welding

pajero · Newbie

welding

rgren2 · Guru

Yes, too many electronic gizmos with sensitive little electronic thingos in them. This should start some robust discussion about the distance of the arc, current flow and EMF. Just disconnect and don't overthink. Life's too short.

-- Edited by rgren2 on Wednesday 29th of March 2017 09:29:32 AM

Mike Harding · Guru

I would.

If you can readily disconnect the caravan's box of electronics I'd do that too otherwise I'd disconnect both cables from the battery.

Arc welding can generate some significant V & I and I like to keep it as far away from electronics as possible.

Aus-Kiwi · Guru

Yep . Disc battery . I even run an earth to water pipe using jumper leads.,

pajero · Newbie

Thank you

Tony Bev · Guru

I am not a Boilermaker, or Welder

In my opinion, from experience

When welding on any vehicle with a battery

Always disconnect the battery
Always have your earth lead of the welder, as close to the area of welding, as you can get it

Cupie · Guru

I'm anxious to hear from Macka17 on this thread.

edit ... Just recalled reading something that strongly advised against welding or even drilling modern 4WD chassis. I think that it was in a discussion about cracked chassis on modern utes. Probably not relevant to welding a van chassis though. So I'll just pull my head in. HooRoo.

-- Edited by Cupie on Wednesday 29th of March 2017 09:33:39 PM

-- Edited by Cupie on Wednesday 29th of March 2017 09:35:33 PM

madaboutled · Guru

Most House battery / solar set ups in caravans are not earthed to the chassis so there shouldn't be any need to disconnect the batteries provided it's completely disconnected from the tug. BUT, if you are not sure then disconnect anyway as a precaution.

Motorhomes however could be earthed if they have charge lines coming from the engine compartment, be it from battery, alternator or DC to DC charger etc.... Again though I would disconnect anyway as a precaution.

macka17 · Guru

Me Cupie.

I know a lot less than others on here on some subjects.

Chassis welding. On the modern Chassis less ones.
they "probably" High tensile steel folded to give strength and flexibility.
Bad idea drilling or welding.
The old D Max. steel no problem
Just remove, as said. earth strap. I also disconnect the plug to my computer box too.
then jumper as others to shed frame.and low amps.

My welding days finished now with this implant in me.
NO WELDING at all. EVER.

Bummer. I just renewed small stick.($370)
Anybody want a coupla cheap welders??.

bill12 · Guru

I'm a welder , and would disconnect the battery and put the welder earth as close to the weld area as possible. You should realise that repairs to chassis need a qualified welder or enginneer to pass rego. Bill.

macka17 · Guru

Yea. And if not. make sure you drill stopper holes at each end of crack\split.
Plus preferably (if poss) weld on a gusset\cover plate rather than just a weld run.
Preheating, and other things come into a proper job.

I learnt my welding with the "stovies", and fill\cap welders on pipelines
in early, mid '60's.

Pipe work, I could do lovely bead runs.

Flat plate. Yukk. Hopeless. leave it to blokes like the one above me here.

oldtrack123 · Guru

The MOST important step is to have the earth clamp made to clean bright metal as close as possible to the actual weld area.

Make certain it is continuous metal with no bolted or riveted connections between to the earth clamp & the area being welded

If you are welding two pieces together which are in contact with or parts of the chassis ,run an earth cable to both

This WILL reduce the risk of burnt out wiring, alternators ,damaged batteries, etc, ensuringDhere is no other path for the welding current or voltage to go!!!

All other requirements against damage to wiring etc are secondary precautions!!!!

.PLUS:

Make sure you KNOW the type of steel :

Does it need preheating ??

does it require low hydrogen electrodes or processes

Inspection & testing of weld in critical areas. ?

Have you created stress areas in critical sections

Are there stress areas that need to be blended out ?

-- Edited by oldtrack123 on Thursday 30th of March 2017 04:26:04 PM

oldtrack123 · Guru

Aus-Kiwi wrote:
. I even run an earth to water pipe using jumper leads.,

WHY ????????

