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Using Heat and Compressed Air to Remove Dent from Gas Tank

11/23/2008 12:33 AM

I have two very expensive fuel tanks from motorcycles that are dented.

Both have been sitting around for a long time open to the air and are free from any aroma of fuel.

Both tanks pressurize well. They both will hold 35 psi indefinitely.

I am entertaining filling the tank with water partially, tilting the tank so the dented area is the highest part of the tank, applying compressed and pressurize the tank with 100 to 125 psi.

Then slowly heating the dented area with a torch until the compressed air within, expands the dent back to the original shape.

I know it's been done but I am concerned about safety. One tank has not seen fuel in six years. The other hasn't seen fuel in 9 years.

Can anyone see any flaws in the procedure or think of an alternative method?

Thanks

L.J.

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#1

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 12:48 AM

I've heard of people doing this also but I don't know how successful it is. I've got a tank from an older 1100 Suzuki that has a dent that I had actually thought about trying the same thing on. I ended up picking one up off ebay years back.

I was more concerned with the tank distorting or rupturing at a seam than anything.

Be curious to know how it turns out though... I still have that dented tank out in the rafters.

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#6
In reply to #1

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 10:42 AM

Switchman wrote: "Speed doesn't kill. Sudden stops, brick walls, and old women in Buick's do."

The small tank was on my 600cc VLX, V-twin I had to lay the bike down at 35 mph to avoid hitting the 80 year old lady (no kiddin!) who ran the stop sign. When the cop wrote 2 tickets (for negligence and failure to stop) I thought she was going to have a heart attack!

The dent on the big tank (my 1800cc VTX, V-twin) happened while banked steeply in an exit coming off an expressway. A large dog or deer jumped in front of me. I forgot you don't use brakes when banked. The animal survived and I managed to drive home.

L.J.

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#2

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 1:20 AM

There were some comments on CR4 about pressure testing a tank. I know that your pressures are much lower, but still the stored energy of compressed air is a worry to me. From your posts, I believe you are smart enough to think your self through this. The safest way I know of to pressurize something is your hand pumped grease gun.

If the cap is on, and you fill it up with water, then adapt your fuel outlet to 1/8" pipe thread. You can then fit a grease fitting to that. Just pump the grease gun till the pressure in the tank causes the dent to be forced out. If the fuel filler cap starts to leak, you may be able to use a rubber freeze out plug as a substitute. It might require some tapping with a plastic hammer to help coax the dent out. With luck it will not need painting. The volume of grease should only be equal to the volume of the dent. Should be a cheap SAFE way to repair it. Good luck.

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#5
In reply to #2

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 10:28 AM

Hi Bob!

Thank you for nice comment.

I propose to first try a hand held torch running MAPP gas initially, not my acetylene rig, simply to keep the temps down. I only want to heat the metal to where the pressure forces it out.

Then idea of using water was only to inhibit the combustion of any residual volatiles. Probably not needed but it appears the prudent thing to do. Besides which the extra weight, about 14 pounds on the smaller tank, will help stabilize the tank.

The drawback to the water is that it will most assured draw off heat, thus requiring more heat than if dry inside. I'd hoped to keep this procedure simple and not have to manifold a pressure gauge into the preparations. However, if there is risk of elevated pressures from steam, I may have to.

The main concern was preventing a violent rupture of the tank.

About 30 years ago I knew a man who ran a radiator repair shop and who worked at repairing auto gas tanks. One day the shop closed and he was no where to be seen.

Someone volunteered that he'd been seriously injured when gas fumes in the tank blew up while he was welding on a new filler neck.

That tank had been fully immersed in some kind of leaching fluid for two days, prior to the attempt, a process he had used successfully for many years without incident.

Although I never saw him again, those who did say he looked like he'd fallen into a huge sewing machine.

It's my memory of that man and that explosion that prompts this request for comentary from others.

We'll see.

Thanks

L.J.

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#8
In reply to #5

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 3:50 PM

There is a company in So.Fla that is called Dent Magician. They seem to be franchised, so they could be anywhere. They are specialists at removing dents from sheet metal without damaging the paint, or surrounding metal. You might find one near you that could help.

