Result at the tip this morning

[stalagmike]

It looks as though it has had a right ear piercing !
Are you going to try to get it back into shape ?

I'm not going to try myself. I think I might take it to a local metal working place and see what they think they can do - without heat.

 

[classic33]

Remove the nut lugs, replace with something like this.

If an oversized seat bolt won't fit.

 

[stalagmike]

I'd use something like this,

View attachment 403451

Sold out from there. But I get the idea.

 

[si_c]

You're correct, drilling the frame is a drastic measure, and a nut & bolt with heavy washers on the pinch clamp won't be too pretty either. However, you have to put this in context; the bike was FOC and, had it not been salvaged, it would have been melted down as scrap. Even if you bodge it up, at least it survives to be enjoyed and used some more. If you start brazing, you destroy the paint, which doesn't actually look that bad overall. So, by the time you've done a "proper" repair, and repainted the heat damage, the cost of your skip bike might approach that of buying one in good condition. There is nothing inherently wrong in owning and riding a quality bike in a cosmetically poor state or with a bodge repair or two. It will still be nice and light and it will still ride exactly the same as a perfect example would.

I know, I have a beater bike too, it's old, it's steel, the paint is less than amazing, but it serves it's purpose. I wanted the OP to think beyond just getting something where the seatpost stays up, and to realise that getting it fixed properly wouldn't be cripplingly expensive.

I'd quite like to keep the original paint work if I can. I could always go for the bodge now with the option of the brazing/new paint job later if I am feeling flush. I'm not wedded to a full resto job, just a tidy looking retro ride really.

Indeed, bodging it temporarily is a good option, and certainly wouldn't preclude doing it up later. Nothing wrong with repainting and putting new decals on an old 531 frame, it would look spectacular if done properly.

 

[raleighnut]

Sold out from there. But I get the idea.

I'd expect most bike shops would sell em although they may only have them with a pair of 'security' axle skewers in a set. (Direct replacement for QR set)

 

[mjr]

Remove the nut lugs, replace with something like this.
View attachment 403511
If an oversized seat bolt won't fit.

That would be my preferred option too. Are there ones that fit over the top of the tube in vintage sizes?

 

[stalagmike]

Right. So I have bought a big bolt and some large washers and I will have a go at knocking the area back into shape myself.

With regards to the general clean up operation, oxalic acid bath seems to be the good option for me. But I've a couple of questions about doing it.

First, roughly how much would it take in terms of weight of dry crystals to make enough solution to do the whole bike and all the small parts etc.? What concentration should it be? I don't want to buy too little but equally don't want to waste money on a tonne of the stuff.

Second, how do I know which parts are suitable for bathing in acid and which are not?

E.g it's got Christophe clips on the pedals. I am guessing these are chromed? Would they be ok in an acid bath or should I use wire wool to clean these up?

As I have been informed on here, the bike has got some nice parts on it, so I don't want to mess them up by my own ignorance!

And another thing. Once the bathing has been done, do I need to use a rust inhibitor of some kind to stop it coming back. I think I will be lacquering the frame but for all the other parts (e.g. rims or derailleur) what can I use on them? A wax spray or does duck oil do it?

Questions, questions...

 

[Randomnerd]

I use oxalic acid for treating oak, and at fairly high concentration. It's quite aggressive stuff, and burns the skin if you're not careful. Treat it as you would any other cleaning product. Watch your eyes, kids etc. Natural product, so can be poured away on the grass and diluted with the hose.
It will clean chrome and steel of rust, but don't use it on alloy or aluminium - will turn it black. Or any other steel that's been given oxide treatment. Try at a very dilute rate and up the dose if it doesn't work. For my purpose, I use around 1 - 2 tablespoon per litre of water.
Rust will still be there at an atomic level, so coat to prevent spread can be helpful. For tools I use camelia oil, very thinly applied on a cloth. Should be good on a beater bike. Or wax polish. Or beeswax and linseed oil warmed together and polished on. Boeshield can be sprayed, but is more for woodworking machinery and workshops, and I think is expensive

 

[classic33]

The rules are changing.
https://www.gov.uk/government/publi...rs/supplying-explosives-precursors-and-poison

 

[BalkanExpress]

@Drago has used oxalis acid on a couple of his bikes, there is a thread on here about his Claude Butler.

Here are a couple of threads from elsewhere. The message seems to be low concentration and take it slow.

https://www.bikeforums.net/classic-vintage/799591-oxalic-acid-finer-points.html

https://bmxmuseum.com/forums/viewtopic.php?id=351132

 

[stalagmike]

Has anybody had success with this kind of thing for prevention after rust removal?

https://www.toolstation.com/shop/Automotive/d60/Lubricants+&+Sprays/sd2795/Protection+Wax/p41925

 

[stalagmike]

A few pics of the Mistral after giving it a good clean and degrease. Paint is not too bad although there's quite a bit of flaking around the BB. This is going to be a slow rebuild as I have been told by management not to start it until work on our house is finished. It's really hard because it just sits there in the garage begging me to fettle with it!

 

[stalagmike]

I've just begun to do a bit of work on the Mistral now I'm off work for the summer. Took the chain off earlier. The bike is 10speed. The chain says 'KG' and 'narrow' on every link. I'm wondering if it's worth saving and putting it back on? If so, should I be boiling it up in something? It's not really badly rusted from what I can tell. Just seems a bit stiff, so much so that it doesn't run smoothly through the rear mech. Or is replacement the only way to go?

 

[biggs682]

@stalagmike check it with a chain tool for wear if within tolerance then re use if not fit new

 

[Illaveago]

I've just begun to do a bit of work on the Mistral now I'm off work for the summer. Took the chain off earlier. The bike is 10speed. The chain says 'KG' and 'narrow' on every link. I'm wondering if it's worth saving and putting it back on? If so, should I be boiling it up in something? It's not really badly rusted from what I can tell. Just seems a bit stiff, so much so that it doesn't run smoothly through the rear mech. Or is replacement the only way to go?

It looks like it could do with some oil .