Looking for a non-magnetic, strong, easily glued material

Once a source of 1mm sheet is located maybe we will be asked for ideas on how to cut it and down chamfers on the edges...

Using nothing more than string and the power of stubborn thinking

Thank you for all your thoughts, folks. [Albeit what a strange reaction from some of you!]

I was hoping that you might be able to furnish me the names of model-making suppliers because as we all know sourcing small amounts of industrial materials can be difficult to locate, slow to arrive and suffer from large minimum order quantities.
I just wanted some suggestions as to what materials that I hadn't thought of, and which might also be swiftly available.

Time is short and I don't need a perfect solution. And I am assuming that you lot have better things to do than to read my PhD. But to save time I have carefully given you the broad constraints which should suffice.

I couldn't locate any higher performance Aluminium last night, so to keep things moving I have ordered some Grade 1050 Aluminium plus some 316L Stainless Steel in 1mm sheet from Amazon. I suspect that the 1050 is probably a bit soft and I am suspicious that the 316L will be under 1mm (as well as the paramagnetic concerns), however one or other may do the job well enough for now, and both of which should arrive within 24 hours.

I spoke to direct-plastics.co.uk, (good suggestion, thank you Andrew!) about Tufnol of which there are various sub-types. However they said that a) it can chip on impact and b) it's not black. Instead Direct Plastics suggested black Nylon 6 so I ordered a small 1mm thick sheet. Nylon 6 it can be hard to bond with standard epoxy resins, but they suggested Permabond TA4246 (a "2-part, no-mix, room temperature curing structural adhesive"  ), which I have also ordered from GlueOnline.co.uk who offer a next day delivery. The Permabond TA4264 should like it will be useful for other stuff I am working on.

If the 1050, 316L and Nylon 6 all fail, then fibreglass (FR4) will be next on my list.

I think most woods are will be softer and less good a resisting abrasion than each of 1050 Aluminium and 316L stainless. Any normal paints will presumably abrade off as well as require a really good bond so I'm not going that direction for now.

Don

Edited By Donald MacDonald 1 on 28/04/2022 13:01:04

How about coating something with CeraCoat (spelling?) an industrial ceramic coating?

Correct, but I'll make a deal, you read mine and I'll read yours. Mine is mostly mathematics, associated with pulse compression radar signal design and Fourier transform processing.

It's magnanimous to fed us the constraints that you feel are sufficient, but if you're having to ask these questions I wonder how you know what is sufficient? Can you put some numbers on the requirements?

The sheet of 1050 is almost pure aluminium. Consequently it is very soft and horrible to work, by machine or hand, like warm fudge. It's basically useless except for low stress sheet metalwork, which is why it is only available in sheet form.

Andrew

PS: A copy of my Ph.D. is available for reading in the Cambridge University library, where is yours?

Edited By Andrew Johnston on 28/04/2022 21:06:35

@Andrew Johnston
Good. So I think can both agree that we both have better things to do than boost our Egos by reading anybody's entirely unrelated PhD theses just to prove some point on a forum.

Yes, we also agree that although cheap and widely available that 1050 Aluminium is a broadly horrible engineering material. Knowledge of the point was precisely the reason for my starting this thread. Only because time was against me did I buy some more 1mm thick sheet.

@Bill Pudney Yes, assuming that the 1050 works adequately magnetically, I shall keep searching for a small piece of Grade "2024 T3" "7075 T651". But first I also have the Nylon 6 to experiment with, which should arrive shortly.

If anyone happens to know of a model-making friendly supplier of such grades of Aluminium [1mm sheet, small samples, fast delivery] please let me know

And if I find a good supplier myself I shall let you folks know.

Don

Mr McDonald seems to have forgotten to answer Andrews question, just a gentle reminder for him.

When anyone asks me 'Where can I get it' but they do not say where they are, I wonder if they have really thought through their question. It always helps to stand in the shoes of the other bloke, and tell him what he needs to know - even if he might possibly already know it. Or her, of course.

Tim

Baz, I can't see any genuinely relevant questions, and I'm not going to get into a war of words. Sorry.

Tim, I am on mainland UK. Given that I am not very mobile, I don't intend to leave the house if I can avoid it in any case but deliveries work well.

The relevant question is that you claim to have a PhD, Andrew told us about his and stated it can be read in Cambridge University library and asked where yours was, it is not a war of words it is a simple question, please let us all know about it and where we can read it.

It's all got a bit silly. I think we need to remember we are all here because we support an enjoyable, inclusive hobby.

I've failed to meet Requirement ' G. Needs to be available... fast! (ideally within 24 hours)'!

Have to say, when searching for an engineering material, it's not good to limit choices with purchasing considerations and colour restrictions.

However, on the face of it, an Austenic Stainless steels comes close to meeting Donald's needs. Unfortunately, he rejects Carbon Fibre, suggesting he's doing something very special because Carbon fibre magnetically outperforms most Austenic Stainless Steels.

It would help to know if the sheet's purpose is to protect a permanent (or electro-) magnet from dirt and dings, or to allow a magnetic field to reach a sensitive detector. The attenuation caused in the first situation can be overcome by using a more powerful magnet. The second case is more difficult. Having to join the dots in Donald's partial requirement is unhelpful: I guess the unstated need is to protect a big magnet rather than a sensor because electric fields haven't been mentioned - yet! Could be wrong.

