fact or fiction

[toby.1944@hotmail.com]

hi to all from australia.
i am a new member to this forum and need some expert opinion on an issue regarding an opinion on welding an alumimiun boat with the engine still mounted to the boat my source tells me that the high frequency will destroy the engine power pack if it is left in situ while welding. i cant see this happening, whats your opinion.
aussie jim.

[trstek]

Hi Jim,

Do a search, there are already a few threads on the subject.

I always take the ground off the battery and put the welding ground close to where I am welding.

Some electronics if you blink while touching the case they fry, (bad design) in those cases you would want to remove from vehicle.

If you're not sure, or the power pack is expensive, you might want to error on the side of caution and pull it out, be carefull with static electricity, that will fry them too.

Tom

[ridesideways]

the high frequency will destroy the engine power pack
a better way to say that would be "the high frequency _could_ destroy the engine power pack". there is no way to know how sensitive the thing is. so as trstek already said, if it's expensive then take it out.

[Laiky]

if you asked the standard welding on a car question i would say no, but high fequency is a different animal. I think it is a good practice to remove it.

[Sberry]

I wouldn't say its a fact, work is done all the time on boats without disconnecting.

[HMW]

If in doubt, my opinion would be disconnect it, especially if easy to get too. I'm sure some boats,especially big boats, this would not be practical. Probably nothing would happen if you didn't, but why take the chance. Much easier than replacing it. We disconnect the batteries on our trucks when welding on them now, didn't use to, but now everything has a least 2-3 [if not more] control modules. CAT recommends not just disconnecting the batteries but unplug the PCM too which we haven't done yet, hasn't bit us yet. Just my 2 cents worth.

[neoslim22]

i would take it out to be safe. I used HF to weld in a new cross member on my race truck, come to find out three days later the MSD ignition box and the module in the distributer were burnt up. Welding does strange things to cars, i have had head lights blow out,fuses,interior lights and i always unhook the battery.

[Sberry]

i have had head lights blow out,fuses,interior lights and i always unhook the battery. So all this happens when you disconnect the battery? Why not leave it connected then?
I have welded on hundreds, likely more, cars trucks tractors about anything with wheels or an engine and never had an incident.

[RWC]

A different situation, but similar happened to my laptop computer when it was being used about 4 feet away from a Lincoln squarewave tig machine. The hard drive became unusable and had to be replaced. It was sitting on a metal clad bench.
I have welded on many cars without incident by just disconnecting the batt. There is also a filter that clips to the battery leads that does not require disconnecting the leads. That device has worked on many BMW's and Chevies without a failure.
Russ

[Laiky]

i'm going to guess (pretty sure but not an electrical engineer) that when the high frequency is active there is a large pulsing magnetic field, kinda like the emp pulse they say will fry all electronics in the event of a nuclear war. Even though disconnected from the battery it can induce a high voltage into sensitive circuits, and overload them. Modern microprocessors have conductors that are measured in microns, if a small static charge can kill it why wouldn't the high frequency arc start? That is why you have the option of lift arc when working around electronics. I think those that haven't had any issues probaby are using other than high fequency TIG.

[FusionKing]

I have been welding on aluminum on boats for 11 years straight now. Boats is almost all I do and almost all of that is repair work. Almost 99%+ is high frequency tig. I go to several marinas in my area daily besides having countless individuals bring boats to my shop each year.
I give this vitually no thought at all on any hull or engine type other than I always make darn sure whatever I weld on is what I attach the ground lead to. And I make sure that is well connected. Believe me if I ever caused a problem those marine techs would let you know about it.

I had a muffler shop also and never had any problems either. But that was mig;)
My dad owned a trailer hitch biz and he always unhooked the batteries tho.
To each his own...If I had to remove electronics to do my job each time I doubt I would still be in biz. Too much dilly-dallying around to fix something they really don't want to in the first place.:rolleyes:

[RWC]

i'm going to guess (pretty sure but not an electrical engineer) that when the high frequency is active there is a large pulsing magnetic field, kinda like the emp pulse they say will fry all electronics in the event of a nuclear war. Even though disconnected from the battery it can induce a high voltage into sensitive circuits, and overload them. Modern microprocessors have conductors that are measured in microns, if a small static charge can kill it why wouldn't the high frequency arc start? That is why you have the option of lift arc when working around electronics. I think those that haven't had any issues probaby are using other than high fequency TIG.


Laiky,
Actually we do use high freq for starting on DC, and continuous high freq when running aluminum. (this was using a non-advanced machine) I have not tried the Dynasty on cars with ECM's as of yet. We do place the return close to the weld area.
I guess we have just been lucky! tick tick tick.....
Russ

[Laiky]

I'm just speculating, we have all heard the high frequency horror stories. Maybe welding on a big metal hull blocks the magnetic field?? i don't know, but i can tell you i would never use the high frequency around any sensative equipment like a pc. Maybe the metal case of the ecm tends to protect it?? maybe some modules that are in ungrounded plastic enclosures (PCs) are more susceptable.

[Portable Welder]

Fusion King, I couldnt agree with you more, I never ever have disconnected a battery on a boat, Motor cycle, semi truck, Heavy equipment, car, or the motor homes.

My experience comes from welding on 1-3 vehicles of all sorts mentioned above over the last 21 years.

Just as fusion king said, I keep my ground where I'm welding.

For those of you who still plan on disconnecting the battery, dont forget to disconnect all of the ground straps.

Is there a possibility that the high freq could hurt something certainly, However since my record is as good as it is I figure I'm safe.

I will say this.

The high frequency used to set my answering machine off, ruffle my computer, cause my beeper to chirp and distort my phone when talking to some one and welding at the same time. The welder used to sit about 5' away from mentioned items on the opposite side of a wall.

However it never did any damage.

[FusionKing]

Thanks portable...to re-state what I meant about the ground...make darn sure it is connected HARD to the piece!!! Hi-Freek will let the arc jump thru someplace else and maybe carry the arc to an unwanted place if you don't.:eek: it happens:mad::(
I usually clamp a vicegrip on real good and then ground to that on most everything I weld and most of the time I use a 400 amp stinger for my ground clamp. Works real good and esp on sheet metal.
I welded forever before I started the marine gig so I had plenty of insight to potential problems beforehand.
If you start messing with the electronics on some newer stuff you could void your warranty.
I would love to post on this more but am just now walking out the door and heading to Ely MN for a week long fishing trip.
Hope you get it worked out so nothing fries:cool:

[BDJ]

I welded with high frequency tig on my boat yesterday about a foot away from my motor. In retrospect it probably wasn't the smartest thing the power pack didn't cross my mind. I did however disconnect the batteries and connected the ground about three inches from where I was welding with no ill effects. I suppose its possible for the high frequency to effect the power pack but haven't experienced any problems personally with power packs, depth finders or any other electronics in the boat.

[toby.1944@hotmail.com]

hi from aust.
thanks fellas for your opinions,its wide open isnt it like SBERRY says he welds all the time without disconnection and no problems resulted,but to be sure and not sorry [pocket wise] i will be disconnecting from.now on.
thanks again mates. aussie jim.