Brass soldering

[freelance]

Need some advice on soldering brass rada, lattace work, what temp would one use if using a soldering iron, how about a torch ?
Thank you..

[Greg W]

It depends on the size of the brass you are using. For fine work I would stay away from a torch, I use either my 100/140 watt gun for larger stuff and a 35 watt pencil iron for the small intricate stuff so I can control the heat better.

[freelance]

Many thanks Greg.

[Tinedge]

Hi Freelance
This post maybe to late, I suspect. Anyway if your soldering fine PE than you dont require a lot of heat ...maybe even a 25w soldering iron. If thicker brass then something a bit hotter.

The reason for staying away from the torch would be that it can generate too much heat and may even bow the brass, remember metal expands when hot & when cooling the deformity can "set" with solder.

A hint for keeping items together as you solder without de-soldering what you have just done is to use something like metal bulldog clips to act as heat soakes clamped to the previous soldered area.

Hope this helps.
Regards Mike

[PetrOs]

I usually use the 15W electronics soldering iron, and low-temp solder. Allows for much better control...

And for precise soldering of, say, crosstrees - I take a plain piece of wood, mark the wished positions of all the parts, and install the pins (drill 0.5mm holes, and put some brass rod pins there) which restrain the parts from moving...

[Laurent]

Hi all ,

I always solder with a torch , I'm completely unable to use a soldering iron

using a tin/lead wire , to me , is out of the question either

with the torch , the secret is to hold it on a distance , and I use a tin/lead liquid paste , used in the plumbery industry ...

Regards ,

Laurent

[Ticonderoga]

Hello All,

Sorry to "bump" such an old thread, (It shows I tried research first though )

For my Slava I will be "manufacturing" quite a number of rather complex radar antennas. Dave's Kiev thread is great source of inspiration and help and he demonstrates great techniques.

However I have a few "technical" questions. My experience with a soldering iron is not too bad, confined mainly to PCB's etc.; and I am aware of terms such as "easy flow", "flux paste", "plumber paste" and so on.

Can someone please explain these terms and what the products are used for?

When soldering two pieces of fine brass together, I assume you can use "easy flow", "flux paste", "plumber paste" to more easily make the joint? If this is so, how do you do it? Do you need solder as well?

These probably sound like noddy questions, but it feels like a bit of a black art to me at the moment. Once I have a clearer idea on what the products are, and how they are supposed to be used, I will get some scrap material and start practicing.

Advice and guidance is much appreciated.

Thanks and regards,

Andrew


PS

I found this post on Model warships UK - more reasech

it refers to http://www.electricalreview.co.uk/news/ ... ction.html

Would still appreciate other ideas, opinins, product recommend etc. (this one is probably not available in Aus)

Andrew

Brilliant stuff........but messy on the skin and DONT GET IT ON THE CARPET!

Made by Carrs or Fry's who call it Solder Paint.

Should be able to get it from a good plumbers merchants.

Clean the brass surface first.

I then use an old modelling paintbrush to apply Baker's fluid (flux) which can also be used to 'thin' the paint if it gets a bit 'claggy'.....my bottle is.....umpty years old...so it lasts for ages!

Next I apply a little of the solder paint just to the 'North' of the parts I need to join with the end of a cocktail stick.

A hot tinned soldering iron is then applied to the 'South' of the joint.
The paint will turn silver as the solder in it melts, and this will track along towards the heat source........as a general rule, to get a good joint the heat should be applied to the finer wire/structure.

Don't worry if all the solder paint doesn't melt and flow just as long as the joint is well 'wet' with the molten liquid solder.

Remove the heat.

Allow the joint to cool down, ensuring there is no movement of parts whilst the solder 'sets'.

I usually wash the joints then using warm water and an old 'end of life' soft toothbrush to remove the excess flux and solder paint.

(If you don't remove the acid flux it will sure as eggs is eggs appear on the surface of your nice new paint job.)

Allow to dry and Robert is your father's brother.

Good luck (don't know how I managed without it for so long!)



One last edit folks - sorry

Found this link, http://www.bdsonline.net/BMProducts/soldflux.htm

Looks like I can get the paste in Aus. From what I read this is a great product to use for the fine soldering of the radar antenna frames.

Please let me know what you think.

Andrew

[Dave Wooley]

Hi Andrew Well the Slava has plenty of arrays that will call for a bit of soldering and keep you busy. You can soft solder with just about any type of solder. The trick is to ensure that the joints to be soldered are good and clean. A little bit of emery paper will not only clean the joint but provide a slightly rougher surface which will help the solder bind to the surface of the job . The purpose of using flux is to prevent oxidation and to act as a wetting agent , whether baker�s fluid which is in effect a liquid flux or flux paste will ensure that the solder will flow into the joint. Solder paste is great for very fine solder jobs but I prefer to "tin" the joint with solder first then apply the heat but not directly to the joint being soldered. {I find the electronic soldering iron a real plus, as the temperature can be controlled } As the job heats up the solder will melt and �flow in a capillary action and there is less chance of a "dry joint�. Another advantage is in being aware of the melting temperature of the solder. Some solders like electrical multi core {contains its own flux and will flow very easily others like silver solder require higher temperatures. For this I do like the butane pencil soldering torch. Here you can concentrate quite high temperatures very precisely. Again their use is down to practice. A final task is to �clean" the joint and the area around the joint .Remove any traces of flux as it presence has an adverse effect on the metal, particularly brass and paint will have difficulty bonding to the surface if there is any trace of flux material .Apart from this briefest r�sum� of tips just practice on the odd bit .You will soon become a dab hander as they say. I am sure there are others on the board like Phil Ardell who�s Bismarck superstructure is entirely soft soldered.. If you encounter any problems just ask, I might not know the answer but, as they say I know a man who does.
All the best with your Slava build .
Dave Wooley

[DrPR]

Here is another belated tip. The liquid citric acid based fluxes work very nicely for fine soldering, especially when joining overlapping or edge-to-edge plates. Also, they smell like orange juice - much better than hot resin! Best of all, because they are water soluble they clean up with a quick rinse under the faucet.

We use liquid fluxes for very fine electronic soldering. They spread the heat faster than resin or paste fluxes, and as they evaporate they seem to draw the solder into the gap. Solder will flow into much narrower gaps and holes with liquid flux that with other fluxes I have used.