Member postings for ChrisH

Paul, I would agree with everything that Harold has advised. I have both the books he mentions and they are well worth getting. Also, look at TomsTechniques website - he has instructional videos on lathe work, milling, tool grinding and safety which are very good, under the umbrella of "common sense machining", and as the saying goes, a picture is worth a thousand words.

Also, don't - never in fact - feel you can't ask a daft/stupid question on here, it's been often stated on here that if you don't know the answer then the question isn't daft or stupid and this is a very good site for getting good advice, so welcome and enjoy!

Chris

Wow, what a fast response by so many - thanks chaps.

I was thinking of going down the route of trying a few test pieces first using Hammerite black, car body spray black, a a drop of black from a Sharpie, but now I have Michael's kind offer I will try that first, so sending you a pm Mike.

Chris

Not exactly model engineering but definitely a workshop related query:

We have a black composite sink in our kitchen, which now has a small (say 5mm dia.) chip in it revealing a white sub-surface. Not exactly discrete! Would be 'no-worries' had the sub-surface been black, but white.....

Had thought to repair chip and disguise same by applying a wee amount of Araldite epoxy resin, but what to use as a black pigment to try and ensure the repair sort-of blends in?

Any ideas anyone then, for a black pigment to add to Araldite epoxy resin? There might be a bonus "shed exit visa" in it for me from Senior Management if I get the repair right, so I need your help!

Chris

Well put John, if it ain't broke...........

I am also looking forward to this thread. I have a sleeve valve aero engine, a 3 cylinder poppet valve aero engine and a steam feed pump all in part build and help and inspiration in "how-to" methods of machining and work holding from your build will be much appreciated.

Chris

Michael and Ian - thank you for saying what MEM stood for. Was obviously having a 'Senior Moment", as I had completely forgotten that website, not only that, but that I had registered on it too!

Now, saying I had a "senior moment" I am quite happy with, as I am taking the piss out of myself which is perfectly acceptable to me, well, others do it anyway regardless!

Which put me in mind of a doopy bird on the other end of a telephone line a few years ago who, when I said I was having a "senior moment" immediately scolded me and informed me that one could not say "senior moment" anymore, one must now say (the frankly ridiculous) "agest moment". Judging by the speed she then supplied me with the information I was seeking and then hung up, I gathered that my reaction of "oh blooming heck, not another bit of Politically Correct Nonsense" was not the Politically Correct response she expected me to give! "Hard chess" as they say in Russia I thought, but too bad, I have never been politically correct in my life.  "Senior Moment" is amusing to me, "Agest Moment" is insulting.

Chris

Edited By ChrisH on 15/11/2015 20:56:26

Not really what I did today, more just a comment, that I for one will be disappointed that the "My Little Engine" thread has been discontinued, as it was both interesting and informative, even if the reasons the thread ended as it did leaves me confused as to why exactly.

One query but, what does MEM stand for, which forum is that?

Chris

Climate change - global warming - call it what you like, but the climate is always changing and always has.

Around 1000AD or so, and I believe before that, in Roman times perhaps, they were growing vines for wine 'way up North'. Who warmed the place up for that?

By the mid 1600's the River Thames used to freeze over, you could ride horse drawn carriages over it, they held fairs and markets on it, alledgely, I wasn't there to see it, it had got so cold. Who cooled the place down?

Now it's in between and still moving and I guess it always will. The only question, is are we contributing to it? Well maybe, the world population is increasing at an ever more rapid rate so that must presumable have some effect as the needs for energy increase.

However, rather than climate change I think we should be more worried by the population growth - is it out of control now? - increasing the need for food, water and fuel (energy) across the planet; these issues are more likely to lead to war, world war, as people struggle to provide for their basic needs in the years ahead. I will probably not see it as I shall have gone by then, but my children and grandchildren? Not a nice thought for them I think.

