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Member postings for Martin Dowing

Here is a list of all the postings Martin Dowing has made in our forums. Click on a thread name to jump to the thread.

Thread: Removing Aluminium From a Cutter
29/04/2018 20:00:16

Sodium Hydroxide solution (Caustic soda) is the best to get rid of Al deposits. Does not react with TiN, if in Doubt place undamaged TiN coated item in it.

I am using caustic soda for standard treatment of Al clogged files. They need fast rinse with water, then isopropanol and then very slight oiling with WD40 afterwards to prevent rusting.


Thread: Phone Scam
24/04/2018 12:54:21
Posted by Mark Rand on 23/04/2018 21:11:08:

Not exactly the same, but sort of:- When we moved into this house in 1985 we got the phone re-connected (house had been empty for 3 years). After a while, we started getting aggressive phone calls from the revenuers asking if we were a particular company and we owed them a lot of money. We kept telling them that we were a couple living in a house and they kept coming back. After half a dozen calls, I asked them to tell me what details they had of the company and to give me a number to call them back on. They gave me the name and address they'd got for the company and I went to visit them, a small engineering firm. I wandered in and asked one of the employees if they were that company and he told me that the owners had gone tits up, declared bankruptcy renamed the company, got new phone numbers etc. to carry on trading. I phoned up the tax people and gave them all of the details, for which they were most happy. I believe that they bankrupted the company for real when they collected the owed tax devil.

Edited By Mark Rand on 23/04/2018 21:12:08

Don't worry. At some point someone will give away *your* details too.


24/04/2018 12:51:27
Posted by Neil Wyatt on 23/04/2018 12:27:58:

Just had a phone call from 'Her Majesty's Customs and Revenue Service' telling me an arrest warrant had been issued in my name, and inviting me to press 1.

Naturally it gave no personal details and was just intended to frighten and initimidate the vulnerable.

Much as I would have been delighted to speak to one of the **** scum operating this scam, I feared a premium rate ripoff.

1471 gave me the callers number and I have reported it to

If you get a similar call,m don't panic, just report it.

I am afraid one day it will be for real. Bankrupting government can try anything, even invent unpaid taxes.


Thread: Department of Work and Pensions
23/04/2018 09:02:27
Posted by SillyOldDuffer on 21/04/2018 11:12:51:
Posted by Bazyle on 21/04/2018 08:56:02:

...Pensions are a mess. I have no idea what to recommend to my kids.


25 years ago I have realized that money transferred to finnancial institution as "savings" are in fact money stuffed into dog ass.

So no bank savings, no life insurance, no private pension etc.

Paid attention to investment in business, land, property, private investments in shares etc. Hopefully it will keep its value.

My son have made a little fortune out of crypto. He is a skilled shorter.


PS. Should get partial state pension due to "lenght of service" but if state have elected to default and cheat me I don't care. Come in - nice, if not - can do without.

Edited By Martin Dowing on 23/04/2018 09:12:32

Thread: Silver steel
22/04/2018 20:20:55

Your steel might be delivered in annealed form or you may purchase it as such. Otherwise heat it to about 800*C in molten salt bath (NaCl/KCl), cool down *slowly*, wash with water and dry.

Wind a spring, heat it to 760-800*C, best in furnace or molten salt (KCl/NaCl) bath and austemper it, eg quench into molten sodium or potassium nitrate bath at 300*C bath themperature.

Keep at 300*C for 30 minutes more, take out, cool and wash with water.


Thread: Home workshop fatal tragedy
22/04/2018 19:37:52
Posted by David Clarke 21 on 22/04/2018 19:16:12:

Back to the original posting,

As Hydrogen is clearly not the useful fuel-gas that it might seem, maybe the intention was to create Oxygen to boost the power of a conventional (propane, etc.) torch?

Electrolyse water, collect and use the Oxygen, the Hydrogen (lighter than air) will just float away and ...

From practical point of view it is rather difficult to produce sufficient amount of hydrogen to cause a reasonable explosion without deliberately collecting it somehow.

Approximately 2 x 96500 C (say 200000 C) of electricity would be fequired to produce 1 mole (22.4 L) of hydrogen (H2) gas at 1at/RT.

To blow up a shed in a spectacular way as reported by neighbours at least 100L of hydrogen would be needed and this would need to be generated fast enough to prevent dispersion.

To get there you would need about 1-2 hours of work of 200A power supply, depending of exact setup and well sealed shed to prevent hydrogen loss to outside.

