Resistance Soldering Unit

[DaveHarris]

I, like many others i suspect, have looked at resistance soldering and wondered if the cost versus use equation was worth it. I have recently found an advert for a British company, Frost Equipment, who offer a resistance soldering unit at half the cost of the popular LRM model.
Has anyone any experience of this unit, good or bad?

[David B]

Is this the unit? https://www.frost.co.uk/carbon-resistance-soldering-system/

I see the two reviewers both mention railway modelling, one 7mm, the other does not say what scale. The unit has an output of 6v which is much higher than the LRM RSU (though how this relates to current I do not know) and only two settings, 'standard' or 'high' current. On the LRM unit, I have never used more than 3v and that was on a 7mm job.

With only two settings, it will not be as controllable as the LRM unit which has a voltage range from 1 to 4.5v more settings so I would not like to use the Frost unit on smaller, delicate jobs or white metal as I do regularly. I find that changing the voltage on the LRM unit by just 0.5v makes a difference. If I am putting brass on to white metal, 2v is more aggressive than 1.5v. I can't speak for the Bernard Weller unit or any others.

The price is certainly attractive, but I question it's suitability and flexibility for 4mm modelling. My thought is that this would be better suited to 7mm or larger modelling, but others may think or know differently. Having the experience with the LRM unit, I would not consider one of the Frost units for myself.

You ask of an RSU, 'is it worth it'? It is an investment and I suggest the answer depends on your age and how much use you might make of it in your modelling. An LRM unit would be a better investment for a younger person but once one retires with hopes to spend more time modelling, it can still be a worthwhile investment. The unit is durable and will last for many years. They also have a good second hand value though they do not come up very often. I have heard of LRM units changing hands for more than £120. If you don't want to pay out for a new LRM unit (currently £210 + p&p), look for a second hand one.

[Bill Newstead]

There is a review of sorts here: https://platform1mrc.com/p1mrc/index.ph ... ment.3346/ The thread ends with no evidence that the buyer actually used it.

I have an LRM unit. In my experience it is a quality bit of kit, aimed squarely at railway modellers and worth every penny.

Bill

[DaveHarris]

Thanks for the comments gentlemen.

Not being an electrician I wasn't sure about the differences in outputs, but was thinking that the cheaper unit wasn't as 'flexible' as the LRM unit, hence my question.

As you say , the LRM has been around for a long time with a good history.

Will just have to consider if I can justify the cost to the 'boss'!

[Philip Hall]

Having looked at the review mentioned I wouldn’t touch it. The transformer box is very small, plastic, with quite a thin mains lead, and for the kind of current floating around makes me nervous. The foot switch (what a name for a small button!) being mounted on the transformer box means that you would have to look down at the floor each time to find it.

You get what you pay for. The LRM unit is built well robust and safe and works very well.

Philip

[David B]

I hadn't realised that red button was the so-called foot switch. It's quite inadequate. No, this does seem very 'second' when put up against the LRM unit.

[nigelcliffe]

I agree with Philip and David, from what I can see on the maker's website and the "review" posted, don't bother. Output levels are not clear, foot switch is hopeless (I'm less worried about the mains lead - the currents at mains voltages shouldn't be high ).

I've had a LRM unit for many years; its rock solid, and I use a lot of the different outputs.

[David Thorpe]

It perhaps speaks for itself that the "review" Bill mentioned above says a lot about the unit prior to use, but nothing at all about it actually being used.

I've got one of Peter LeJeune's Swanage Models units; solidly built with a hefty metal case, CE certification,6 outputs, proper footswitch, and when I bought it it cost about the same as the LRM unit, which was not then available. It's worked perfectly and I expect it to continue to do so. i've no idea whether they're still available.

DT