Outer Limits 4x4 Board

was TIG welding some recovery points onto the tow bar this afternoon and in certain spots along the weld it seemed to pop a little leaving holes in the weld, it didnt matter how long i held torch over that section, the weld just didnt seem to stay, im thinking that there was contamination in the weld pool, oil or something.

I prepared it by grinding the lug back to bare metal and grinding the tow bar with a flapper disc, both surfaces looked clean before i started, any ideas? i am no boilermaker but i can hold a steady torch

cheers
Waz

was it at the end of your weld or just a random spot?

what wire were you using

moslty likely porosity. where the parys firt or oily, you did say you grouned it back but it could still be dirty.
also what wire did you use? another thing could also be dirty wire. even free from the packet they contian a light oil coat. try wiping the rod down with some metho and see how much shit comes off them

.....did you use welding wire for oxy welding?m

it just comes up in random spots no where in particular, im using commweld wire, i might try rubbing the surfaces with metho next time and the wire too and see how that goes

It's almost certain to be a porosity problem. Could be from dirty/rusty/painted material, poor gas coverage, incorrect weld torch angle, incorrect filler wire. Filler wire not kept in the gas coverage whilst welding or more likely a combination of the above.
Standard Mild Steel can be a problem especially if it has pronounced scale and MUST be clean. Don't use oxy filler rods EG: R45, R60. Use ER70 S2 as it's triple de-oxidised and suffers less from porosity.
Try not to move too slowly it only makes the problem worse, turn the amps up get a pool and move pretty fast adding the filler to settle the weld pool down.
Hope this helps.
Regards Andrew.

You using a full bottle?

I'd check out the gas flow and make sure it's not running empty.

Also make sure it's not too low a gas flow but not too much either.

thanks for the replies, some very detailed information in there, sounds like porosity is the problem, i might have to spend a little more time prepping next time. My bottle has 4000kpa left in it and im running around 5-6 ltrs a min, does this sound ok? ER70S_6 is what is stamped onto the filler wire

Check the gas cup size is suitable for the job and the gas flow is not too high, gas turbulance can also cause this problem.

Cheers

Are you welding to the box section part of the towbar or just to flat plate. The most common issue would be those above but could you actually be going so slow with a fair few amps that you are heating the air in the sealed box and actually getting an air pressure blow out. Not so likely on bigger sections but possible also.

one_waz wrote:thanks for the replies, some very detailed information in there, sounds like porosity is the problem, i might have to spend a little more time prepping next time. My bottle has 4000kpa left in it and im running around 5-6 ltrs a min, does this sound ok? ER70S_6 is what is stamped onto the filler wire

Your gas flow may be too low, I always measure my gas flow at the torch not at the regulator and I aim for 7-7.5 litres/min at the torch nozzle. To get this on my torch (25' length) I need to run it at 10-12 at the reg.
ER70S 6 filler is fine, it's the same as LW1 Mig welding wire.
Regards Andrew.

After you have finished be doubly sure that you would risk your life hanging off you welded recovery points too

Bazzle

thanks again for the replies, there are a few things i will try differntly next time. as for the weld id say they will be able to withstand the shock of a snatch, there is only a couple of tiny holes, it isnt through the entire weld

one_waz wrote:thanks again for the replies, there are a few things i will try differntly next time. as for the weld id say they will be able to withstand the shock of a snatch, there is only a couple of tiny holes, it isnt through the entire weld

But what sort of penetration did you get with a TIG on what should be hopefully fairly substantial plate. As much as I love TIG I would still be going for the MIG on something like that quicker and easier to get solid penetration and strong weld.

fester2au wrote:

one_waz wrote:thanks again for the replies, there are a few things i will try differntly next time. as for the weld id say they will be able to withstand the shock of a snatch, there is only a couple of tiny holes, it isnt through the entire weld

But what sort of penetration did you get with a TIG on what should be hopefully fairly substantial plate. As much as I love TIG I would still be going for the MIG on something like that quicker and easier to get solid penetration and strong weld.

i will have to disagree with you there. TIG when done right is the most highest quality weld you can get. alot of pipe work is TIG welded and/or MMA. yes mig may be quicker but mig can suffer from lack of fusion. im not downing MIG just stating. every process has it place

brendan_h wrote:

fester2au wrote:

one_waz wrote:thanks again for the replies, there are a few things i will try differntly next time. as for the weld id say they will be able to withstand the shock of a snatch, there is only a couple of tiny holes, it isnt through the entire weld

But what sort of penetration did you get with a TIG on what should be hopefully fairly substantial plate. As much as I love TIG I would still be going for the MIG on something like that quicker and easier to get solid penetration and strong weld.

i will have to disagree with you there. TIG when done right is the most highest quality weld you can get. alot of pipe work is TIG welded and/or MMA. yes mig may be quicker but mig can suffer from lack of fusion. im not downing MIG just stating. every process has it place

There is a big difference betwen home handyman TIG and good quality TIG work even more so when comparing to pipework whihc can be quite specialised. Heavy pipework often is done with TIG root/sealing runs then capped with MMA for strength. Lot of amps required for strong joining of what I would hope would be 6mm plate at a bare minimum ( I would use no less than 8-10)and it's alreadys stated that it's not a perfect weld. Not trying to attack the guy but no way would I be prepared to snatch from this recovery point.

