Resistance Soldering

[doilum]

23 minutes ago, Bucoops said:

 

 

Not sure how you managed to make that quote look like it came from me

 

I've got mine but not tried it yet. I'm making a metal plate thingy but not found a suitable bit of wood to mount it to yet.

Surprised no-one has previously mentioned bits of wood. The ability to knock together scraps of wood to act as a third hand is one of the secrets of soldering in general and loco/stock building in particular. A set of miniature G clamps become indispensable.

[EKR]

I should add that when I first got my rsu I purchased both solder paste and solder creams.

Haven’t touched them over the last ten years, as I too disliked the “spitting” and the silly prices.

 

I just use standard 145 solder and a phosphoric flux, the same as I use with my regular iron, as it also works well with whitemetal.  In the situations where a paste or cream would be helpful I find tinning does the job, and where a thin flux would run away, I use a paste flux like Copalux. Normally I have a small pot with short lengths of precut solder to hand.

 

The main reason I prefer to use a clip is that it is quick and allows me to turn the item I’m working on in any direction for the best view and access.

 

As to keeping the probe clean, I always have some grit paper on the workbench and a quick wipe works wonders.

It’s worth adding that I used to use a pencil sharpener (read on forums) to keep the probe to a point, but now I don’t bother. Two faces are all thats needed, and it’s easier to push with.

[mantheakis]

On 24/07/2020 at 13:37, davidbr said:

I wrote a couple of articles for Scalefour news a couple of years ago which people told me they found useful, so I will attach a copy here in the hope that it will contribute to people's use of the technique.

Spirit of Resistance (opt).pdf 1.15 MB · 30 downloads

 

Excellent article with useful tips - thank you for posting.

[davidbr]

3 hours ago, mantheakis said:

 

Excellent article with useful tips - thank you for posting.

Thank you Harry.  Glad you found it useful.  Any questions, drop me a pm.  This goes for anyone else.

[michl080]

Morning all,

 

I am using a ceramic soldering plate wrapped in aluminium foil instead of a metal base plate. Almost no heat sink and no cleaning necessary. Just replace the aluminium foil and your ready for the next session.

 

 

looks like this one:

 

reg.

Michael

[Deano747]

I do similar to Michael, but wrap foil round my metal plate. Thin card between plate and foil prevents heat loss but magnets still work (as long as they are adequately strong enough)

 

Regards

Deano.

[michl080]

Good morning,

 

I must say I didn't have much luck with magnets. Whenever I tried to place the second one, the first magnet was pulled from its position and the whole assemble was out of alignement. So I found these hooks that can be combined with the above ceramic baseplate and I love them to fix components:

 

 

I found them at Fohrmann, I am sure there are also UK based suppliers.

 

Michael

[EKR]

I’ve just watched a Video of a Japanese modeller scratch building a brass EMU with minimal tools.

He used no clamps or jigs whatsoever.

Just sellotape to hold pieces in position till he could tack them in place.

I’m reminded that some fishing tackle is designed to catch fish, other to catch anglers.

Applies to us too

[Siberian Snooper]

It's always worth checking that the polarity of the magnets is the same each time, when using two or more,  I  have been caught out several times,  because I forgot to check first.

 

 

[davidbr]

Old fashioned iron magnets are either too large or too weak.  You need rare earth magnets - neodymium are the commonest - so that you get a good attachment.  I bought 8mm diameter x 20mm long rod magnets which have a pull of just under 3Kg.  I got the length so that I could get hold of them!  If they are too short, with the pull they exert, they can be b*****s to get off.  I have not had any problems with them attracting each other as they do not need to be very close.  

 

There are two websites (UK) which have an excellent range of shape, strength and size, some of which are self-adhesive which can be useful:  eMagnetsUK and First4magnets.  I am sure there are others but these have provided all I need.

 

A word or two of warning.  These magnets are strong, so a) if you have a medical appliance such as a pacemaker, do take advice from your doctor and b) try not to let them bang together because they can chip and shatter and nip fingers quite painfully.  I have a couple of battered magnets people have tried at demonstrations and been taken by surprise.  They have also been known to wipe credit cards!!

[Enterprisingwestern]

1 hour ago, davidbr said:

A word or two of warning.  These magnets are strong, so a) if you have a medical appliance such as a pacemaker, do take advice from your doctor

 

I find it quite amusing/worrying that the warning about this is printed on the carton they come in, which you hold just in front of your chest to read!

[polybear]

12 hours ago, michl080 said:

Good morning,

 

I must say I didn't have much luck with magnets. Whenever I tried to place the second one, the first magnet was pulled from its position and the whole assemble was out of alignement. So I found these hooks that can be combined with the above ceramic baseplate and I love them to fix components:

 

 

I found them at Fohrmann, I am sure there are also UK based suppliers.

 

Michael

 

Thanks for posting this - can you tell me what the vertical part consists of please?  They look pretty straightforward to make - buying them from Germany works out expensive.  The ceramic bases are available very cheap from china via ebay, albeit a bit smaller.

[chrisf]

I have found the range of magnets sold by Squires very useful.  It does help if you have a sheet of steel though.  Clamping the work to it in a suitable configuration frees up more hands than the Good Lord gave us.

