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how to fix white metal parts together


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You've just listed all the ways I have seen white-metal joined together and sometimes very firmly indeed.

 

Are you sure it's white-metal and is there any coating or accretion on it which is preventing any adhesive or solder gripping as you might normally expect?

Hi there , no there isn't anything like that on them ,there clean and I rub them down with a small grade paper before I do anything ,the epoxy resin is LOCTITE.the superglue is a professional {JAK} glue and I use ZIP KICKER accelerator ..
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Presumably you are using a low temperature solder and a temperature regulated iron? If the solder doesn't flow on the fluxed workpiece, then the iron is not supplying enough heat. If the solder melts but does not flow out onto the workpiece to make the joint - no wetting - then the flux isn't the right type. That's about all there is to go wrong.

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Presumably you are using a low temperature solder and a temperature regulated iron? If the solder doesn't flow on the fluxed workpiece, then the iron is not supplying enough heat. If the solder melts but does not flow out onto the workpiece to make the joint - no wetting - then the flux isn't the right type. That's about all there is to go wrong.

Your later answer just might be the reason.because the solder does not flow .Im useing a soft solder made by CRAFT
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Whether you glue or solder, and there are pros and cons to both, cleanliness is absolutely vital. Consider using meths or lighter fluid to de-grease the parts after you've rubbed them down. Don't use white spirit as this leaves a residue behind (or so I believe).

 

Just out of interest - what exactly are the parts that you're having trouble with?

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Wrong solder and wrong flux. You must use low melt solder and a suitable flux for "gluing" white metal parts. I believe what you have tried to use is that nasty "lead free" solder that is no good for anything. The low melt solder is special and it is not just the low temperature melting point but also the metal mix used.

 

I hate Araladited white metal but sympathise a little if soldering scares you. A good quality Araldite should work. Forget superglue. The metal interface will never be perfect fit for its use. Nearly all superglues are useless at filling gaps and gluing mismatched parts.

 

But above all white metal soldering requires the parts to be scrupulously clean - physically and chemically. When soldering the flux provides the chemical cleaning and also assists the low melt solder to flow. This flux should ideally be a liquid flux rather than a paste as pastes tend to leave a residue. Multicore solder is useless, it is the wrong metal mix and should be used for electrical work only, the resin used in the core will not help it flow and certainly not into white metal joins. If you really have to use araldite :( then clean the parts chemically with an abrasive cleaner like Cif or Vim after you have removed all the oxide coat with an abrasive (brass brush, wet'n'dry, emery, glass fibre pen). The metal should be slight;y shiny.

 

Soldering will always give the strongest join. Your iron should have enough capacity to heat the solder to melt it and to heat the parts at the join to the same temperature - an awful lot of folk are scared to use sufficient heat for fear of melting the whitemetal and start by using a temperature set at the point the solder just melts (70'C) This is completely the wrong approach. If you really have to use a temperature controlled unit then it should be set just under the point at which the white metal melts. Even then white metal soldering can be done just as easily without a temperature controlled station. I don't have one and consider them to be a waste of time and a route to bad habits in soldering.

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Can anyone tell me the best way to fix white metal parts together, I have tried epoxy resin ; superglue ; solder, using a good grade solder and flux flux I may add ,but to no avail.can anyone suggest , or tell me what I'm doing wrong.

 

Jimi

 

I have no problem using 2 part epoxy glue ( I use a cheap own brand make) to stick whitemetal, only use superglue for small parts.

 

Solder is the best, I use Carrs 70. tried using 8% liquit flux but had best results with 12% again a cheap brand

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Are there different "grades" of white metal used in kits? I have used the right solder and the right flux with mixed success, using a 25w ordinary soldering iron. On a Knightwing 00 gauge water crane I was successful but on a couple of small items (a fork lift truck and a wheel barrow) I have both failed to get the solder to flow and melted the white metal - at the same time. I am building up a useful supply of scrap! In the case of a Reliant three-wheeled van, the only separate bits were the floor (which was a snug fit anyway) the driver and his seat, all of which have been secured with Evostik but they don't face any pressure.

 

Harold.

