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Post Flow
Posted: Thu Mar 12, 2015 6:51 pm
by DSM8
The post flow timer on my 300HF crapped out so I replaced it with a pool timer, I get 5 seconds of post flow every time, all the time.
That said, what I am not certain of is how do you know if you have ENOUGH post flow?
Typically I am welding between 100-200 amps so 5 seconds should be find or
I have noticed the tungsten is not staying silver but I think that is in part to some of the crap I contaminated it with while welding. Need to put a new one in there and see how it goes.
Re: Post Flow
Posted: Thu Mar 12, 2015 7:49 pm
by Otto Nobedder
My preference, in that amp range, would be 9 or ten seconds of post-flow. This is good for the weld and the tungsten.
Your mileage may vary...
Steve S
Re: Post Flow
Posted: Thu Mar 12, 2015 7:52 pm
by DSM8
Otto Nobedder wrote:My preference, in that amp range, would be 9 or ten seconds of post-flow. This is good for the weld and the tungsten.
Your mileage may vary...
Steve S
Was afraid of that , will have to use the pedal to extend the post flow time, it is hard set @ 5 seconds.
Re: Post Flow
Posted: Thu Mar 12, 2015 9:14 pm
by weldin mike 27
If you have adequate post flow, the crap on the end of your electrode will be silver, and will not degrade as quick.
Re: Post Flow
Posted: Thu Mar 12, 2015 10:17 pm
by Superiorwelding
Not getting to deep into welding theory but I agree that you should have shielding gas to keep the tungsten silver or not contaminated from the atmosphere. The next important item is to have shielding gas from the atmosphere until the given metal is below it's reactive temperature. Bottom line in my opinion is 5 seconds will not be enough but it will work until you get it fixed properly.
-Jonathan
Re: Post Flow
Posted: Thu Mar 12, 2015 10:42 pm
by soutthpaw
On an air cooled torch, post flow also helps with cooling at the expense of Argon of course, that's another consideration
Re: Post Flow
Posted: Thu Mar 12, 2015 11:22 pm
by Wes917
I typically set mine at 15s, even at home where I pay for the gas.
Re: Post Flow
Posted: Thu Mar 12, 2015 11:53 pm
by GreinTime
Wait, I thought you were supposed to leave the argon run all the time.... Why didn't you guys tell me this!!!!!!!!
Re: Post Flow
Posted: Fri Mar 13, 2015 1:29 am
by Oscar
GreinTime wrote:Wait, I thought you were supposed to leave the argon run all the time.... Why didn't you guys tell me this!!!!!!!!
Why did you think that?
Re: Post Flow
Posted: Fri Mar 13, 2015 2:21 am
by TRACKRANGER
Jody's latest video talks about welding at 190/200 Amps and using 8.5 seconds of post flow
See 5:15 mark in this clip:
https://www.youtube.com/watch?v=q505lTz ... ubs_digest
Re: Post Flow
Posted: Fri Mar 13, 2015 4:28 am
by noddybrian
Unless using low amps on thin stainless I like 8 > 10 seconds on an air cooled torch - much less seems to invite problems - 5 I think is a bit short - there are plenty of stand alone adjustable timers available at a fair price - why not use something more suitable - I like RS products even though they're not the cheapest - I include a link to one I think will suit your purpose but check first !
http://uk.rs-online.com/web/p/time-dela ... s/7740304/
Re: Post Flow
Posted: Fri Mar 13, 2015 9:18 am
by rick9345
Lack of, or under estimating adequate post flow can/will cause/create difficult welds.along with not holding long enough at end of weld. This can cause problems with weld and tungsten contamination.
The thinking seems to be that post flow is wasting the Argon.
Re: Post Flow
Posted: Fri Mar 13, 2015 9:43 am
by Superiorwelding
DSM8,
Since you are stuck with a 5 second post flow for the moment, to cool off your tungsten faster after your arc goes out touch the tungsten to the material. This will have a cooling effect allowing the material to draw out some of the heat. This especially works if you are welding alum.
-Jonathan
Re: Post Flow
Posted: Fri Mar 13, 2015 12:27 pm
by GreinTime
Oscar wrote:GreinTime wrote:Wait, I thought you were supposed to leave the argon run all the time.... Why didn't you guys tell me this!!!!!!!!
Why did you think that?
I was just teasing man
Re: Post Flow
Posted: Fri Mar 13, 2015 1:16 pm
by DSM8
Superiorwelding wrote:DSM8,
Since you are stuck with a 5 second post flow for the moment, to cool off your tungsten faster after your arc goes out touch the tungsten to the material. This will have a cooling effect allowing the material to draw out some of the heat. This especially works if you are welding alum.
-Jonathan
That is part of an approach I was thinking I can also bump the pedal really quick to give me another 5 seconds of flow after the fact, basically turn it off count to 4 then bump again really quick for another 5 sec of gas.
I will have to find a better solution I like the idea of just getting one that is set to 10 second and be done with it.
Re: Post Flow
Posted: Fri Mar 13, 2015 3:31 pm
by motox
grein time
l bet you also use a garden hose and sprinkler for purging...lol
craig
Re: Post Flow
Posted: Fri Mar 13, 2015 4:41 pm
by GreinTime
Wait.... That's not right either?! I must be doing it all wrong!!!
Re: Post Flow
Posted: Sat Mar 14, 2015 10:34 am
by exnailpounder
motox wrote:grein time
l bet you also use a garden hose and sprinkler for purging...lol
craig
Whats wrong with that? Youre supposed to be wet and grounded when you're welding. I learned that at the Earl Scheib welding school in the 80s.