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#21
In reply to #5

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 8:23 AM

Just how well do you like being on the top side of the grass? Insurance paid up? Will made out? Pressurizing a non-pressure rated container of any type is dangerous, and besides, if the dent has a crease,forgetaboutit.I suggest a dent puller to remove most of the dent, then fill in with solder. That's right,lead plumbing solder. Bondo will not hold under gasoline very long. A very high wattage tinsmith soldering iron is recommended: no flame.The torch- heated type of tinsmith soldering iron will also work.I have done it with butane, but I do not recommend it to the novice. If soldering,flush tank with detergent and water thoroughly first,and fill all but the small area around your dented work area with water.This will keep the remainder of the tank cool.Clean the area down to bare metal,using coarse grit sandpaper.The little scratches create a lot of bonding surface area, and use RUBY FLUID,or other tin flux to clean and prime the area.Apply a thin tinning coat of solder first,to make sure you have a good bond with the surface.If it does not adhere to any spot,clean and flux again.Once you have a clean,shiny,silver surface of solder,then go back and build up above surrounding surface.Any solder that looks like a round or half round drop of water standing on the surface is not bonded.More heat is required.Careful application of heat is required to build up without melting previous layers and dripping into tank from dent-puller holes. After this, sand,prime, and paint.Properly done, no leaks, and invisible. Be careful. Know safety,no pain. No safety,know pain. As a card shark once told me:If you can't afford to lose,don't gamble. HTRN

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#3

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 1:25 AM

Hi LJ,

One approach you may wish to try first is to work the dent out from the inside using a length of bent pipe with a rubber or soft plastic tip at one end. A bicycle handlebar with the hand grip in place works well provided it can be worked into the tank through the gas cap hole around to the dent. Or you can ask a shop equipped with a pipe bender to bend a length of medium-to-heavy-gauge pipe to the right shape, and then affix the business end with a rubber cane or walker tip.

If the dent is creased, you'll probably not have complete success using this or any other method and you may find it necessary to remove and replace the section which has the crease. This is the worst-case scenario.

Motorcycle fuel tanks are not pressure vessels, of course, and so you're entailing a certain amount of risk in pressurizing the tank. Partially filling the tank with water is a wise approach because it minimizes the stored energy represented by the pressurized air. Should the tank blow, you would be releasing less energy than without the water.

One thing to keep in mind if you try this approach is that, given enough pressure, the tank can deform to the point where the attachment points no longer accommodate the frame. To minimize this effect you may wish to leave the tank attached to the frame (provided you have the frame! You didn't say). Doing so will reduce the stress on the tank proper and distribute some of it through the frame whilst allowing the pressure to do its work on the dent. Of course, too much pressure can balloon the tank and ruin it. You'll want to pressurize it slowly whilst keeping a close eye on what's happening.

Assuming you pressurize, do your tank 'surgery' from behind some form of heavy shield that will protect you should the tank blow. You'll have a hose attached to the tank and won't really need to access it while pressurizing. You may wish to place the tank in a heavy wooden box, for example, leaving an opening large enough to view the action from the dent-side by means of a mirror. Do not observe the tank directly, not even through a small opening, not even while wearing safety glasses. Safety glasses are not suitable for the kind of shrapnel that could result if the tank blows. Put one or more shop lights in the box. Position one of them so that the dent shows up with as much contrast as possible -- makes it easier to see minor changes in the dent shape as the tank pressurizes.

If you can't find a suitable box, you can build one yourself. Build it large enough to accommodate the frame and construct the box using 5/8" or (better yet) 3/4" plywood. Use 2x4 gussets and fasten everything with heavy drywall screws or lag bolts. Don't use nails, as they can weaken the wood.

Should the tank blow, you may be out your mirror (and have to explain the loss to your wife when she comes looking for it), but EMS need not be notified. We'd like to see you back here -- with pix of the carnage, hopefully!

Once you have successfully popped the dents, you can make the box into a nice dog house for your French poodle, Phydeaux. Your wife may require this of you in lieu of a new mirror.