Yeah I would grind back your weld (get rid of the contamination) and start again... but thats just me hey;)

Clean, clean, clean and clean more before you weld... i wipe the rods with metho too, with alloys i wipe rods with scourer & metho

It wouldn't hurt to get some scrap metal in the same thickness etc to practice on and setup your tig & gas before going to your job;) save time grinding back a bad weld to

fester2au wrote:

brendan_h wrote:

fester2au wrote:

one_waz wrote:thanks again for the replies, there are a few things i will try differntly next time. as for the weld id say they will be able to withstand the shock of a snatch, there is only a couple of tiny holes, it isnt through the entire weld

But what sort of penetration did you get with a TIG on what should be hopefully fairly substantial plate. As much as I love TIG I would still be going for the MIG on something like that quicker and easier to get solid penetration and strong weld.

i will have to disagree with you there. TIG when done right is the most highest quality weld you can get. alot of pipe work is TIG welded and/or MMA. yes mig may be quicker but mig can suffer from lack of fusion. im not downing MIG just stating. every process has it place

There is a big difference betwen home handyman TIG and good quality TIG work even more so when comparing to pipework whihc can be quite specialised. Heavy pipework often is done with TIG root/sealing runs then capped with MMA for strength. Lot of amps required for strong joining of what I would hope would be 6mm plate at a bare minimum ( I would use no less than 8-10)and it's alreadys stated that it's not a perfect weld. Not trying to attack the guy but no way would I be prepared to snatch from this recovery point.

yer your probably right, it just isnt practable to tig 5mm+ plate. not saying it cant be done but there are btter ways of doing it.
i woul prob MMA that stuff on only because i enjoy it more then mig

i thought that stick welders were best for deep penetrating welds?

hando wrote:i thought that stick welders were best for deep penetrating welds?

using a 6011 or 6010 they are very harsh and deep penetration. i recon stick welding is still the best all round tpe of welding. can use it in the wind, rods are cheap, no need to lug a gas bottle around. inveters can weight nothing so can move it from the shed to front easy.
and im my option stick welding looks alot better then mig and i get a better sence of feeling when i see my stick welds conpared to my mig welds.

again not bagging mig it has it place. i acelly just finshed off making a set of rock sliders for my zook all mig welded

The recovery point is made from a 1 ton lifting lug its about 12mm plate steel welded to the box section of the tow bar. I used TIG because its easier to do verticles. I will take your adice and gring it back and re weld.

Cheers
Waz

one_waz wrote:The recovery point is made from a 1 ton lifting lug its about 12mm plate steel welded to the box section of the tow bar. I used TIG because its easier to do verticles. I will take your adice and gring it back and re weld.

Cheers
Waz

Is the lug just a flat piece welded at 90 degrees to the towbar or is it a flat plate with the lug off that. If it's a flat piece at 90 degrees I'd still be concerned about the weld penetration and fillet size that you will get from the TIG. You can do multiple passes of course but if you are woried about positional welding I'd still think you'd be better pulling the towbar off and MIGing or MMA (stick). Would be easier to get good strong weld without excessive heat affected zone which could weaken the parent material (towbar). With the amps required with TIG I'd still be concerned with pressure blow out if the box is sealed. If it is it wouldn't hurt to put a tiny hole somewhere discrete.

hey mate im a boilermaker just wanted to say if you run about 8 litres of argon gas per minute you should be prety rite and yeh if you gring up befor belding just blow it off with the compressor. and as long as your tungsten is sharp and only sticking out of the nozel about 5mm you should be right with as small as a size 6 and thing bigger is fine to. and are you using thoriated or zirconiated tungstens?

fester, the lug is just plate steel welded at 90 deg to the box (a fillet weld i believe) fiftyfrenzy, the setting you have suggested is pretty close to what i am running, im using thoriated (red tip) tungsten with size 6 gas cup sharp point on tungsten about 5-7mm stickin out depnding on the room.

one_waz wrote:fester, the lug is just plate steel welded at 90 deg to the box (a fillet weld i believe) fiftyfrenzy, the setting you have suggested is pretty close to what i am running, im using thoriated (red tip) tungsten with size 6 gas cup sharp point on tungsten about 5-7mm stickin out depnding on the room.

Have you tried using a gas lense.. there all i use these days, you can get away with the tungsten hanging out a bit due to better gas sheilding

im not sure what do you mean by a gas lense?

FYI, after work tonight i ground the welds back and attemped the weld again and all was good, no more porisity! i must not have cleaned the surfaces properly in the first place, welds look sweet as now would definatly snatch off them.

Thanks for the advice everyone.

got any pics?

also a nother thing that i dont think was mentioned was moisture. what kinda of day was it?

one_waz wrote:im not sure what do you mean by a gas lense?

FYI, after work tonight i ground the welds back and attemped the weld again and all was good, no more porisity! i must not have cleaned the surfaces properly in the first place, welds look sweet as now would definatly snatch off them.

Thanks for the advice everyone.

Heres a bit of a read for ya..
http://www.off-road.com/trucks4x4/artic ... ?id=464755

hando wrote:i thought that stick welders were best for deep penetrating welds?

It really depends on what you require from a weld.

Stick will have the highest amount of opions and be able to do anything you wanted in welding.

like Deep sea welding is done by stick, only because nothing else will work properly.

Mig is fast and generally pretty good but is very limited in what you can weld.

Tig much like stick but is limited in ways due to using gas etc.