3mm T welds.

150A minimum, 180+ would be best.

 

[bigbadbugga]

Thanx guys, I have made enquirys to weldquip.

currently saving for portamig

I'll just use my current setup for tacking it all together during mock up, at least it will be east to break apart if I make any mistakes

 

[Tino]

Just a thought, would it be possible to pre heat, with a blow torch, before welding. It would significantly improve your chances of getting some penetration.