Low temperature TIG filler

[GrahamGKD]

Hi Folks,
Is there a low temperature filler that can be used with TIG - even lower temperature than the SIFbronze No.8? I was thinking along the lines of a sort of TIG equivalent to silver solder? I want it for sticking thin (e.g. 1.6mm 316l TIG wire) tentacles to insect sculptures. I haven't tried with the SIFbronze No. 8s yet but I have a feeling I know what will happen! I guess I could just get a pool going and dunk the 316 wire into it but I'm not sure that will come out very nice?

 

[Shox Dr]

You can use the Arc of the TIG to "heat" the metal and then add silver or soft solder to the area.

Try it with a rounded end on the tungsten, it will help to defuse the arc

 

[GrahamGKD]

You can use the Arc of the TIG to "heat" the metal and then add silver or soft solder to the area.

Try it with a rounded end on the tungsten, it will help to defuse the arc

Thanks for that suggestion. Would I use flux with that?

A while ago I tried ordinary brazing rods with the TIG and it was all over the place - that was without flux. I would just give the silver solder a try but I don't think I've got any to hand - will need to source some.

 

[Shox Dr]

I wouldn't bother with Silver solder, it's expensive, and the piece isn't load bearing as such, Just use flux impregnated solder, easier than messing with flux, that or use paste and stick the solder in the paste and then apply

 

[GrahamGKD]

Yes, I just had a look - it is expensive isn't it - I thought the SIFbronze No.8s were bad enough!! Not sure about soft solder if that is what you meant - I think I'd ideally like something a bit more 'permanent' than that. I'll try the No. 8s on a practice piece, you never know!

 

[GrahamGKD]

Well, I managed it with the SIFbronze No. 8s (see 'Attempt at a butterfly' thread) but it is pushing the envelope of my skill level! Probably need to find a better method for next time.

Edit: Thinking about it, I guess I should make something (e.g. a tiny bit of plate) to clip the wires in place rather than braze the wires themselves as the problem is that the wires become brittle at the joint).

 

[Delgado]

Could you not drill a 1.6mm hole (not all the way through) then stick the filler wire tenticles into it and quickly zap it with the tig on fairly high amps, using your now free other hand to dab a bit of filler in quick?

 

[hotrodder]

Keep practicing and it'll click. Things to practice would be autogenous tacking, example in this post... http://www.mig-welding.co.uk/forum/showpost.php?p=115960&postcount=13 As said secret is a quick burst at highish amps with a very short arc length. The wire hoops in that post were bits of 1.6 filler wire, welds were literally a quick tap of the button with the machine set at 80+ amps. Can cut up some filler wire and practice tacking it back together or to an offcut

With the sifbronze can lay the wire on the joint and just run over it. Quick and dirty example of a lap and butt using 1.6mm (finer wire would've been better) on some manky scraps of 0.8mm zintec...

back of the butt...

With some finer wire less heat would've been needed to get it to flow and there'd be less soot and damage to the zinc coating. Attaching tenticles/things made from wire with it isn't going to be easy but if they're tacked autogenously (or pressed into a hole as suggested) then laying the wire on the joint and briefly striking an arc should work with some practice

 

[graffian]

I bought a roll of .8 sif 968, I have brazed 20swg sheet with it, works really well.

 

[Shox Dr]

it's lovley stuff once you get used it. I would have suggested what HRH HR* posted after me. But that wasn't quite the OP question


*(only joking fella)

 

[hotrodder]

It's a forum, missing the point/answering a question the OP never asked is tradition

 

[GrahamGKD]

Thanks for all those suggestions - I'll have another practice. Funny, instinctively I was going for low amps. So use the button rather than the pedal - presume I need to put my Lorch into two stroke mode?

 

[hotrodder]

2T mode will make life easier when using a quick burst for tacking/spot welds (no up slope, at most fractions of a sec downslope), not as easy but it can be done with a pedal. I'm not familar with the Lorch but there may be spot weld settings to make it easier, something similar to Kemppis microtack setting?

 

[GrahamGKD]

I've had a go and I'm getting some success but I'm not yet reliable. Sometimes the wire heterogeneously fuses but other times it seems to melt back more and more wire without fusing, even though I have the heat focussed on the plate? Ring any bells with anyone? I'm getting best results with 2mm bike spokes (not sure what grade of stainless they are). My plate is 1.2mm 304 and I'm in 2T with no up or downslope and about 45A. With the 1.6 TIG wire I can get it to fuse OK but some of the wire flows into the joint leaving a weak neck in the wire at the joint.

 

[Delgado]

Personally I use 4t mode and just give it a quick "tap,tap" on the trigger as that's what I'm used to, I did try to use 2t mode once, but I kept double tapping it, so quickly reverted back. An easy way to do these tacks, or at least how I was taught, is to rest the edge of the ceramic on the work with the tungsten touching, then lay it back slightly so the tungsten raises ever so slightly off the work and then blast it. Always make sure the 2 pieces to be joined are touching as tightly as possible or it wont work, and always, always have filler in your other hand ready to jab it in if it doesn't. With a bit of practise doing it this way you'll be able to do multiple autogenious tacks quickly.

Oh, almost forgot, it'll make it easier if you keep your tungsten nice and sharp.

 

[Paul.]

Try melting a blob on the end of the wire to bulk it up a bit before you attempt a tack. you might be able to see what I mean on this Daffodill, the stamen are tacked to a dome nut inside the bell using that method, and a blob on the outer end finishes them off.

 

[GrahamGKD]

Wow, that looks great Paul. How do you go about melting the end of the wire without completely blowing it away? I did try to blob some braze onto the turned over ends of my tentacles but I was getting nowhere with it - I tried it on a plate and it stuck to the plate - I tried the free end held in the vice and it melted and fell on the floor!

 

[GrahamGKD]

Personally I use 4t mode and just give it a quick "tap,tap" on the trigger as that's what I'm used to, I did try to use 2t mode once, but I kept double tapping it, so quickly reverted back. An easy way to do these tacks, or at least how I was taught, is to rest the edge of the ceramic on the work with the tungsten touching, then lay it back slightly so the tungsten raises ever so slightly off the work and then blast it. Always make sure the 2 pieces to be joined are touching as tightly as possible or it wont work, and always, always have filler in your other hand ready to jab it in if it doesn't. With a bit of practise doing it this way you'll be able to do multiple autogenious tacks quickly.

Oh, almost forgot, it'll make it easier if you keep your tungsten nice and sharp.

Thanks Delgado - I did find myself wondering whether people normally switch between 2T and 4T - I've been using 4T up to now. I have sharpened the tungsten. I'll have a go with your method. Thanks.

 

[Paul.]

Wow, that looks great Paul. How do you go about melting the end of the wire without completely blowing it away? I did try to blob some braze onto the turned over ends of my tentacles but I was getting nowhere with it - I tried it on a plate and it stuck to the plate - I tried the free end held in the vice and it melted and fell on the floor!

These are welded, not brazed, you need a very sharp tungsten 1.6 is my choice, a steady hand and probably no more than 20 amps to form the ball. I can do it with the rod laying on the bench, but if you find you are arcing to the bench or welding the job to the bench lay it on a piece of copper, a bit of flattened water pipe will do, if the ball oxidises clean it with a bit of scotchbrite before you weld it on.

 

[GrahamGKD]

OK Paul, Thanks for that, I'll have a go - I have some copper pipe and also a piece of copper plate I use as a heatsink sometimes. I'm not too hopeful I will manage it but it will be something to aspire to.

BTW - I've been using a 1mm tungsten up to now for this light work - I'll ditch that and try the 1.6 back in.