Member postings for Fowlers Fury

Given up trying to use an old laptop in the workshop - usually too much clutter to find space to put it down anywhere.

However, IMHO a couple of useful apps for the Android phone offered (via "Playstore":-

(1) "Toolbox" - contains a surprisingly useful collection of little apps including a heart-rate monitor for when you discover that cock-up after hours of machining some part

(2) "Thread Pitch" - initial expectations were low for this but once you've calibrated the phone's screen it's quite useful compared with fiddling around trying to find the thread pitch gauges. Have to watch you don't scratch the screen though.

Not perhaps a response to the original post, but there's an interesting section in The Engineers' Pocket Book of 1943 covering the design aspects of steam engines. (A fascinating little book despite its age & useful for diagrams of locomotive ancillaries such as lubricators, vacuum pumps etc).

In the part covering connecting rods with its formulae for determining rod diameter, it states "The inertia bending effect is covered by the rather greater factor of safety and the taper of the rod". From which, I suppose, it might be inferred that a fish-bellied rod having two tapers, is stronger ~ as Martin Kyle comments.

Not so on either count.....with all that low down flywheel weight, as a solo, they handled very well, at least as far as mid 50s, thin tyres would allow. Looking at those sloper engines you'd think they were long strokes but they were only just 'longer than square'.

But before John complains about all this non-model engineering stuff, as a homage to Phelon & Moore who made Panthers, I did give my Clayton wagon P&M livery. Totally fictitious though as P&M never had a Clayton wagon.

Not fence post Gary, but lamp post !!

That 600cc ohv single had 35lb flywheels and if you had the engine nicely tuned you could, with care, do a "party trick".

With it on the stand, start the engine having engaged the half-compression lever (to reduce risk of broken ankle). Then when warm, disengage choke & half-compression lever and progressively retard the ignition. The lump would slow right down until the tick over was so slow it could move itself right off the centre stand due to the massive inertia in the flywheels at each ignition stroke.

They certainly had massive low-down torque, hence sidecar use, despite only producing about 20 bhp..

A couple of years ago, I was lent a Fireblade for a few weeks. Ignoring all its 'mod cons' and brakes that actually worked, the lack of any low-down grunt was startling by comparison.

> Michael Giiligan.

Thanks for posting those pics the Panther. I think it's a 1930 Model 50 from a quick scan of Barry Jones' book "History of the Panther". So ~ I'll excuse your derogatory comment about "grubby old things" tho' I have to admit there were a lot of 'rat bikes' at the Panther rallies !!.

One picture in Barry's book always amuses me.

Certainly for the 'bike restorer with a parallel interest in model engineering, life is quite a bit easier. I remember having to fabricate new oil feed pipes and instead of paying to get the copper chrome plated, I tried Rex Tingay's method in M.E. for silver plating clock faces. The result looked excellent providing you didn't use chrome cleaner on them !

I still have the first 6 years of "Motorcycle, Scooter & 3 Wheeler Mechanics" (reminder to myself to put 'em on Fleabay sometime). and it's fascinating to read the dodges & bodges in the mid 50s suggested to keep your bike on the road. All the postings here about keeping chain cases oil tight reminds me of one. It was suggested that after reassembling, you should lay a candle in the primary case and gently heat with a blowlamp until the candle melted. Fish out the wick, and when cool the solidified wax would effect a seal. Doubt it would have done much for the paint but it may well have worked.

I like this thread - the newsgroups on 'bikes have deteriorated greatly whereas this looks promising !

Just as Nick Berrisford posted "Bloody typical, a bike thread is started just as I have had to call it day after 40 odd years of biking". Likewise, I decided I was too old for the big BMW, sold it and now wish I hadn't. I've kept all the riding gear so delude myself I haven't totally given up on the idea of getting another bike.

Prior to the big BMW, I'd rebuilt quite a few Brit bikes and the pride & joy was undoubtedly my Panther - sold on about 20 years ago :- (

1955 M100 600cc Panther single

**LINK**

For me, the best perspective on the demise of Brit bikes is still Bert Hopwood's book "Whatever Happened to the British Motorcycle Industry".

~Will,

My workbench top is covered with thick stainless steel, it's been in use for 40+ years and is deeply scored and dented. This morning, I've used first coarse, then medium and finally, fine Garryflex blocks on a smaarea. I used the blocks in an "up & down" motion.The area was rubbed for no more than about 20 seconds with each block. The fine grade block was only applied to the left half of the area - so that bit has had, say, 3 x 20 seconds of rubbing.

