Tank Dents

D.A.T. said:
Thank-you for posting this. You have likely saved many lives--if people take it to heart not to do this. I do a lot of pressure testing with water only--up to 1500psi and the only pneumatic testing I ever do is 5-8 psi or less and any flat surface is evaluated for exactly what you don't want it to do--have it pop out. I will even "stay" them or put several tons of steel plate in the way of the potential burst path when I cannot adequately confirm to myself the engineering pressure retaining safety factor or likelihood there-of. For me to do it without such--safety factor of 350% with known shapes or no go--I leave the property.

That muffler could be tissue paper thin from corrosion in some other part of it not dented. Heating the steel to weaken it past 1000F (about red heat) and then standing in front of it with 30+psi of air pressure (the outside skin of the section is in tension from the internal pressure) is just looking at and then asking for death. How it will let go and rupture is not a pinhole--but down the long way of the section. Identification of the deceased is usually by any tooth fragments for dental records or fingertips remaining for fingerprint records.
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Glad you enjoyed
 
crashtech said:
I think our local tire shops won't touch those split rims anymore.
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yeah they dont want to. i watched a kid at a tire shop make some mistakes and i can see why they dont want to do it. we still have some on heavy off road equipment, i do my own so no one is in danger.
 
Treeslayer said:
yeah they dont want to. i watched a kid at a tire shop make some mistakes and i can see why they dont want to do it. we still have some on heavy off road equipment, i do my own so no one is in danger.
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The issue is that sometimes the ring gets distorted prying it off and then it doesn't seat correctly.
The danger is when the tire bead pops into place.
If I didn't have a cage, I would have a remote air valve to inflate the tire and stand WAY back during initial inflation.
 
crashtech said:
Those tires can launch higher than you'd ever believe possible. And then they come down. Anyway, this is a hijack, and I won't mention it again. Carry on, guys.
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OK. One more story and then I will quit hijacking as well :)
So, the Texaco station I worked at shared a lot with a NAPA auto parts store, about 100 feet between them.
The parts guys were "real" parts guys. You could walk in and say "need an oil filter and set of points."
Gaylor (the real parts guy) would say, "the beige Ford pickup that pulled in earlier?"
Yeah.
The parts would come arcing out from between the aisles and you'd better be ready to catch them!
Gaylor was also a volunteer firefighter and EMT.

One day we had a split rim wheel/tire that wouldn't fit in the cage, so we did it "outside" the cage. And wouldn't you know it, the ring came winging off and hit the side of the sheet metal building. Rang the whole shop like a bell!

Gaylor came running over with his EMT "go bag." He knew EXACTLY what that sound was and expected major trauma.

Luckily, no one hurt and we stood around drinking Cokes and laughing about it.
 
Treeslayer said:
air........i have herd of guys popping out dents in aluminum semi tanks. i wouldnt do it. i once used air to blow apart a stubborn hydraulic cylinder. it was nearly five feet long with a 3" rod. its a good thing the shop door was open cuz the rod blew right out in the yard. it weighed a hundred pounds. if it had hit any one they would have broken legs. air pressure is tricky. ever seen the old split ring wheels? there have been a few killed airing those up with out making sure the ring was well seated. it is a handy tool, but caution and careful thought is required.
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I did the same thing once, only my garage door wasn't open. It decorated my garage with hydraulic oil.
 
Dean Jenkins said:
The issue is that sometimes the ring gets distorted prying it off and then it doesn't seat correctly.
The danger is when the tire bead pops into place.
If I didn't have a cage, I would have a remote air valve to inflate the tire and stand WAY back during initial inflation.
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if my father had ever caught me inflating one with the ring facing me, i would not have had to worry about the ring getting me.
he was hard on me some say, but i never forget any thing he said. hell, some times i can still hear him in my head.
 
I used air on a 73 Kaw Z1 tank in my younger days, I did not have it jigged. It did remove the dent, but also spread the tank like a butterflied shrimp where it rests on the backbone of the frame, I used bf trucker straps to bring the chaos back to form. Never would I attempt that again.
On a side note it was a rare original tank that is still in service, I guess I was lucky.
 
If you can get a round rod in there to touch the back side of the dent, you should be able to work out the damage.

In a variation of the art of repousse, if you can clamp a rod into a vise, feed the free end into the tank to touch the back side of the dent, and smack the rod just outside the tank with a hammer on the side facing the dent, the hammer force should transmit down the rod where it will impact the back side of the dent. In essence, pounding out the dent.
 
That was the method I was taught in the 70s
Bicycle handle bar off a schwinn stingray that got crushed by the other neighbors crazy wife in a Riviera….sacrificed for an SL350 Honda tank.
 
I have in the past used various rigs to work from the inside sort of like the PDR method. I don't have all the varied tools the PDR guys have. Too much time rigging/fabricating to go that route. I used a stud gun. Doesn't need perfect, just close for minimal filler.
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The shadow deceives, the low is under 1/32". Epoxy primer and polyester glaze will finish it. A lazy 2 hours while BS-ing with a long time buddy who stoped to visit. On to the fenders, at least I have access to both sides on those.
Crummy photos, sorry.
 
so for years i would do it like this. stud gun and pull the dent out to get it close then fill the rest. the only issue was that once in a blue you would have a stud pull off leaving a hole that i would need to mig in or a stud would leak. it became such a liability. i didn't want to do a fancy paint job that failed because of a leaky tank that i had repaired. i quit doing it. if i couldnt push it out easily from the inside then the customer could simply buy a new one. they can usually be had for cheap if you find them used. 150 bucks maybe. if that didnt happen then i would just fill it. its a bit of a hack thing to do to put sometimes an inch of filler on it but it was the lesser of the two evils and using something like adtech i never had a single failure this way.
 
Agreed Jim, grabbing the studs at the base with a vise grip and twisting it of is a no-no. Leaves a divot. When that happens I use a tiny Tig weld to fill it.
I always pressure test tanks after any repairs, stud work, modifications or even new out of the box, prior to paint.
I did a couple of tanks with studs and used lead for the final fill, that's the best fill because it really seals any stud damage. But nobody wants to pay for that level.
 
These 1977 3.5gal fat bob tanks were severely dented and damaged. I cut the inner sides off for full access and was able to completely metal work and finish them. No studs, no filler. Welded the inside panels back on right on the original factory joint.
Worth it?, No but they hang on the wall in raw metal as a sample of what is possible.
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Nice job with the lead work, when its done right it will never be a problem. For lighter pulls with studs, it only takes a very light tap on the trigger, then use side cutters at the base of the stud to twist it loose, but you have to make sure the only pressure on the pin is outward with the slide hammer. The slide hammer must stay in alignment with the stud, or it might just pop off. Takes practice, but it doesn't take much metal with it when its removed.
 
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