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Member postings for Rod Renshaw

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

Thread: Where's this rust come from ?
01/10/2020 19:12:04

I accept that PVA glue as supplied may be chemically neutral and safe for children but that is not the end of the story!

PVA is a water based glue. The manufacturer adds water to the mix to make the glue fluid enough to be used.

When the glue is used 2 separate things happen. The water in the glue evaporates - and rusts anything nearby!

And the glue "sets", a chemical reaction which releases acetic acid, hence the smell of vinegar. Acetic acid is what a chemist would call a "weak" acid, as distinct from "strong" acids like nitric or hydrochloric, and it is not dangerous - but it will also rust anything nearby! (weak and strong in this context has nothing to do with concentration)

So if you use PVA, and it is cheap and effective, it is best to allow it to dry thoroughly and ventilate the job well before trusting it not to affect your tools.

Rod

01/10/2020 11:04:48

I agree with most of the above as possible reasons for the rust. The chest was most likely made abroad and shipped by sea and stored in unheated warehouse space and so has had every chance to get damp. The OPs workshop may be heated and drier so that the moisture is coming out of the wood and being trapped in the drawer spaces. Also, PVA may have been used to stick the "baise" down and this glue creates acetic acid as it dries (and may decompose releasing Formic acid? ) Perhaps best to locate a newly owned chest ( even an old one)  empty in the space it will occupy and with the drawers out, for a time, and to use VLC paper liners at least for an initial period. All these problems should disappear over time?

Rod

Edited By Rod Renshaw on 01/10/2020 11:25:20

Edited By Rod Renshaw on 01/10/2020 11:26:43

Edited By Rod Renshaw on 01/10/2020 11:28:49

Thread: 3/16 Cast Iron Rod
29/09/2020 17:40:01

I wonder if the sash windows in dolls' houses have cast iron sash weights?

Thread: Restoring a wooden tool box, help needed
27/09/2020 20:53:10

Thanks Ian. I will try the meths and fire, it sounds like something a wizard might do!

Thanks John. If the meths does not work I will get some oxalic acid and try that.

Rod

Thread: 5BA Threads
27/09/2020 10:26:53

+1 for EKP screws.

They make many of the screws themselves on Swiss automatic machines, all controlled by cogs and eccentrics etc., and which must be almost antiques by now.

Rod

Thread: Restoring a wooden tool box, help needed
27/09/2020 10:12:31

Anyone found a way of getting old (machine) oil out of the wooden parts of a well used toolbox so that glued repairs can be attempted? I have tried using turps substitute which got the dirty oily surface clean but left a residue which the glue would not adhere to.

There is a product called "Chair Doctor" made by Veritas, and sold by Hobbies and Amazon etc., which is a very low viscosity glue. It wicks by capillery action into loose mortise and tenon joints of chairs, and it sounds as if it would be useful for toolbox joints which cannot easily be dismantled.

Rod

Thread: Ideal Dimensions of Vice Clamps
26/09/2020 20:41:21

Bill

Valid questions all.

"Ideally" the tongue of the clamp should enter exactly horizontally. But exact is not always easy and it may wear anyway. So the usual plan is to make the clamp slightly too short ( low) at the front and slightly taller at the back so that the tongue points slightly downwards when tightened. Only a few thou difference is needed.

If you imagine the clamp taller at the front, the tongue would tend to push the vice away from itself when tightened, which would not be safe or accurate. If you imagine a large difference it is easier to see the problem.

The tongue should be made slightly too thin for the slot so it does not jam when tilted.

Rod

Thread: What geen grinding wheels for tools
22/09/2020 20:22:20

Might I suggest you look at a Youtube video entitled "Diamond lap for sharpening tungsten tools" for use of a very low cost diamond disc for finishing carbide cutters. It's a homespun sort of solution which might suit.

Rod

Thread: What's a Tubular T-Nut
19/09/2020 15:15:50

GHT makes it clear somewhere in his writing that the point of the tubular T nut is that the longer thread engagement means you can have a set of T bolts at longer intervals than with regular T nuts and still be able to grip work of any intermediate size.

Rod

Thread: Taking Leave
17/09/2020 09:45:02

I think many of us will miss your expertise Andrew.

