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I posted this on ADVrider too, but I figured I'd post here too, since there are many knowledgeable people who may not visit ADVrider that much.

This is the gas tank from a 1981 Suzuki SP500 that I'm restoring:



Can you see the dents? A nice crease along the top, and a small dent on the left side.

I spoke to my favorite local body shop; they quoted me $450 to repair and paint it, which is quite a bit more than I'm willing to spend on a bike I plan to sell once it's done and running. For what I can get for it, $450 just isn't gonna cut it.

Any idea if there's a cheaper way to do this? Or maybe other shops I should talk to, back-yard types, etc? Part of me is tempted to use the plasma cutter and cut a rectangle out of the top (the creased part), then reach in, bang out the small dent, flatten the cut piece, then weld it back in. Naturally, after I totally wash the tank out to eliminate any explosion possibilities. :)

BUT... getting the signs of the welding smoothed out would also be a lot of work. So maybe that won't do either.

Ideas?

Rob
 

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Rob,

That "cut and weld" you speak of seems pretty intensive. Not sure I would go that way, but I am not as skilled as you seem to be.

I have seen some guys use compressed air (just an air compressor and blow gun) to take out some smaller ones. But then I have also seen some guys balloon the tank doing that too. If trying, use lower psi first to make sure you don't blow it up. Another concern with doing it this way is that if you have any weak spots, like rusted welds, it may blow out that seal and now leak.

I had a Honda Accord that a paintless dent removal company removed some dents in and that worked incredibly well, in my opinion, but that metal was a bit thinner than a m/c tank.

If already thinking of welding, couldn't you just use a spot weld on slide hammer and then grind the welds down, sand, and finish?

Also, check out "lock out kits". They have a blow up air bag in the kit that you wedge in door and pump up to hold door slightly open so you can get the rod through and hit the unlock button.

https://www.lockpickshop.com/AO65.html

but there may be cheaper ones.

Any way you can get in there with a adjustable crowbar with tape on end (to soften hard edge) and massage from inside?

Crowbars | Rentallaser. Uitlijnapparatuur voor het uitlijnen van uw machine

Mine is a Craftsman. Not too expensive and actually is pretty handy.

All I got for now.

jl
 

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With a welder and a clean, paint free tank I think I might tack weld a nail to the outside where the dent is and use a slide hammer to slap pull it out.

I have been considering the compressed air on a tank I recently bought from a member here. It has what I will call and indent, looks like a knee got between the tank and a hard place and just caved in one side but there is no crease or paint damage. I have also considered dropping a fire cracker in and see if the explosion might pop it back out. The paintless dent repair guy who did my car after a hail storm was a wizard but he won't touch a MC tank. He has to get in behind the dent to do his magic and a TW tank is near impossible to get inside of.

GaryL
 

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I've spot welded on stuff an pulled and I've used screws and welded up the hole. I like the former better. Fill tank with water or fumes from a modern
car (low emissions) when welding or you might get a much bigger tank. Done that too. Variable results. I've also been known to scuff up real well and
apply fiber bondo. Truthfully, the last had the best looking result for the least effort. Between rust, dents and paint, I love plastic tanks.
 
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I was talking with Darrell (TWForum member WS23) and he has had some good success at removing dents like yours using one of these hot glue type dent puller kits from Harbor Freight.

They are pretty cheap so it might be worth a try.

(If it doesn't work, the hot glue gun might come in handy for repairing plastics, etc. ;))

Crossbar Dent Repair Kit

 

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I was talking with Darrell (TWForum member WS23) and he has had some good success at removing dents like yours using one of these hot glue type dent puller kits from Harbor Freight.

They are pretty cheap so it might be worth a try.

(If it doesn't work, the hot glue gun might come in handy for repairing plastics, etc. ;))

Crossbar Dent Repair Kit
I have seen his work and it looks OK. However it is slow going requiring several attempts per dent, and he broke several of the dent pullers. No problem -- return them to HF for a new one and he was back in business.
 

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The problem with pulling from one point is that it might just make another dent. Body repair is typically done from the perimeter to the center. So I am suggesting drilling a small hole in the bottom and inserting a slightly rounded rod to press or tap with-- round and round, and center will take care of itself. The side dents can be accessed by bending the rod into an L shape and tapping the side.
 

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Also, as I think about it, I would probably to a combination of things, such as putting a rod in a vise and putting the tank over it, and tapping on the creases from above with a body or other light hammer. I enjoy this, as its a good way to ponder life's mysteries, but it takes a certain attitude. For profit I would use Bondo.
 

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fill with water , and freeze it. Check on it often. As the ice expands it will push the dents before deforming the tank.
 

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Fill with water , and freeze it. Check on it often. As the ice expands it will push the dents before deforming the tank.
 

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Fill with water , and freeze it. Check on it often. As the ice expands it will push the dents before deforming the tank.
This did not work for me! I tried it, kept the tank in the deep freeze for 2 days and constantly watched it. Frozen solid but no expansion of the ice so I gave up.

