Soldering brass mesh.

I bought some fine brass mesh to make a tubular filter for a classic car fuel system. The mesh has 40 holes per inch, so is pretty fine. When I proceeded to solder the joint to form the tube, the solder just does not seem to want to take to the brass. I am a bit mystified as I am using a heavy duty electric iron and good multicore solder and mesh is brand new and spotless. Any help here as I am tearing my hair out. (what I have left that is !!)

Mike.

Try using the flux that plumbers use, rather than just relying on the resin cored solder. Called La-Co if it's in a black tub, or PowerFlow if it's in a yellow one. Even if it looks clean, a buff up with wire wool or Scotchbrite is also useful.

Hi Steve,

Tried all that but no go. Was a sparky before retirement, so soldering skills were fine. (I am beginning to doubt my own capabilities now !!) Re-checked the spec of the material and it is brass 65% /zinc 35% so I am now wondering if that is the problem. May have to re-order some pure brass mesh.

Mike.

Um, brass is an alloy of copper and zinc! Is it perhaps lacquered?

Just a guess Mike but fine brass mesh is an excellent conductor of heat. It was used in Mining Safety Lamps to ensure that a flame inside the lamp couldn't ignite gas outside.

Possibly the mesh, which has an enormous surface area, is cooling your iron. You could try insulating the mesh except around the edge where it needs to be soldered.

Dave

As John says, brass is Cu and Zn so there is no doubt that it should solder ok. In fact I have done exactly the same job as you are doing, except that my filter had a larger mesh as it is for the cooling water inlet on a boat. Have you tried a gas torch - maybe the heat from the soldering iron is being conducted away too fast.

I did exactly this job earlier in the year. I used a big soldering iron (250W) and thought that it was too large when I was soldering. It was easier than I had expected but I was not proud of the result (a bit messy). I used new clean fine gauze, a plumber's white active flux and ordinary lead/tin solder.

I think if I had used a touch I would have melted the gauze. True the gauze has a large surface area but there is very little of it to heat up.

JA

I tried a torch but the gauze very quickly turned red hot. I am seriously wondering if I have been sent wrong material such as stainless mesh ?? Magnet has no resistance ,so I assumed brass, but stainless also only has weak pull towards a magnet depending on grade I think. Brass or copper should be easiest thing in the world to solder, but not this stuff !!

The same seller is also advertising pure copper mesh,so what percentage brass/copper would that be ?

(rapidly going greyer by the minute,)

Mike.

This is widely used in the Netherlands **LINK** on the Dutch website you find more products special for difficult to (soft) solder materials and for stainless which I do not see on the English website. Pure copper has nothing to do with brass which is an alloy of (pure) copper and sinc as already said, perhaps you can ask the supplier for advice. Niko.

Edited By speelwerk on 13/10/2016 21:47:33

Have you tried abrading the surface to see if a superficial layer of brass comes away?

Michael W

Mike ,

In the past I have had the same experiences as yourself with mesh . Tried the gas torch route , and that was a spectacular failure . In the end , like JA I used a large soldering iron which I allowed to get really hot before using it . I found that if I thoroughly cleaned the mesh with clean emery , wiped it with Bakers Fluid and then tinned it with resin cored solder first and then went over with lead solder , it worked fine for me . Regarding stainless , it depends on whether it is austenitic or non-austenitic , which determines whether it is magnetic or not . If your mesh is actually stainless steel , then if required I can supply you with a small amount of solder specifically designed to soft solder it.

I hope you will find this information of use .

Trevor

Mike, brass by definition is an alloy, not an element. It contains copper and zinc, and in some grades possibly some other elements in small,amounts.

When I was thinking about making my filter I considered epoxy resin. It is a way to go but the gauze would have to be held in place while the glue sets.

If the gauze is stainless you will probably need a different flux such as phosphoric acid. The material of the gauze can be checked against known brass by setting up an electric cell with an electrolyte such as brine (this has been a topic of threads in the past).

JA

My problem when making mesh filters for stationary engines is that the solder flashes over the mesh and blocks the holes up, I use white plumbers flux and the old tin/lead solder. The brash mesh I use may not be as fine as that used for cars, so perhaps the problem with this fine mesh could possibly caused by the use of lead free solder?,getting mesh red hot will certainly prevent soldering as the brass will oxidise.

Removed. I mis-read the original post. sorry.

Ed.

Edited By Ed Duffner on 13/10/2016 23:32:31

Try some Bakers Fluid flux? Brush it on. Perhaps fit the mesh onto a sleeve of rusty steel rod, and heat via the rod. (If you want a rusty steel rod dip it in Bakers Fluid then revisit a few days later!)

As on 'off the wall' suggestion try threading the mesh together with brass wire. I have use fine stainless silk screen mesh for injector filters for many years making 'finger' type filters with this method.

Cheers,

Julian

Edited By julian atkins on 13/10/2016 23:24:12

+1 for julian's suggestion, when making a tender water filter  I sort of frayed both ends by removing a few wires from the short sides, bend one lot back on itself to keep the last bit in, then thread the sticky out bits from the other end back through the holes in the bit you've just folded back, and bend them back. I'd like to say you could do it in less time than it takes to describe it, but it's a fiddly job.

Edited By duncan webster on 14/10/2016 00:34:43

Hi all,

many thanks for all tips. I reckon it must be wrong material. I have a spot welder here ,so will do a test weld with gauze to another bit of stainless plate to see the result.. Material has a silvery tint as copared to yellowish brass.

Re. formers, I was using a piece of plastic tube each side of the join (or not join !!) to hold the tube to correct diameter. I was also using good old lead free multicore solder and the white plumbers paste as well.

Mike.

If you have no joy I have some bronze mesh from a paper mill you are welcome to.

It sounds like you have been given some SS mesh, take advantage of the offers of mesh from members.

Clive