The image (hopefully reproduced here !) was taken with ambient light as flash caused too much flare. Obviously Garryflex has not removed the deep scoring in that time but the surface finish is much improved. That probably doesn't constitute an answer to your " can you get a good even aesthetic linear pattern with the blocks if care is taken", but depending on the surface you have to begin with - Garryflex ought to work OK.

I've had good success using the Garyflex blocks (Craytex in USA). The blocks are substantial enough to hold in the hand and move in a linear or circular manner. They are available in at least 3 grades. Depending on the surface to begin with, start with the coarse and move to fine if you need it.

We are getting seriously off topic here, so Neil permitting.........!

"John's" sensible posting above suggests providing LD50s to give "some idea" of toxicity. That bit needs qualification I'm afraid.

LD50 is the dose which kills 50% of animals receiving the substance. "Dose" is critical, it means the amount taken in and not the exposure concentration killing 50% of animals - for that we need the LC50 value and there aren't too many of them published. Most if not all LD and LC50 values are derived for mice and rats. Their relevance to humans is questionable. Apart from WWI data and a few other accidental exposures there are very few chemicals with LC50 data for humans.

LD or LC50 values tell you nothing about chronic effects such as carcinogenicity, solvent neuropathy, lung damage etc.. Yes - sodium nitrite does produce carcinogenic nitrosamines (implicated in bladder cancer) when in contact with amines but we humans are "full of" of amines as amino acids and other compounds.

What's the relevance of all this for engineering operations?

Simply, risk = hazard x exposure.

Hazard is intrinsic toxicity of a substance so reduce exposure and you reduce risk. Carry out an operation outside and wear proper protective equipment and your exposure is reduced. Do the job infrequently and your overall exposure is reduced. Old tar-based cutting oils, fluxes, grindstone grit, mineral acids and solvent vapours are some of the hazards model engineers face. Thankfully exposure to them is usually low and intermittent.

I've got several books from the 1st half of the 20thC advocating use of all sorts of chemicals which were then freely available, including Prussic acid (hydrogen cyanide) for plating in the home workshop. No doubt many users of the recipes lived long and happy lives but sensible precautions today to reduce risk are always worthwhile as "John" and others advise.

Sorry about above and what happened to formatting - try again !

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What mixture?? Do you mean "parts" rather than mixture?? How do you heat an aqueous solution to 140 degC at atmospheric pressure?

Imho a mixture of 3 substances is a mixture and not a part...

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Alright, maybe I should have added.... "Do you mean parts to be blued ?" instead of assuming it was obvious. But I now realise that the article did mean mixture (of NaOH and NaNO2).

As for bp of NaOH:-

On first reading that post I thought that the quantities of both salts had been omitted. Though unclear, I now guess the proposed "1 litre volume of sodium hydroxide" might mean "1 litre of solid sodium hydroxide". To that it's proposed to add 1 litre of water making a 50% w/v of NaOH solution, which I now find, boils at nearly 150C.

Ignoring the evident hazards of a 50% solution of boiling NaOH, I've no idea what effect on that bp the additional "1 litre of sodium nitrate" would be.

It's a witches brew nobody should contemplate handling in a domestic environment.

The respected NIH comments thus on sodium nitrite:-

"Used in many industrial processes............The compound is toxic and mutagenic and will react in vivo with secondary or tertiary amines thereby producing highly carcinogenic nitrosamines........... will accelerate the burning of combustible material. If large quantities are involved in a fire or if the combustible material is finely divided, an explosion may result. ........... Prolonged exposure to heat may result in an explosion. Toxic oxides of nitrogen are produced in fires involving this material."

Imho a mixture of 3 substances is a mixture and not a part...

_________________________________________________________________________________

Alright, maybe I should have added.... "Do you mean parts to be blued ?" instead of assuming it was obvious. But I now realise that the article did mean mixture (of NaOH and NaNO2).

As for bp of NaOH:-

On first reading that post I thought that the quantities of both salts had been omitted. Though unclear, I now guess the proposed "1 litre volume of sodium hydroxide" might mean "1 litre of solid sodium hydroxide". To that it's proposed to add 1 litre of water making a 50% w/v of NaOH solution, which I now find, boils at nearly 150C.

Ignoring the evident hazards of a 50% solution of boiling NaOH, I've no idea what effect on that bp the additional "1 litre of sodium nitrate" would be.

It's a witches brew nobody should contemplate handling in a domestic environment.

