Acid rust removal

[R3k1355]

Saw this on TikTok, thought it was worth a shot. Have tried Vinegar/Coke method before but it was slow and results weren't exactly amazing.
This uses toilet cleaner, specifically Harpic (it's 10% Hydrochloric acid) as bleach based won't work.

Obviously I wouldn't try this with anything coated, or ali/alloy/plastic as it could well ruin it, and you'll want to paint them after as it'll rust pretty readily.

I wouldn't bother with basic bolts/fixings, but some stuff can be dealer order only, or NLA, or just kinda expensive for a few stupid bits.

Stuck these in a jar of the stuff and left it for a couple of days

 

[Matt Cup]

Huge improvement. Something useful from TikTok which is rare.

 

[Brigsy]

Citric acid also works spot on, mix up a little bit with water and stick it in the solution for a couple of days and all rust is gone.

 

[Touring_Rob]

Citric acid also works spot on, mix up a little bit with water and stick it in the solution for a couple of days and all rust is gone.

Cheap as too if you buy big bags of citric acid powder off eBay. I got a little fish tank heater for the tub so I can leave it outside (can smell a bit). Heating to 30-40 massively speeds the whole thing up.

Good for removing limescale from kettles too!

 

[Ph1 Tom]

Alkaline soap cleaner followed by hydrochloric acid is what we use for cleaning mild steel in work before plating.

 

[Rob]

Damn good results!

 

[aldo_87]

Phosphoric acid is mint for it too. Can buy it via ebay.

 

[Djw John]

Anyone got a swimming pool I could put a sprinter into?!

 

[Touring_Rob]

Anyone got a swimming pool I could put a sprinter into?!

Yes its called the sea, happy to have been of assistance sir.

Adieu.

 

[Touring_Rob]

Alkaline soap cleaner followed by hydrochloric acid is what we use for cleaning mild steel in work before plating.

Do you work for a plating company Tom or does your company just plate their own stuff inhouse?

 

[Ph1 Tom]

Do you work for a plating company Tom or does your company just plate their own stuff inhouse?

We just do our own stuff, mainly for defence.

Zinc plating
Tin plating
Chromic anodising
Conversion coating

 

[Djw John]

Yes its called the sea, happy to have been of assistance sir.

Adieu.

It's already been parked in there I reckon

 

[R3k1355]

Citric acid also works spot on, mix up a little bit with water and stick it in the solution for a couple of days and all rust is gone.

Cheap as too if you buy big bags of citric acid powder off eBay. I got a little fish tank heater for the tub so I can leave it outside (can smell a bit). Heating to 30-40 massively speeds the whole thing up.

Good for removing limescale from kettles too!

Got some Citric Acid off eBay to give it a go. Results were really good. As you might imagine it's milder than the Hydrochloric acid in Harpic, so it's no quite so critical how long you leave stuff in there.
I found on heavily rusted bolts it forms this greyish sludge, where the Hydrochloric acid just powers right through. You can just pop those bolts into some Harpic and they come out beautiful. It seems quite good at removing residual paint as well, so small brackets and stuff come out very well.

As with HCL the Citric Acid will remove any Zinc plating on bolts, so be aware what you're putting in and how you're going to protect them when they come out.

I made the solution up at 10% weight/volume. A 250g bag of powder was £4.50, enough to make 2.5L.

 

[Touring_Rob]

I dislike how it smells after a few days of festering

 

[Brigsy]

Works spot on if you have time.

I believe you can mix it up with wallpaper paste to make gel if you want a cheap version of BH deox gel.

 

[Paddy_g46]

Got some Citric Acid off eBay to give it a go. Results were really good. As you might imagine it's milder than the Hydrochloric acid in Harpic, so it's no quite so critical how long you leave stuff in there.
I found on heavily rusted bolts it forms this greyish sludge, where the Hydrochloric acid just powers right through. You can just pop those bolts into some Harpic and they come out beautiful. It seems quite good at removing residual paint as well, so small brackets and stuff come out very well.

As with HCL the Citric Acid will remove any Zinc plating on bolts, so be aware what you're putting in and how you're going to protect them when they come out.

I made the solution up at 10% weight/volume. A 250g bag of powder was £4.50, enough to make 2.5L.

View attachment 1644870

Ant idea how this would react with car paint? Like if you wanted to use it in some very small localised rust spots?

 

[Brigsy]

Ant idea how this would react with car paint? Like if you wanted to use it in some very small localised rust spots?

BH deox gel does not bother the paint, ive de rusted localised spots with it on a few cars.

 

[R3k1355]

Yea go for the Gel, the 10% citric acid (in water) solution wouldn't stay in place, it'd just run off and cause bother.

If it's a little spot can you hit it with a dremel or something?

 

[Ash007ks]

BH deox gel does not bother the paint, ive de rusted localised spots with it on a few cars.

Frighteningly great stuff. Tried it on a set of calipers and brake discs i got from the scrappers which had been stood a long time and they came out pretty much like new.

 

[loggyboy]

Electrolysis is the better route as its actually reverses corrosion and can convert metal thats partially corroded back to a better state rather than eating away at what could be good metal.

 

[Touring_Rob]

Bit difficult to dip the whole of your Clio into an electrolysis tank though 😂

 

[loggyboy]

Bit difficult to dip the whole of your Clio into an electrolysis tank though 😂

Keen to see a whole Clio done with Harpic!

 

[Touring_Rob]

Keen to see a whole Clio done with Harpic!

Hold my beer.

 

[Louis]

I'd have nothing left

 

[Daz...]

Most would look like an empty bottle of Harpic.