The Offcial Machinist Thread: Revised 01/04/2014

[jackssmirkingrevenge]

How did you do the side engraving? Acid?

Yup, masked the highlights with masking tape and added dropwise about 5mL total concentrated nitric acid on it.

[sharpshooter11000]

May I ask where on earth you managed to get concentrated nitric acid?

[Crna Legija]

his work

[sharpshooter11000]

Lucky! I wonder what my chemistry teacher would say if I asked for some

Also, does the masking tape stay intact? I would have thought if nitric acid is strong enough to go through metal it would definitely go through masking tape!

[jackssmirkingrevenge]

One of the benefits of managing a lab

You can get similar results with hydrochloric acid which you can usually get reasonably concentrated from a hardware store, you just have to leave it for longer.

[sharpshooter11000]

Unfortunately B&Q don't seem to stock it where I live

Here's something I thought you might be interested in

[Zeus]

JSR, stop reminding me that it'll be around 10 months before I'm working in a lab.

Another method (which I can't be arsed finding a link for) uses electrolysis to remove material (not EDM). If you use nail polish or model paint, remove what you want etched, and electrolyse in a solution of (NaOH sound ok JSR, I haven't tried it. NaCl would spew off Cl2 and scare people away).

Should work well, experiment first.

[sharpshooter11000]

Am I right in thinking NaOH is drain cleaner?

NaCl would spew off Cl2 and scare people away

Ironic (is that the right word?) considering your sig

[Insomniac]

Yes, all drain cleaners I've ever seen are NaOH. Some oven cleaners are as well, though there are 'non-caustic' types which do not contain it.

[sharpshooter11000]

Thanks Insomniac

Back on topic, would it be possible to use a tool for facing as a makeshift boring bar? I'm making a nylon washer and don't have a big enough drill bit for the hole in the middle.

[Zeus]

NaCl would spew off Cl2 and scare people away

Ironic (is that the right word?) considering your sig

Ironic is right, as I said, Cl2 scares people away, I've come to enjoy the smell in small quantities.

Most drain cleaners are indeed NaOH, sodium hydroxide. Red Devil lye is quite common in the US if I recall correctly.

[inonickname]

Yes, all drain cleaners I've ever seen are NaOH. Some oven cleaners are as well, though there are 'non-caustic' types which do not contain it.

In addition to NaOH and the "non caustic" varieties there's also sulfuric acid, sodium hypochlorite and KOH

If you want an even more potent etchant try a mix of 1:3 nitric/hydrochloric acid.

And no, buy/make a boring bar. If it was a boring bar it'd be called a boring bar, not a facing tool.

[Fnord]

Back on topic, would it be possible to use a tool for facing as a makeshift boring bar? I'm making a nylon washer and don't have a big enough drill bit for the hole in the middle.

Just get a cylinder of metal the size of the hole and heat it up with a torch/ punch it through. If not use a dremel/soldering iron.

Also I really like your shell jsr.

[sharpshooter11000]

Ah, thanks Fnord, that's a great idea!
Inonickname, it's doing pretty much the same job, just facing on the inside
I'll probably end up buying one anyway, they're just pretty expensive for what they are!

[ramses]

Back on topic, would it be possible to use a tool for facing as a makeshift boring bar? I'm making a nylon washer and don't have a big enough drill bit for the hole in the middle.

Just get a cylinder of metal the size of the hole and heat it up with a torch/ punch it through. If not use a dremel/soldering iron.

Also I really like your shell jsr.

Tube might be more effective.