The respected NIH comments thus on sodium nitrite:-

"Used in many industrial processes............The compound is toxic and mutagenic and will react in vivo with secondary or tertiary amines thereby producing highly carcinogenic nitrosamines........... will accelerate the burning of combustible material. If large quantities are involved in a fire or if the combustible material is finely divided, an explosion may result. ........... Prolonged exposure to heat may result in an explosion. Toxic oxides of nitrogen are produced in fires involving this material."

I stand by my original comment "I don't think reproducing a web article like that is either helpful or desirable".

Edited By Neil Wyatt on 09/09/2015 19:29:30

Just checked and my little pot of gun blue purchased years ago from NRA at Bisley, was made by the American company Birchwood Casey. (they also made the solution for brass).

There's a YouTube vid of "how to do it" - I don't have the their degreaser or rust remover, but use other products.

**LINK**

Vic is quite correct, most of the Gun Blue formulations contain selenium salts. His advice to wash your hands after use is sensible.

But we shouldn't become 'chemophobic' - selenium is an element essential to life, albeit in trace amounts. As the father of toxicology, Paracelsus said (in loose translation) "The dose alone makes the poison".

Gun Blue used sensibly represents no significant risk. (Certain anti-dandruff shampoos contain more selenium as sulphide salt, weight for weight)

Living close to the NRA at Bisley, I bought my small pack of gun blue gel from their shop. But if you put "Bisley Gun Blue" into Google, there are several suppliers at around £9.50 per pot which lasts for years.

Off topic - the NRA shop also stocks a similar sized plastic bottle of a sister product which blackens brass. That really does require good surface preparation but the results aren't bad.

Rapeseed or sunflower oil from the supermarket is cheap enough not to bother with old engine oil.

Once done, rub the item all over with black shoe polish - allow to dry & polish off. It will help to delay any subsequent rusting and looks good.

You can also get a pretty good black appearance on an item you might not want to heat by purchasing some "Gun Blue". Follow the instructions carefully with regard to degreasing and certainly use the shoe polish afterwards as the black is only a "few molecules" thick.

May I return to the worrying issue of internal corrosion?

I've had a small (1.5 HP) compressor for about 20 years in my home workshop and it gets intermittent use. Every time I've finished using it, I allow the pressure to drop to about 15 psi and slowly undo the drain plug as one might do with a loco boiler blow down.

An appreciable amount of clear water freezes around the plug which I've assumed is water vapour from the resevoir. The plug is always removed until the compressor is needed agian. The resevoir is presumably mild steel and like other users, internal rusting has always been an anxiety. Despite searching, I've not found any information about the life expectancy of these 'little' compressors, or rather, their resevoirs. I've been told I shouldn't worry about catastrophic faliure, rusting would just lead to pin holes at first !

Has anyone sound advice to offer please?

<>

Use of old fridge compressors in the workshop should probably be discouraged once the special lubricant (e.g Emkarox) has been lost. They are designed to operate in closed systems with constant lubrication. When run dry they can overheat dangerously. But, yes, there are many which have been used at high CFM for some years but I'd rather use a 'proper' compressor nothwithstanding the corrosion concers,

After frustration with a 'simple' boring bar, I made one to the Geo Thomas design. It was well worth the effort, especially when using a micrometer to set an incremental increase in cutter radius. As the old boy wrote ~ the force on the cutting tool is not at 90 deg to the bar which aids producing a parallel bore.

There's a simple, effective and free solution to all the cr*p if you use Firefox as browser.

Download the add-on "Noscript".

It's also via http://noscript.net/

If some functionality on the website is not working then you decide whether to allow it or not.

Once the surface scale is removed, try Garryflex blocks. Work down from the roughest to finest.

3 blocks at about £3 each (from Amazon or Fleabay) will last for years. Quick and easy to produce a satin finish. They won't remove deep machining marks though.

The "cheap" Chinese scales I have installed on my mill are surprisingly accurate but those small plastic plugs (like small but flimsy telephone cable plugs) on the cable ends were nothing but trouble.

Mine are not "mini usb" like yours so this may not be relevant.

They'd work loose from the scales and give rogue readings. However it's quite possible to cut them off and solder the wires directly onto the little pcbs and when sure they work ok, drop a blob of Araldite onto the soldered connections.

Machine DRO assured me that the soldering heat would not damage the pcb and this was correct but it is a fiddly job and requires a very small iron and a steady hand.

My 3 axis DRO didn't power the scales, so I got rid of the button batteries and powered the 3 scales from a stabilised DC power supply.

The guys at Machine DRO say that each scale should ideally be insulated from the machine to avoid problems with erratic readings (something about feedback loops?). I haven't done that though and since the direct soldering and stabilised pwer supply - everything is very stable (touch wood).