What useful purpose does it serve???

If the van is connected to the mains ,you could actually create a serious problem

-- Edited by oldtrack123 on Thursday 30th of March 2017 04:31:45 PM

macka17 · Guru

Like he said.
AN EXPERIENCED welder. NOT one of us..

PeterD · Guru

Another thing is there are cables running through some sections of the chassis, particularly the drawbar. Check that there are none in the section you are working on. If there are any cables remove them first and replace them afterwards.

Aus-Kiwi · Guru

If you have potential between earth and elect earth ? You have other issues which MUST be addressed !! It's to stop any surge or damage from elect surge .

oldtrack123 · Guru

Aus-Kiwi wrote:
If you have potential between earth and elect earth ? You have other issues which MUST be addressed !! It's to stop any surge or damage from elect surge .

It is exactly the sort of thing that should not be done!

It serves no useful purpose & could actually cause problems

Mains earthing conductors carrying welding currents being the big one

A GOOD CLEAN METAL TO METAL CONNECTION OF THE WELDING RETURN CABLE /CLAMP/S to the sections being welded is the critical requirement.

IF THAT is done correctly, there is NO OTHER path for welding currents to travel

Based on practical experience supervising Manual ,semi automatic & fully automatic welding ,using many operators & multiple machines, concurrently ,on structures /machinery connected either directly or indirectly to the MAINS earthing systems[.Combined welding currents in 1000s of amps] smile biggrin

Aus-Kiwi · Guru

Stop being a wanker !! Disconnect power if it's an issue. Get it checked if you think it's unsafe . No one should be at risk stepping out of van .

iana · Guru

Well to day I welded a bracket on a truck tray, just made a good earth, and welded the bloody thing, for Christ sake stop making a mole hill into a mountain.

oldtrack123 · Guru

Aus-Kiwi wrote:
Stop being a wanker !! Disconnect power if it's an issue. Get it checked if you think it's unsafe . No one should be at risk stepping out of van .

confuse

Not sure who the wanker is???

Now if you had said "make certain the mains lead feeding the van is UNPLUGGED",it could have had some worth !!

IT is NOT a good idea to deliberately connect the RETURN lead of any welding machine to any thing that could form a part of the MAINS earthing system ,either directly or indirectly/

In OLD times when the welding return was called the the "Earth lead " & a requirements of the Electrical Standards for welding machines required one end of the secondary be deliberately connected to the machine frame at that time & people thought it was OK to have it connected to any "earthed "metal ,serious damage to mains earthing cables AND 240V wiring was common

It certainly seems you do not understand anything about stray welding currents or the damage they can do to any "earth" wiring

INCLUDING MAINS earth wiring if some one was stupid enough to do as you suggest!!!

Just as small portable 240V generators should not have an earth stake or be deliberately connected to any earthed mass including EARTHED metal

To others I REPEAT

DO NOT connect the welding return cable/s,to any other metal, than the metal/s that you are actually welding.

Any ELECTRICIAN, who understands basic electrical principles, should understand the reasons why it is best to keep a fully isolated power source free of any other connection /s !!!??.

oldtrack123 · Guru

oldtrack123 wrote:
Aus-Kiwi wrote:
Stop being a wanker !! Disconnect power if it's an issue. Get it checked if you think it's unsafe . No one should be at risk stepping out of van .

Not sure who the wanker is???
By all means get it checked BUT make absolutely certain that person doing the checking actually KNOWS what is the safest way to prevent damage
Now if you had said "make certain the mains lead feeding the van is UNPLUGGED",it could have had some worth !!
IT is NOT a good idea to deliberately connect the RETURN lead of any welding machine to any thing that could form a part of the MAINS earthing system ,either directly or indirectly/
THAT includes WATER pipes!!!
In OLD times when the welding return was called the the "Earth lead " & a requirements of the Electrical Standards for welding machines [at that time]required one end the "earth end 'of the secondary be deliberately connected to the machine frame . people thought it was OK to have it connected the "earth" lead to any "earthed "metal ,serious damage to mains earthing cables AND 240V wiring was common

It certainly seems you do not understand anything about stray welding currents or the damage they can do to any "earth" wiring

INCLUDING MAINS earth wiring if some one was stupid enough to do as you suggest!!!
Just as small portable 240V generators should not have an earth stake or be deliberately connected to any earthed mass including EARTHED metal

To others I REPEAT
DO NOT connect the welding return cable/s,to any other metal, than the metal/s that you are actually welding.
Any ELECTRICIAN, who understands basic electrical principles, should understand the reasons why it is best to keep the welding RETURN lead free of any other connection /s !!!??.