 

Chris 

[michl080]

1 hour ago, polybear said:

 

Thanks for posting this - can you tell me what the vertical part consists of please?  They look pretty straightforward to make - buying them from Germany works out expensive.  The ceramic bases are available very cheap from china via ebay, albeit a bit smaller.

 

They are quite simple. See the picture below.

 

 

The M3 thread has a hole in its end that holds a stainless 1.3mm needle. This needle sticks in the hole of the ceramic base plate. The brass arm slides loosely in the thread and is simply pressed down to hold the part you want to solder. The length of the brass tube sliding on the thread is about 12mm, the arm is self-locking on the thread. The angled arm is silver soldered to the brass tube.  Not complicated, but a clever design. The grid is 10mm.

 

Michael

[polybear]

13 minutes ago, michl080 said:

 

They are quite simple. See the picture below.

 

 

The M3 thread has a hole in its end that holds a stainless 1.3mm needle. This needle sticks in the hole of the ceramic base plate. The brass arm slides loosely in the thread and is simply pressed down to hold the part you want to solder. The length of the brass tube sliding on the thread is about 12mm, the arm is self-locking on the thread. The angled arm is silver soldered to the brass tube.  Not complicated, but a clever design. The grid is 10mm.

 

Michael

 

Hi Michael,

That's excellent - many thanks

Brian

[davidbr]

The OP asked about suitable solder and mentioned paste and cream.  I don't get on with either because it invariably spits or splatters but some people do manage to use it successfully, so it clearly has a place.

 

1.  I have not, though, found a successful way to use solder cream or paste.  Does anyone have any pointers to their secret of success with the product(s)?  I know I am not lone with my negative experience.

 

2.  I am also aware that paste and cream has a shelf life, so has anyone successfully rejuvenated their 'past it' paste or cream and if so, how did they do it?

 

Two questions I know many modellers would like to know the answers to.

[dpgibbons]

4 hours ago, davidbr said:

 I am also aware that paste and cream has a shelf life, so has anyone successfully rejuvenated their 'past it' paste or cream and if so, how did they do it?

 

There are numerous YouTube videos about doing this using flux, such as this one

[Killybegs]

I use Carr's No Clean Solder Cream that comes in a large syringe and doesn't appear to go off. I mix it with a little Powerflow Flux, before applying it, to help it flow better. Using Powerflow does destroy the 'no clean' property of the solder cream so you do need to clean up afterwards. I use my RSU for the majority of my soldering.

[EKR]

I have revived paste in the past with a few drops of water, but whilst it adds to it’s application, it also adds to the spitting.

Phosphorous flux is c.90% water.

 

A small amount of water can also revive powerflo flux that has gone that horrible brown muddly colour.

[Killybegs]

Here's my pot of Powerflow. It keeps for years if you keep the lid on. I take a little out with a cocktail stick as and when I need it.

 

[57xx]

On 29/07/2020 at 18:52, davidbr said:

The OP asked about suitable solder and mentioned paste and cream.  I don't get on with either because it invariably spits or splatters but some people do manage to use it successfully, so it clearly has a place.

 

1.  I have not, though, found a successful way to use solder cream or paste.  Does anyone have any pointers to their secret of success with the product(s)?  I know I am not lone with my negative experience.

 

2.  I am also aware that paste and cream has a shelf life, so has anyone successfully rejuvenated their 'past it' paste or cream and if so, how did they do it?

 

Two questions I know many modellers would like to know the answers to.

 

1. I have had good and not so good experience. The good on small detail parts, a tiny drop work well, you see the solder flash and the part is attached. The "not so good" is when using on larger areas, I tend to find tinning works better there. If the probe isn't directly over the paste, it doesn't always melt. I've never had it spit at me, maybe due to using such small amounts.

 

2. Both my paste/creams are old. I've reactivated them with IPA and also by mixing with flux (La-co and rosin have both worked. The La-co itself needed reactivating with water a whole back). I'll only mix a small amount at a time when I need it.

[Bucoops]

Had my first quick play last night. I have a tube of Carr's 179 which I've had for a couple of years. All I did was join a couple of bits of scrap etch, but I didn't get any spitting. I used a bit too much initially and where it oozed out the sides when I pushed the probe down, that bit didn't melt, but the two bits of etch were very firmly soldered together.

[hayfield]

36 minutes ago, Bucoops said:

Had my first quick play last night. I have a tube of Carr's 179 which I've had for a couple of years. All I did was join a couple of bits of scrap etch, but I didn't get any spitting. I used a bit too much initially and where it oozed out the sides when I pushed the probe down, that bit didn't melt, but the two bits of etch were very firmly soldered together.

 

 

Out of interest which mate have you bought please

[Bucoops]

13 minutes ago, hayfield said:

 

 

Out of interest which mate have you bought please

 

This one - 

 

https://traders.scalefour.org/LondonRoadModels/various/soldering-materials-and-tools/

 

There was a bit of a waiting list but I understand there will be another batch in a few weeks.

[davidbr]

The London Road RSU is very good and easy to change the voltage.  I made a label for the different combinations which people might find useful: