Rolled out most of a dent in the top tube, now want to fill in the rest

Discuss light weight issues concerning road bikes & parts.
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Catagory6
Posts: 118
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

i was able to roll most of the dent out of the top tube without causing any damage to the paint.

can i fill in the rest with either bondo or jb weld? i assume i need to remove the paint in the dent.

which would be better for this? and are there any tutorials or videos you could point me to?

alcatraz
Posts: 924
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Maybe you can inform us of the size, position of the largest dent and the frame material

Catagory6
Posts: 118
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

steel
1/3 out from seat cluster

this picture makes the dent look deeper than it is

ImageImage

alcatraz
Posts: 924
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

I haven't done paint jobs for a long time.

I do think that it should be fairly straight forward as you are on steel. It's like car bodies I would imagine.

Can't be afraid to sand it down though because you need some spackle adherence. Figure out what kind of primers and cleaners you need to do it in the right order. I hope someone else can better inform you. You'd need some different grain sand paper between 120-400, mix and spray spackle for big and small unevennesses, primer in suitable color, cleaner spray (silicone remover works well I hear), paint, clear coat if you have.

One thing I do know is that the result is only as good as the prep is. When the area is sanded 10 times and you think it's perfect, you better do it again just to be sure. Depends on your expectations too.

I know you think it's not deep but it might be deep enough to cause the spackle to retreat over time. So don't fill it in one go. The deeper part needs a chance to dry too. It doesn't look good when after a few months you see the repair has sunk down a bit and the contour is visible.

There are some tricks on youtube to get the transition between repair and original to blend. I used to do it by lifting the edge of the masking tape a bit before doing the next layer.

I think it'll come out fine. Just take your time.

/a

2lo8
Posts: 412
Joined: Thu Mar 31, 2016 10:32 am

by 2lo8

Not advice for a "as good as new" touchup, but I've gotten some decent results on paint chips by putting a dab of color matched nail polish, then covering with scotch gift wrap tape, letting it dry for a week or so. It needs a very long dry time because it is not exposed to air and may be thicker than a normal coat of paint. The tape makes the paint very flat and follow the curve of the surrounding tube, tapers/matches the edges to the surrounding area, and means no wet paint exposed. It matches up well enough that usually a little buffing and polishing is all it needs to look decent. The nail polish can be stripped with acetone later. It works well if you don't feel like messing with the original paint job or sanding.

If you want to do the job proper, it would help to put a graphic over it like a name decal or a stripe or anything It's not always easy to get a good match with faded paint. I repainted a small section of a tubular motorcycle frame with factory match paint with very good blending, but you can still tell the color is off if you look for it.
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glepore
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Location: Pa USA

by glepore

What the pros use for something that size is auto glazing putty. But the thing is, to get it to look better than it does now, you have to sand and putty beyond the edge of the dent and feather it by sanding. This will leave a large enough area that it will need repaint. The advice above is worth trying. Me I'd leave well enough alone.
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Catagory6
Posts: 118
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

thanks for all the advice.
i am already over the moon at how well this dent rolled out
i think i'll give the finger nail polish a try on the paint chip

TheKaiser
Posts: 499
Joined: Thu Sep 05, 2013 3:29 pm

by TheKaiser

I'll second the decal suggestion. If you just want to experiment with the frame and see how good you can make it, then sure, strive for perfection, but otherwise, a decal will cover a multitude of sins. If it is going to get covered anyway, then don't feel obligated to mess with it any more than necessary. That's the perfect spot for one of those "pro look" name tags.

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