-- Edited by oldtrack123 on Monday 3rd of April 2017 10:34:05 PM

oldtrack123 · Guru

iana wrote:
Well to day I welded a bracket on a truck tray, just made a good earth, and welded the bloody thing, for Christ sake stop making a mole hill into a mountain.

It would be a lot more than a mole hill, if, due to following some of the advice given, you ended up with burnt wiring in the van ,vehicle or mains wiring in your house, garage/ workshop.

And it is not just theory, seen such far too many times in my career.

-- Edited by oldtrack123 on Monday 3rd of April 2017 10:43:32 PM

oldtrack123 · Guru

PeterD wrote:
Another thing is there are cables running through some sections of the chassis, particularly the drawbar. Check that there are none in the section you are working on. If there are any cables remove them first and replace them afterwards.

A BIG DITTO to the above biggrin

Aus-Kiwi · Guru

I earth to ground when TIG welding . ( polarity depending on metal being welded ) I find lying on ground welding I don't like being the bond & shocks so I use cable . Much much less shock with time each weld . Adding the mains side of things is being a wanker in complicating the OP's question . Yes disconnect any mains too . It may freek some out that Elect companies use mains neutrals.. Even the railways use neutral mains to earth the lines .. in some cases to weld . Earthing what your welding is no diffetent to welding the metal on the ground . If it was so seriously dangerous all welding would require insulation from the ground . Talk about elect tech getting out of control !!

-- Edited by Aus-Kiwi on Thursday 6th of April 2017 03:56:41 PM

macka17 · Guru

Children. Children.

Grow up.

Most of us have welders. 95% of have probably welded.
As far as sticking 2 bits of metal together.
With varying effects.

On a good day Mine passed X-Ray 40 yrs ago.
nowadays. 75 shaky full length rod tip.
I have trouble striking at times. (two handed job)
As do others if honest.

Play with your welders nad have fun
BUT.
Same as sparky work.
Serious job.

GET A TRADESMAN. 99% of us are only guessing..

Tony Bev · Guru

Many (45), years a go

A family member took a brand new Toyota into a local place to have a tow bar fitted

It came back with the alternator not charging

Took the new car back to the city, they would not honour the warranty, as soon as they saw the towbar

They pointed out where the welder earth lead, had touched the bodywork

I have never had electrical problems after welding on a vehicle
In may just be a coincidence, but I always disconnect the battery, and have the earth lead as close to the welding as possible

oldtrack123 · Guru

Tony Bev wrote:
Many (45), years a go

A family member took a brand new Toyota into a local place to have a tow bar fitted

It came back with the alternator not charging

Took the new car back to the city, they would not honour the warranty, as soon as they saw the towbar

[1]They pointed out where the welder earth lead, had touched the bodywork

I have never had electrical problems after welding on a vehicle
In may just be a coincidence, but I always disconnect the battery, and have the earth lead as close to the welding as possible

{1] That tells the story & disconnecting the battery would have made little difference

The WELDING RETURN lead was either not fully insulated ,or clamp had not been firmly connected to the part being welded

Welding current flowed through other body paths & possibly wiring to the alternator.