In well aerated shed you would probably look for 1000 A power supply - unlikely at amateur disposal.

Conclusion: Hydrogen was deliberately collected and something went wrong. Possibly it was not separated good enough from oxygen produced on anode... and a burner was tried or cigarette lighted on etc.


Thread: Plastic Ban
22/04/2018 19:18:14
Posted by An Other on 22/04/2018 18:54:41:

I live in eastern europe (about 10 years now), and it is clear there is a major attitude difference here: rubbish can be and is dumped anywhere - there is no education or information about the damage this causes. Although countries like the UK may be taking steps to curtail single-use plastic, such as PET bottles, the manufacturers are increasing their use of them in other countries. Drinkable water is a luxury here, so literally tons of bottled water is sold every day - all in PET bottles. Companies churn out cola, sticky 'fruit' drinks, in fact anything which will go into a bottle, goes into a PET bottle - and its no exaggeration to say most of these end up thrown to the side of the road here. (Rubbish collection is also almost unknown).

Hi, I also live in EE (Poland) for sometime and in our local area they have a nice recycling policy.

Local authorities are encouraging residents to segregate plastic by offering 50% discount for refuge collection.

Many of residents are doing it. Then bin men are coming and taking segregated bin only to mix them in the landfill again. Local chancellor is officially happy because EU quotas are satisfied and authority does not pay fines for underrecycling but in private she would admit that entire exercise is a nonsense. There are some hopes that we will be sending it to Ukraine where it is used as a fuel. These are good news but not for Ukraine.


Thread: Cutting a dovetail
22/04/2018 19:02:41

Read Harold Hall's milling tutorials for good idea how to do it.

In general make first square slot, then finish it off with dovetail cutter in few passes from each side. Make both sides in one setting to ensure good degree of parallelity, which is usually not too critical anyway as a gib strip will take care of it.

If it need to work really smooth, you will need to scrap it at the end and that is not easy.


Thread: Home workshop fatal tragedy
22/04/2018 18:34:11

Regarding Hydrogen Economy.

From my life long experience as a research chemist and in depth understanding of the subject - it has no future and it is going to be more expensive than alternatives, including batteries.

Small amounts of hydrogen might be produced during chemical processing including waste processing and used locally small scale but using electrolysis to produce hydrogen for ICE on a large scale is just stupid.

Cheaper is to charge battery with available electricity and adequate tech is already there.

Regarding HOH "wonder gas" - just fraud to milk cash of stupid.

Hydrogen is great for manufacturing chemicals like ammonia but thats about all. It is a very good fuel but only for Apollo missions or a shuttle.

Numerous projects to develop it as a general fuel are around only because government (or taxpayer) money are freely available to waste.


Edited By Martin Dowing on 22/04/2018 18:43:02

22/04/2018 18:21:32
Posted by Muzzer on 21/04/2018 23:51:37:

There's nothing magical about hydrogen. If it's not mixed with air / oxygen, it simply burns like any other fuel, albeit no carbon, so no soot. On the other hand, almost any combustible material will explode if correctly divided and mixed with oxygen eg coal dust, sawdust, flour, petrol, LPG...hydrogen etc etc.

Using hydrogen as a coolant is "2000 times better than air" presumably because it changes state from liquid to gas ("phase change", "heat of evaporation" etc) in the process. Rather like water or ammonia or any number of liquids / refrigerants.



Hydrogen is better heat conductor because it has smaller molecule and much higher velocity of molecules than air components like oxygen or nitrogen do under the same p/T conditions.

For the same reason argon and even more so heavier noble gases are good heat insulators - slower mooving molecules.


22/04/2018 18:03:27
Posted by vintagengineer on 21/04/2018 13:13:36:

Propane is a welling gas so should not be stored below ground level!

Hydrogen is very easy to produce, just pass an electric current through water!

Edited By vintagengineer on 21/04/2018 13:14:48

It is even easier to produce hydrogen by dropping a piece of aluminium to caustic soda solution. This way you can produce it up to any reasonable pressure, eg 200at if done under proper enclosure, eg in empty gas cylinder. Make sure you know what you are doing while attempting that because you may end up like this unlucky chap.

Btw, neighbours of the guy who were talking about something like "nuclear explosion" obviously didn't see one.


Thread: Plastic Ban
22/04/2018 13:36:56
Posted by Clive India on 22/04/2018 10:59:13:

Put my hand up - I use straws and cotton buds so why should they be phased out because some dispose of them irresponsibly? I recycle where I can, stupidly taking the tops off bottles and saving them for the tip as hard plastic.

