removing dings in ss fender

I am not sure if this has been covered before, and a quick search didnt reveal much. My fender has some dents from the PO, I would guess from a fairing bracket or something. I would like to get them repaired, if possible, rather than replace. Is this feasible, or should I just look to replace and make this one part of the ever-growing spares pile?

I'll start by saying that stainless is tougher to do than most steels, because it work hardens.
If you tap it out with a small wooden or plastic mallet, and back it onto a soft cloth or canvas wadding to cushion it,
with care you can remove almost all trace of the dents.
Proceed very carefully, one little bump at a time (no big whacks !).

I did a course on this sort of stuff a while back, in the local tech education classes - motor vehicle repair.
And removed a few minor dings out of a stainless guard I had then.
Almost invisibly. Almost......

I say almost, because with regular steel you file finish it and then polish it to remove every last trace of deformation.
This is rather more difficult to do in stainless, so removing every last trace of the dent is quite tricky.
An experienced metal worker might be able to, but it probably wouldn't be cost effective.

And we didn't even get to heating it to anneal it, or heating it and wet wiping it to shrink it,
or using a hammer and dolly to gather the metal back in again if you stretch it too far.

You haven't got anything to lose if it doesn't work out, if you are going to have to buy a new one anyway.
Have fun, tell us how you go. And good luck !

gortnipper said:

I am not sure if this has been covered before, and a quick search didnt reveal much. My fender has some dents from the PO, I would guess from a fairing bracket or something. I would like to get them repaired, if possible, rather than replace. Is this feasible, or should I just look to replace and make this one part of the ever-growing spares pile?

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Ha, Ha,,, not making light of your damaged fender here, but it is funny because it is the spittin' image of my fender. Caused by me when the bike was new. I thought Hi-Way pegs that clamped onto the frame downtubes (along with 8" rise handle bars) would the cat's nuts. The nuts and clamp bolt whacked the front fender every time you hit a moderate bump. "Damn, never thought that would happen". I tried tapping the marks out with a ball-peen hammer and got it just ok. Fender's too shiny to not reflect the damage. The Hi-Way pegs and handlebars are long gone but the fender stays because it reminds me of my younger days.

A swan's neck roll would do it best. (what gets called an english wheel?)
I would have a look around to see if there is a bodyshop/coachbuilders about that still has one.

Using cheap hand tools, a sand bag to support the underside, and a pear shaped bossing mallet.
Most people hit the dents too hard and stretch the metal.
Gently, from the outside inwards.

Stainless being harder, may test your patience.

Have fun.

An english wheel might be very useful to do the final finishing, since it could roll out the minor ripples that are otherwise difficult to remove.
But it wouldn't be very good at removing the initial dents ?, since it is more suited to gently rolling and shaping large areas of metal into curves.
Tackling the raw dents by rolling would likely stretch things out of shape, which would be difficult to recover from ?

nickguzzi said:

Gently, from the outside inwards.

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That comment needs some further explanation, for clarity.
I was taught to work from inside the curve of the guard.
(not from the outside of the guard, which is how this can be interpreted !).
And to gently work around the edges OF THE DENT
Not too much at a time, so as not to stretch the metal.
Quite deep dents can be gently massaged back into shape this way.

Tinmans mallet.
The head of these is wood, in case there is any doubt.

Sorry if that was not clear. Yes you are right - work round the outside of the dent.
After each "lap" round the damage, moving very slightly closer to the centre of destruction.
Most mom professionals I have seen wallop the highest spots first, then wonder why it all ends in wrinkles. Or bruise marks because they did it on the back of their vice.

Nice picture of pear shaped bossing mallets. A planish with a slapper on the convex face maybe?

Swan's neck rolls have adjustable rollers, once you have the right curvature, and the dent will pass though, gradually bring the lower roller up (on all the ones I have used) roll back and forards, again starting at the outside of the dented area and working to wards the centre.

Thanks for the good advice, and as said, there isnt much to lose by giving it a go when I strip the bike down this southern hemisphere winter.

I used to have a planishing hammer of my grandfather's that I dont know what happened to. It sprouted legs a few yuears ago. :evil:

I will track down a bossing mallet, and maybe just make a wooden slapper and sandbag and see how it goes and will post results when I get there.

Thanks again.

I have had two different trucks completely covered with hail dents and the dent removal guys that come to the local body shop removed every one of them without any ill effect on the paint. I realize stainless is a lot stiffer than 20 gauge body sheet, but there must be something to their methods.

The folks around here do that with magnets and stuff, which doesn't go very far on stainless....

the way i was taught and that works for me is to settle the dent on a polished flat plate (dent concave to plate),then with a tinmans mallet you hammer around the dent you can hear a sharp hammer blow as it makes direct contact through the metal to the plate below, as you work your way inwards the hammer blows become dull you keep working at it until the hammer blows become sharp as you work your way inwards, this has always worked for me but the plate must be be clean and flat best to be polished cheers baz

baz said:

the way i was taught and that works for me is to settle the dent on a polished flat plate (dent concave to plate),then with a tinmans mallet you hammer around the dent you can hear a sharp hammer blow as it makes direct contact through the metal to the plate below, as you work your way inwards the hammer blows become dull you keep working at it until the hammer blows become sharp as you work your way inwards, this has always worked for me but the plate must be be clean and flat best to be polished cheers baz

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So, how would this work in this case, where there are very small dents - almost a field of micro-dents on an already convex surface? I wouldn't want to flatten the fender and then reshape it.

It would be difficult with the small dents you have on this mudguard but give it a try see how you get on cheers baz

On a normal steel fender, once the highs and lows are bumped "off dolly" to the rough shape, where the metal is stretched, I would use a shrinking disc: it heats up the high spots, and then once the steel is quenched with a cold wet rag, the hot spots shrink. I do not know if this can be done on SS, although. I would worry about discoloring the metal, and I dont know if it makes the grain structure do bad things like get brittle. It is very hard, I think, to "gather" the metal and then pounding it thicker once you get to a certain point.

While I do appreciate the intrinsic satisfaction gained from performing a repair with a restored original part, the likelihood of
success in removing those dents and the fact that a new fender from A/N costs only $100 US plus shipping speaks for itself. :roll:
That said, sure, I'd give it a bit of a try just for the experience.

lazyeye6 said:

While I do appreciate the intrinsic satisfaction gained from performing a repair with a restored original part, the likelihood of
success in removing those dents and the fact that a new fender from A/N costs only $100 US plus shipping speaks for itself. :roll:
That said, sure, I'd give it a bit of a try just for the experience.

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Yup.

Any heat discolouration in stainless can be polished off. At least with a power polisher.

Rohan said:

The folks around here do that with magnets and stuff, which doesn't go very far on stainless....

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I just pulled up some videos showing dent removal done with hot-glued pads and pullers. That wouldn't work well on stainless either.

I think I might spend the $100 .... install the fender ..... then no rush to get dents out , less pressure equals better job .... for me that is very true ..... if there is no rush from the looming ride season , you can save it for when you are mentally ready for the task ...
Craig