Resistance soldering

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David B
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Resistance soldering

Postby David B » Sat Sep 26, 2020 10:51 am

I am officially here until 12.30 and again for half an hour from 1.30 but will be looking in fairly regularly for the duration of the show, ie until 5.30.

Do send in any questions.

Mark-Leigh
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Re: Resistance soldering

Postby Mark-Leigh » Sat Sep 26, 2020 1:13 pm

Hi David

Thanks for producing this informative video.

I burst out laughing in the 1st few minutes when you mentioned my situation. Too many years ago for me to remember i purchased an RSU and to date it has ventured out once to check it was ok. Its been in the box since then.

Tomorrow it will have its 2nd outing out of the box and some testing. I definately have a need for it and this has given me the encouragement to give it a try.

Mark

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David B
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Re: Resistance soldering

Postby David B » Sat Sep 26, 2020 1:22 pm

Hi Mark. Glad the video has got you going again. I spoke from experience because that was just what I did. I recall needing to do something - it was unsoldering a Churchward Models signal box I had begun years ago - and I thought 'RSU' which is when it came out again, and it hasn't been away since.

If I can help you with anything, please drop me a line through the Forum or as a PM. I am happy to use either the Forum or email.

I feel confident that if you can get over the initial resistance and you get in to using the tool, you will find it very useful.

mervynb
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Re: Resistance soldering

Postby mervynb » Sat Sep 26, 2020 1:33 pm

Thanks for a really useful presentation, and comprehensive accompanying notes. Like others I expect, I purchased the excellent LRM unit quite a number of years ago, and it frankly didn't see much action for, oh.... some time. Now, oddly, it's more likely to be used than my conventional irons. There's only 1 life and I can't be bothered to wait for a conventional iron to warm up. My ratio is something like 90:10 in favour of RSU. I now regret not buying the exactoscale RSU accessory base unit & magnets, which I've never seen secondhand. I tend to rely on a loose piece of metal, but guess I'll have to invest some time in making a proper base as you have David.

Mervyn 7215

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David B
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Re: Resistance soldering

Postby David B » Sat Sep 26, 2020 1:37 pm

Hi Mervyn,

I am pleased you found the presentation useful. Thank you for your appreciation.

On the last slide is a picture of my set-up with the soldering iron on top of the RSU. When I switch on to begin modelling, both get switched on at the same time, so the conventional iron is always available.

andrewnummelin
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Re: Resistance soldering

Postby andrewnummelin » Sat Sep 26, 2020 3:12 pm

I've been using an Exactoscale RSU for many years but found your excellent presentation very useful in showing techniques that I have not employed. I'm sure I'm going to do better in future.

I do have, and sometimes use, the Exactoscale base but I think David's approach is somewhat better. I find it a real pain to have to de-rust the lump of steel frequently - I wonder if a bit of non-corrosive metal wouldn't be better.

I've a couple of difficulties with the Exactoscale unit - firstly the "chuck" on the probe is failing to grip very well, the "collet" having lost its temper. I guess the solution to that is to get an LRM one. (Or is there a better diy approach that doesn't involve knurling on a lathe?)
I'm curious to know the voltages that the unit provides - does anyone know or is it safe to stick a multimeter on it?
Regards,

Andrew Nummelin

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Paul Willis
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Re: Resistance soldering

Postby Paul Willis » Sat Sep 26, 2020 3:40 pm

andrewnummelin wrote:I do have, and sometimes use, the Exactoscale base but I think David's approach is somewhat better. I find it a real pain to have to de-rust the lump of steel frequently - I wonder if a bit of non-corrosive metal wouldn't be better.


Andrew,

I've recently acquired a couple of 200mm squares of thin plate from the Bay of e's. Not very much money, as there are many specialists selling what you would call "offcuts".

One is steel, and one is aluminium. I will be fixing them to a wooden base like David has. However, with the aluminium being only 1mm thick, I'm hoping that as a top surface it will both allow magnets to be used and be corrosion resistant. I'll see how the experiment goes.

For the moment, I use a piece of hardboard wrapped in turkey foil - that's kitchen foil, but twice as thick so much more tear-resistant.

I'll report back how the experiment goes...

Cheers
Paul
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

Petri Sallinen
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Re: Resistance soldering

Postby Petri Sallinen » Sat Sep 26, 2020 3:44 pm

Extremely well made presentation! I and my friends are eager to get the machine.

Petri Sallinen
6549
Helsinki, Finland

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David B
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Re: Resistance soldering

Postby David B » Sat Sep 26, 2020 3:48 pm

Hi Andrew,

Thank you for your kind comments. I am pleased I have been able to introduce you, as a more experienced user of the RSU, to something new.