Chris

Edited By ChrisH on 05/11/2015 11:23:19

Muzzer, Not Daily Mail at all - more an appraisal of hard facts.

Solar Panels generate only during the day, you can't store the energy they produce and they don't produce at night, fact. Interestingly ,Australia which has masses of barren, uninhabited, fit for nothing but lizards and snakes land and has very bright sunshine all day every day has no great solar farms. Plus in the UK productive farmland is lost for each solar farm. We also need to eat.

Wind generators can only produce energy within a specified band of wind speed, above and below that, nothing; in between generation is a variable, fact. In winter when it's very cold and more energy is required it's usually because we're in an area of high pressure which means no wind, so then it's another consumer of electricity rather than a producer when we need power the most.

So we always require the coal, oil and nuclear power generating back ups. Hinckley Point, like all nuclear stations by the way, is able to produce all day every day other than when refuelling.

Look also at the gridwatch website mentioned by others above. Last night nuclear was producing over 22% of our needs, as was coal, wind just over 2%. And 2% is good, I have seen it up around 4% on one occasion, but also often at less than 1%.

So not political, just factual - and whoever believes what they read in that rag the Daily Mail for goodness sake!! I suppose there will always be someone..........

Chris

I have now re-read all of Neville Shute's novels, plus his autobiography 'Slide Rule' and have them all still on my bookshelf, and thoroughly enjoyed all of them (except "On the Beach" which I thought was most depressing - shall not read that one again) including "Trustee from the Toolroom" - sorry Julian! One of the reasons I enjoyed them all, besides being good stories, was that they described a way of life, and attitudes to life and to other people, that existed at the time the book was set in and that now gone forever. I will read them all again in the years to come, I hope!

Neville Shute did work with Barnes Wallis on the private enterprise airship that was built at the same time as the one the government was building, the ill-fated airship (R101 from memory) that crashed in France killing all on board (I believe), which effectively ended our countrys' involvement in airships, even though the private enterprise airship he was working on was turning out to be a very successful design. He then helped set up and ran a company building aeroplanes and advanced successful ones for the time at that. What he did during the war I don't know, but eventually he retired to Oz living in the countryside in Victoria which enjoyed very pleasant weather conditions all year round and at the time of his death was actually into model engineering having a small lathe in his workshop. I believe!

Chris

The so-called 'renewable energy', is all very well and I have used it myself in the form of a wind generator on the boat I had and a solar panel on the campingcar I now have, BUT, they only generated 12 V dc and were used to charge up 12v batteries.

The trouble with mains voltage wind gennies is the cost and energy used to build them, their relatively short operational life (quoted at about 25 years), the fact that they spoil beautiful countryside views and are not very bird friendly, plus when the wind doesn't blow they generate nothing, in fact use electricity to keep them turning very slowly over, and when the wind blows a gale they are braked otherwise they overspeed and burst into flames or self destruct or other not very useful outcomes. So not very consistent or efficient producers but expensive ones. Solar 'farms' which seem to be springing up all over the place are less intrusive, but now you can't grow crops or graze cattle in those fields so we have less to eat, but when the sun shines we can switch the lights on, whoopy, but you still need the coal and gas and nuclear power stations for when the night time comes as 240v battery banks don't exist for the solar panels to charge up during the sunlight hours, so they are not consistent either.

Call me a cynic if you like, but............

Chris

You can do a risk assessment but still have an accident, but, having done the risk assessment you are OK H&S-wise.

The get-out is that the risk assessment obviously did not consider a situation that that resulted in the accident. The fact that you had done the risk assessment puts you in the clear. So now you do an updated risk assessment and off you go again.

Years ago I attended a seminar on the incoming (at that time) of the Construction and Design Management (CDM) Regs. The bloke doing the seminar broke off half-way through and said that he had been in H&S for 25 years and it seemed to him the most important thing was to get the paperwork right to cover yourself, if that resulted in a reduction in accidents then that was a bonus. I believe he was right in his assessment!

The problem is common sense is not taught in schools anymore, so we are not taught to think for ourselves anymore, we have a instead replaced it with a culture that nanny (state) knows best and will do our thinking for us. Us older folk still think for ourselves as we were trained to do, but the younger the folk you find...........

Chris

In a previous life I used to do a lot of NDT (no destructive testing) of welded joints, so the methods available are as follows: dye pen, mag particle, ultrasonic and x-ray.

What you can do yourself is limited to dye penetration testing and magnetic particle testing. The Dye Pen method is to clean the test area with a special cleaner, spray the test area with a dye, usually red, and let it dry, then clean it off with a cleaner 'soaked' (lightly coated) rag, then spray with a very light coat of a usually white topping. The crack will show up as a red line. Magnetic particle is much the same, clean, spray with a white coat, let dry, spray with a fluid containing iron filings and then apply a magnet. The filings line up along the crack. Although both methods are a bit on the DIY side, they do need the right instruction and application to enable the method to be done properly, so some training is required. Like most things the tests are useless if you don't know what you are doing.  A finer more sensitive method for both is a UV version of both - and for both these training is definitely required!

The problems with both these methods, good as they are, is that it only shows up surface defects on the tested side, not any defects within the weld. To do that you have to examine the weld using either ultrasonic testing or radiography (X-Ray), or both (boiler tubes on coal-fired power stations would employ 100% ultrasonic PLUS 10% X-ray). For both you need very well trained and competent personnel to carry out the test and interpert the results, an x-ray is not as easy to view and determine what it shows as one might think. X-ray testing is not foolproof either, the angle at which the image was taken can mean a weld with a crack within it can seem to show a perfectly good weld on the x-ray print. An example of this at the power station was one weld where the ultrasonic guy said there was a crack in the root of the weld but the x-ray was OK - I know as I also viewed it. The ultrasonic guy was adamant the crack was there, the weld was retested with a shot from a different angle and there was the crack clear as clear can be.

With ultrasonic testing, one basically used a probe which sent out an ultrasonic sound wave out and through the metal and an electronic screen which displayed what waves came back. The probes are produced to send the ultrasonic waves out at a predetermined angles from 0 deg. (straight down) to close to 90 deg. The equipment is calibrated before use by using known targets on the probe in use and so setting the screen to display the results to a certain magnitude. A 0 deg probe finds the thickness of the plate or tube being tested and also any laminations within the plate, the other probes send waves out to search the weld. If all is good the waves just disappear down the metal but any defects within the weld send a signal back (like radar) which is then plotted on a drawing, noting where the probe was when the signal was received, so a bit of maths was involved, to show what and where the defect is and likely to be, like lack of root penetration, root crack, slag inclusion and so on and so forth plus its size and position.

There are times when, having made an ultrasonic examination and you have put yourself on the line by saying for example that there is a crack in the boiler furnace tube from here to here and to within 3mm of the surface and therefore the boiler needs an expensive repair before being returned to service, you are rewarded by the boiler repair guys tell you after that the crack was exactly where you said it was, from there to there and to within ⅛" of the surface - that would do for me! There would also sadness when an ultrasonic test of a boilers riveted seams shows a massive amount of cracks at just about every rivet hole meaning the boiler was a scrapper. Especially when this boiler was at a wood 'factory' or yard and all the scrap wood and sawdust was burnt in this boiler to produce the steam the yard required for its processes, a very waste-not want-not system, and a sad day telling the manager his boiler was a scrapper, he'd have to get a new one.

Chris

Edited By ChrisH on 23/10/2015 14:48:43

Edited By ChrisH on 23/10/2015 14:50:58

First it was 2 quid, then 3 quid, now it's 4 quid plus 2 quid from I presume 'down under'.

Not good on the ol' cash flow balance stuff JS!

Goodness but I've stirred up a hornet's nest here!