Kindest regards,

TV

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#4

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 5:24 AM

Laughing Jaguar. You may need to change your name if you attempt this method of dent removel. This amount of pressure far exceeds anything this vessel is designed to handle. A vessel of this volume under this much pressure is capable of launching the cap at a velocity great enough to kill. There is no need to exspose yourself or others to something this powerfull and unstabile. Use the safe method of filling the tank with an inert gas and drilling holes in the under side of the tank and use a rod to access and push out the dent. The end of the rod can be bent over or shaped to correspond to the surface of the tank. Afterwards fill with an inert gas and weld up the holes. Another method would be filling the tank with an inert gas and use a dent puller that utilizes a stud welded in the middle of the dent for a puller to be attached. Put safety above all else. J.Conway

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#7

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 1:09 PM

You need to determine a couple of things. First is real cost to replace your tank. A new tank from the Honda dealer is going to be very expensive, like you said. But there are a lot of bike breakers out there and of course ebay. I did a quick search and found a few ranging from 150bucks upwards of 750 for a new one.

http://motors.shop.ebay.com/items/Parts-Accessories_Motorcycle-Parts-Accessories__W0QQ_nkwZvtxQ201800Q20gasQ20tankQQ_fromfsbZQQ_trksidZm270Q2el1313QQMake247a0eZHonda42abae4

You also need to determine whether or not it is feasible for you to get a good clean home repair / paint that you can be proud of. If the damaged area is really pinched or creased then the method you're thinking about is not going to help. The dent will need to be pulled and edges knocked in then bondo applied. If you really enjoy and are very skilled with body repair then go for it. But I have seen many examples where attempted repairs really should have gone out for repair. I have also seen people spend 50hours doing a repair and then do a $20 rattle can paint job.

I don't know your location but if in the US take a look at EmpireGP... I know a couple of people that have had repairs done by them. http://www.empiregp.com/ . And there are many more shops like this.

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#9
In reply to #7

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 5:50 PM

That Link to Empire GP is appreciated.

I'll take some pics of both tank damages and send them for a quote.

Thanks Switchman!

L.J.

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#10

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 11:16 PM

If you decide to try the pressurized dent removal, provide a method of pressure relief such as a regulator valve. The temperatures required for the metal to become maliable will most likely cause the pressure in the tank rise fairly quick.

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#11

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 11:16 PM

Another option may be to check out 'paint-less dent removal' in your local phone book. I used to work at a car dealership, and we had a company with a mobile unit (i.e. a pickup truck with tools in the back) come in to do all our work on site. You'd be surprised at the tight spaces they can get in and out of without damaging any other parts. Another bonus, I never saw a bill for more than about $50 from anything that they could do. As mentioned before, so long as the dent is not creased you're likely that it will come out totally, and probably will not damage paint.

Note also that if you can't find a specialist in paint-less dent removal, swing by your local car dealership and ask them who does their body work. Most places don't do it in house, but they have someone they recommend.

Best of luck!

-MechMatt

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#12
In reply to #11

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 11:42 PM

Hi MechMatt!

I don' have to go that far to find such talent: the guy in the hanger next to me owns such a business.

In this weather, I doubt he'll be doing much flying but I'll tack a note on his door anyway.

Thanks for the suggestion. I'd completely overlooked this.

L.J.

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#13

Re: Using heat and compressed air to remove dent from gas tank.

11/23/2008 11:47 PM

I think that is outright dangerous. If you try that I hope you will be around to tell us.

Especially applying heat after pressurizing it with air. The air expands and pressure builds up more. At some point there will be a load bang. If you are lucky it won't kill you, but I would not bet on it.

You can only use water that is non-compressible without any air inside. If the tank bursts, there is no explosion only a leak occurs that can be brazed closed again. A suction cap may help, or trying it from the inside as already suggested.

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#14

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 12:40 AM

I had dented racing car exhaust pipes repaired in exactly this way, (without using water) by a braver man than I. Let me suggest that you pressurize the tank with a non-oxygen gas like CO2 that will not effect combustion of any residual hydrocarbons.

Good luck!

RC

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#15

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 12:55 AM

If you will completely fill your tank with water or oil and pressurize in a controlled way it will more than likely push the dent out of your tank unless there is a sharp bend in it. If there is a kink in it, tap the bend with a hammer and work it out. With the hydraulic pressure inside it will act like an anvil that you can hammer against since it is non-compressive.