Buy 100 packets, bar your wife from touching them (if you have a wife) and you have got life long supply. They are cheap enough.


22/04/2018 07:18:00
Posted by Mick Charity on 22/04/2018 07:02:08:

The only truly green product is a product that was not manufactured. This is totally at odds with a capitalist economy & therefore there will never be a truly green product until you tackle the economy.

Collecting plastics & shipping them off to China is not recycling, it is dumping.

Engineering is an art of compromise. Surely we *can* manufacture packaging materials of sufficienty low environmental impact and degradable fast enough not to bother us. Technology *is* there.

Solution for electrosh*t on the other hand could take a form of compulsory manufacturer warranty for 5 or 10 years to legislate out cheap disposable crap. I have TV 30 years old (Sony Black Trinitron). Quality of reception still beats many modern plasmas and LCDs. It have *never* seen service albeit on 1 occassion I have replaced a fuse myself.

I have also several warm light energy saving compact fluorescent bulbs made 20 years ago. They were 10 queeds each at the time but maybe 2 of 20 are blown by now. Current versions won't last more than a year or two.


22/04/2018 06:47:07
Posted by Georgineer on 19/04/2018 20:27:04:
Posted by Michael Gilligan on 19/04/2018 12:22:38:

According to BBC News:

Announcing a consultation on a possible ban ministers said 8.5bn plastic straws were thrown away in the UK every year.

Assuming the population is about 70 million, that's three straws per day for every man,woman and child. And somebody must be using six per day, because I haven't used a straw in years.


Your maths is off by approximately 1 order of magnitude. More like 0.3 per person per day.

If they want to attack plastic problem, the first place to look at is food packaging industry. For example by setting a standard stating that no more than 0.01% of brutto weight of food can be a plastic.

Return to glass bottles for drinks and force shops by law to accept returns for money deposit. Oblige shops to accept returns without proof of purchase from a given shop. Set a price of bottle high enough to make sure that 95% of consumers pay attention to its value and set final price paid by drink manufacturer for recycled bottle high enough that shops are making profit too. If cheaper to manufacture new than collect recycled, tax new bottles until making new is more expensive. Make unified standard for soft drink bottle, wine bottle etc so they are easy to refill by any manufacturer. The same for jam jars and other common packaging. Permit aluminium for light weight "convenient" drink packaging. It corrodes fast enough and already there is a good incentive to recycle anyway.

Make an exception for biodegradable plastics, eg those easy digestible by microorganisms with environmental halflife less than 6 months or so.

Bans on toothpicks or cotton buds are lipstick on pig but in an era of reign of stupid everything is possible. I wonder when they will legislate in paper condoms.


Edited By Martin Dowing on 22/04/2018 06:58:06

Edited By Martin Dowing on 22/04/2018 07:03:10

Thread: Wind turbines get bigger and bigger
06/04/2018 22:22:08
Posted by richardandtracy on 06/04/2018 21:41:42:

With subsidy rates tumbling, it is no-longer about the subsidies. If you are stupid enough to rely on subsidies, you are basing a business plan on the word of a politician. Politician's words are worth the water they are written on. If there is a subsidy it needs to be the icing on the cake, with a sound business underneath. Subsidies can be withdrawn at a moment's notice - as they were for solar plants in the UK. The withdrawal of subsidies has not stopped solar farms, because they are economically viable without subsidies. There is a community funded one up the road from me, started after subsidy withdrawal, and most local residents are now getting cheaper power because of it, and the farm is still making money.

If it's all about making money, where is the harm in it. It's the way capitalism incentivises people. But relying on subsidies is the best way of destroying your business because it puts your business in the hands of those who have nothing to lose when the political wind changes.




Richard, I disagree with you. You are writting how things *should* work, unfortunately they are working entirely different and we are no longer living in capitalism.

Subsidies are extremely important for businesses now because they are one of last remaining lifelines for them.

So lets beging with our Western banking sector.

Do you really believe that it would still exist in current form without *subsidies* from taxpayer following Lehmann Brothers collapse?

Now look on all these European projects. There are subsidies, EU funds everywhere. Any green, less green and not green at all but politically well connected entity will get EU subsidies for some esoteric green projects.

