Need help sourcing 3mm plywood

[Daydream believer]

WhenI had my joinery business ( sold it 20 years ago so may be out of date now) I used to buy cases of 1.5mm aircraft plywood ( for laminating into curved sections) from James Latham. I expect that that they can supply other thicknesses.
I see that they now have a branch in Purfleet so it is just through the Dartford tunnel & not too far from Kent
Main depot used to be round Hackney area

 

[Lomax]

WhenI had my joinery business ( sold it 20 years ago so may be out of date now) I used to buy cases of 1.5mm aircraft plywood ( for laminating into curved sections) from James Latham.

I have looked at their website dozens of times over the past year - they certainly mention a lot of interesting board materials, but they make everything sound super exclusive and never say a word about what is available from stock or what it would cost. Which makes me think that the old maxim "if you need to ask what it costs you cannot afford it" applies. Doubly so when you realise most of the materials I'm interested in are produced in France, Italy, Germany, Finland, Sweden, Poland or the Baltic states - all of which became inaccessible on Jan 1st, unless you're willing to accept extortionate fees and month-long delays. And James Latham are far from the exception here; it seems most companies who deal with anything which might resemble a quality product are schtumm about prices or availability; mere mortals it seems are better served in that big orange place where everything comes from China - and everything is ****. I have tried multiple times to contact companies who sell various kinds of laminate sheet materials and nothing has ever come from it. I only need six 8x4' sheets to cover the ceiling, which is probably not enough to warrant a delivery from the mainland. I either don't get any reply at all to my inquiries or I'm fobbed off. It's gone so far that I've had to develop my own theory for why thinner board products have disappeared; I think it's partly because there's less room for cheating, and hence less profit margin. 18mm ply can be made up of pretty much any kind of crap, while producing usable boards below 5mm requires skill and effort. The other part is that our current economy encourages volume above anything else, and many things we used to be able to buy over the counter have now become "specialist products". This applies to anything from tools & machinery to raw materials, fasteners, and chemicals. Massive inflation is hidden in mainstreaming and loss of quality.

 

[boatiebert]

Not sure of the sheet dimensions but you can get 2mm bamboo. At that thinness, you're down to a thick veneer which you can get in woods as well, e.g. 2.5mm Sapele.

BTW, without invoking the B-word, are we going back to imperially sized 8 x 4s now, instead of those ridiculously monikered 2440 x 1220s?

 

[Lomax]

are we going back to imperially sized 8 x 4s now, instead of those ridiculously monikered 2440 x 1220s?

I don't know about you but I've never had any trouble incorporating both systems. Metric is of course far easier, since it uses base 10 and has well defined relationships between different physical quantities, but I'm happy to accept imperial for historical reasons. 1/8" 8x4' doesn't make any more (or less) sense to me than 3mm 2440x1220mm, but a third the thickness is definitely easier to visualise as 1mm. Your right to call it 1/24" (and be off by ~6%) has never been in question.

 

[boatiebert]

1/8" 8x4' doesn't make any more (or less) sense to me than 3mm 2440x1220mm

It may be equally sensible to you, but it's one hell of more of a mouthful to say. Even a "gimme a metric 8x4" still has less syllables than "give me a 2440x1220 sheet".

Count them out

two half inch eight by fours please.​

two twelve mil two thousand, four hundred and forty by one thousand, two hundred and twentys please.​

​

What do they sell sur le continent, 2 x 1s? (Metres). That would make sense.

As far as I understand, 8 x 4s were basically designed around the principle of what a manly Anglo-Saxon could pick up and move by himself.

 

[Lomax]

Thank you for the entertaining contribution. It might interest you to learn that most of the western world used some form of base 12 inch/feet length units for hundreds, if not thousands, of years, and for traditional reasons those units are still reflected in the dimensions of many things like timber, nails, packaging of eggs - and the dimensions of boats. Inches, feet, dozens and fractions are no British constructs, just oldy worldy things that the rest of the world have long since moved on from. It's quite ridiculous to think that you would like to see their return, presumably because they are somehow untainted by foreign influence, when in reality you got the system from the Saxons and the Romans. And a metric customer would never call it a "twelve mil two thousand, four hundred and forty by one thousand, two hundred and twentys" - it's just a sheet of plywood.

 

[boatiebert]

America though.

