EN1a Copper Soft soldering

[Derrick WatsonParticipant @derrickwatson66926]

Hi,

 

If you’ve read my previous posts you’ll know I’m a beginner. My first proper attempt at building something is to try to make one of Jan Ridders vacuum engines. So far I’ve got the cylinder, supports, piston rod and a couple of other bits done (I’ll post some pics at some point if I can figure out how). Anyway, eventually I’ll need to think about the burner – hence this question.

 

I’ve got some copper tube of about the right diameter but obviously it will need a bottom and top. I’ve also got some EN1a which (turned) would be about the right size to make a top and bottom cap. So would there be any problems in soft soldering (none leaded electronic solder) the EN1a to the copper tube?

 

cheers, d.

[Derrick WatsonParticipant @derrickwatson66926]

[JasonBModerator @jasonb]

Should not be a problem

 

Though personally I would use a separate solder and flux rather than the cored electrical stuff, as when working on larger areas there is a risk of the metal oxidizing before the flux gets onto it. With the separate flux you apply it to the joint before soldering and it will keep the surfaces clean as they are heated.

 

Don’t forget to give it a good was after soldering to remove any trace of flux as it will rust the steel

 

Jason

Edited By JasonB on 13/11/2010 19:32:17

Edited By JasonB on 13/11/2010 19:33:14

[John OlsenParticipant @johnolsen79199]

Soft solering steel is not too much of a problem in itself, but the rosin flux provided in electrical solder is not fearce enough to be much good on steel. You can ussually get little bottles of flux from a hardwaqre store, they will generally be based on zinc chloride, otherwise known as “killed spirits”. This can be made from hydrochroric acid (muriatic acid) as sold for cleaning concrete etc. You take bits and pieces of zinc and drop them into a small quantity of the acid, until the fizzing stops. The zinc can be obtained from the older type of dry cells, eg carbon zinc cells, not the more modern type of alkaline cell or rechargeables.

 

Be careful where you use and store this sort of flux, it is a wonderful thing for causing rust on steel, eg leave the bottle near some bare steel, come back in a day or two and regret. Using it is even worse, the fumes that come off will spread around th area and do nasty things to anything they can reach, including probably your lungs. I do this sort of thing outside under a sheltered area. (Including easiflo and welding.) 

 

regards

John

 

 

[Ian S CParticipant @iansc]

Hi Derrick, don’t know about the lead free solder, I’v never used it. I don’t know how it goes on steel, and what its like in a heated situation. I use easyflo, or similar on meths burners. I see that Jans’  drawings say soft soldr for the top and bottom, and silver solder for the wick tube.Ian S C

[JasonBModerator @jasonb]

If it does say that make sure you do the silver soldering bit first not only due to the obvious temperatures needed but silversolder does not like any surface that has the minutest trace of soft solder.

 

Jason

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Soldering steel can be a bit unpredictable even if you’ve done it successfully many times before . Apart from the good advice given above it is useful to use the old fashioned procedure of ‘tinning’ the steel before assembling the parts for final soldering . Tinning just means giving the surface a thin coat of solder and the real advantage is that you can see exactly what you are doing and if anything goes wrong it is easy to correct by scouring back and having another go .

 

Common grades of lead free solder are awful when used for big joints and penetrative joints – they have almost no wetting capability or penetrating capability . The much more expensive silver bearing grades perform much better but even they are not as good simple tin lead solder for most purposes .

 

There is a legal issue with using lead bearing solders now but the EU legislation is at the same time so all embracing and so wonderfully ambiguous that I haven’t quite got to the bottom of it yet as far as hobby use is concerned .

 

My real advice would be to find some copper for the top and bottom of your meths tank – it is not only much easier to solder but it will look nicer as well .

Edited By MICHAEL WILLIAMS on 14/11/2010 11:52:20

[Gordon WParticipant @gordonw]

Steel is easy to soft solder, but it must be clean and oil free. Use zinc chlorate type flux, I use Bakers, now sold in a plastic bottle, so much less problems with corrosion. As said ,tin the parts first. Use only lead/tin solder. As far as I know lead free solder is only mandatory for potable water systems, and imho no use for mechanical work. As said keep well away from silver solder, do not use the same hearth, fire brick, or what have you.

[Chris TriceParticipant @christrice43267]

Posted by MICHAEL WILLIAMS on 14/11/2010 11:45:48:

There is a legal issue with using lead bearing solders now but the EU legislation is at the same time so all embracing and so wonderfully ambiguous that I haven’t quite got to the bottom of it yet as far as hobby use is concerned .

 

Only in commercial product and plumbing/foodstuff industry. Legally, there is no problem using tin lead solders in private hobby work.

