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Member postings for Derek cottiss

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

Thread: home made forge
08/01/2021 17:15:38
Posted by Ady1 on 08/01/2021 14:06:01:

A long time ago in an internet galaxy far far away I recall reading the website of a chap who was taking the microwave route for smelting

He was heading up past 800 degrees C at the time, maybe his site is still out there if you search about

Here's a simple one but the more serious guys are definitely out there

guess he had to change his trousers

08/01/2021 13:43:10

Interesting hour on the phone with Noel last night , more questions to think about i think .

Yes it is 12 inch diameter im thinking maybe ceramic blanket but not sure if this needs a 'hardener '

more research i guess

Thread: Yet another scam lathe sale on ebay to be aware of
07/01/2021 16:02:42
Posted by Anthony Kendall on 07/01/2021 11:10:44:
Posted by Derek cottiss on 07/01/2021 10:14:41:

so if we get the guys name and bid his stuff up to silly money then cancel 24hrs before or win and collect ?

You could, but you would be an irresponsible trader and, hopefully, dealt with as such.

I find ebay a valuable resource - been in it from the start with 1500+ transactions. Altering algorithms etc. has so far only resulted in making it more difficult for genuine traders whilst trying to prevent others from being stupid.
I think anyone who bought a lathe unseen and then, still unseen, paid by bank transfer would be being amazingly stupid.
Leave ebay alone please.

i guess with 2300 odd feed i kind of know how it works sadly people trust each other on the whole and people like that seller ruin it for the majority as do the dodgy buyers . E BAY dont really care as long as they get the listing fees i guess as for them its all about the profit (something we caught them out on years ago with their incorect interpretations of VAT chargable but that was on our old business account ) .Make it difficult or time consuming for the scammers and they will go away . But you know best mate crack on ...

07/01/2021 10:14:41

so if we get the guys nane and bid his stuff up to silly money then cancel 24hrs before or win and collect ?

Thread: home made forge
03/01/2021 19:52:06

So after having this bottle for over 20 years , Calor didnt want it back the valve put up a serious fight until the cutting wheel on the angle grinder came out that is . Current thought is to cut the top off (creating a lid ) and remove the centre section to create a flue . Any thoughts ?

03/01/2021 19:48:11

gas bottle.jpg

01/01/2021 18:13:36
Posted by not done it yet on 01/01/2021 14:31:43:

Sorry to say, but most modern-day cartridge cases will be magnetic, so probably hard luck on that one. Caps may be brass, at least on the outside. Many bullet cases will be brass, but not checked any recently.

Shotgun cartridge cases yes rifle cartridges cases are normally brass the bullet goes in the case normally lead but copper is being introduced for some game shooting ..

01/01/2021 14:27:06
Posted by Engine Builder on 01/01/2021 12:52:36:

Let's get the terminology right, it's a furnace that melts metal, a blacksmith would use a forge.

This waste oil burner uses a low cost nozzle..


Edited By Engine Builder on 01/01/2021 12:54:27



yep my mistake thats the clip that got me thinking you can get most of that burner online for about £30

Edited By JasonB on 07/01/2021 10:53:31

01/01/2021 11:54:44
Posted by SillyOldDuffer on 01/01/2021 11:31:37:

Oil is the best fuel available and engine oil is no exception. Plenty of heat in it but it's not easy to burn efficiently. To maximise heat and minimise nasty side effects it's necessary to use a burner as described by Les. The burner controls the mix of fuel and air for optimum results. Otherwise, engine oil is difficult to ignite and liable to incomplete combustion producing clouds of thick smoke, likely toxic, and not much heat.

Lead is easily melted (368°C), but Copper, Aluminium and Brass need about three times the temperature. Copper 1084°C, Aluminium 450 to 700°C depending on the Alloy, and Brass 900°C to 1100°C again depending on the alloy. All within reach. Cast-iron and steel require even more heat, and an improved design.

Outdoor job, well ventilated, not for pregnant ladies. Get lead much too hot and off come poisonous fumes. Molten brass loses Zinc, altering the properties of the metal and a serious health hazard if done on a large scale or in a confined space. Brass founders usually add Zinc back to replace that lost during the melt, but for amateur purposes the exact composition may not matter. Aluminium is safe enough, but if melting scrap don't mistake Magnesium for Aluminium. Magnesium is much more likely to catch fire than most metals and it explodes if water is used to put it out!

A potential problem with home melted scrap is the unpredictable output. Alloys vary considerably depending on exactly what's in them. Cartridge Brass is different from Plumbing Brass which is different from Hard Brass. For making rough castings and ornaments it probably won't matter, but expect trouble if anything high-tech is attempted, like machining.

Can you report back when you get it working? It's an interesting subject.


i see lead and scrap aluminium being the main candidates although turning cartridge cases into something that doesnt look like cartridge cases would make them acceptable to the scrap dealers

01/01/2021 11:52:10
Posted by John Haine on 01/01/2021 11:39:13:

Do you want a forge, or a furnace? A forge sounds very inefficient for melting metal. Also burning waste engine oil is likely to be very polluting with the various additives from petrol and their degradation products let alone the CO2.