Mind you, even Harleys are becoming a confusing mixture of Imperial and Metric.

And a metric customer would never call it a "twelve mil two thousand, four hundred and forty by one thousand, two hundred and twentys" - it's just a sheet of plywood.

If they were an 8 by 4, I called them an 8 x 4 because a "sheet" could be a full or half sheet. But I'm sure, as with pallets there were Euro sizes too. At least in Euro land.

I mean, who's going to boast that theirs is 304.8mm "but that they did not using it as a rule?" Just wouldn't make sense.

Metric should have been invented around fractions of 8x4 and not off a pendulum or meridian.

It might interest you to remember that the Paris inch was longer than both the English inch and the Vienna inch, as the ladies in Montmartre were wont to remind one; and, historically, the Scottish pint was more than twice the size of the English counterpart, which figures. (If it's your round, I'll have pint of Scottish beer). They weren't inches though, they were pouces or zolls.

Were you born or educated after 1985?

Personally, I'm feet and inches over an inch, but millimetres if less then an inch, except if it gets down to thous, at which point I'm back in inches again. It's an age related thing. Like alzheimer's.

 

[Tamar]

As for needing a trade card for Selco, it's not correct for my local branch, I just bought a load of stainless steel screws, no problems at the till, although the girl did ask if I wanted to open an account.

 

[boatiebert]

Is there any material that matches the old teak faced ply old Westerly (pre-Centaur) used to use? It was fantastic stuff. 50 years later, it's still all stuck together. Looks far more classy than the later stuff.

As an aside, I learned today that 400 years ago a clergyman Edmund Gunter, after whom the rig is named, was actually one of the first people to develop a decimal system. He invented a chain that was 22 yards long with 100 links., ten of which made a furlong. One acre was equal to ten square chains, hence 100 000 square links. Gunter's chain reconciled two seemingly incompatible systems: the traditional English land measurements, based on the number four, and decimals based on the number 10.

A chain is the length of a cricket pitch. Or was it a cricket pitch was made was the length of a chain by some railway surveyors during their lunch break?

And apparently, it was an English bishop & Oliver Cromwell’s brother-in-law, John Wilkins (1614-1672) who is said to have invented the system part of the decimal metric system, although I dare some some Arab or Indian really did only to have it stolen during the Crusades or Empire days. A system that could be used to measure all things based on a single universal measure. Wilkins' short proposal for a 'universal measure' in 1668 contained almost all the elements of the International System of Units (SI), the modern metric system.

Quite poetic really,

“The several Nations of the World do not more differ in their Languages, than in the various kinds and proportions of these Measures. And it is not without great difficulty, that the measures observed by all those nations who traffick together, are reduced to that which is commonly known and received by anyone of them; which labour would be much abbreviated, if they were all of them fixed to an one certain Standard.”

It took 123 years, from 1862 when a House of Commons Select Committee unanimously recommended adoption of metric units for public administration, to it finally started to be implimented in 1985 only to get roughly half way and then stuck and be left suffering from all sorts of problems.

Apparently it's up there with immigration as an issue politicians won't dare touch for fear of upset those of the old faith.

How did we get into this mess?

How has Britain got into this mess? And why have successive British governments been so reluctant to bring the changeover saga (which began in 1965) to a conclusion? Why has it been so difficult to persuade British people to accept the obvious benefits of the changeover?

Regrettably, the answer must be that successive governments have lacked the political courage to carry through a necessary reform.

• By failing to argue the case for what they knew to be right, by pretending that the change could be made voluntarily without overt government backing, by sheltering behind European Directives, they have allowed opposition to grow and misconceptions to fester.
• They have done nothing to counter the mistaken perception (encouraged by the media and now very widely believed by the general population) that the metric system has been imposed on Britain by an undemocratic, foreign bureaucracy,

 

[Lomax]

Metric should have been invented around fractions of 8x4 and not off a pendulum or meridian.

I don't think you understand how and why the metric system was conceived.

It might interest you to remember that the Paris inch was longer than both the English inch and the Vienna inch, as the ladies in Montmartre were wont to remind one; and, historically, the Scottish pint was more than twice the size of the English counterpart, which figures. (If it's your round, I'll have pint of Scottish beer). They weren't inches though, they were pouces or zolls.