Air is real dangerous because it's so compressive but using the hydraulic method is much safer in that it isn't so explosive if it should rip your tank apart. A hand pump is the best way to do it because of the control you have and should the tank come apart there is only a small squirt of oil and normally not enough to cause any damage.

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#16

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 1:15 AM

You are proposing a hydroforming method when you pump water into the sealed tank. This usually forces the material against a mold. Simply pressurizing the tank may pop the dent, or it may find a weaker area - like a seam - that will give away first. A dent, especially an inverted dome shape, can be quite strong. I would suggest some support for the tank walls. I'm sure that an actual mold would not be economical here, but burying the tank in sand, with a void created for the dent area to expand into would increase your chances of success. If the tank did rupture in the process, it would be less dangerous under sand than in free air.

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#17

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 1:20 AM

Fuel residue can be a problem for a long time. you could vaporize a tarry residue and produce flammable gas.

The problem with dents is that you have usually stretched the material and now it has to go somewhere but that somewhere usually won't fit in the original shape.

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#18

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 1:39 AM

I am going to explore an alternative.

Instead of the risk associated with heat, pressure, etc., I may simply remove the paint from the damaged area, fill in the dents and, after sanding and priming it, coat both tanks with mold release.

Then pull a fiberglass plug from each tank to use as a mold for fiberglass replicas.

I've been making composite parts both with and without autoclaves, bagged and not, for almost 30 years.

Why not?

Thanks for all the comments and supports

Have a great holiday.

L.J.

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#19

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 4:27 AM

I am entertaining filling the tank with water partially,

Please explain, are you going to fill the tank or only partially fill the tank? . I would assume the latter.

The LEL for petrol is 1,4% and the UEL is 5,9%........the tank could still be a problem on heating with compressed air, the rough surface of the tank could still hold minute amounts of petrol and vapours could be liberated on heating. May I suggest that you partially fill the tank with water and pressurise with an inert gas, e.g. Nitrogen. Always better to be safe than sorry.

Although this is a much larger tank, the same problems can exist.

This method of removing the dent may well work if there are no sharp edges on any on the dents.

Do NOT forget the inert gas!!!!

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#20

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 6:07 AM

I am have a tank with the same problem. Been thinking about using air pressure and propane with oxygen instead of actelene. Propane heats slower and more controlable.

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#22

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 8:46 AM

I am not recommending this, but if I were to try to remove a dent here's how I'd do it.

Bury the tank in sand, with the dent on top and uncovered. Fit a hose to the cap with a quick-release valve. Fill the tank with water, drop in some dry ice, and cap it. Move to a safe distance (preferably behind a shield) and watch for the dent to pop out, then open the quick-release.

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#23

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 9:09 AM

DO NOT DO IT!

When I began reading that you pressurized the tank to 35 psi with air I was a little concerned. But when you suggested going up to 100 psi I became VERY concerned. It is more dangerous than you think. I've worked with pressure testing many times and I have seen some nasty results. Even as low as 5 psi in large volume vessels.

Completely filling the tank with fluid and purging any air from your pressure system is an option. But your heating idea will probably not work with that volume of fluid cooling the metal. And you will (as mentioned) probably pop a seam before the dent comes out.

Also..... I've repaired a few motorcycle tanks. I worked with a guy that did tins for Harleys and other bikes. The metal of these tanks is typically very thin. Thinner than typical body metal. Applying heat to the thin metal would be difficult without popping it or deforming it out too much. Once it gets hot enough to move what's to stop it?

Even using the proper tools to repair a tank it is a little difficult to not create a hole in the tank. The last tank I did I used a stud welder. It fastens a puller stud to the dent like a spot welder. And even with this tool you have to be very careful to not burn through or pull out the thin metal.

I would try one of those suction type pullers first. It should work well on the thin metal. Get it as close as you can and then glaze over the area to blend it in. You will probably find that blending it so it looks good will be a bigger job than pulling the dent.