My plate is steel but it is easier to keep dry and I am careful to wipe it after use each time. Very occasionally, I give it a wipe with IPA (non-beer alcohol!) and if I need to use something more abrasive, which is very rarely, then I use a kitchen scouring pad rather than abrasive paper which, if over-used, will take away the flatness of the surface.

I suggest you bite the bullet and get a new probe from London Road. The old design with a push-on ring has been replaced with one that screws to tighten on to the carbon rod. I suggest this is the simplest course of action and will save a lot of time which can be usefully employed on modelling. See here for a picture of the new design of probe.

I spent a day with the Bristol Group in August 2019 and Paul Townsend brought a meter which he used on people's various units. Paul wrote about the session on the main Forum, together with various readings. His post is here.

I hope this helps.

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David B
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Re: Resistance soldering

Postby David B » Sat Sep 26, 2020 3:50 pm

Petri Sallinen wrote:Extremely well made presentation! I and my friends are eager to get the machine.

Petri Sallinen
6549
Helsinki, Finland

Petri,

Hi Petri,

Thank you very much. If (I hope it is 'when') you get a unit, do drop me a post or email/PM if you have any questions.

martin goodall
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Re: Resistance soldering

Postby martin goodall » Sat Sep 26, 2020 4:37 pm

David,

This is the most brilliant and informative instruction video I have ever seen! Some professionally produced training films don't match up to this excellent standard.

I have seen your demo previously at Scaleforum, but this video really got the message across. It was truly inspirational.

My LRM RSU has (like others) languished in its box for far too long, but this video has encouraged me to make proper use of it in future.

Keep up the good work! (Instructional videos from you on other model-making subjects would be very welcome.)

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David B
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Re: Resistance soldering

Postby David B » Sat Sep 26, 2020 5:21 pm

Martin,

I am blushing - thank you for your very kind comments. I am so pleased it is encouraging you to get yours out of the box and in to use. Do let us know how you get on and ask if you want any help.

I shall now float in to the kitchen and get some supper!

Kari Hovinmaa
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Re: Resistance soldering

Postby Kari Hovinmaa » Sat Sep 26, 2020 5:37 pm

Hi David
ThankYou for a great and professional presentation on virtual.
Very much interested in getting the PSU and the rest.
Problem is me and some of my advanced collagues live in Finland.

Could You kindly inform me the supply contact.

Kind regards
Kari Hovinmaa member 6621
kari.hovinmaa@kolumbus.fi

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David B
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Re: Resistance soldering

Postby David B » Sat Sep 26, 2020 5:46 pm

Hi Kari,

Thank you. I am glad you found the presentation so useful.

There is an accompanying sheet which you can download from just under the video which has the supplier on plus a number of other things you might be interested in.

The unit is supplied by London Road Models. The web page is here: https://traders.scalefour.org/LondonRoadModels/various/soldering-materials-and-tools/

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David Thorpe
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Re: Resistance soldering

Postby David Thorpe » Sun Sep 27, 2020 8:08 am

David, that was exceptional. I've been using an RSU for some years, but not as often as I should, and your video has not only inspired me to use it more often, but has also shown me how I can use it more effectively and for tasks for which I hadn't even dreamed of using it. Many thanks.

DT

petermeyer
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Re: Resistance soldering

Postby petermeyer » Sun Sep 27, 2020 8:15 am

I think London Road are going to have to make a lot more RSU's after this. Thanks for the Masterclass

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David B
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Re: Resistance soldering

Postby David B » Sun Sep 27, 2020 9:22 am

Thank you, David. Glad it's given you some ideas.

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David B
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Re: Resistance soldering

Postby David B » Sun Sep 27, 2020 9:25 am

petermeyer wrote:I think London Road are going to have to make a lot more RSU's after this. Thanks for the Masterclass

They did after my articles in S4 News when sales increased several fold.

I hope those people bought then didn't just end up like so many others, gathering dust because it would be such a shame. Perhaps the video will give them the encouragement to get going with them because the technique is so useful.

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45609
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Re: Resistance soldering

Postby 45609 » Sun Sep 27, 2020 11:45 am

Hi David,

As I mentioned to you in a PM. Great video and even as a seasoned RSU user I picked up a couple of tips. Ceramic tipped tweezers being the best one.

Now, hopefully something I can add. Early in the video you mentioned the carbon rods to fit in the probe. My RSU is an old MMS (Mingnon Model Studios) device and sometime ago I needed some more carbon rod. Sadly none of the typical model railway tool suppliers could oblige with the correct diameter rod. However, a coincidental trip to a welding supplies shop a few months later I saw on a shelf something that I recognised as RSU probes. I asked what they were. “Gouging Rods” came the reply. The conversation went on and I learned that they are used for cutting metal and burning welds out. They are available in various diameters to suit the size of cut and power requirements of the industrial application. Cutting a long story short I left the store with a box of the appropriate diameter (a lifetime supply) for only a few pounds. In fact I had so many I gave a lot away to some mates with RSUs.

