De-rusting taps and dies

[Chris152]

A neighbour dropped off some metal working kit today and among it is two sets of skf Dormer taps and dies, one BSW and one metric. A few bits are missing and a few are Goliath, but all seem decent. But some have rust. I'm used to getting rust off old tools with polydiscs, wire brushes and so on but guess that'd be a bad move with cutting edges.
Looking at the pics below, would a bath in an ultrasonic cleaner followed by a tooth brush be best? If so, which additive is good for rust? We have some that we bought for cleaning ally carbs and general components, but that's mostly grease/ dirt etc.
Failing that, any other/ better suggestions on how to clean them up?
Thanks for any thoughts, C.

 

[Sideways]

Electrolysis lots of threads about how to do it on here.

 

[Chris152]

I'm off to use the search function now

 

[Old.bodger]

Citric acid works a treat and is cheap.

 

[Inspector]

Acids even as mild as citric acid or vinegar works all surfaces including the edges. Which basically means it dulls the cutting edges. better is Sideway's suggestion of electrolysis or the products like Evaporust or Restore products (made in the UK) They don't remove the parent metals.

Pete

 

[Chris152]

Thanks chaps.

With electrolysis, given the parts are small and quite a few, could we wrap them into bundles of, say, four to connect to the earth?
And what'd be the best way to get the blackness off them, given that we don't want to damage the cutting edges?

 

[Tweedy]

Be slightly wary with electrolysis and hydrogen embrittlement.

To be honest running them through some material will likely clean off he worst in the teeth. Lots of lube!

 

[Chris152]

Be slightly wary with electrolysis and hydrogen embrittlement.

To be honest running them through some material will likely clean off he worst in the teeth. Lots of lube!

I did wonder if maybe I was a tad over concerned about what looks to be fine, 'fluffy' rust, so last night had a go at cleaning one with a toothbrush and wd40 (see pic). Seeing your comment about them possibly becoming brittle, I'm inclined to think just do the same for the other ones with rust and use them. If there are any issues, we'll look again.

That said, we had a watch of this video
https://www.ukworkshop.co.uk/threads/rust-removal-by-electrolysis.129695/#post-1456984
and it looks a great process so we're going to have a go on some of the other rusty tools we have here.

Thanks all.

 

[MorrisWoodman12]

Be slightly wary with electrolysis and hydrogen embrittlement.

To be honest running them through some material will likely clean off he worst in the teeth. Lots of lube!

How serious is hydrogen embrittlement?

 

[guineafowl21]

I cleaned a big lot of taps quickly by scrubbing them with a small wire brush in some old chainsaw petrol. The petrol then evaporated away, leaving a nice oil film.

 

[Spectric]

Soak in some diesel for a day or two and then wire brush, wash off in something that evapourates fast like petrol and then oil.

 

[Tweedy]

How serious is hydrogen embrittlement?

I'm no metallurgist, apparently you can bake them to fix it but given the unknowns of the alloys used there's variables to consider.

Given the chemical and mechanical options for cleaning are fairly foolproof and none too dangerous I'd stick with those myself.

 

[John on the Wirral]

We used to leave things like that in a can of diesel

 

[themack]

Ballistol works well. Get a big glass, put the rusty bits in, put a bit of Ballistol in, close lid, shake it all about and leave for a couple of days. If it is surface rust, it'll come off.

 

[clogs]

themack...
just saying, that might be ol for nuts n bolts but taps, dies, files and drill bit should NOT be rattled around together....
always store seperately.......
bit of a wire brush and some use is what I'd do.....

 

[budgie98]

Acids even as mild as citric acid or vinegar works all surfaces including the edges. Which basically means it dulls the cutting edges. better is Sideway's suggestion of electrolysis or the products like Evaporust or Restore products (made in the UK) They don't remove the parent metals.

Pete

Yet acids are used to sharpen files and scythes.

 

[Agowood]

Shield products are designed to remove rust without attacking the base metal and I have used the derusting solution to remove rust from a die before without any detriment to the cutting action. In my experience acids must be avoided as they will dull the cutting edge very quickly and can cause other problems as mentioned earlier.

 

[themack]

themack...
just saying, that might be ol for nuts n bolts but taps, dies, files and drill bit should NOT be rattled around together....
always store seperately.......
bit of a wire brush and some use is what I'd do.....

You are correct, I didn't express myself properly. I didn't mean shake the whole lot, I meant shake the oil about. My apologies. I usually put rusty bits in a glass cover them with oil and "slosh" the oil around the bits, so all is covered, unless you fill the glass well above the level of material.

 

[John Hall]

I use a wire brush on a bench grinder…works really well..easily cleans between the teeth and flutes just need to be careful if the writing is printed instead of stamped

 

[Chris152]

Do you think there's a danger the wire brush will reduce the cutting edges?