....just my 2 cents

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#31
In reply to #23

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 10:55 PM

7to 11 lbs of pressure is what I will try, if I ever get around to it. Just to see if it would work. The old tanks will have good quality steel unlike the brittle new tanks.

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#24

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 9:10 AM

Tanker trucks are repaired al the time by pressurizing the tank with water. The tech told me there is no danger of a tank explosion at all. the logic behind this is hydraulic action. However, you MUST BE SURE that there are NO AIR BUBBLES in any of the pieces of the system. Eg. the tank, hose and pump. Good luck and be Safe.

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#25

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 9:23 AM

maybe you might want to consider not putting pressure on the tank or heating it with a torch. as much as i would not use a damaged tank when my crotch will be over top of it that may not be of concern to you, but then again thats your choice.that related you might want to consider using the same type of epoxy patch material that is used to repair pin hole leaks in car ant truck gas tanks, this requires the work to be done by a very experienced and heavily insured company, it

repair or resealing a motorcycle gas tank is NOT something to do in the backyard.

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#26

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 11:34 AM

Is it much of a dent? I've used a tool called Ding King on the car to pull out shallow dents but it won't work on one with a real crease round it. You can buy it in lots of places.

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#28
In reply to #26

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 3:33 PM

There is a metal shrinking trick used by auto body guys back in the day where they heat a very small area to cherry red with a torch and cool it rapidly with a sopping wet rag. However the thickness of steel used in body panels is probably thinner than that used in an M/C gas tank. So it may not work so well in your situation. It is also somewhat of an art and you can have a bigger mess than with which you started.

I wouldn't pressurize the tank as you suggest. My guess is that you would have to get the dent cherry red or close to it before the steel would deform from the pressure against it. Heating a small area to that point you're more likely to just have it blow a hole. Flying hot shards of metal does not sound fun.

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#33
In reply to #28

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 4:22 AM

I've seen this demonstrated on a car body dent but using an aerosol hair spray can for cooling. Much less heat was used & it did not damage the paintwork but, obviously, the steel is pretty thin on a car body.

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#37
In reply to #33

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 12:03 PM

an aerosol har spray can? sounds interesting, how was that trick done, by whom?

'da ber

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#39
In reply to #37

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 12:08 PM

My dad used to use dry ice applied to the center of hailstone dents after the vehicle had sat in the hot Texas summer sun to pop them out, I presume the freeze spray used to troubleshoot thermal problems with PC boards could work similarly.

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#41
In reply to #37

Re: Using heat and compressed air to remove dent from gas tank.

11/26/2008 4:19 AM

This video shows how it works, different aerosol to the one I remember but same technique. I think it relies on gently expanding the whole area then cooling just the dent which pops out as it shrinks.

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#42
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Re: Using heat and compressed air to remove dent from gas tank.

11/26/2008 8:55 AM

HA HA HA... very cool!!!

I'm going to go kick my car right now so I can try it.

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#43
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Re: Using heat and compressed air to remove dent from gas tank.

11/26/2008 9:44 AM

Don't forget to video it so we can all see.

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#27

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 2:24 PM

If your dent is not creased, you can try the suction cup method. Don't try it with a toy. Use a real suction cup designed for this use. To increase the effectiveness, fit the tank to something stationary, and use oil, or grease to increase the holding power of the suction cup. The comments I am reading are implying a thin metal tank. The heating might cause the metal to expand, making it harder to pop back out.

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#29

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 4:38 PM

If the suction cup method noted above does not work, there is a more aggressive bit of kit you might look into. There are stud welders that body men use to temporarily weld a 2 or 3mm stud to the panel and then they use a sliding hammer to pull the dent. Then they use an angle grinder to grind the stud off. I know harbor freight carries them, other places may as well. I've also heard of devices that use a special high strength hot melt glue to glue studs to the panel that will release when re-heated, although I've never seen one.

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#30

Re: Using heat and compressed air to remove dent from gas tank.

11/24/2008 8:14 PM

Laughing Jaquar: pay attention to this response, cause there may be a test, and if you get it wrong and use open flame you just may fail the test, loose your hearing and possibly your eye site.