The same holds true with entities promising innovation. There are countless subsidies there, owners and managers are getting rich enough to buy mansions, luxurious cars and porn star girlfriends but hardly any innovations are coming out of that. One time I wanted to buy an item from engineering company which is thriving on subsidies. Purchasing procedure was so complex that I have realized that I have incurred more cost on this company than any possible profit they could make by selling me ordered item. I have asked manager over the phone why it is so and he was surprisingly honest. I was advised that they are living off EU subsidies, they may not sell anything at all as long as they are keeping up with production of documents as required by Brussels and that it *is* their business model. I have asked "what then?" Answer was "Then we will be rich so we can close down or apply for grants in another project".

Doing business in an honest way is long time gone. Now we are left with fraud, ripoffs, corruption, subsidies etc. This is last show in town before lights go off.

Capitalism no longer exists.


Edited By Martin Dowing on 06/04/2018 22:25:11

Thread: How to paint aluminium
06/04/2018 15:16:50

Many thanks for suggestions.

I have purchased spray etchant in specialistic shop supplying car repair businesses. Seller is very confident about its performance.

Yes, it is sometimes good idea to search older threads.


05/04/2018 22:04:09

I have made of aluminium quite nice switchbox dedicated for motor control.

How to paint it? It is known that most of paints do not stick to aluminium and anodizing means much troubles. Chemistry is easy enough but I really want to avoid troubles related to purchasing appropriate chemicals and making appropriate bath, all just to make an odd item looking nice.

So any paints which will stick to aluminum well?


Thread: Trade wars and this hobby
05/04/2018 20:14:47

For those who believe in Sandvik carbide tools/inserts are made in Europe mythology here is an interesting reading:

Don't forget to check the date of this release...


Edited By Martin Dowing on 05/04/2018 20:26:09

05/04/2018 19:28:17
Posted by HOWARDT on 05/04/2018 18:26:39:

Perhaps we in th uk have been told we can’t do this and that for too long. I have worked through it as have most on here for all our working lives. Too many people looking for the easy option in work, 35 hour weeks not 60. While I accept we can’t compete with the Far East on many things there are still others we can. We are all guilty looking for the cheapest option yet many will pay £4 for a cup of coffee that cost 4p at home. So do you make and buy UK or accept to buy cheap with lessening Uk manufacturing income.

You often don't even know what you are buying. On many occassions you are convinced that you are buying UK goods only to get Far Eastern/Romanian/Bulgarian imports.

I have ML7 lathe so buying spares for it from Myford (Mytholmroyd) or RDG should imply that I am buying UK production. Yet I am quite convinced that custom made Far Eastern or Eastern European imports are usually delivered and all what is done in UK is label sticking and packaging. Quality is often questionable as well, perhaps because cheapest (and crapest) Far Eastern manufacturers are selected and their price still bargained down as much as possible.

Another thing is that for items like carbide inserts, torx screws, boring heads, broaching sets, ACME taps and many others I will not overpay 3-50 fold to keep bureaucrats happier, welfare m(b)ums even fatter and lazier and for immigrants to get more benefits.

By buying it in UK you are usually *not* supporting local manufacturer only cheeky trader who imports it, sometimes sticks "made in UK/EU" label on, rips you off and laugh all the way to bank. If not that it will ofen be a corpo with production facilities in China and some of managers and accountants located here. That is what "made in UK/EU" usually means these days.

For those abhorrified about possible tax evasion:

You can buy carbide inserts £ 0.2 each via Banggood from Netherlands stores and diamond coated grinding discs worth 4 packets of peanuts, countless other similar products all of superb quality. So EU duties paid, all done lege artis and pimps may p**s off.


05/04/2018 15:57:02

DMB & others,

I am not a fan of EU at all. In the past it was great as free market agreement but now it is no more than troubled and failing social engineering project. The faster it goes to dustbin of history, the better. However I would still support former formula, eg free trade agreement.

One way or another countries belonging to so called Western civilization must realize that they no longer have a global influence like used to be in the past. They have constructed defunct socialist/liberal systems no longer competitive on global scene. At the moment it is only a threat of military force, which prevents other nations from grabbing most of wealth and influence but superiority of this military force is already questioned. It was easy enough to bully Iraq, Afghanistan, Libya or Serbs but really nothing lasting was achieved and a lot of money gone wasted

Syria is the first place where Americans have suffered conclusive defeat in this century, North Korea seems to be a non starter, Iran too. Relations with Turkey are turning more and more disastrous.

It seems that "democracy", "freedom", "women rights", "gay rights" or any other BS no longer can be exported elsewhere. Interests of huge foreign powers are under threat and further efforts in this direction will only result in trade wars, economic collapse and who knows, maybe even atomic war.


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