Dent removal

Pete Beall said:

Rusty has an aluminum bike with a cosmetic dent
in the top tube. I contacted a local auto body
shop and they won't touch it. Any suggestions on
who to approach for removal?

My advice: If the tube is straight, leave it alone. If the
tube is bent, get it (or the frame) replaced. Trying to bend
that ding back out will further distort and stress the
metal. I've taken dents out of tubing by ramming a bearing
of the appropriate diameter down through the tube to
essentially broach the entire hole, but this is not a useful
technique in your case.

If all you want to do is disguise the ding, swipe a little
automotive scratch filler into it, tape over the area around
it with a double layer of masking tape, block sand it to a
reasonable contour *without* digging into the surrounding
paint, and apply touch-up or cover it with decorative tape
or a decal.
--
Typoes are a feature, not a bug. Some gardening required to
reply via email. Surrealism is a pectinated ranzel.

Pete Beall said:

Rusty has an aluminum bike with a cosmetic dent
in the top tube. I contacted a local auto body
shop and they won't touch it. Any suggestions on
who to approach for removal?

Dents are usually just filled before repainting. A
framebuilder that offers resprays can do this for you. I had
some horrible chainsuck scars filled in on my racing bike.

Quoted post said:

Originally posted by Pete Beall
Rusty has an aluminum bike with a cosmetic dent in the top
tube. I contacted a local auto body shop and they won't
touch it. Any suggestions on who to approach for removal?
--
www.petebeall.net

If there is no creasing, you might be able to use dry ice to shrink the dent back to profile. This works well on aluminum owing to its large thermal expansion coefficient. It works best when the bike has been in the sun for a few minutes to get it slightly warm.

Be careful and hold the lump of dry ice with tongs, very thick gloves or pliers. You need to "melt" the lump to get good contact and to hold it against the dent rather firmly.

Depending on how much the metal has yielded, you might be able to completely remove the dent. If the paint has chipped off, results will be poor.

Pete Beall said:

Rusty has an aluminum bike with a cosmetic dent
in the top tube. I contacted a local auto body
shop and they won't touch it. Any suggestions on
who to approach for removal?

It's technically different from rolling a steel dent and in
either material you'll lose paint.

A body shop probably wouldn't have the right denting blocks
for that anyway ( you can't get a pick and dolly behind a
top tube dent!)

It won't ever be stronger than it is right now and you could
possibly lose some of an aluminum tube's integrity - got
photos? How deep is it? A sharp-edged dent? From a handlebar
end or from driving into a carport?

--
Andrew Muzi www.yellowjersey.org Open every day since 1
April, 1971

Hi Pete,

I am not sure if I have a solution for you. There is a
device which welds a rivit to metal and then use a puller
to bring the metal up. I am not sure if it will work on
aluminum. I will give you a link to check it out here htt-
p://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnu-
mber=3223 you will need to get some advice. First the
paint will have a spot where you weld the rivit and then
you need to paint it again. You'll have to use a grinder
to get the rivit off if it will even weld to aluminum. You
might do well to check with the manufacturer of such a
tool to determine if you can use it on a bicycle tube. I
am handing it off to you - good luck O' by the way I
crashed my bike and my knee put a ding in my top tube and
I left it alone cause the tube appears straight, bike
rides straight. Greg 🙂

"Pete Beall" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Rusty has an aluminum bike with a cosmetic dent
in the top tube.

I

Quoted message said:

contacted a local auto body shop and they won't touch it.
Any suggestions

on

Quoted message said:

who to approach for removal?
--
www.petebeall.net

Gregory McGuire said:

Hi Pete,

I am not sure if I have a solution for you. There is a
device which welds a rivit to metal and then use a puller
to bring the metal up.

Versions of the "rivets" exist for steel and stainless; it
is generally NOT a good idea to try this with aluminum, as
it will often just create a weak spot where the item spot-
welds itself down, which then *rips out* when the tension
is applied.

Welding aluminum is best left to those who have the
equipment and skill to do it well.
--
Typoes are a feature, not a bug. Some gardening required to
reply via email. Surrealism is a pectinated ranzel.

A Muzi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Pete Beall said:

Rusty has an aluminum bike with a cosmetic
dent in the top tube. I contacted a local auto
body shop and they won't touch it. Any
suggestions on who to approach for removal?

It's technically different from rolling a steel dent and
in either material you'll lose paint.

A body shop probably wouldn't have the right denting
blocks for that anyway ( you can't get a pick and dolly
behind a top tube dent!)

It won't ever be stronger than it is right now and you
could possibly lose some of an aluminum tube's integrity -
got photos? How deep is it? A sharp-edged dent? From a
handlebar end or from driving into a carport?

In a former life, I played trombone. There is a tool used
for fixing dents in brass instruments that is basically a
series of balls, increasing in size, attached to a string.
You pick the ball with the bore that matches the tube, the
one that passes through the dented area, and all the
assending sizes in between. You then ram the whole works
through the tube until it passes the bore sized ball freely.
It usually leaves a mark, but this can be buffed out later.
I don't know if there is a simular technique for bike tubes,
since they are much thicker and less plyable than brass and
copper, but I would think it would be possible. The only
problem is that you are flexing a piece of metal over and
over, but any repair will do that anyway.

Eric

Quoted message said:

A Muzi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Pete Beall said:

Rusty has an aluminum bike with a cosmetic dent
in the top tube. I contacted a local auto body
shop and they won't touch it. Any suggestions
on who to approach for removal?

It's technically different from rolling a steel dent and
in either material you'll lose paint.

A body shop probably wouldn't have the right denting
blocks for that anyway ( you can't get a pick and dolly
behind a top tube dent!)

It won't ever be stronger than it is right now and you
could possibly lose some of an aluminum tube's integrity -
got photos? How deep is it? A sharp-edged dent? From a
handlebar end or from driving into a carport?

Eric said:

In a former life, I played trombone. There is a tool used
for fixing dents in brass instruments that is basically a
series of balls, increasing in size, attached to a
string. You pick the ball with the bore that matches the
tube, the one that passes through the dented area, and
all the assending sizes in between. You then ram the
whole works through the tube until it passes the bore
sized ball freely. It usually leaves a mark, but this can
be buffed out later. I don't know if there is a simular
technique for bike tubes, since they are much thicker and
less plyable than brass and copper, but I would think it
would be possible. The only problem is that you are
flexing a piece of metal over and over, but any repair
will do that anyway.

And you get these into a top tube how?

--
Andrew Muzi www.yellowjersey.org Open every day since 1
April, 1971

yawl won a free trip to P.R. 3 nights, two days. free booze
and girls. waytogo!