Project - Removing Rust from Bike Frame

[jimster99]

Some discussion about kickstands here
viewtopic.php?t=120018

Thanks Steve - that's very interesting (and overall reassuring). I particularly like the comment that it's unlikely both chainstays will fail at once, as that's my main concern!

[jimster99]

So I got my fake Lidl dremel (a £16.99 special) and gave the rust patch a good going over with a steel wheel. Unfortunately, the fake-dremel switch is faulty (normally Lidls stuff is quite reliable so a surprise to me!) but I managed to get enough of the rust off to satisfy myself that it should still be structurally safe...at least I hope so! I'll carry on once I have replaced the Dremel thing and pics below:

BEFORE

DURING

AFTER

[Jdsk]

I'd remove all of the rust showing around the edge in that After picture.

Jonathan

[jimster99]

I'd remove all of the rust showing around the edge in that After picture.

Jonathan

Thanks Jonathan - yes indeed! My fake-Dremel stopped working properly so that's why it looks incomplete. It was very annoying because I was in the groove and suddenly - bam - no more spinning.

There's also some small rust spots I won't be able to get to with the Dremel, not sure how how to resolve them. Any suggestions? Is there some kind of long pointy equivalent of a steel wheel for getting at rust in tight spaces? And the rust around the hole where the pedal crank arm go through the bicycle is also annoying. To get that off, would I have to remove the pedal cranks? I've never done this before but I think the bearings are a bit grindy so it might be worth learning a new skill.

[Jdsk]

I'd remove all of the rust showing around the edge in that After picture.

Thanks Jonathan - yes indeed! My fake-Dremel stopped working properly so that's why it looks incomplete. It was very annoying because I was in the groove and suddenly - bam - no more spinning.

There's also some small rust spots I won't be able to get to with the Dremel, not sure how how to resolve them. Any suggestions? Is there some kind of long pointy equivalent of a steel wheel for getting at rust in tight spaces?

There are end brushes and cup brushes for the Dremel where the wires point forwards rather than radially.

And there are abrasive pens that can go down holes.

Jonathan

[jimster99]

There are end brushes and cup brushes for the Dremel where the wires point forwards rather than radially. And there are abrasive pens that can go down holes.

Thanks Jonathan. Very helpful. Could you confirm what you mean by abrasive pens? I have some pointed "milling" tools that are long and thin and have a tiny abrasive point on the end, is that what you're talking about? I'd be a bit scared of milling the bicycle steel itself.

I already have some cup brushes, and I'll try to pick up some end brushes the next time I pass a tool shop.

I have to say (apart from from breaking the first time I used it...) I love the dremel tool, very useful!

-edit- you posted pictures, thanks again so much

[Jdsk]

Could you confirm what you mean by abrasive pens? I have some pointed "milling" tools that are long and thin and have a tiny abrasive point on the end, is that what you're talking about? I'd be a bit scared of milling the bicycle steel itself

The pens are human powered! Often multiple stiff glass fibres pointing forwards. I'm not sure how well they'd get into that paint surface but they're good on loose rust and crud.

Jonathan

[jimster99]

So I checked my dremel set and I already had a wire circular brush, a cup brush & an end brush. Only thing I was missing was the abrasive pencil, so I have nipped down to Halfords. A bargain(?) at £4! https://www.halfords.com/motoring/paint ... 32470.html

It looks extremely useful but I am a bit scared of the fibreglass (due to some painful memories of repairing broken fibreglass tent poles...ouch!).

In particular, it doesn't have a case, how do i safely store it when not in use? I imagine leaving it loose in a toolbox would be a recipe for disaster!!

[jimster99]

Just to update this, I have now wire-wheeled away the rust, and painted over the rusty spot with some good old Red Oxide Primer paint purchased from Screwfix. I still need to finish it off with a top layer of nail polish, but looks much better than before. I've also replaced the bottom bracket (with much difficulty!)

I'm also going to try putting a rubber layer (maybe from a cut up bike tyre?) between the kick stand and the frame to prevent this rust recurring again.



BEFORE

AFTER

[mjr]

Well done. Hope it works well.

Just for future reference and other readers: I believe that stand was fitted incorrectly, in that the top "bodge clamp" is for frames without a stand plate and it looks like the bike had a plate, which looks like it means the bodge clamp was further back than it was designed for, so it didn't clamp firmly and could move a bit. In such frames, the stand should be bolted directly to the plate to remove the wiggling (mechanical abrasion) and slight crush risk of the bodge clamp... and removed after each winter to make sure nothing has seized and it's not hiding corrosion!

[jimster99]

Thanks so much mjr, that's a great spot! I will try clamping the stand to the plate directly like you suggest.

I would like to put some kind of rubber sheet between the bike and the stand to reduce the mechanical abrasion, does that sound like a good idea? I was thinking about cutting up an old tyre but not sure how to deal with the metal wires that are inside the tyre (can I pull them out?)

[Sweep]

I was thinking about cutting up an old tyre but not sure how to deal with the metal wires that are inside the tyre (can I pull them out?)

Aren't the metal wires just along the edge to hold the tyre on the rim?
These can just be snipped off leaving the main body of the tyre.
I've done this to use old tyres for various things.

[jimster99]

Thanks Sweep - I have never actually cut up an old bike tyre so I assumed the wire was all round the tyre, but your explanation makes a lot of sense, so I will follow your excellent suggestion

[Biospace]

So I got my fake Lidl dremel (a £16.99 special) and gave the rust patch a good going over with a steel wheel. Unfortunately, the fake-dremel switch is faulty (normally Lidls stuff is quite reliable so a surprise to me!) but I managed to get enough of the rust off to satisfy myself that it should still be structurally safe...at least I hope so! I'll carry on once I have replaced the Dremel thing and pics below:

Bit of a late reply but regarding structural integrity and that rust, pitting of a tube's surface as in the pics can reduce its strength significantly.

Once corrosion has buried more than 15-20%-ish through steel, I'd be wary of its properties, especially when in a particularly stressed area. A past life included dealing with all sorts of corrosion, you tend to gain a feel for the stuff!

Something of a viscious circle can result with stress promoting corrosion, there will be more stress even in an only slightly weakened section of tube and although the outer surface is now protected, I was left wondering about the inside surfaces. I'd definitely be protecting them and keeping a very close eye for any cracking in the paint - or deeper.

[jimster99]

Hello! More help with my rusty junker bike please! I had the bike on my stand for replacing the brake cable and spotted that both the front and rear wheel mounting points have rusty sections. Pics below. Any specific concerns on these, or can I just do the old "strip rust & paint off with dremel wire wheel then paint the clean metal with red oxide primer then red and finally clear nail varnish" routine which has served me so well to date?

PS In light of the earlier comments about the rust on the chain stay possibly affecting structural stability (and especially as I discovered this is actually a Halfords cheapie Apollo branded bike therefore probably made of budget foil and old crisp packets) I have stopped using this bike for transporting my son, although I still do use it for shopping and it has survived some massive loads (like 30kg+) without snapping in half, although I could feel the wobbles (although that's true of any heavily laden bike).