I have seen many threads where, after the usual suspects have all had a well meaning, but not always expert, guess at the solution you have contributed a well argued answer and demonstrated a depth of knowledge which not everyone has.

Still, sometimes work comes before play and you will have thought about this decision. I hope we see you back in due course.

Rod

Thread: Sumitomo insert identification
15/09/2020 10:06:20

Many thanks to Kiwi Bloke for filling in the history of the Sumitomo Titanium carbide tips marketing, I had not realised that there were 2 separate firms involved. Also thanks to Ian J for the copy of the Carter order form which provides useful information on the types of tips available 20 years ago. I bought my holders and tips from Mr Carter rather than from Mr Rivers - so it seems ( per Ian J ) that mine are ISO standard sizes, so I am luckier than Kiwi Bloke. The original tips sold by Mr Carter are no longer listed.

It seems unlikely that the Titanium carbide technology has just disappeared, so is anyone making tips with similar performance characteristics now?

Rod

13/09/2020 21:02:36

There used to be a firm called Carter Precision Tools, run by a chap called Carter who was, I understand a gunmaker who sold Sumitomo titainium carbide tips as a sideline. He was also, I think, the man who demonstrated the exceptional finish the tips could achieve at ME shows, perhaps 30 years ago. He specialised in Ti200A tips and I bought some and got good results with them, unless damaged they seemed to last almost forever. Mr Carter retired some years ago and I have not been able to find another supplier of these tips. They are not listed on the Sumitomo website or catalogues and the website contact line does not seem interested. Anyone know anything about these tips and/ or a possible source of supply?

Rod

Thread: Mystery Object ... This one has me beat
13/09/2020 11:02:19

I understand that a benchmark is a survey mark left by the Ordnance Survey when the area was mapped and, more relevantly, "levelled". The position and height of each benchmark is indicated by a small dot on an Ordnance Survey 1 inch to the mile map, and the height of the benchmark, the "spot height" is recorded alongside the spot on the map. The horizontal line of the benchmark is the exact height recorded on the map, and the arrow below is to draw attention to the fact that this is a benchmark. So if you need to find the height above sea level of anything in GB you only have to find the nearest benchmark ( use the map for location and height) and measure the difference in height between " it" and the benchmark.

Rod

Edited By Rod Renshaw on 13/09/2020 11:06:02

Thread: BSF and Whitworth "Across the flats " sizes.
12/09/2020 18:51:31

Sorry Michael, missed that one, lots of posts on this thread, but not really a good excuse.

Thanks for posting the chart.

Regards

Rod

12/09/2020 17:17:49

Interesting thread, I have often wondered about this and often used "the nearest I had handy" when in a rush. I have tried to use the link to the Handy Table posted by Brian G on 9.10.17 but it does not work for me (it is 3 years old ). Will someone post a more up to date link.

Thanks

Rod

Thread: New Covid Rules
12/09/2020 16:49:50

Re the last 2 posts:

I got the impression John was speculating that being on a working party on "the business of the club" would count as "working" and therefore be exempt from the rule of 6.

Whereas Graham has ( I think) interpreted John's post as being about being exempt from the need for a H and S plan,

So they could both be correct?

Though if John would argue that his team were working and not at leisure, they would ( per Graham) need a H and S plan?

Rod

Thread: Denford Box-Ford lathe
12/09/2020 11:23:55

There is a short article, with photo and specifications etc , on the introduction of the Box--Ford 3 Inch lathe.This is much smaller than the usual range of Boxford lathes, in ME, Vol 96, Issue 2383, page 67.

Rod

Thread: Mystery Object ... This one has me beat
12/09/2020 10:44:14

Looks like one of those things they sell in kitchen shops to measure out portions of spaghetti.

Rod

Thread: Boring chatter (on the lathe)
07/09/2020 11:44:57

+1 for the blutack. Even plasticine or putty will do at a pinch. I think it's something to do with the added weight changing the resonant frequency.

Rod

Thread: Mill Tip
03/09/2020 10:50:47

Vic

This seems like another good way to square up blocks. Not tried it yet but I will, as I will be able to use my replacable carbide inserted tip face cutter, or even a fly cutter, rather than an expensive and difficult to sharpen HSS end mill.

Amazing how these new ( to me) methods keep being invented.

Rod

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