 

As a general comment, I echo the sentiments expressed about electrical solder. The solder is fine but the flux core is next to rubbish for fabrication work. It’s deliberately tame so it can be left on circuit boards without causing a problem. For soft soldering, either tin/lead or lead free, just use the ordinary Powerflux in the yellow plastic tub you can buy in any DIY store in the plumbing section. The knack is not just melting the solder but getting the parts themselves above soldering temperature.

[Sub MandrelParticipant @submandrel]

The yellow flux Chris mentions is Fry’s Powerflux and it works well opn steel as well as copper.

 

Google for Fry’s products (Chronos stock a good range) for a big selection of low tempertaure solders (not brazes).

 

Neil

[JasonBModerator @jasonb]

Jason

Edited By JasonB on 14/11/2010 20:46:41

[Ian S CParticipant @iansc]

Brass or copper looks nice for the top  and bottom, but steel for the top and the wick tube have the advantage of reduced heat conduction from the flame. Sure the steel will discolour (so will brass or copper), but it depends on whether the motor is for display or to be used. I built one of Jan Ridders’ flame licker motors, and made the burner from steel. I took a piece of steel tube and squashed it into a rectangle, then silver soldered the top and bottom ,  wick tube and filler tube with screw cap. Ian S C

[Anonymous]

Lead free solder is ‘orrible! It doesn’t flow and wet the surface when molten. While a bad joint looks dull a good joint looks …… dull. I was talking to our electronics assembler yesterday and he hates lead free too!

Within Europe any new electronic product to be placed on the market must use lead free solder. However, medical, military, large scale industrial and safety critical automotive systems are exempt. So, if it’s a safety critical product and/or requires high reliability, it can use leaded solder; go figure that one out!

The regulations do not apply to any product on the market before the stipulated date. Nor do they apply to the repair of such products. Prototypes, experimental and hobby kit are also exempt.

 

So it is still perfectly legal to buy and use leaded solder for electronics as well as other uses.

 

Regards,

 

Andrew

[Derrick WatsonParticipant @derrickwatson66926]

Thanks all for the sound advice as ever. For the wick tube I was thinking about putting a thead in a hole in the top and on the tube to avoid having to silver solder it. Although it’s a while until I’ll get onto this part at least I feel like I have a plan now.

 

Also anyone know where can I get suitable wicks from (UK), can’t seem to find any local suppliers or any on the web.

 

Thanks again, d.

[Ian S CParticipant @iansc]

Derrick, heres how I do the wick etc. The wick tube should be as thin walled as possible, at least at the top near the flame. Now the wick, a bit different, found this in a copy I’v got of the 1898(first year) of Model Engineer. Cut to length (from bottom of tank to a bit over 1/4″ above the wick tube), some reasonably fine iron wire (florists use it), about 26swg. Pack the tube with the wire and thats your wick, it will last for years, I seem to remember a similar way of doing it with rolled up fine mesh stainless steel gauze, have’nt tryed that one.  Ian S C

[KWILParticipant @kwil]

Oil burning “table lights” use a fine glass like wick,  so a fancy lights supplier may be able to help.   http://www.candlesontheweb.co.uk    lists wicks

Edited By KWIL on 17/11/2010 11:35:20

[TerrydParticipant @terryd72465]

Hi Derrick,

 

I bought some 6mm dia wick off the web about 18 months ago. Unfortunately I’ve lost the address but it is there if you search well enough.  I bought a couple of feet as it was so cheap and they have a range of sizes and types.

 

I’ll try to find the address but the company was/is in the UK.

 

Terry

[chris stephensParticipant @chrisstephens63393]

Hi Guys,

You can or at should be able to get wicks from any chandler dealing with narrow boats. If you are in the west London area, I find the Uxbridge Boat Centre to be very helpful.

 

If any of you have difficulty getting proper solder locally, “sorry mate can’t get it any more, don’t you know it’s illegal ‘cos of the lead” there is always those helpful people at CuP alloys. For tinning purpose might I recommend their “solder paint”, this is a ground up soft  solder and flux paste, that you just paint on and heat.

chriStephens 

EDIT; just a thought, you might need extra flux on steel if using solder paste, although I have used it for motorcycle control cables (brass/steel joint) with no problems. I do though know the secret of making cables and it does not rely wholly on solder for success, nor just flaring the end of the wire. Bragging, who me?

Edited By chris stephens on 17/11/2010 15:47:26

[JasonBModerator @jasonb]

Cups solder past goes onto steel with no problems, wel I’ve not had any. Just make sure you give it a good stir as the heavy solder settles out. The flux in it is quite corrosibe if not cleaned up afterwards.

 

Jason

[Michael Cox 1Participant @michaelcox1]

I have used Wickes Active Flux Paste many times for soldering steel, stainless steel as well as copper and brass. This flux is designed primarily for use on plumbing fittings but I used as a general purpose flux for everyting (except electrical work) and never had a bad joint.

It is corrosive and the part should be thoroughly washed after soldering is complete.

Mike

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