I have tested under ground water mains that I supervised the construction thereof. Because we fear explosion as the result of high pressure, we totally fill the water main with water. We place bleeders where they are needed to relieve any possibility of trapped air. We often test a mile or more of this kind of system at one time. The pipe diameter may be any where from 12" to 24 " and is constructed generally of c-900 poly pipe. The blue stuff!

After filling the pipe and bleeding off any possible trapped air we use a stand pipe with a fitting on it that will permit us to pressurize the system with 150 psi of atmosphere.

If the system leaks down more than 2 lbs of pressure in 24 hrs, we must find the leak and repair it. The reason that we saturate the system before applying the pressure is just plain common sense. If we get a catastropic failure it will not amount to anything more than a PSSST and the little bit of air is no longer meaningful, and we don't blow up anything.

Therefore with your caved in tank I suggest that you invert the tank and where the fuel pet cock is, install a fitting that will permit you to apply a fixed amount of air pressure and increase it gently by adjusting the pressure controller on your air compressor. Then turn the tank upright and fill it with water and put the unvented cap on it. Turn it back over, place it into an empty trash can and slowly apply the air pressure. One of three things will happen. Likely the dent will pop out, or the cap will leak, or a seam will fail., but you are not likely to be harmed!

If the dent is in an area that you could get a small plumbers expansion blatter into you might try just using that and your compressor to accomplish the same thing , but somehow I don't think you are that lucky.

TMF

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#40
In reply to #30

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 12:11 PM

apparently you havbe seen first hand what happens to a pressure cooker when it is not allowed to vent properly. from what i read sent the enquire's original and subsequent posts it seems to me he is either looking for ways to come up with a commerically viable way of repairing motorcycle fuel tanks something along the lines of the old gas tank king franchise, or he/she does not intend to think about what can be done to come up with ways to solve his /her problems or more likely has a death wish he /she wants someone to bear the bear the problems attached to the granting of.

'da ber

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#32

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 3:39 AM

The traditional method of dent removal in a steel petrol tank- purge vapours, fill with inert gas or water, invert so bottom upright, use air chisel to open enough to gain access to dent- use hammer & dolly to get as perfect as possible- weld up opening using oxy-acet or mig- test for weld soundness with comp air & water(or petrol)- use body filler to get surface perfect prior to rubbing down/painting.

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#34

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 4:22 AM

I would try filling the tanks with water, then stick 'em in the freezer. The ice will expand and there's a good chance you will get a satisfactory result, depending on the dents and their position on the tank. Keep a close eye on 'em though, as you run the risk of splitting seams...

Cheers

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#35

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 8:23 AM

After all of this input I can't wait to hear how it works out.........

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#36
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Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 9:37 AM

gdevine wrote: "After all of this input I can't wait to hear how it works out........."

After all of this input I may take up gardening!

L.J.

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#38
In reply to #36

Re: Using heat and compressed air to remove dent from gas tank.

11/25/2008 12:05 PM

Ah but if you aren't careful you might be pushing up daisies from the wrong side of the dirt....

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#44

Re: Using Heat and Compressed Air to Remove Dent from Gas Tank

11/27/2008 10:28 AM

I did exactly this on a DR400 tank may years ago, when I applied the compressed air the tank tried to flatten out from it's saddle shape and when I pulled it back together I got a crack in the aluminium. I ran a car exhaust through the tank for a while and gave it to a welder who fixed it.

The exhaust fumes did the trick cleaning and scavenging but I wonder if catalytic converters would make any difference to the effect?

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#45
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Re: Using Heat and Compressed Air to Remove Dent from Gas Tank

11/28/2008 8:56 AM

The exhaust fumes did the trick cleaning and scavenging but I wonder if catalytic converters would make any difference to the effect?

Not a problem, in fact better, all the catalytic converter does is reduce the toxicity of motor vehicle emissions..........especially carbon monoxide.......and to meet EPA requirements, including prevention of emissions of unburnt fuel. The gasses are inert and will not support combustion.

NOTE:- By using exhaust gases without a catalytic converter there would be a risk of explosion. i.e. Carbon monoxide and unburnt fuel are both highly flammable.

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#46

Re: Using Heat and Compressed Air to Remove Dent from Gas Tank

11/30/2008 7:02 PM

freeze it

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