My tank had a good cave in but with absolutely no crease in the dent, looked like a knee pushed it in and there was no scratch or other damage to the paint or metal at all, just a cave in.

After trying all these methods, suction dent pullers, freezing, trying to get inside to pop it out I finally plugged up the removed petcock hole and fashioned a rubber plug for the fill cap hole. I drilled a small hole in the plug and used compressed air. This did worry me because I could have blown the seams or even blown the tank right up. Surprisingly, I filled the tank with just 25 PSI and the dent popped right out so you would never even know it was dented. Keep in mind this method is dangerous and will never remove creased dents but it will very easily pop out cave ins like the one I had.

GaryL
 

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Check out a company called Dent Doctor. They have special tools that take out small dents
 

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Check out a company called Dent Doctor. They have special tools that take out small dents
My nephew runs a rather large auto body shop here and has a guy who specializes in paint-less dent repairs. He looked at my tank and refused to even touch it because the metal of our tanks are too heavy for his art work and there is no way to get inside of the tanks without cutting or drilling. I had to be my own DIY dent doctor on this repair and I got my PHd.

GaryL
 

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I just heard from TW Brian and the compressed air procedure was a complete fail for him and may have ruined his tank. Be very careful if you attempt this fix. Hope Brian will come in and show pics of what his results are. I got very lucky but there is no guarantee this will work for anyone else.

GaryL
 

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It sure seemed like a good idea!

Here's an update on my failed dent removal attempt.

During some correspondence about the venting system on California tanks, GaryL shared this:

"Just for your future info. The tank I got from Joe had a good size dent in the side that looked like a knee hit it pretty hard and caved it in. There was no creases or scratches or even a chip, just a cave in. I tried all the tricks, suction cup dent pullers and I even filled it with water and left it in the freezer for 2 days hoping the ice would expand and pop it out. There was no way to get at it from the cap. Nothing worked! Finally as a last resort I fashioned a big rubber stopper for the cap hole and plugged the petcock hole and filled it with air from my air compressor. Slick as shit the dent popped right out at 25 PSI and you would never know it was ever dented."

So I thought - Cool, I have a small knee bruise on the left side of my tank so I am going to give this a try!

After a quick trip to my local Cycle Gear store for a discarded inner tube, and then a cruise through several aisles at the Home Depot, I made up what I thought was a pretty slick little tool using a threaded valve stem and a 4" stainless steel cleanout cover.

100_5299.JPG

Then I cut out a sealing disc from a section of inner tube and installed it on the bottom of the cover.

100_5302.JPG

Eager to try this out, I bled my little pancake air compressor tank down to about 35 psi and then tried pressurizing the silver tank shown below. I didn't have a good seal and lost most of the air from leaking out around the filler neck. I applied a thin layer of grease to the underside of the sealing disc, refilled the compressor tank and tried again. This time I did a better job of holding the tool down on the filler neck. The dent in the side of the tank remained unchanged, however I noticed that one of the rubber pucks that secure the front of the tank to the frame had fallen to the ground. WTF!

I pulled the tank off the bike and the tunnel look noticeably splayed. Comparing it to the white tank, the silver tank was now almost 1" wider at the area where the rubber pucks go in. It was now spread too wide apart to engage both pucks on the frame.

100_5292.JPG

So now I figured that I am really screwed. I went to bed last night thinking that I had two options. A) was to to pull the trigger and order one of those 2.7 gallon Clarke tanks that I have been considering, or B ) see if I can figure out a way to squeeze the sides of the silver tank back together without crushing the sides in.

I really didn't like either of these options, so this morning I decided to go with plan C). After cruising through the Home Depot again, I found a couple of custom rubber puck extenders.

100_5304.JPG

After a little grinding to get the right length, I popped these on and remounted the tank. All is well now, and my new wide-body TW is back in business.

Of course I still have that small dent in the side of my tank, but now I can't wait until my next fill-up to see how much this new, expanded FatBoy tank holds! I'll bet it is close to 3 gallons :D!

Like I said at the top, it sure seemed like a good idea . . . . . . .

Brian

(p.s. let me know if you want to try my inflator tool on your dented tank. I don't think that I will be using it again ;))
 

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I've removed lots of dent using hot glue guns, glue just about anything to it them pull dent out. Use denatured alcohol to remove the glue spot, peels right off. I use anything from plastic to wood scraps glue to spots and sometimes it works, just depends on where and how big the dent is.
 

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here's two pics of gary's tank before he attempted the "inflation dent removal" technique.

IMG_3485.jpg IMG_3488.jpg
 

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Do you think a screwclamp on the ridges at the front bottom of the tank might pull that back into shape?
screwclamp.jpg
I'd position it just about where the 3 and 9 are on the tape, and then probably really screw things up :)
 

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