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[flashtwo]

Hi Mayhemers,

On my experimental steam jet engine, I've been obtaining steam temperatures in excess of 720degC and the silver soldered joints have been melting at the steam outlet.

I did use copper pipe with swaged connections to get around the problem, but I am now considering using stainless steel tube with welded connections.

Can anyone guide me in the right direction for obtaining and using a small hobby TIG welder for carrying out small welds.

I did do conventional gas and arc welding and a small bit of aluminium welding in my apprenticeship many years ago, but have no experience of TIG welding.

Ian.

[triumphjon]

sip tools , try your local machine mart , they normally have decent workshop type tools at reasonable prices ! or do you have any garage or welding suppliers in your area , the welding supplier may be able to point you in the right direction for being able to hire a machine or even a demonstrator machine . its worth looking into as its not the sort of equipment that most people would find a use for . mig welders are cheaper and can be used with a stainless steel filler wire for doing stainless welding , they are also cheaper to buy than a tig machine ! jon

[john44]

Hi there, I have and use a hobby mig welder & a hobby arc welder both, from machinemart.I use them for making gates etc.
 I don,t know what thickness and size you want to weld. If it is car body thickness, forget it because even at low settings these
welders would blow it away.

[triumphjon]

isnt the filler method slightly different for tig welding ? ive not had the pleasure of trying this method myself , although ive used a couple of different hobby mig welders when im restoring classic cars , with the settings turned down they will weld some thin steel . Depending on how much pipe joining you have to carry out it might be cheaper to find a company who is already set up for this method of welding ?

[chingdevil]

I use a TIG welder at work on stainless steel, Machine Mart sell the welders and the Argon gas required. If you can remember how to gas weld then TIG welding uses the same technique, adding a filler rod to the weld. If you are welding stainless tube gas purging the tube with Argon will give you a smooth weld inside the tube and ensure the weld penetrates all the way through.

If you want some more information on how to TIG weld send me a PM.


Brian

[chingdevil]

I have used a MIG welder with stainless filler rod, I do not think the penetration is as good as a dedicated TIG welder with gas sheild.

Brian

[dadandlad]

I think you may find the cost of buying a Tig welder very prohibative,we have a small portable 160 amp set at work which is a 240 volt supply and cost in excess of £1600
Im sure a lot of the cheaper sets are scratch start and not High Frequency start which i find makes them very awkward to use.
In my opinion the MIG running stainless wire is a non starter you will not have the control required for small diameter pipes
You could send me a sample of pipe and nipple and i can weld it for you post it back and see where you want to go from there

[gondolier88]

Hi Ian,

Have you tried oxy-propane brazing instead of silver soldering?

Greg

[chingdevil]

The scratch start TIG sets are ok, you just need to practice. You strike the arc thes same way as if you was Arc welding. If you buy a set and want a lesson in using it let me know.

Brian

[dadandlad]

Yes the scratch start sets are ok,but they arent the easiest to learn on im sure you will agree.When i first started i spent more time sharpening the tungstens than welding :embarrassed:oh and trying to unstick the torch from the job
There are some really good available from about £400 upwards but they will only weld steels and not alluminium.
Personally i would steer clear of machinemart and find yourself a good local welding suppliers who is in the industry he will more than likely have a range of welding sets in which you can demo and if buying will more than likely give some basic tuition

[chugbug]

Many moons ago the accepted way to strike an arc with non high frequency tig welding was to use a piece of carbon close to the joint and strike up on that,then transfer the arc. This topic drags up memories.
                   Dave Gibson.(welder for 48 years)

[john s 2]

Does any colledge near you run an evening class? Before enrolling worth making sure they have Tig facilities. I do realise that
teaching metalworking is dieing a death. Health and safety etc. John. 

[irishcarguy]

I have a lot of practice with gas welding (oxy?acet)  It will probally do a good job for you. If you are brazing brass just make sure that melting point of the rod you are using is lower than than the brass you are welding. (there are different brazing rods available)