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Are there different "grades" of white metal used in kits? I have used the right solder and the right flux with mixed success, using a 25w ordinary soldering iron. On a Knightwing 00 gauge water crane I was successful but on a couple of small items (a fork lift truck and a wheel barrow) I have both failed to get the solder to flow and melted the white metal - at the same time. I am building up a useful supply of scrap! In the case of a Reliant three-wheeled van, the only separate bits were the floor (which was a snug fit anyway) the driver and his seat, all of which have been secured with Evostik but they don't face any pressure.

 

Harold.

 

Yes there are several different grades of whitemetal.

 

I personally have best results using 0.4mm Lead free cored solders and a full temperature 25W Antex Iron, but I don't like to use for small fittings for obvious reasons. I tried Carr's 70 degree stuff and red label flux but the flux just didn't do anything except evaporate from the heat.

 

Regular consumer superglues are usually pretty useless on metal, Expo medium was always good with good gap filling and would make a structurally sound whitemetal kit no problem the thin stuff was no good though, but the Bee's knees would be something like Loctite 435.

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Wrong solder and wrong flux. You must use low melt solder and a suitable flux for "gluing" white metal parts.

 

I hate Araladited white metal but sympathise a little if soldering scares you. A good quality Araldite should work.

 

[snip] - an awful lot of folk are scared to use sufficient heat for fear of melting the whitemetal and start by using a temperature set at the point the solder just melts (70'C) This is completely the wrong approach. If you really have to use a temperature controlled unit then it should be set just under the point at which the white metal melts. Even then white metal soldering can be done just as easily without a temperature controlled station. I don't have one and consider them to be a waste of time and a route to bad habits in soldering.

Whilst I agree that many problems are the result of people being hesitant about using sufficient heat for fear of melting the whitemetal. I take the opposite approach. The longer the iron is on the job then the greater the chance of melting the whitemetal, so I want to be in there and out as quickly as possible, the iron I use is often well above the temperature at which the whitemetal would melt.

 

Admittedly most of my jobs are attaching whitemetal to brass or nickel. So I don't think that you "must" use whitemetal solder, I have an ABS whitemetal wagon kit built entirely using a 50W Weller iron and standard multicore solder. Where possible I will tin the joint on the side of the brass or nickel, I would then place the whitemetal casting where required and apply the heat to the brass. As soon as I see the multicore solder melting next to the whitemetal I remove the heat and blow on it to cool as soon as possible.

 

This is probably more accurately described as welding rather than soldering but it works for me. If I can't get in with the soldering iron then I will resort to epoxy resin glue. In which case I would heavily score the whitemetal joint to provide a key and I use the plastic padding epoxy resin as it is much better than araldite. When mixed it has a lower vicosity and is not as brittle when it sets.

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Your iron should have enough capacity to heat the solder to melt it and to heat the parts at the join to the same temperature

 

Under no circumstances should you attempt to heat the parts to the same temperature, The white-metal parts should be held together then flux applied to the joint (I use phosphoric acid), apply a blob of solder to the iron and when melted bring the solder to just touch the fluxed joint. You will see the solder flash into the joint by capilary action. You need to use a temperature controled iron as a normal iron with cause the low-melt solder to dis-associate.

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Jim - I am probably repeating advice already given - but for small parts I use Wilkinson's own brand Super Glue. I put a few drops on a spare piece of thick card and then use a tiny screw driver to apply it to the parts to be glued. Perhaps because it is a cheap product but setting time can be variable and sometimes pieces need to be held together for what seems an age. If it goes wrong it is relatively easy to break the newly formed joint, scrape clean and start again. Most recently I have been using Super Glue for a variety of Mike's Model kits. Previously I had been using Loctite two part epoxy instant adhesive which I was finding very stressful - it sets hard instantly without allowing time to position fiddly items.

 

Good luck

 

Ray

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The problem we have here, as so often with soldering issues, is that there are many different techniques used. Some 'seem' to work and some are correct and work reliably every time. Unfortunately the 'correct' way tends to be learned by gaining lots and lots of experience. In the end as long as it seems to work for you then that will be sufficient. But don't stop experimenting as there are other techniques.

 

Adrian has made a very important point which although not part of the original issue is very important. Brass and n/s parts must be tinned before joining to white metal.

 

The key thing here is to know and understand heat transfer and the properties of the metals, including the solder. 70'C low melt solder is a very different medium from normal solder and has also been pointed out above the technique of using it is not really soldering and is more equivalent to hot gluing.