The metric system came about in part to avoid the need to have a "master object" for each unit of measurement. Rather it was to be based on observable properties of physical reality. It would have failed if the only definition of the metre was the platinum/iridium metre bar, or "le grande K" for the kilogram, since it would have given Paris too much control. Using an observable would allow anyone with the right equipment to establish their own reference, hence the choice of a dimension of the earth itself as the definition of the metre. As time has passed this definition has been replaced by ever more precise definitions, and today the metre is defined as the distance light travels in 1/299 792 458 seconds, or as you would say "one over two hundred and ninety-nine million, seven hundred and ninety-two thousand, four hundred and fifty-eight seconds".

Such democratisation of the ability to perform accurate measurements should surely appeal to the United States - and indeed the metric system was adopted as the base reference for all US weights and measures in 1893 ("the Mendenhall Order"). Thus there no longer exists an independent definition of the inch - it is simply defined as exactly 25.4mm. The same goes for the pound and the pint, and so on. It's all metric all the way; even the Fahrenheit (a Dutch unit, btw) was adjusted so as to align with (you guessed it) 0° and 100° Celsius, which is in turn defined by the Kelvin scale (the SI unit for temperature).

So these old units now only exist as convenience units, and to satisfy the nationalistic urges of the uneducated. When you think you're using them you are actually using the underlying metric units. As such, I think it is inevitable that they will one day fade into obscurity, just like the cubit, the rod, the shekel, the grain, and countless others have already done.

 

[boatiebert]

I don't think you understand how and why the metric system was conceived ... these old units now only exist as convenience units, and to satisfy the nationalistic urges of the uneducated.

The articles linked to above, about our current mess, are very interesting but I think I have a very good grasp of the hows and why. It's just that they're poorly or incompletely conceived at present, & I still see the benefits of those based on human reference points and ergonomics.

And, of course, one day the electricity will all go off, & batteries run out, & we'll be back to do fractions by pencil.

I have no way of measuring the speed of light, nor a degree of a meridian, but my foot's about a foot, my "rule of thumb" is a workably perfect 1-1/2", I can lift & carry an 8 x 4 myself even if I appreciate it would require two standard unit Japanese to do the same (their basic measurement unit being the size of a tatami mat [6 shaku by 3 shaku], an area every Japanese person can immediate imagine, hence it being used to describe property sizes, according to the number of -jo or mats, for rent or sale), and the fact is, at present, metric is still basically 'doing' imperial, albeit very badly.

I do see shift in engineering where, eg all the old imperial & analogue lathes are finally going obsolete and new equipment is all metric & digital but it doesn't appear to have happened in wood, of which the sizes are still all over the place.

And, if you want some REALLY mind boggling confusion, try bicycle wheel and tyre sizes.

So, fine, when it comes to really big things, requiring huge investments & internationally cooperation, and going off to space, I get it. But not at a human level.

It warms me to think that in 400 years some Japanese carpenter will still be making houses by eye, and according to some 400 year old system; & I'd guess many boat builders will be doing so too.

I'll go further to suggest that's something in it that resonates with human beings, a bit like in the debate over digital versus analogue sound.

 

[Lomax]

I have no way of measuring the speed of light

Perhaps not, but it is neither difficult nor expensive to do so. If you really wanted to perform your own measurement of the speed of light, the second, and the metre, I expect you wouldn't need to spend more than some tens of thousands of dollars on the equipment to get nanometre accuracy. A certified copy of the Imperial yard standard that's kept by the Board of Trade would cost significantly more, while being several orders of magnitude less accurate. Such objects are of course today nothing but museum curiosities. Today we routinely measure distances that are a fraction of the width of a single proton, and common household devices are capable of measuring time with sub-nanosecond precision. Perhaps you hold such exercises to be a waste of time and money, but most scientific advances of the last century would have been impossible without them.

The base unit of length or distance in the British Imperial system was the yard. The yard was defined as the distance between a pair of lines etched in gold plugs inserted in a bronze bar in the custody of the clerk of the House of Commons, which had been designated a standard yard in 1760, measured at 62 degrees Fahrenheit. The new yard was actually a standard that had been commissioned by the Royal Society in 1742, which in turn had been based on an earlier Elizabethan standard. In 1834, the burning of the Houses of Parliament destroyed this standard, which had served in an official capacity for only 9 years and 198 days, and new copies were prepared by reference to the best copies of the old standard that had been found. This standard became official in 1855. In 1878, an act confirming this standard was adopted, referring to one of those copies, kept in the Standards Department of the Board of Trade in London. This yard had a length of 0.914398416 m.

