I hate myself... Grrr...

[philosopheriam]

So, I'm on the way home last night, and I had my first OMG WTF HOLY S*** moment:

I'm was making a right hand turn and it was difficult to see (in retrospect, I should have been going slower, knowing that it was tough to see) and as I was making the turn, I saw the curb, and it was way closer than I thought....

I went right over the curb into the grassy median - didn't drop the bike, no damage to the fork/wheel, etc.

However, when I went to take the bike out of the median, I hit my header on the curb and put a small dent in it :-(

Not a huge dent, but I definitely know its there.... Not very deep, about 3/16 of an inch, no larger than a quarter.

So, now I'm left with having to remove the dent - air pressure and a torch, spot welder/dent puller, etc. Got any ideas, folks?

Thanks

 

[(none)]

ummm or you could just leave the dent... and ride the thing

 

[CCHOUSEKY]

Or buy a belly pan...lol. I only contributed this comment because I literally know nothing about removing a dent like that, so please take it for what it's worth...which is not much. :thumbup:

 

[FZ1inNH]

Start the bike on the center stand and rev it to about 8k until the pipe it hot. Then take one of the cans of compressed air like to blow dust out of a computer? Tip it upside down and shoot the dent with it in a circular motion to rapidly cool it. This can/might pop the dent right out. I've seen this done on car body panels.

 

[YamahaMAXdRPMs]

If i were you, i would either A. Get a belly pan and cover it, or B. buy new headers. or C. live with it.

Not that the air pressure thing WOULDNT work, but if if it were me i wouldnt try it. It may work on body panels, but not sure a circular pipe would be the same. and i wouldnt want to take the chance of cracking it... Ever see someone pour water on a hot car engine? Not pretty. Not only that, as hot as those headers are, to hit it with cold air right after may be asking for trouble. Especially since those air cans have all kinds of chemicals in them. I dunno, it may work perfectly, but i would live with it, or cover it. :thumbup:

 

[YamahaMAXdRPMs]

here is another "cover" option

 

[FZ1inNH]

Not only that, as hot as those headers are, to hit it with cold air right after may be asking for trouble. Especially since those air cans have all kinds of chemicals in them. I dunno, it may work perfectly, but i would live with it, or cover it. :thumbup:

Ever blistered the bike on the road or the track? Get the header pipes nice and cherry? Then you hit a puddle you cannot avoid? Ever done a track day in the rain and still held on at 10K+ RPMs?

A shot of cold on the hot header isn't going to harm them, trust me. :rockon:

 

[YamahaMAXdRPMs]

Ever blistered the bike on the road or the track? Get the header pipes nice and cherry? Then you hit a puddle you cannot avoid? Ever done a track day in the rain and still held on at 10K+ RPMs?

A shot of cold on the hot header isn't going to harm them, trust me. :rockon:

Ya, but thats kinda splash and go... not spraying "freezing liquid" at it... lol... i dunno tho, im no scientist, hehe, just lookin out :thumbup:

 

[philosopheriam]

Well, I've been doing some research, and I might try this:

I'm going to plug both ends of the header tube in question with rubber plugs, however, one end will have a nipple through the plug. THis will allow me to hook up my air compressor and pressurize the tube to around 75psi...

Then, I'll take my acetylene torch (gently, gently) with a fine tip and heat the dent in question - hopefully, it will pop out.

I'm not worried about discoloration, as I am eventually going to have the headers ceramic coated.

I'll let you know how it works...!

 

[philosopheriam]

UPDATE: My plan worked like a charm! Yay!!!

I removed the header from the bike and unscrewed the oxygen sensor. With the header on my bench, I cut some 2 1/2 x 3 1/2 pieces of 3/4" plywood and drilled them to match the header flanges. Using 1/4-20 carriage bolts and hex nuts, I snugged the plywood against the header inlets - for a seal, I sandwiched rubber plumbing washers between the the plybood and the tube. To ensure a seal, I used a bit of RTV on the washers, too...

To plug the outlet, I took two 1 5/8 sink stoppers, cut the pull tabs off the tops, drillled the centers with a 3/8" bit, and then sandwiched the two stoppers between some 1 1/2 fender washers. Then, I put a 4" hex bolt through the center with some nuts on either side. I insterted the bolt/stopper assembly into the outlet and tightened the hex nut, effectively smushing the stoppers together causing them to seal against the interior of the exhaust outlet.

To pressurize the header, I bought an oil drain plug w/gasket with M18-1.50 threads (same as the O2 sensor, $3 from CarQuest) and drilled the center. Then, I threaded the plug with a 1/8-27 NPT tap. I installed a male 1/8 NPT to male 1/4 NPT transition in the drain plug, and then I threaded a female air nipple onto the transition. Bingo - I could now attach my air compressor.

To start, I pressured the pipe to 35psi, using the regulator on my compressor as a guide. Because I'm a mechanic, I have an oxyacetylene rig in my garage, thus, I used this to heat the pipe - I adjusted the flame on the acetylene rich side to reduce the chance of overheating the pipe (I was usine a cutting tip, not a heating tip).

After heating the area surrounding the dent to a dull red, I didn't see any movement. So, I upped my compressor to 45 psi and tried again. The dent moved a bit, but not much. To make a long story short, I had to up the pressure to around 90psi to get the dent to completely pop out. Becuase our pipes are stainless, and my dent was in the radius of a bend, more pressure was required. If I was working on mild steel, much less pressure would have been needed.

Overall, the dent in almost completely gone - all thats left is a barely noticeable indentation thats less than 1/32" deep. I doubted that I could make any more progress without damaging the pipe, so I quit while I was ahead. When the pipe cooled, I hit it with a some 150 grit sandpaper to remove the surface discoloration. Later tonight, I'll hit it with some 1500 grit paper followed by a full steel wool polish of the entire header.

Conclusions and Delusions:
1. Heat the pipe gradually - move around the dent slowly heating it to the center. DON'T KEEP THE TORCH IN ONE SPOT FOR TOO LONG!
2. If you don't have an oxyacetylene rig, a MAPP gas torch can be used - propane isn't hot enough.
3. The ends of the header must be plugged securely - just 20 to 30 psi can shoot a rubber end cap off quite forcefully.
4. My dent removal is near perfect, but DO NOT expect perfection - the pipe will never look 100% brand new. My goal was to remove a dent that impeded exhaust flow. A slight indentation (1/32nd or less, smaller than half a thumbprint) is OK, and will not affect the performance of the engine.

 

[Botch]

Wow, I would not have expected that to work. Glad it did! :thumbup:

 

[DefyInertia]

Now that this has been resolved, what are you going to do to avoid making mistakes like this in the future.

 

[philosopheriam]

Now that this has been resolved, what are you going to do to avoid making mistakes like this in the future.

Point taken...

 

[sabre]

Personally I would have left it alone for fear of causing more damage, or just replaced it. Glad it worked, I never thought it would.

 

[joe1971]

You could have placed a wet rag on the dent as well, after it mostly came out that would have pulled it the rest of the way out with no ill effects. I was a welder for most of my adult life.