Attaching axleboxes and buffers

[jimphillips]

Could I ask what does anyone use to attach white metal axleboxes or buffers to underframes? I feel soldering would invite disaster in the form of molten globules of white metal. I have used araldite for various DIY jobs but this seems a bit messy for delicate mouldings such as springs and axleboxes. Is there an adhesive particularly suitable for this job?

[David B]

For brass or nickel silver buffer beams I use 100 degree solder (and flux) with a temperature controlled iron set to about 180C, though the temperature may vary up and down a little depending on how big your soldering iron bit is - the bigger the bit, the lower end of the temperature range.

If you are worried about melting the white metal, practise first on some scrap brass and white metal sprue. Practising on scrap is always a good idea and can save many tears!

[Will L]

Could I ask what does anyone use to attach white metal axleboxes or buffers to underframes? I feel soldering would invite disaster in the form of molten globules of white metal...

Not if you take the trouble to lean how to do it properly. Strangely enough, in the dim and distant days before temperature controlled soldering irons became available, we still managed to solder white metal without melting it. Yes there is a trick to it, but once you've got it, it is not all that difficult or all that likely to lead to unintended melt-age.

1. Unless you are unusually determined as well as kack handed, big bits of white metal are actually quite resistant to melting as this takes a LOT of heat.
2. When soldering small bits of white metal use a small soldering iron bit, as this limits the speed of heat transfer. I had a 1mm bit I used for this job but I ran it at normal iron tempratures.
3. Most important of all, flood the joint with lots of liquid flux. This will hiss and boil off while you solder but the solder will flow while it does that and it wont allow the temperature to rise above 100c until it's boiled off. When the hissing stops remove the iron.

A bit of practice helps of course.

Any successfully soldering requires that there is enough heat in the iron to heat up the bit being soldered quickly. Reduce the iron temperature too much and soldering becomes much more difficult, because you have to dwell longer. With white metal that actually increases the chance you'll melt something.

That said do be careful that you don't touch anything with the side of the bit as this is a lot bigger as well as closer to the element and can be a fair bit hotter than the tip.

I'm with David about using 100c solder to attached white metal to brass and nickel silver as avoids having to tin them first, and achieving this just means you are applying some version of the above rules.

[jimphillips]

Thanks for all that helpfull info Dave and Will. I must consider getting a temperature controlled soldering iron then. Soldering in itself isn't a mystery to me, I just assumed white metal had a very low melting point.

[Julian Roberts]

I'm not meaning to contradict. For me soldering small white metal castings feels risky and I take all precautions...which in my case means tinning the brass with 145 and then soldering the WM casting with 70deg, otherwise exactly following Will's excellent procedure.

[Noel]

To answer your original question, I use Evostick [even on the plastic chassis I usually build...] Just don't use too much.

[grovenor-2685]

Robbo wrote the definitive article on this topic, albeit before the introduction of 100 degree solder.
See http://www.norgrove.me.uk/Robbo.htm
Rgds

[Julian Roberts]

That's quite a read Keith! My introduction to soldering was Iain Rice's excellent exposition in his Wild Swan book on Whitemetal Loco Construction. He makes it sound easy, and with that attitude, basically it is - except that the smaller the part, the better one's technique needs to be! Since reading it I've always enjoyed the actual feeling of soldering things together, and the knowledge of the permanence of the joint is pleasantly satisfying (assuming it's not a "dry joint"). In contrast I find working with adhesives feels like fooling about, but of course they are best for some things.

[jimphillips]

Thanks for all the advice gentle men, Noel I can well imagine the consequences of too much evostick!

[Mark Tatlow]

I'm a 100 degree solder man.

As Will says most castings have sufficient mass that it actually takes quite a lot of heat to get them above their melting point. So as long as you don't faff about repositioning the piece with the iron in contact with the part or underlying body or the casting very slender, it is not a problem.

70 degree solder is not nearly so effective as thermal mass of the casting also retains heat sufficient to keep the solder wet for a surprisingly long time.
On more than a few occasions I have sought to move the part to admire the last item to be secured to find it wasn't yet secure!

Pre-tinning the underlying body prior to the casting is being applied with 145 degree solder is also worthwhile advice, it makes the 100 degree flow slightly better (and 70 degree much better).

I now only use 70 degree as a weighting material - because it melts at such a low temperature it can be flowed into nooks, crannies and hidden areas to add weight. You can get a good amount of weight into an ashpan and a bit more in a cylinder or sand box using this technique.