 

[zoidberg]

.....and common household devices are capable of measuring time with sub-nanosecond precision.

Tell that to my wife. When she goes shopping, time stands still.... and when asked when supper will be ready, the normal answer is 'Whenever'.

 

[boatiebert]

Perhaps you hold such exercises to be a waste of time and money, but most scientific advances of the last century would have been impossible without them.

Science ain't got it all in life. It's strangely inert most of the time. I mean, you may be able to come up with a scientific reason why a certain chord progression moves you to tears, or a voice makes the hair on your arms stand up (no equation ever did that for me), even apply mathematices to explain the influence of the Golden Ratio. But I was thinking more of territory that Rudolf Laban explored with his Space Harmony theory, & many architects from antiquity onwards have pursued, designing environments based on human experience & in human scales.

Can you use your sub-nanosecond precise stopwatch to tell what it is just the right time to say someting or hug someone?

A top down theoretical approach is anti-human. It has it's place, in building railways that connect, & sending rockets into space etc, but those things are part of the analogue/imperial human realm.

I mean, a piece of wood; 2 x 1, 2 x 4, 4 x 4, 8 x 4 you know immediately what they are in 3 syllables. Our world was built around them. What are the metric equivalents? Are there even standard metrical equivalents?

It was a better system that the big systems should have been built up upon. As was the duodecimal system for simple, natural things humans had to count a lot.

* [file under "work in progress" as I've not quite work this one through yet].

 

[Daverw]

Humans are funny, we still refer to 2x4 8x4 timber sizes etc as we know what they are but never think that they are actually machined metric anyway, i always refer the imperial thickness size timber but then the metric length, we still refer to miles per gallon but do most know how many gallons are in the tank, bet we know how many litres in the tank.

 

[boatiebert]

Humans are funny, ...

Often they are but, in fairness, I think we're specifically talking about the British here, or even the over 40s Brits.

I didn't actually know timber mills had metricised, and don't even try me on litres per 100 kilometre. MPG I can judge straightaway. Why didn't we ditch miles & commit fully to the new system? Was another Farage-like momement in our history?

The bureaucrats clearly failed to realise that it takes time to pay off plant & replace it with new equipment.

How's the OP's hunt for adequare plywood coming. I'm interested in what they are doing with it and seeing the results.

 

[Graham376]

I mean, a piece of wood; 2 x 1, 2 x 4, 4 x 4, 8 x 4 you know immediately what they are in 3 syllables. Our world was built around them. What are the metric equivalents? Are there even standard metrical equivalents?

Every timber yard I deal with has been cutting to metric sizes for the past few years. Some sizes tie in with imperial, some don't. Timber business is crazy at the moment, had lunch today with a friend who works for Atlantic timber near Altrincham and he says they are sending even to Devon and Cornwall as various areas have no stock of many sizes or types. Prices have rocketed.

 

[boatiebert]

Go on, thrill me. What are the sizes now, 436 x 578 or 136 x 724 or something really easy to work with?

That's the problem when you ask egg head physicists to design a system instead of the tradesmen who actually have to deal with them on a daily basis.

 

[Graham376]

Go on, thrill me. What are the sizes now, 436 x 578 or 136 x 724 or something really easy to work with?

Nothing much in stock to measure at the moment but 4" & 6" par (planed all round) listed as 100mm and 150mm but of course it's smaller by about 6mm. I often buy sawn rather than planed, it's cheaper and I can re-saw and machine it myself.

 

[Lomax]

How's the OP's hunt for adequare plywood coming. I'm interested in what they are doing with it and seeing the results.

I haven't ordered anything yet, but I'm strongly leaning towards the (oil tempered) hardboard option; I would save ~£150, and since it's going to be painted white you won't be able to tell the difference. My only concern is whether those boards are rigid enough not to sag, and whether both the front and back are smooth, or if the back has that nasty coarse surface you get on most hardboard. No information about this on the Selco website.

something really easy to work with

You mean like 7/16" + 1/4", or 3/4" / 5?