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Discussion Starter #1
I remember reading in the book "The Long Way Around" how one of the guys fried the ignition on his BMW when he let someone arc weld on the sub frame.

I need to do some welding on my 72 cb450, will I be OK just disconnecting the negative battery terminal or is there something more I should be aware of? Thanks!

-mark
 

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standard practice is to diconnect the battery before welding on a vehicle

no some modern vehicles require more precautions to insure extremely static sensitive devices aren't damaged

but for points....... just disconnect the battery...... also not a bad idea to move it away from the bike when you are welding on it

I've also seen bikes burn from welding too close to fuel lines or carbs........
 

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Discussion Starter #3
Thanks for the pointers. I wasn't thinking about the carbs. I should probably just pull those and the gas tank off to be safe, only takes a minute or two.
 

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I once welded up a gas tank while gas was coming out of the hole............

Ok...that's a lie, but it made me laugh.
JohnnyB
 

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Discussion Starter #5
I once kicked over a motor while holding the spark plug and wire IN MY HAND to see if was getting any spark. That's not a lie, I wish it was. It hurt like hell.
 

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quote:Originally posted by motomark32

I once kicked over a motor while holding the spark plug and wire IN MY HAND to see if was getting any spark. That's not a lie, I wish it was. It hurt like hell.
you are supposed to ground the plug to the head or the frame. I think everybody here has done that at least once. I did it about 5 times when I was 15 and trying to figure out why the snowblower wouldn't start. I must have shocked my brain because I couldn't figure out why the plug had no spark but my hand hurt, and I repeated the act 4 more times looking for spark.
 

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Discussion Starter #7
Thanks Geeto, I don't feel so bad now. And for anyone else's future reference, the entire welding rod gets very hot, not just the tip. I found out the hard way. Sometimes I'm just an idiot, but only sometimes.
 

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shit, i get shocked like that everytime i work on a bike. the black 750 with the ignition upgrade, now that hurts. the others aren't too bad.
 

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What's funny is to watch people work with MSD systems that don't know enough to be scared. I put a 6a box on one of my dad's tractors(long story). After I got it running pulled a plug wire off with my tongs to show him why he isn't to work on that tractor any more. Was actually scared it might put a 70 yr old down.

I'm lazy, just ground as close to the weld as possible, never burned anything up.
 

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When I welded on my bike, I just covered up the carbs and gas tank with an old thick denim work jacket. My bike is still running and hasn't blown up. Yet.
 

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this may sound totally unbelievable but I have both tig and gas welded tanks which contained fuel, both gas and diesel.

It is extremely dangerous and when it has been necessary, I've really charged the big bucks.


The last time I did it, I taped a heavy exhaust vent hose to the exhaust of a non-emissions bike or car, asbestos fibered tape works well for this

dump the end of the hose into the tank and let it purge out the oxygen

this can take quite a bit of time for very large tanks

seal excessive area around the hose and play with the "vent" size as to not choke out the running vehicle

purge the area to be welded with the same exhaust gas t'd off the hose

be smart and cover yourself with nomex and full leathers

body armor isn't a bad idea and for sure keep your eyes protected and don't wear a cheap flimsy welding hood


it is very dangerous and one of my least favorite things to do when requested

I always try and find another way around having to do it
 

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this may sound totally unbelievable but I have both tig and gas welded tanks which contained fuel, both gas and diesel.

It is extremely dangerous and when it has been necessary, I've really charged the big bucks.


The last time I did it, I taped a heavy exhaust vent hose to the exhaust of a non-emissions bike or car, asbestos fibered tape works well for this

dump the end of the hose into the tank and let it purge out the oxygen

this can take quite a bit of time for very large tanks

seal excessive area around the hose and play with the "vent" size as to not choke out the running vehicle

purge the area to be welded with the same exhaust gas t'd off the hose

be smart and cover yourself with nomex and full leathers

body armor isn't a bad idea and for sure keep your eyes protected and don't wear a cheap flimsy welding hood


it is very dangerous and one of my least favorite things to do when requested

I always try and find another way around having to do it
 

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Years ago I was talking to an old time mechanic/handyman and he told me that he would fill the gas tanks with water, and every once in a while while welding, he would just flash his torch over the fill hole to burn off the vapors, he did say it would make anyone around him jump!

I can't remember if this was for car gas tanks or in ground storage tanks. Can't say for sure if he was pulling my leg or not....
 

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Years ago I was talking to an old time mechanic/handyman and he told me that he would fill the gas tanks with water, and every once in a while while welding, he would just flash his torch over the fill hole to burn off the vapors, he did say it would make anyone around him jump!

I can't remember if this was for car gas tanks or in ground storage tanks. Can't say for sure if he was pulling my leg or not....
 

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quote:Originally posted by JackC

Years ago I was talking to an old time mechanic/handyman and he told me that he would fill the gas tanks with water, and every once in a while while welding, he would just flash his torch over the fill hole to burn off the vapors, he did say it would make anyone around him jump!

I can't remember if this was for car gas tanks or in ground storage tanks. Can't say for sure if he was pulling my leg or not....
I had to fix a dent in a harley tank not too long ago at work, I used a stud welder to pull the dent out, what I did was drain all of the gas out of the tank, and fill it with water to the top, worked perfectly.
 

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quote:Originally posted by JackC

Years ago I was talking to an old time mechanic/handyman and he told me that he would fill the gas tanks with water, and every once in a while while welding, he would just flash his torch over the fill hole to burn off the vapors, he did say it would make anyone around him jump!

I can't remember if this was for car gas tanks or in ground storage tanks. Can't say for sure if he was pulling my leg or not....
I had to fix a dent in a harley tank not too long ago at work, I used a stud welder to pull the dent out, what I did was drain all of the gas out of the tank, and fill it with water to the top, worked perfectly.
 

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Depending on what kind of welding on your bike, it may also be smart to only weld small sections at a time. The longer you work on a single area the hotter it gets, and you could melt or warp other pieces near the area you are welding (i.e. electrical wires!!!). Also remember to clean the bike and the surrounding area, just splatter from the weld can light oil or gas on areas you are not even welding on. Good luck.
 

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Depending on what kind of welding on your bike, it may also be smart to only weld small sections at a time. The longer you work on a single area the hotter it gets, and you could melt or warp other pieces near the area you are welding (i.e. electrical wires!!!). Also remember to clean the bike and the surrounding area, just splatter from the weld can light oil or gas on areas you are not even welding on. Good luck.
 

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when water works you only got lucky

does a stud welder even make an arc?
 

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Discussion Starter #20
Finished up welding last night, my home brewed rear sets are finally on the bike. She still runs and nothing burned down or blew up. Thanks for the all the help!

-mark
 
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