Teflon liner info!

[lumpyweld :-}]

Hi guys,
Looking to put a teflon liner in a mig torch to try a bit of aluminium welding but do i need a jumper liner in the torch neck? Seen a video on YouTube where guy puts teflon liner right to tip of torch. Will it melt is my question?

 

[Hood]

Depends on how much welding you will do and how thick it will be.
The liners I get for my push pull from @Jim Davey and @andymdavey82 usually come with the brass spiral section on the end, might be worth asking them.

 

[Hood]

One other thing to mention is at the machine end, make sure you take the liner right up to the feed rollers.

 

[lumpyweld :-}]

Depends on how much welding you will do and how thick it will be.
The liners I get for my push pull from @Jim Davey and @andymdavey82 usually come with the brass spiral section on the end, might be worth asking them.

 

[lumpyweld :-}]

One other thing to mention is at the machine end, make sure you take the liner right up to the feed rollers.

Cheer Hood will do

 

[andymdavey82]

Depends on how much welding you will do and how thick it will be.
The liners I get for my push pull from @Jim Davey and @andymdavey82 usually come with the brass spiral section on the end, might be worth asking them.

Hi @Hood , thanks for the mention! We can indeed help with the above...

 

[Ross365]

Real PTFE does not melt, but progressively decomposes and fumes are extremely hazardous. One of the decomposition products is hydrofluoric acid, which is damn bad. Opinions differ on the upper temp limit for PTFE; 250'C might be ball park. A fluorine-free polymer would be safer; maybe take a look at PEEK, which according to Wiki melts at at ~340'C?

 

[PhillipM]

Real PTFE does not melt, but progressively decomposes and fumes are extremely hazardous. One of the decomposition products is hydrofluoric acid, which is damn bad. Opinions differ on the upper temp limit for PTFE; 250'C might be ball park. A fluorine-free polymer would be safer; maybe take a look at PEEK, which according to Wiki melts at at ~340'C?

Teflon is a normal, off the shelf liner material however. custom PEEK liners would be eye watering...it also has a much higher friction coefficient, which is the entire reason for switching to teflon over steel in the first place...

 

[Ross365]

Teflon is a normal, off the shelf liner material however. custom PEEK liners would be eye watering...it also has a much higher friction coefficient, which is the entire reason for switching to teflon over steel in the first place...

Sounds like the temperatures must stay low enough for Teflon to survive, but it would be worth remembering, if you ever encounter one that looks "cooked" do not touch it. Use a tool and/or gloves. I know of one case where a guy removed some Teflon tape (which had been cooked) with his bare hands - he ended up losing a finger. HF does not take prisoners!

 

[hotponyshoes]

Generally the wire will start binding in the tip before it gets hot enough to bother the liner.

Carbon Liners are also available and I think they have a higher service temperature

 

[Hood]

Generally the wire will start binding in the tip before it gets hot enough to bother the liner.

Carbon Liners are also available and I think they have a higher service temperature

They are what I use in the push pull, I reckon they are better than teflon.

 

[PhillipM]

I think they're mainly just nylon with a bit of carbon/graphite powder in for lube, wouldn't be any better for temp really, probably for wear.

 

[hotponyshoes]

I thought they were carbon in addition to the teflon?
Better heat resistance than normal ptfe.
Although you might be able to get carbon/nylon types as well?

 

[Hood]

Aye, Carbon Teflon they are marketed as.

Edit.
To make clear I am saying they are marketed as Carbon/Teflon so I would presume that is what they are made from.