 

Low melt solder degrades very quickly if kept above its melting point for any long period. Those of us who use 25W and higher irons without temperature control are very much aware of this and the effect that has on the properties of the solder. You should never reuse spent low melt solder, unlike normal lead solder than can be reworked. When heated for any period it becomes even less amenable to flow and the melting point increases (all bad things) This is due to the Bismuth and Cadmium parts of the solder alloy being evapourated. (NB both of these metals are unpleasant and toxic, and another reason for not denaturing them) I would never carry solder on the tip of the iron to the work, cooking it as you do so. I use small shaved flakes of the solder strategically placed along the join which is drenched in Carrs flux. Apply the iron and the solder melts quickly and will flow into the gap, don't try to push it around, don't come back for a second attempt unless it is to fill a gap with more fresh solder. Nearly always I can hold the part in my fingers, it gets hot but not that hot, I do not hang around for the heat to get that far. Don't forget to consider heat sinks on those small parts as a big lump of whitemetal will absorb a lot of heat but the tiny part next to it will absorb it much quicker.

 

The technique has worked for me for years and most days I am soldering something, though these days far more brass than whitemetal. I always try to solder from the back of the join and yes for those silly thin parts that are only cosmetic am still prepared to use Araldite.

 

Remember the goal is a complete model - it really doesn't matter how you get there = especially if it is a one off and simply a hobby. Don't let it defeat you just keep trying.

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Low melt solder degrades very quickly if kept above its melting point for any long period. Those of us who use 25W and higher irons without temperature control are very much aware of this and the effect that has on the properties of the solder. You should never reuse spent low melt solder, unlike normal lead solder than can be reworked. When heated for any period it becomes even less amenable to flow and the melting point increases (all bad things) This is due to the Bismuth and Cadmium parts of the solder alloy being evapourated. (NB both of these metals are unpleasant and toxic, and another reason for not denaturing them) I would never carry solder on the tip of the iron to the work, cooking it as you do so.

 

I use small shaved flakes of the solder strategically placed along the join which is drenched in Carrs flux. Apply the iron and the solder melts quickly and will flow into the gap, don't try to push it around, don't come back for a second attempt unless it is to fill a gap with more fresh solder. Nearly always I can hold the part in my fingers, it gets hot but not that hot, I do not hang around for the heat to get that far. Don't forget to consider heat sinks on those small parts as a big lump of whitemetal will absorb a lot of heat but the tiny part next to it will absorb it much quicker.

 

The technique has worked for me for years and most days I am soldering something, though these days far more brass than whitemetal. I always try to solder from the back of the join and yes for those silly thin parts that are only cosmetic am still prepared to use Araldite.

 

Remember the goal is a complete model - it really doesn't matter how you get there = especially if it is a one off and simply a hobby. Don't let it defeat you just keep trying.

 

I would like to second Kenton's tips

 

I put the 2 pieces to be joined together

Then apply plenty of flux (12%)

Add a flake of solder to the joint

In and out fast with a 25 watt Iron

 

Job done

 

I may have even learnt this way of soldering from Kenton in the past, if so thank you.

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Apart from needing to develop the skill, I think the problems I experienced must have been caused by carrying the solder to the joint on the iron. Thinking back, on the fork lift, the bits that succeeded were where I placed a sliver of solder strategically and then applied the iron - mind you, that was on the main body which is relatively bulky. I was surprised when I bought the solder to find it supplied as a small ingot rather than a coil.

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In recent years I have generally used low melt solder, but back in the early seventies managed to assemble several K's kits using Evostik - and they haven't fallen to pieces yet.

 

Even recently I have been known to "tack" pieces together with Evostik and then reinforce the joint with Araldite when soldering has been awkward.

 

I once tried Super Glue and got nowhere with it - the castings are usually too rough (no matter how much I work on them) or are slightly porous. But then I can't glue anything with Superglue - not even my fingers to each other.

 

David

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shortliner(Jack) makes a very good point.

 

If you build with epoxy glues all you need to do is soak in Nitromors overnight and you get all your white metal parts back to have another go.

 

If you build with low melt solder all you need to do is boil for about 5-10minutes in a pan of water and you get all your white metal parts back to have another go.

 

What is there to loose? Build it once one way then get the parts back and build it again the other way.

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