[Guy Rixon]

For internally-sprung buffers, I prefer to assemble them separately from the vehicle and then to fit them with glue. For me, this is easier than trying to set the buffer throw and secure the ram when a buffer guide is fixed to the headstock. I use a very small amount of CA glue applied to the buffer spigot, and this seem to hold it well enough if the spigot is a decent fit into the headstock. If the glue be put on the headstock rather than the spigot then the chance of it getting into the buffer and locking up the ram is too high (given my shaky hands).

I fix axleboxes with CA glue, too, but that's just rank cowardice and lack of proper materials :-/ Must get some of this new-fangled 100-degree solder some time soon.

[jimphillips]

Guy please excuse my ignorance, could you explain what CA glue is please?

[andrewnummelin]

I go along with Guy Rixon - use glue. Cyanoacrylates (CA or super glue) come in various forms so one may choose to use a very low viscosity one for parts that fit closely, a gel one when gap filling is needed, or an impact modified one for items that may take a knock.
I agree with Jim, epoxy resins (eg Araldite) are probably less suited for this application but may come into their own behind a buffer beam (for reinforcing) depending on the designs of beam and buffer shank and how well they fit.
I confess to never having tried to solder white metal, but in the case of pre-assembled sprung buffers I would worry about flux getting anywhere near the coil spring.

And an aside on the use of epoxies - I’ve sometimes used two on the same joint. A slow setting one for maximum strength, with a little bit of fast setting glue to act as a clamp on items that are difficult to clamp mechanically.

[jimphillips]

Thanks Andrew, this is what I am thinking at present, not that I am shying away from soldering. I spent over forty two years with BT and did a considerable amount of soldering in that time, but not much of it was delicate work and none of it involved white metal! Spring buffers would have to be treated carefully even with CA. Those springs are tiny.
Ok online now to look at CA adhesives.

[Will L]

I go along with Guy Rixon - use glue. Cyanoacrylates (CA or super glue) come in various forms so one may choose to use a very low viscosity one for parts that fit closely, a gel one when gap filling is needed, or an impact modified one for items that may take a knock.
I agree with Jim, epoxy resins (eg Araldite) are probably less suited for this application but may come into their own behind a buffer beam (for reinforcing) depending on the designs of beam and buffer shank and how well they fit.
I confess to never having tried to solder white metal, but in the case of pre-assembled sprung buffers I would worry about flux getting anywhere near the coil spring...

I was a superglue early adopter, I even had an article published by Cyril F in the Muddler on how to get them to work. The very early 70's if my memory serves me correctly. I still have a white metal locos and several wagons kits primarily assembled that way. Then I leaned how to solder properly and I wouldn't go back. I still use superglues for very specific task, mostly mending pottery and I assembled the Seven Models kit of the Telford Iron Bridge with it as I really couldn't see any other way of doing it as its tiny.

But the speed and reversibility of a solder joint means it is the method of choice in most circumstance.

As to white metal sprung buffers, I was an early adopter here too and I agree turned steel buffer heads, fine springs and solder don't mix, but surely the buffer shanks get fixed to the wagon during basic assembly, and the buffer head and springing are practically the last job be done long after the iron and flux have long been put away?

[Guy Rixon]

As to white metal sprung buffers, I was an early adopter here too and I agree turned steel buffer heads, fine springs and solder don't mix, but surely the buffer shanks get fixed to the wagon during basic assembly, and the buffer head and springing are practically the last job be done long after the iron and flux have long been put away?

That's fine if there's enough space to work on the buffer tail when the wagon is nearly complete. I've built a few with short frames and/or clasp brakes where there's room for the buffer tail to move but not enough to get a tool on it to bend it round and secure the ram.

[David B]

But the speed and reversibility of a solder joint means it is the method of choice in most circumstance.

As to white metal sprung buffers, I was an early adopter here too and I agree turned steel buffer heads, fine springs and solder don't mix, but surely the buffer shanks get fixed to the wagon during basic assembly, and the buffer head and springing are practically the last job be done long after the iron and flux have long been put away?

Good point about the reversibility of soldering. I almost never use glues with metals and then it is a last resort.

I agree about the sprung buffers - fix the bodies during construction, the heads and springs coming later. I have made a small jig, a piece of brass with a slot in it to go over the ram to keep a consistent distance between body and head.

[David B]

That's fine if there's enough space to work on the buffer tail when the wagon is nearly complete. I've built a few with short frames and/or clasp brakes where there's room for the buffer tail to move but not enough to get a tool on it to bend it round and secure the ram.

Make a small washer to fit over the tail and fix with a dab of solder!