Anyway, if 'A. Completely non-magnetic' really is important, then Donald needs a particular grade of Stainless and it needs to be worked carefully. Not 316, or 316L, but 316LN. 316LN is formulated to minimise it's magnetic effect, and to be less susceptable to having it's magnetic properties trashed by cold-working, flame-cutting, or welding. It's not just the material, it may be import to use it properly. (A few other grades like 304LN, 305, or 310 would perform as well as 316LN.)

But I suspect Donald's requirement may be carelessly worded and ordinary 316L is fine. If so that's a good thing because 'almost non-magnetic' stainless steels are easier to find and use than 'Completely non-magnetic'.

Not throwing rocks at Donald, the point is Requirement Writing is difficult! Sadly, what's crystal clear in the mind of the writer is often morphed by the written word and the reader trying to decode it into an ambiguous, contradictory muddle. Some advice on Requirement Writing, here and here. Note the second link kicks off by saying: 'It has become clear that enormous numbers of engineering design errors originate in the requirements document.' Too true!

In formulating requirements I recommend:

• Giving as much information about goals as possible. (Writing requirements when the goal is secret is exceptionally difficult because the writer has to get everything right. He cannot rely on the reader to second guess what he's after. If the writer doesn't get it spot on, the reader loses confidence in him.)
• Ideally, requirements should concentrate on what things have to do, not how they should do it. Avoid steering towards particular technical answers.
• Always use the word 'must' or 'should'.
• Aggressively self-criticise 'Must' requirements before release because they severely cramp the solution, often in unexpected ways.
• Word 'Must' requirements to get clear yes/no answers. Reword the requirement if 'yes but' or 'no but' answers are acceptanble: it's either badly worded or is a 'should' requirement.
• 'Should' requirements are only desirable and should be weighted to indicate their relative importance. The requirement must be worded such that the response is measurable.
• Numbers should be used wherever possible.
• Avoid unquantifiable words like reasonable, easy, fast, quality, good, strong. They don't help!
• Don't use show-stopper words like 'completely' unless absolutely essential. Many projects fail because over tight requirements carelessly commit them to expensive, unattainable, or time-wasting solutions.
• Get someone else to review the draft and don't take offence when one's pride and joy comes back plastered in red-ink!

Dave

The voice of sanity.

HONESTLY!

Don

Just a thought [almost sure to be rejected but here goes] …

The thin glass sheets which are used as screen-protectors are hard, non-magnetic, and easily glued with LOCA UV-curing adhesive.

MichaelG.

Woohoo - hello People!

I saw my name being mentioned.... so I thought I'd drop in.

I have to tell you people, that this thread is absolutely HILARIOUS.

I don't know if you gents are being serious or whether it is deliberate self-parody but this thread is absolutely heaving with self-parody.

Poor you Don - now you know what I went through. The wolves won't let go until you publish every single detail of your life & your project... At which point expect to be told that your living in the wrong house and doing the wrong project!

How you people have time to write all this Lord knows, but I hope everyone is enjoying themselves... or is it "oneself", I forget grammar never was my strong suit.

Good luck!

J

PS Don, you have no right to any opinion on which hobby model engineering materials to use on until you have done at least a degree in mathematics, radar signalling and Fourier transform processing algorithms, and obviously you need to have read several papers on how to write an engineering specification before daring to seek any such advice.

But if your PhD is on "Comparing and contrasting the social anthropology of washer-women with online forums of highly educated gentlemen with too much time on their hands, based on the the competitive power dynamics of male specimens of the common Chimpanzee" then you've come to the right place.

Wait, I have just the book for your PhD: "Chimpanzee Politics" by Frans de Waal. I'm told it used to be on the list of required reading for US White House interns.
https://www.amazon.com/Chimpanzee-Politics-Power-among-Apes/dp/0801886562
It's an excellent read, BTW. Highly recommended.

I'm going to scuttle away now before Armageddon kicks in!

Have fun chaps! Byeeeee... xx

Edited By John Smith 47 on 29/04/2022 16:52:30

Where?

Robert Butler

Looks as if the Mod's removed it !!!!

I would have thought you guys would have woken up by now - there's basic time wasting and there's advanced time wasting and then there's some bloody serious time wasting

Donald's PhD subject possibly - he certainly appears to be a master at it

But then what would I know - I've never been educated - in some eyes

Tug

At the risk of going back on topic…. Lasaero.com list both 2024-T3 and 7075-T6 in 0.040” thickness. 2024 is out of stock, but would not really suit: they only do Alclad, which has a thin coating of pure ally both sides, so it fails the scuffing requirement. They do have 4’ x 2’ sheets of 7075-T6 showing as in stock at £45, and they are based in the UK.

I used to work for a seal-less pump manufacturer we manufactured our own magnetic drives, they used stainless steels of varying specifications to meet the product conditions, some of which were highly abrasive or corrosive, the magnetic drive operated through the stainless steels with no problems, my choice for this application would be the appropriate stainless steel. Dave W