The excellent Mike Cox describes a furnace for melting metals here that uses propane - much more environmentally friendly (and neighbour friendly too I suspect).

You could be right that design would probably be better as for the waste oil burning versus propane re emisions i can measure the exhaust content to a point so will have a look into it and compare the differences ,Wate oil is currently burnt in heaters once vaporised at acceptable levels though

01/01/2021 10:55:44
Posted by Les Jones 1 on 01/01/2021 10:47:37:

I have made a waste oil burner for my furnace using a Hago Delavan syphon nozzle.
This is a link to the design of my burner but you will find some other designs on the web.
This is a link to the blower system I used.


what sort of presure do you use to vaporise the oil ? and i take it it burns clean ?

01/01/2021 10:23:15


i have another hobby which involves the need to melt and cast lead as well as a pile of copper aluminium and brass so i need a forge (or want)

I get the idea of building one but i want to run it from waste oil .

So will it produce enough heat from vaporised waste engine oil and has anyone tried it ?


Thread: Arduino programming?
23/11/2020 09:45:43

i have a project that a guy was doing the coding on but has become less than reliable .I can handle the mechanical manufacture side but cant or dont (too lazy maybe) have a clue with the programing . So if anyone fancies a chalenge please get in touch

Thread: Could a Car A/C pump be converted into a compressor
11/11/2020 12:44:03

would a range rover suspension pump not work easier ?

Thread: Warco Major Mill
28/09/2020 21:20:50
Posted by John Rudd on 28/09/2020 18:21:43:

Go to your friendly local electrical wholesaler and buy a 240/110 control transformer rated at 200VA.....

if you can wire a 13A plug, you can wire up the transformer easy enough....

I paid around £30 for mine then another £20 for a suitable enclosure....still cheaper than buying from 'tool merchants'

what did you use as the motor ?

No doubt other members will share their pearls of wisdom...

28/09/2020 18:08:30
Posted by Nicholas Farr on 28/09/2020 18:02:49:

Hi Derek, you can get a power feed at power feed Warco. Just scroll through the accessories

Regards Nick.

Edited By Nicholas Farr on 28/09/2020 18:05:31

saw that just wondered if there were better /cheaper optioms as if i buy it all from Waco its more than the mill ...

28/09/2020 17:30:46

im about to take possetion of a major mill drill s/h

would like to add power feed and a dro any suggestions what to look for and from who ?

thank you

Thread: milling machine which one ?
30/05/2020 15:21:43
Posted by Howard Lewis on 30/05/2020 07:27:38:

Having decided upon a machine (If possible, a little larger than you first anticipate ) The budget needs to cover some extra items.

You will need some tooling with the machine, whatever you buy.

You will need a vice (Buy a good one. A flimsy vice will spoil accuracy, at least.) It needs to be an appropriate size for the machine. Tilting Vices can be useful, but are less rigid, and can be bought as and when the need arises.

A Clamping kit may eventually prove useful, depending on what you do.

You will need a proper chuck to hold cutters, NOT a drill chuck. My choice would be the ER system.

Depending on what you want to do, you might need more than one size. ER25 will cover upto 16 mm, so may be a good starting point.

You will need End Mills, probably Slot Drills of various sizes, possibly one or more Face Mills..

You will certainly need twist Drills and either Spotting or Centre drills.

You are likely, eventually to want to cut threads, so you will need Taps and Dies. Again, you may well end up with several sets covering different thread types (Metric, posibly BSW, BSF, or even BA )

If, in the future, you want to produce regularly spaced holes, curved surfaces, or cut gears, you will need a Dividing Head or Rotary Table, preferably with a Tailstock.

You will need measuring equipment.

A digital Calliper would be a starting point, plus, possibly a Plunger Clock, and Finger Clock, maybe with a Magnetic Base. Later, you may decide to buy individual Micrometers, maybe even a Bore Set.

A six inch steel rule will be useful, if only for rough setting up.

Things like a n Edge Finder, or a Wiggler, and a Centre finder, are low cost accessories which make life easier.

You don't need to buy everything at once.

Buy the basics first of all, and add extras, as you see the need arising.



most of the bits and pieces i need are in my workshop allready as i have had access to a bridgeport . sadly space for a bridgeport isnt available hence the question re the other machines

29/05/2020 22:31:54
Posted by Steviegtr on 29/05/2020 17:57:44:

Look at top right of this page. arc eurotrade


thank you

looks like they dont supply anything big enough

29/05/2020 17:23:20
Posted by Brian H on 21/05/2020 15:43:13:

Hello Derek, I'm assuming that a vertical mill would be more use to you.

The Tom Seniors are nice machines but the 'S' type vertical heads command a premium price and of course, being second hand, the quality is not certain.

I have no personal experience but the Sieg range of machines from ARC always seem to get a good write up and their latest machine falls within you budget.

If you find a machine and want to know the history and technical details without bias then go to;


There are often machines for sale on there.


cheers for that who are ARC ? any links ?

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