Author Topic: Repair a dent in a gas tank (Read 8267 times)

Otto · « **on:** January 30, 2009, 05:45:41 PM »

I have a tank for my 76 550K that I picked up as a spare to mess around with over the winter. I has a couple of dents in it. Normally I would drill a 1/8 hole and get out the dent puller and give it a pop, which I am sure would do the trick, then sand to bare metal , fill, sand, repeat...

However, before I drill a hole in the tank.... what should I use to fill the hole before applying body filler? JB Weld, epoxy, or?

I figured I'd ask BEFORE drilling the hole....

I did a search and came up empty..

Thoughts please.

Thanks-

Bob

Hockers Choppers · « **Reply #1 on:** January 30, 2009, 06:09:12 PM »

DON'T DRILL A HOLE!!!! just go to a body shop and have them use there stud gun (uni spotter). need to have dents ground to bare metal. they have a tool that weld a small metal stud that you attach a slide hammer to and pot the dent out. then twist the stud and it pop off. no hole.

Otto · « **Reply #2 on:** January 30, 2009, 06:29:21 PM »

Now THAT's Kool!

Thanks-

Bob

GammaFlat · « **Reply #3 on:** January 30, 2009, 08:14:38 PM »

Speaking NOT from experience but hearsay from folks that probably know....

You can pressurize the tank and gently tap around the dent with a rubber mallet. No more than 3 psi is what I hear. Bad things happen if you pressurize too much (blown seams, mis-shapen-ness). If that does not do it, you can also heat the "bent areas" in combination with the pressure and tapping which will wreck the paint but it sounds like you are painting anyway.

I'll be playing this game soon and will post my results

I'll also be trying my hand at painting... unless somebody on this forum has figured out what I already am thinking (it won't go well), has pity on me and wants to make a few bucks.

rbmgf7 · « **Reply #4 on:** January 30, 2009, 08:24:27 PM »

maybe i wasn't doing it correctly or technically didn't have the correct tools but i TIG'd filler rod to my dents and used a slide hammer to pull them. bad idea. an actual sliding (hammering) motion produces a conical shape then rips the sheet metal around the weld. i'm sure the prefered method is to pull with force, no jerking. i'm not a pro so probably was doing something wrong. just a heads up.

i just gave up pulling. if it was deep, i'd fill with JB to the point i'd finish with bondo

depending on the dent, pressurization may work. i've heard/read it only working on a large dent that's suspended in elastic deformation, which means, IF i could push from the inside, it would spring out with the slightest push. other praise the freezing water method. if you have a chest freezer, wouldn't hurt to give it a whorl

Hockers Choppers · « **Reply #5 on:** January 30, 2009, 08:43:06 PM »

Quote from: Hockers Choppers on January 30, 2009, 06:09:12 PM

DON'T DRILL A HOLE!!!! just go to a body shop and have them use there stud gun (uni spotter). need to have dents ground to bare metal. they have a tool that weld a small metal stud that you attach a slide hammer to and pot the dent out. then twist the stud and it pop off. no hole.

oh yeah, I have been a body man for 25 years. You can't put enouph air in these tanks to push out a dent. use a stud gun.

mcuozzo · « **Reply #6 on:** January 30, 2009, 09:07:38 PM »

You guys are talking about a dent puller like this right:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3223

I have one on order. It was on sale for $90 and I had a 20% off coupon. So it figures they were sold out!

So if the slide hammer is not the way to go (as mentioned above), what do I need to pull up on the stud? A pair of pliers and a tight grip

When done you just grind off the stud correct?

Sorry for the stupid questions, I'm new at this stuff and I'm trying to learn as much as I can!

Thanks.

Patrick · « **Reply #7 on:** January 30, 2009, 09:08:22 PM »

Don't use water and a freezer. Ice is stupid and doesn't know where you want it to push when it freezes. You probably won't agree with the spot it chooses.

HondanutRider · « **Reply #8 on:** January 31, 2009, 06:48:30 AM »

Another "cold shock" technique that I've heard works (never tried it) is to apply some dry ice (frozen CO2) to the dent. The extreme coldness shrinks the metal and causes the dent to pop back in shape. The problem would be to find some "dry ice".

ofreen · « **Reply #9 on:** January 31, 2009, 07:49:40 AM »

Depending on the dent, many times you can make a 'spoon' and push the dent out from the inside. I usually try this method first.

jeepurz · « **Reply #10 on:** January 31, 2009, 10:53:20 AM »

I made a spoon, used alum shaft and a chunkOpine, bent to shape as I inserted it to pry off tunnel, I couldnt believe it but it worked. Ive also heard (never done it) jam an inner tube in & inflate or freeze it by putting water in tank, the later would scare me .

mcuozzo · « **Reply #11 on:** January 31, 2009, 11:02:16 AM »

Actually it's pretty easy to get dry ice (for me at least).

Any Co2 fire extinguisher can create dry ice. Just spray it on the tank and it'll form.

A Co2 fire extinguisher is expensive, but if you know someone who has one (most car repair places\body shops), just borrow it and have it refilled for them. A 5lb'er should cost $15 more or less.

