Free Drills

Hi Richard,

I am trying to set up my own workshop and would be very grateful for any drills you have spare. I have just completed a 3" allchin.

I am trying to set a workshop at home as I had use other peoples machines to make my Allchin. You can view some pictures here:

I live near Chetenham and could pick up the drills.

If you can spare any drills please contact me, as they would be gratefully appreciated.

Many Thanks

David Oliver

Do you have any more information on the electrolytic cleaning process? There was an article on electrolytic cleaning in MEW this year which I noted as being possibly interesting but have not got round to trying yet. I have a nice set of collets which have accumulated a lot of surface rust and I was wondering how best to try and remove it!

Alan

I took info from the following

For you I would suggest a stainless steel pot (kitchen type from Wilkinsons, for coffee or sugar, cheap. Dangle a collet in the solution. Maybe a jubilee clip to clamp a piece of steel wire to the collet, wire hooked over a support over the pot. Keep any copper connection leads out of the solution. Do not allow the collet to touch the pot!

Check the collets now and then and regularly clean off with a toothbrush to check the progress. Wash and clean in water with a rub over with a Sotchbrite pad.

I was very pleased with the results of my cleaning considering the state of some of the drills when I started.

Best of luck.

That's the arrangement I've used, with a stainless bowl from an old food mixer. A plastic colander stopped parts touching the bowl.

-adrian

hi guys

Ive done quite a bit of electrolytic rust removal - before I started I researched it quite well and various sources said NOT to use stainless steel as the anode as Hexavalent chromium is produced as a by product. It is poisonous and carcinogenic. See

Just for your information

regards

Tim South Africa

Snip

Your comment is noted. The main problem is knowing what levels we may be generating. Is this a problem that really is not there in this process?

What Anode material do you use?

Good point. I tend to give the components a brushh off with a toothbrush from time to time.

Richard

Handling pure methanol, even siphoning it, using benzene as a cleaner etc was/is very common - anyway they educated me and also stressed the problem of your body accumulating poison that it does not rid itself of.

They are coming for tea this afternoon (hey we used to be a colony !!) and I will ask them about it.

- go for a piece with a large surface area. While I don't recommend stainless I know others have used cheap teaspoons bought in bulk.

For small jobs I use cheap clip cords to connect to the anode and piece to be cleaned. It's easier than twisting wire around small things. For very small items like nuts and bolts you can lie them on a piece of metal or better still a metal strainer and connect the negative to the metal or strainer.

Tim

These days I am using lead flashing as the anode. I started with stainless and did note the greenish chromate colouration in the solution. Another, more significant problem with the stainless is that the anode tends to get passivated and you need to reverse the current for a few minutes every once in a while to keep the current flowing well.

Using lead anodes with a sodium carbonate solution _does_ result in the production of some lead carbonate (white lead). luckily, this is practically insoluble, so it's a bit less risky than the hexavalent chromium although you seriously don't want to eat it!

Mark Rand RTFM

Richard

I spoke to my chemist friends and they say they would not use stainless as an anode - in industry hexavalent chromium is called "chrome 6". They are involved in metal testing for the vehicle industry and if chrome 6 is detected in a received batch the batch is rejected, this is due apparently to the problem of disposal of the metal at the end of the vehicle life. (it is a heavy metal)

Back to rust removal - the problem is that the hexavalent chromium is also released as gas in the process so this in a closed area is a very bad idea. They also confirmed that the problem is that hexavalent chromium builds up in the body so the effects will not be evident immediately.

But if you still decide to use stainless at very least do it in a well ventilated area (and they suggest a gas mask).

Tim

So how do you dispose of it? Sell it for caulking boats?

Ah, the cupboard under the stairs is out then ;-) Seriously you have made some good points which are noted. The use of a strainer was a good idea. Currently resurrecting an old one from the bin, thrown in my current tidy up of the garage to make space for the lathe.

It still surprises me how much info one gets when asking a question or generating a thread. It is also surprising what you receive when you mention the purchase of a lathe to people who you think have no interest. 50 drills supplied by one dog walker plus 12 lengths of HSS tool steel from another with a promise of a couple of boring bars when he finds them! You never know maybe someone has a Bridgeport that they want to give away!

