Large Scale Central

Melting points of different solders?

Tools and Tips
#1

So I’m about to bite the bullet and start building a brass model for the first time, and I’m wondering if I should use different types of solder (melting points) so that each sub assembly can be separately built up with a higher temp solder, and then joined to the main structure with a lower temp solder. I’ve heard the term ‘silver soldering’ for live steamers, but what type of solder is used for that?

Right now, I’ve got two types of solder on hand; resin core for electrical projects, and a thicker solid solder that I used for replumbing a part of the house. I’m guessing that these two have different melting points?

Anyone got some help to lead me in the right direction? I recall seeing a couple of brass model projects over the years here…

#2

Craig, the electrical rosin core solder is a relatively soft solder. You want a harder solder for parts that may be subject to stresses. I use the silver bearing plumbers solder for what little I do. By clamping metal clamps onto parts I have already soldered, I can sink the heat away from them when soldering some other part, so that I don’t loosen the previous joint. A resistance solder set up would make such jobs easier, but for the amount of soldering I do, I cannot justify the expense.

#3

Craig,

There are many different ‘solders’ available, some more readily available than others, and some more appropriate for hobby use than others. our thought process is common and not far off the mark. Dave M’s remarks are also on point. If you would like to be totally confused, check out the Wikipedia article https://en.wikipedia.org/wiki/Solder located here.

As for your goal, the two solders you already have, with some judicious practice using Dave M’s technique will serve you well. Finding 95/5 in small diameter locally will be difficult at best. Check some of the solder manufacturer’s web sites, here is Kester’s http://www.kester.com/products/solder-wire/

Bob C.

#4

I believe traditional brass locos were assembled using hard silver solders. I used those solders during my silversmithing career; extra easy, easy, medium and hard. I only used med and hard because the lesser solders were too grey for 90% of my work. An Oxy/Acet torch was my ‘iron’ and soldering was quite near the melting point.

Silver bearing solders are much stonger than typical soft solders, but are marginal in strength, maybe a third of those mentioned above.

Wet paper towels are good heat sinks too and can hug the piece. Wet sand can hold parts up for soldering too. 3rd hands and self-closing tweezers are most helpful.

I admit I used simple soft solder for my Submarine swing set, but I wouldn’t use if on a loco.

John

#5

Thanks for the tips, and ideas. I recently acquired a resistance soldering unit from ebay (250 watt unit), but quickly found out that the hand piece that came with it is useless on any big pieces. So I’m trying to figure out what to do next, buy a different type of hand piece or use the one I have and bash it into a heavier duty piece.

If you’ve been following my Snow Dozer build on another thread, the purpose of this project is to build a brass model to function as a working snow plow so I figure I’m going to need some strength from each of the pieces. I’m going to start with the underframe and work my way up the sub structure, so I’m sure it will be a learning experience.

#6

I am sure you know that lap joints are stronger then butt joints. And I am sure you also know that the parts need to be cleaned, fluxed and preferably tinned before soldering.

I am sure you know, but I am just putting it out there for others reading this thread.

#7

A learning experience indeed! That is exactly what it is. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

At least you seem to have the right equipment - the resistance soldering unit, although I’m not sure you have the right hand piece.

I have this setup.

When I built my brass critter I mostly used the gray handled tip shown in the center - which applies heat to a very specific area.

Also, a mechanical joint is much stronger than just a soldered joint. Of course having said that, I used a lot of non-mechanical joints in this construction. Sometimes soldering is the only choice.

#8

Bruce,

My tweezer’s look similar to yours, it didn’t seem like I could get enough heat from them. I’m not sure if the electrodes are old/dirty and that is contributing or its something else. I’m thinking about buying the other hand piece that you have to see if that works better along with new electrodes for the tweezers.

Did you use two different types of solder, or were you fast enough to not melt surrounding parts off?

David,

Yes, a clean, fluxed joint goes a long way to making a successful soldering job! I have a feeling that this will have a lot of butt joints, but as with the styrene model it started out flimsy and now has a lot of strength.

#9

Craig, some angle stock could be used to make gusset plates, or reinforcing plates, to make the joints more solid. Space and patience permitting.

And I know about how structures stiffen up as more and more bits are added to them.

#10

Craig Townsend said:

Bruce,

My tweezer’s look similar to yours, it didn’t seem like I could get enough heat from them. I’m not sure if the electrodes are old/dirty and that is contributing or its something else. I’m thinking about buying the other hand piece that you have to see if that works better along with new electrodes for the tweezers.

Did you use two different types of solder, or were you fast enough to not melt surrounding parts off?

David,

Yes, a clean, fluxed joint goes a long way to making a successful soldering job! I have a feeling that this will have a lot of butt joints, but as with the styrene model it started out flimsy and now has a lot of strength.

I never used the tweezers as they never seemed to focus the heat. (What you said) I only used one solder the whole project; a silver solder.

#11

Wow …Talk about thread drift…now we are into tweezers and whether you need them or not depending on the amount of heat you need in the (hit the enter key before I was finished typing)

#12

Drifting in a rooster’s mind… as if there’s room there to drift…(http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

#13

Rooster and tweezers, yes there is room.

#14

David Maynard said:

Craig, some angle stock could be used to make gusset plates, or reinforcing plates, to make the joints more solid. Space and patience permitting.

And I know about how structures stiffen up as more and more bits are added to them.

Well the prototype didn’t use them, so why should I? (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)I’m hoping to order some brass bits this week.

#15

Can’t help myself!

Edit: because I want a monkey in a bellhop uniform myself but I am staying on topic with melting points!