I work at an extinguisher company so I'm gonna try the dry ice on my tank before I use the studs.

I'll keep you posted, but it's gonna be a few weeks.

helgiman · « **Reply #12 on:** February 02, 2009, 11:09:55 AM »

I've had great results with Pops A Dent from Auto Zone for $20 bucks. As seen on TV!!!!!!!!!!!!!
Ed

KingCustomCycles.com · « **Reply #13 on:** February 02, 2009, 11:50:20 AM »

Pops-a-Dent and chunkOpine, wow, makes dry ice seem down right technical

I vote for the bodyshop guy with the welded stud puller and then a nice application of liquid Honda (bondo)

Hockers Choppers · « **Reply #14 on:** February 02, 2009, 01:35:12 PM »

6 pack of rolling rock will get a dent removed any day in my shop!! If you push one out with a rod or stick or what ever you can jam in the tank, be very carefull not to bend the filler neck when prying off of it. Dry ice will not work!!!!!!!!!!!!!! The hot glue puller will not work!!!!!!!!!!!!!!!unless it is a very gradual not sharp dent.

HondanutRider · « **Reply #15 on:** February 02, 2009, 05:07:25 PM »

Quote from: Hockers Choppers on February 02, 2009, 01:35:12 PM

Dry ice will not work!!!!!!!!!!!!!!

Why not?

mcuozzo · « **Reply #16 on:** February 02, 2009, 05:45:32 PM »

If my stupid dent puller comes in, I'm gonna do my own mythbusters. I'll give each method a try...

Hockers Choppers · « **Reply #17 on:** February 02, 2009, 06:24:13 PM »

Quote from: HondanutRider on February 02, 2009, 05:07:25 PM

Quote from: Hockers Choppers on February 02, 2009, 01:35:12 PM
Dry ice will not work!!!!!!!!!!!!!!
Why not?

maybe on a Honda CAR, but not a cb tank.EVER!!!!! Way to thick steel.

Don't beleive? go try.

Or maybe I could have told everyone here Oh yeah, it works great! go buy $30 worth of it. it will make your tank look mint!!!!!

Hockers Choppers · « **Reply #18 on:** February 02, 2009, 06:27:22 PM »

Quote from: mcuozzo on February 02, 2009, 05:45:32 PM

If my stupid dent puller comes in, I'm gonna do my own mythbusters. I'll give each method a try...

That would be cool!! don't use the other methods on a GOOD tank!

mcuozzo · « **Reply #19 on:** February 02, 2009, 07:17:36 PM »

No worries I have a dented and dinged $20 ebay tank for me to practice on before I work on the tank I'm really gonna use.

This tank is gonna go through hell as I learn to pull\bondo dents and then paint it. I'm gonna screw up big time I'm sure so I would feel bad if I was doing it on a good tank.

It actually looks like someone did exactly what you said. They tried to use a pry bar to push out some dents but in the process pushed the filler neck down. There's one mistake I'll avoid...

jeepurz · « **Reply #20 on:** February 02, 2009, 07:31:08 PM »

Quote from: mcuozzo on February 02, 2009, 07:17:36 PM

No worries I have a dented and dinged $20 ebay tank for me to practice on before I work on the tank I'm really gonna use.

This tank is gonna go through hell as I learn to pull\bondo dents and then paint it. I'm gonna screw up big time I'm sure so I would feel bad if I was doing it on a good tank.

It actually looks like someone did exactly what you said. They tried to use a pry bar to push out some dents but in the process pushed the filler neck down. There's one mistake I'll avoid...

yup , again bend the rod pry off of tunnel. Itll for sure depend on where the dent is and the ability to get to it.

R. Hykawy · « **Reply #21 on:** February 02, 2009, 08:33:45 PM »

hi, dry ice will work partially to pull out small gradual dents, it will not remove them completely. I tried it on a 400f tank that I had, the dent king( uses hot glue to attach pulling tabs) or what ever you want call it you have to be careful because if you pull to hard you can actually create a high spot. It to will not remove dents that have sharp creases/bends.Also with dry ice do not handle without gloves.

Patrick · « **Reply #22 on:** February 02, 2009, 09:19:53 PM »

We used dry ice in West Texas to help pull out dents after hailstorms bashed the hell out of our vehicles. It works on smaller dents, but didn't do much good on the big gnarly ones. You always used it AFTER you visited the insurance adjuster.

Otto · « **Reply #23 on:** February 03, 2009, 05:39:32 AM »

Update: I took the tank to a local body shop. They used their stud gun on it pulled the 2 small dents, spread some filler and sanded it ready for paint. Cost: $42.00.

I am thrilled with the results!

However, does anyone on this board paint work ? I need my tank and side covers painted for my 76- 550. Local guys don't like to do it?

Bob

GammaFlat · « **Reply #24 on:** February 03, 2009, 05:55:13 AM »

PM this guy - Caaveman82. He says he'll powdercoat. Haven't seen his work but sounds like a nice enough guy.

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Author Topic: Repair a dent in a gas tank (Read 8267 times)

helgiman

KingCustomCycles.com