prepping a gas tank for welding ....

[Egaeus]

Is it really worth the risk of serious injury or death just to save $150 or so?  I got my new tank in pristine condition for $122.50 + $20 to ship. 

[Jughead]

I Invested in one of the More Expensive Brands of Stud welders.It does take some getting use to.I did take some Nasty Dents out of a friends tank and did Blow a Hole in it with the Ground ring when it Didn't Ground too well.I was Able to weld it back with a Little Lincoln Flux welder.When Welding a Tank as long as you rinse it very well you'll be OK.I always take them to the Car wash and spend a few dollars to rinse them out with the High Pressure Soap then Rinse well.
I've also seen several that was being prepared for welding by Rinsing them and Heating them on a wood Stove until steam Comes out of the Filler.Afterwards Light what Fumes are Left in the Tank off with a Piece of Lit Newspaper.

[Wrecent_Wryder]

f3

[3imo]

 

Personally, I would NOT count on sand or anything like it to "displace" gas fumes.

wrecent.....   His suggestion was that the sand could displace the air/oxygen content of the tank, which in theory would not support combustion.
I doubt he intended for me to "not" rinse the fuel out first. 
------

regardless..a gas tank is a steel box.  fuel can be rinsed out enough to minimize risk of explosion.  Of the three cases I've been able to Google about deaths related to gas tank welding. none of those idiots even tried to rinse the tank out.

They can be welded, people have welded used tanks and I believe my balls are big enough to withstand the blow

[3imo]

BTW- Egaeus...  Man, I almost had a new tank on ebay, but got out bid and my pc was too slow to catch it.
the other guy got it for $71  lucky bastard.

[Egaeus]

BTW- Egaeus...  Man, I almost had a new tank on ebay, but got out bid and my pc was too slow to catch it.
the other guy got it for $71  lucky bastard.

That's why you always bid the max that you're willing to pay.  It will help defeat snipers. 

[3imo]

update.....

  So I ended up using household dishwashing soap and water to clean the tank of gas.

I spoke to a radiator shop and the guy went on and on about how his experience with gas tanks was just soap and water.

#1 - I put a bunch of soap and a little water and swished it around the tank. letting it sit for an hour.
#2 - then I filled it with more water and swished again for a good long time.
#3 - unplugged the petcock hole and rinsed with water all the while swishing it around.
#4 - after I got out as much water as possible and no more bubbles were visible, I let it air out for two days. (it was still wet and pooled in the bottom)
#5 - I stuffed two rags and swished them around then left them sitting in the bottom of the tank over night.
#6 - I removed the rags and let her dry out in the sun. By night fall she was dry and I couldn't smell any gas fumes.

So after double checking my life insurance, I sanded down the dent with my dremel and attempted to weld a nail to the tank.
being a dumbass, I had the current setting to high and burned a hole straight through the tank. 

I turned the settings down and went to a thinner fluxcore wire (.30)  I was barely able to repair the hole.
but I got it sealed good and grinded down again.

So... I get a nail welded on to the tank and successfully knock out a good portion of the dent.  I cut and grind that back down.

I weld another nail to the tank and proceed to knock more dent out. it works but I end up ripping the weld off the tank and creating a dime size hole in the tank 

Man..o...Man was I pissed. The tank metal is a way thinner gauge than I expected.  but being hardheaded as I am I wouldn't let it get me down, I figure I guess I'm gonna learn how to fix dime size holes. 

in the end I did fix it but it took a lot of welding  and grinding over and over again to cover that big of a hole.

I still have a bit more dent to get rid of, but mostly it came out great. I couldn't take pics cause my camera is F**ked but I will try to get something.  I think my neighbor took a pic of the second hole. I'll try to get that posted........
So you can have a laugh.     Is anyone even reading this?

[NiceGuysFinishLast]

I read it. I can just see the look on your face.. "It's working! It's working! Oh f%$k there's a hole!" 

[3imo]

yeah I bet I looked just like this guy -->

anyway I'm learning. which is good.
worst case I end up buying a new tank. oh well.

now I know to pop the dent out a little then cut and grind and start again.

I hope I can get that pic of the hole.  Then you'd understand the holy shaZam! factor.

[budget speed demon]

Man..o...Man was I pissed. The tank metal is a way thinner gauge than I expected.  but being hardheaded as I am I wouldn't let it get me down, I figure I guess I'm gonna learn how to fix dime size holes. 

hate to say I told you so, but is that not what I said?

[3imo]

apparantly its almost imposible to weld oem gas tanks because they are made from such thin metal. I'm not sure how true this is on the GS, but I know its true on older bikes.

ah...you sure did.   

but I still disagree on the "almost impossible".
difficult for a noob, yes, but very possible once you get the weld settings right and some practice.

I am not discouraged. I also plan on repairing the dents outta my 99' tank. I'll do better next time around.

[budget speed demon]

Sweet. A man after my own heart. I go to some local bike meets and all these guys don't know sh!t about bikes. They just ride them a bit and take them to a shop to get fixed. That doesn't make any sense to me. I know I guy that just paid like $200 to have a set of fork seals changed on his sport bike. Mean while I did the same thing to my GS for like $30 including parts and oil. It's cool that you're doing all your own work and learning while doing it.

[Blueknyt]

some Paintless dent repair places use diff tools (some handmade for the moment) hammers and Body "Dolly" type things  to work dents and creases out from the back side, i did the same to a KZ440 tank i had and needed very little putty to finnish off any low spots, think i gained back about 1/4 gal in capacity (yes it was that bad).   some times its easyer to fix dents from inside.  wont be perfect but can get you close

[3imo]

do you mean cutting out the bottom?  how else would you get em from the inside?

[Blueknyt]

for starters i used a older American Tire Iron, after removing the gascap i fished around inside with the wrench end pushing on the dents from inside i kept working on it then massaged some areas wih (dont laugh)  a 7 Iron with a bent shaft(no i didnt bend it)  it was far from perfect but it worked well.