Morning All,

Looking for any experiences re teh above.

I have a Thomson post that I would like to strip back to bare metal as its reasonably worn.

I have some bicarbonate of soda* that I plan to use but need some pointers re how long it should take …. minutes …. an hour?

Don’t want to dissolve the post!

Cheers Mark

* Gloves and googles at the ready!

Errrmmm…. I’m not sure that bicarbonate of soda is really what you want to be using (it won’t do much). Caustic Soda (sodium hydroxide) is the stuff. Make a solution of it, ‘wash’ your post in it, using a rag to wipe the stuff about and you’ll see the anodizing wash off like melting butter. The post will be fine. Just rinse thoroughly in lots of water once the anodising has gone…

Watch.your.eyes.

I took the black off some cranks once using Mr Muscle and wire wool. Took a few re-applications but looked good in the end. You’ll probably want to get some decent polish and spend some time making it pretty.

Here you go, instructions from Sam @ Singular when I asked about stripping my Midge Bars:

I used powdered caustic soda (drain cleaner) mixed to what was termed on the bottle as ‘paint stripper’ strength. Mix it in a container which is a size sufficient to fully submerge the tops of the bars (obviously you don’t need to worry about the hooks), I used an old baking tray. Do not use an aluminium container – steel only. Submerge the bars briefly (~15 seconds), you will see them start to bubble on the surface and should see black coming off them after a time. Remove the bars, rinse them and you should have a dull raw Al finish. Repeat only if necessary. Ensure you wash the bars completely with fresh water – you don’t want any residue of caustic soda remaining. Of course all this should be done in a well ventilated place wearing appropriate hand, eye and mouth (it gives off some nasty fumes) protection. Then it’s just a matter of polishing. The best way to do it is to use a polishing kit and buffing wheel (something like this) though it is also possible completely by hand, just takes a lot of elbow grease. I start by using some fine wet and dry, then on to the buffing wheel.

It doesn’t affect the stength of the material itself just the surface hardness. Certainly you want to be careful only to do it for as long as necessary to remove the anodising, any longer and you do start to damage the material. For the same reason they must be well washed to remove any trace of caustic. They will oxidise over time, but not too badly. A bit of regular metal polish will bring them up again nicely. After buffing some sort of wax polish will help stop them oxidising too quickly. I still regularly use some bars which I initially stripped in this way some three years ago. Like any bike part, you should regularly inspect them for damage or cracks. If it does concern you greatly, I think they now do Midges in silver as well 🙂

Worked:

DSC_0884 by ir_bandito, on Flickr

Doh ….. its that BBC2 baking show I havebeen made to watch.

I meant to say Caustic Soda!

Cheers ir_bandito 8)

On a side did you get some rigid forks sorted?

No, ‘m borrowing a road bike for the weekend, so the fork-less hardtail is hanging up on the wall.
I do like the idea of the 20mm bolt-thru Salsas once they’re available. Or the X-lites if they ever appear…

Morning, any tips for doing this to a frame or is it best to have it dipped?

Cheers all.

if your doing a frame paint it on with a brush in sections.

dont fill your bath with the stuff and drop as much alu as you can find in your house in it like I did at uni… smelly dangerous job!

if I was stripping a post I’d brush cs on with some water in quite a strong mix and keep washing under the tap as i was proceeding.

Spray on oven cleaner works a treat, done it to various things over the years, doesn’t seem as strong/quick as I remember from my teens but still works.

Oven Pride (careful, it is nasty stuff), then polish with Peek.

Double post

Hmmm I keep thinking about this and meybe feeling frisky soon. If it all goes horribley wrong I’ll just have it powder coated instead 😉

no you mean if it all goes horribly wrong you’ll have a pitted frame

jamiep
Oven Pride (careful, it is nasty stuff), then polish with Peek.

Seriously, it’s a piece of p1ss to do. I’ve been restoring a few old bmxs (eg raleigh burner from 1983) that, as you can imagine, can be pretty caked with grime and rust.

See these threads (below) about de-annoing and de-rusting.

Before, after the oven pride treatment, after polishing:

http://www.raleighburner.com/phpBB2/viewtopic.php?t=25585

A rusty leg and a de-rusted leg:

http://www.raleighburner.com/phpBB2/viewtopic.php?t=25135

Cola and foil method:


http://www.radbmx.co.uk/forum/index.php?topic=52096.0

Cheers for the links, that’s my train home reading sorted.