Nah. Just mix it with linseed oil and paint the kiddies cot with it. Gives a lovely white gloss finish :-)

Mark Rand RTFM

Ah, the Chinese painting system ;-)

I am all in favour of avoiding significant risks, but let's put this in perspective.

The material you cite does indeed show that chromium(VI) compounds, or at least some of them, are moderately carcinogenic. However, these studies relate to industrial workers involved in welding or using solid chromate pigments or large-scale chromium plating baths which use high concentrations of chromium(VI) salts in acid solution. The latter are hot, use very high current densities and presumably lots of splashing, thus high concentrations of Cr(VI) salts in the form of aerial particles will be formed.

The figures for these people, working in these industries for several decades, show an increased incidence of lung cancers somewhat less than that for people smoking cigarettes over a similar period.

Hobbyists here would be using an electrolytic process in which the electrolyte is not a Cr(VI) salt, or even a Cr(III) salt, and in which any Cr is a minor contaminant from the small percentage of Cr in stainless steel. No large quantities of hot mist (and hence aerial solids) would be expected, and the hobbyist would be doing this a handful of times.

I rather doubt much of the small amount of Cr in the anode would even form Cr(VI) compounds; Mark reports a greenish colour, which is typical of Cr(III) salts in solution (and, incidentally, also characteristic of Fe salts, and Fe is present here in much higher amounts) whereas Cr(VI) salts are yellow or orange/red. Cr(III) salts are not especially dangerous - and are even essential to support life (RDA is I think

Even if there were small amounts of Cr(VI) in the solution, it is unlikely to get into the hobbyist unless he drinks it, or boils it and breathes the vapour - and the studies show that it is mainly breathing it into the lungs which is dangerous.

So just do it, if you wish; just take sensible precautions as for any such processes - don't eat it, drink it, boil and breathe it, dip you hands in it or use kitchen food implements. As with most of these toxins, dry powders are more dangerous than solutions as you may breathe the dust; this process does not involve any dry powders. Gas mask? Sheer paranoia.

Incidentally, several of the sources you quote (or which they quote) seem confused about the science and terminology. Cr(VI) is not, (like dangerous radio-isotopes of innocuous metals) a different type of chromium; it is an oxidation state. As such, it is *not* present in stainless steel or other Cr-containing alloys (otherwise most cutlery would be suspect!). These are all Cr(0), i.e. chromium metal. It can be formed as a dust from Cr(0) by oxidation (arc welding and grinding spring to mind) and if you do that industrially then you may have some significant exposure. I suggest that even this, done a couple of times a year, is a minimal risk to hobbyists. I would bet that the linishing of stainless steels (having just spent several hours doing this) put far more Cr in my lungs than months of this electrolytic process could ever do.

Sensible precautions based on knowledge, not paranoia based on misconceptions and dodgy Wikipedia entries, please.

David

My info comes not from "dodgy Wikipedia" but from 2 people with doctorates in chemistry and actively involved in industry - bottom line for me - if they say they wouldn't do it then I think I will err on the side of conservancy.

In article , TMN writes

Well, you were the one who quoted the Wikipedia entry.

You may care to ask your friends again, as you could have misunderstood. If they have any specific facts to refute what I said, I would genuinely be interested to hear it. But nobody is going to make you do it.

Just hope you don't use stainless steel cutlery, it's probably more dangerous, especially as you use it every day...

David

The link to Wikipedia was for general info about hexavalent chromium. All the information about it being a potentially hazardous process is from two real live chemists.

I don't think you can compare it in solid form to liquid and gaseous form - but I suppose we would all do this in a well ventilated area - not in the confines of a garage :)

David, I realise that there is a lot of over the top safety stuff going around but two people I respect (the chemists) said they would not do it - they site the problem of build up of multiple carcinogenic/ poisonous substances in the body, a bit of chromium, a bit of lead , a bit of cyanide, a bit of methanl, benzine ...... all things that may be encountered in the garage. (they are not MD's thought but clearly know alot more about these things than me !)

They have just patented a process to preserve roses complete with stems by replacing the "sap" with some or other "stuff" which gives these flowers a "live" look for at least 3 years. Pity they aren't working on new metal patinas or something !

regards Tim