The comments made about large diameter fine threads are especially interesting. I do not know whether my thread had a wee bit of swarf on it or not, certainly cannot rule that possibility out, before trying the mating parts together, even though I do try doing that as a routine but perhaps a wee bit was missed - it's not so easy to see everything part of it on an internal thread.  Would certainly explain what happened but if a bit of swarf was present.

So, ensuring that ALL bits of swarf however minute are thoroughly cleared off before trying the mating parts, along with the use of a good lubricant, is obviously a good practice to adopt for the future. Lesson well learned!

ATF was also mentioned as a lubricant, one that I had never considered before too.

One learns something new everyday!

Chris

Edited By ChrisH on 18/10/2015 23:36:28

Edited By ChrisH on 18/10/2015 23:37:09

Edited By ChrisH on 18/10/2015 23:37:54

Jon - glad I'm not the only one! As you say, seizes with no warning, just does it. And it was on a large diameter very fine thread too, where you experienced problems.

Used paraffin when cutting the aluminium as I read somewhere that was good on aluminium, seemed to help but I don't think paraffin has any lubricant within it. Tried WD40 when screwcutting, thought that might be better as it has lubricant in it - fish oil I think it is.

I also have some Tufcut metal cutting compound, which has a grease like consistency and slippy-ness. I had not really considered it at all as I had it in my mind that it was mainly for use with steel but now wonder if it would be good on aluminium - probably worth a go.

Copaslip was used on board ships for coating threads to prevent seizure especially on those bolts used on high temperature applications like flange bolts on steam pipework as it is advertised as a high-temperature anti-seize product, but I tend to use it on any nut and bolt I want to protect from seizure these days, not having any steam to deal with. Have not noticed any electrolytic action with its use within my limited applications, but have noticed when doing car brakes that often replacement parts come with a little sachet of copaslip. I think it's a great product, just not sure of it with aluminium for some reason.

Chris

Edited By ChrisH on 18/10/2015 11:28:56

Duralac! You have kick started the little grey cells! I remember now way back when I had a boat using that or something like it when pop riveting stainless steel fittings to the aluminium mast, otherwise in all probability the two would 'fuse' (for want of a better word) together permanently. I had a tube of it once but I let it go with the boat I think.

I also remember that copaslip was frowned upon (on boats when used between aluminium and stainless) but couldn't remember why, but it should be good on my engine as if sea water gets anywhere near it there will be far more serious issues arising, like my house flooding 20 miles inland! So probably copaslip will be quite OK.

Chris

Had a wee set back the day before yesterday when machining an internal thread in aluminium. A piece with a male thread (obviously!) fits into the internal thread. Was just about there, tried the male thread and it was screwing in OK if a little stiffly when suddenly it seized. My fault, forgot about the chance of that happening, perhaps pushed on for too long instead of pulling out, and hadn't used any anti-seizure lubricant on it even though I have Copaslip right by the lathe.

Managed to cut - machine - the male piece out and should be able to save the piece with the internal thread, but.......

But it made me wonder if Copaslip was the best to use, or is there a better ant-seize product available for aluminium?

Any thoughts anyone?

Chris

Clive - don't wish to disagree with you but I worked for a large horticultural company growing tomatoes for 11 months of each year, from 1990 to 1999, and the company used bees not bluebottles (BobH will be pleased!) to pollinate the tomatoes. The bees came in little boxes from Holland (where-else?) and were placed in the glasshouses and left for a while to settle down before the box was opened. They were given a feed of course. I am uncertain how long each box of bees lasted but they were very successful, the company grew masses of tomatoes. The growers could check on the tomatoe flowers and tell if the bees had visited or not. We obviously had a safety policy for bee stings and staff becoming allergic.

Chris

Following on from yesterday's post, here is the part in question mounted on the mandrel with the bearing half in being just a push fit into the part. First part complete!

Edited By ChrisH on 05/10/2015 19:27:37