Google “gouging rods” and you will be able to chose from a multitude of possible sources.

Cheers...Morgan

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Rod Cameron
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Re: Resistance soldering

Postby Rod Cameron » Sun Sep 27, 2020 3:57 pm

David, just watched this and can reinforce what others have said. At DRAG we have benefitted from your demos face to face of course but your video is just as helpful and I did pick up a couple of tips myself. Mainly I hope this will encourage more people to have a go if they've never tried it.

Quite rightly you say at the end that RS is not a substitute for, but complementary to, conventional soldering. I'm sure I've asked you this before (but I've forgotten the answer) - apart from tinning, what do you typically still use a conventional iron for?
Rod

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David B
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Re: Resistance soldering

Postby David B » Sun Sep 27, 2020 4:58 pm

Rod Cameron wrote:Quite rightly you say at the end that RS is not a substitute for, but complementary to, conventional soldering. I'm sure I've asked you this before (but I've forgotten the answer) - apart from tinning, what do you typically still use a conventional iron for?


Thanks, Rod. There are a number of jobs I wouldn't use an RSU for though, naturally, many don't spring immediately to mind when asked! I would use a conventional iron for fine, delicate work like valve gear and screw couplings, bicycles and a number of other Southwark Bridge kits, sometimes, laminating. I am sure that, given time, I can come up with other examples. I used the doors of the Morgan iron mink as an example of laminating in the video because it was the only thing I had to hand I could use but actually, I prefer to make them with a conventional iron, feeding the solder in from the side so that it is taken in by capillary action. I experimented with these, using the RSU but came to the conclusion that my preference here was to use the conventional iron.

It's a matter of experimenting and finding what works best for you. If you experiment, you will find more ways of using the RSU just as you will find times when it is not the best tool for the job, but you won't know this until you have tried it.

Just posted when I remembered something else - white metal kits!

DavidM
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Re: Resistance soldering

Postby DavidM » Sun Sep 27, 2020 5:20 pm

Great video David. Not just a masterclass on the RSU, but a masterclass on how to do a great presentation as well!
I have one of the original Bernard Weller units from the early 90s - I use it all the time, but I’ve picked up a lot of new ideas here especially with alternative support for the work and soldering whitemetal, something I’ve thought about but shied away from.

It was good to meet you on the Melbourne group’s Zoom meeting yesterday.

regards,
David Murrell

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David B
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Re: Resistance soldering

Postby David B » Sun Sep 27, 2020 5:28 pm

Thank you very much, David. I am glad the video has given you some thing new to think about and try.

It was nice to spend time chatting with you all down below - a very pleasant beginning to a really good day. It was also nice to put faces to names and exchange a few words with people I have only ever conversed with by email or through the Forum.

All the best to you. David

DougN
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Re: Resistance soldering

Postby DougN » Sun Sep 27, 2020 11:18 pm

45609 wrote:Hi David,

Google “gouging rods” and you will be able to chose from a multitude of possible sources.

Cheers...Morgan


Morgan thanks very much for that I have a small bag of spares for my "Blue Rink" RSU this was produced by a local Australian member 20 odd years ago. He did short production runs but unfortunately passed away a number of years ago, it was an item I thought about at times for spares. So now I have no concerns!!!

I have to say to David B that I have used my RSU in fits and starts but looking at how you have used yours I need to use the techniques of flatening the solder, and cutting into little peices. The big one though is the use of a blunt syringe for the flux application. I tend to use a red label version here but the idea of only the smallest amount this way rather than a brush is great. It is a shame my supply of syringes has dried up... but then again the ones for animals tend to be a bit big :shock: for what we need. I certainly dont want some one attacking me with a 100ml one :o
Doug
Still not doing enough modelling

Highpeak
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Re: Resistance soldering

Postby Highpeak » Mon Sep 28, 2020 1:23 am

I've used an RSU (an American Beauty model) for a number of years with some success but have never been entirely happy with it. Your video was excellent and has given me a lot of useful ideas to improve my use of it.

I can only second the suggestion that you tackle other subjects because your presentation skills are excellent.

I would also like to express my thanks to all who made this possible. Even if Scaleforum had been held in the traditional way, reaching it from the US would have been extremely difficult, so this effort was much appreciated.
Neville
If at first you don't succeed, try reading the instructions.


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