I suspect it was the diodes in the alternator that were damaged.

blown bulbs & burnt out wiring can also occur

Disconnecting the battery is a worthwhile added precaution but the key to your success is:

YOUR QUOTE" have the earth lead as close to the welding as possible"

I would add :

NO bolted or riveted joints between the weld areas & the welding return clamp

& ensure no contact of return lead or the welding rod or holder is made to any other part of the body

You may note my use of the words "Welding return lead /clamp"

The sooner the word "EARTH"ceases to be used for the welding return the better

It no longer has any real connection to 'earth in any way unlike older machines [pre the 1950s ]which under the Standards of those days required ANY transformer that stepped down the voltage was required to have one end of the lower voltage winding connected to the MAINS Earthing point /cable of the machine.

This was a safety measure due to designs & insulation qualities of the times & was suppose to ensure that if a fault developed between the Mains voltage winding the low voltage winding Current would flow to the earthing system & blow the line fuses

Sadly ,it often led to many more problems like burnt out mains wiring from the "mains" earthing cables carrying welding current & overheating burning the mains cable insulation or worse.

I KNOW the consequence of one such situation, where I my self received a serious electric shock when switching a welding machine off to repair it

.I had to crawl under a work bench to gain access to the metal isolating switch & as soon as I grabbed the handle I copped a full 240V shock

For those who understand, this was what happened

The complaint was that the machine was not giving full output

My intention was to check the incoming voltage @ the metal clad isolating switch on the machine

What I did not know was that the welding return'"earth"lead had become dislodged from the job , but the job was sitting on bench Firmly"earthed to the steel building framing

The Mains earth cable in the lead feeding the machine had burnt through the insulation of one phase line

blowing the fuse for that leg , & open circuiting the actual line cable at that point ,the MAINS Earth cable also open circuited & the end still connected to the machine .welded itself to the live @240V cable end from the machine.

I kept that section for many years to demonstrate to our welders & boiler making apprentices what could happen if the welding return clamp was not correctly fitted

It also meant that about a 50 metres run length of heavy multi phase,multi circuit wiring had to be replaced!!

YES CORRECT FITTING OF THE WELDING RETURN IS VERY IMPORTANT

Never let it contact in any way to the mains earthing system if it can possibly be avoided

& VERY definitely DO NOT [as suggested by one poster] deliberately connected to any "earthed "metal "[water pipes , buildings, earth stakes etc]

The results can be dangerous , deadly &/or expensive.

End of lecture & example.

oldtrack123 · Guru

Aus-Kiwi wrote:
I earth to ground when TIG welding . ( polarity depending on metal being welded ) I find lying on ground welding I don't like being the bond & shocks so I use cable . Much much less shock with time each weld . Adding the mains side of things is being a wanker in complicating the OP's question . Yes disconnect any mains too . It may freek some out that Elect companies use mains neutrals.. Even the railways use neutral mains to earth the lines .. in some cases to weld . Earthing what your welding is no diffetent to welding the metal on the ground . If it was so seriously dangerous all welding would require insulation from the ground . Talk about elect tech getting out of control !!

-- Edited by Aus-Kiwi on Thursday 6th of April 2017 03:56:41 PM

It does not matter what sort of welding is being done!! The secondary shall not be, has no need to be "EARTHED to ground

Can you explain what you gain by that??

You received shocks for one simple reason , you had ineffective welding return circuits.

I have had welders working in enclosed vessels In very confined space laying on their back,but in those situations we ensured that they had dry insulating medium underneath them .just in case they accidently touched the electrode to hand or their body

Plus a safety spotter watching ,to immediately cut the welding lead if a shock was recieved this was the result of two welders being electrocuted at the same time while welding inside a large pressure vessel.

Even if a high frequency superimposed pilot arc is being used to avoid arc rectification ,such as occur when AC welding aluminium , "earthing" gains NOTHING !!

Disconnecting the MAINS does not disconnect the MAINS earthing conductors so THAT suggestion gains absolutely ZERO

By the way I am not just an electrical tech & certainly am not just an ex electrical linesman

I held a Class 1 welding supervisors ticket for many years[right up to my retirement & have supervised 100S of welders working all many high quality [code Standard] jobs such as high pressure vessels & pipe work for powerhouses in Qld , VIc, NSW

Components for Pumps & turbine for both Tumut & Wivenhoe hydro

While I cannot remember the draft Standard number/year , one specifically stated that all work SHALL be insulated from "earth."

Because the problem I have given above of wiring damage was becoming wide spread[ even in our own workshops]

They had a couple of others like , ALL welders working on the same job or close to each other shall not have a voltage existing between the the various electrode holders.

Ie the output voltage SHALL be in phase!!

Concerns that the voltage difference between electrode holders could be in the order of 140 +V

Again almost impossible to achieve in any reasonable sized job with multiple welders working on it

As the company I worked for was sent many standards for comment & input ,I was given the Draft for comment. I immediately pointed out it was impractical to make full insulation mandatory, but education on correct methods would over come the problems

I suspect many others with practical experience with welding operators & welding gave similar feedback because they did not get past the draft stage. but were made strong "recommendation"

Yes a bit more than a linesman ,amatuer welder or Electrical tech biggrin

-- Edited by oldtrack123 on Thursday 6th of April 2017 10:50:54 PM

-- Edited by oldtrack123 on Thursday 6th of April 2017 11:05:00 PM

oldtrack123 · Guru

Tony Bev wrote:
Many (45), years a go

A family member took a brand new Toyota into a local place to have a tow bar fitted

It came back with the alternator not charging

Took the new car back to the city, they would not honour the warranty, as soon as they saw the towbar

They pointed out where the welder earth lead, had touched the bodywork

I have never had electrical problems after welding on a vehicle
In may just be a coincidence, but I always disconnect the battery, and have the earth lead as close to the welding as possible

Hi Tony

Unless that was a very old welding machine, pre late 50s,the secondary winding [ welding winding]would have been electrically isolated from the machine frame & "mains"earthing system

So the problem was due to that accidental contact of the welding return lead shunting welding current through the body & possibly wiring

The same could happen with accidental contact by the rod to a body part

oldtrack123 · Guru

Aus-Kiwi wrote:
I earth to ground when TIG welding . ( polarity depending on metal being welded ) I find lying on ground welding I don't like being the bond & shocks so I use cable . Much much less shock with time each weld .
]Adding the mains side of things is being a wanker in complicating the OP's question .
[1]Yes disconnect any mains too
.[2] It may freek some out that Elect companies use mains neutrals..

[3]Even the railways use neutral mains to earth the lines ..
[4]in some cases to weld .
[5] Earthing what your welding is no diffetent to welding the metal on the ground .
[6]If it was so seriously dangerous all welding would require insulation from the ground . Talk about elect tech getting out of control !!

-- Edited by Aus-Kiwi on Thursday 6th of April 2017 03:56:41 PM

You should keep clear of anything regarding even basic electrics

Your lack of understanding amazes me for someone who makes some of the claims you make .

[1] The problems have nothing to do with the MAINS apart from the damage that can be done to MAINS by adjacent OVERHEATED EARTH CABLES

Disconnecting the mains cannot prevent that damage!!

[2]Of course , A neutral cannot be created unless it is "earthed" if not "earthed it is simply referred to as a LINE

Without one being made a "Neutral the two lines are commonly referred to as L1 & L 2

But a "neutral "can be made without ANY connection to mother earth ,as common with on board generators in vans etc to allow the on board RCD to operate correctly

[3]Yes ,they create an "EARTHED "neutral for safety reasons

So that if a line comes down the fault protection will function & trip the supply just like ANY OTHER supply

[4] Not sure, but I expect you are saying they use the supply to operate welding machines ??

Nothing unusual about that, electrics tram lines were commonly repaired by welding via converters from the tram line overhead DC line to track supply[ no different to supplying the tram motors ,]

[5] The job laying on the ground is totally different to deliberately "earthing "to water pipes , ground stakes ,steel building etc.

It appears you do not even understand what constitutes an "earthing system"

[6]see {5] & refer to my post about a draft Electrical standard that wanted to make insulating mandatory

That was raised by electrical people who had no /little practical knowledge about welding

But were very concerned about the damage to electrical installations, possible fires , & risks to lives that were occurring