Fabrication Everything From JBwelded/Fluxcored downpipes to Equal length SS Manifolds.

back purging

Old 03-21-2009, 06:29 PM
  #1  
0.0 BAR
Thread Starter
 
Join Date: Mar 2009
Posts: 14
Default back purging

I tried finding this info maybe someone can show me the link or tell me more.

Can someone explain the best way to backpurge when welding (MIG) 304 stainless? 16-gauge.

Plan on building a cat-back for a TDI Golf. Pretty simple build really.

I have not done a lot of welding and just found out about the importance of back-purging. I figured since I spent the money on good bends in stainless, v-band clamps, etc I should backpurge.

Also... Solarflux

Seems like there are some very mixed reviews on here. I don't mind mixing it up. They claim it meets military and some other specs for welding. Thoughts?

What are your recommendations for wire (308?) and gas?

TIA
mile high assassin is offline  
Old 03-21-2009, 06:32 PM
  #2  
0.0 BAR
Thread Starter
 
Join Date: Mar 2009
Posts: 14
Default

I tried the link in this sticky but it just re-directs me to the main page:
https://www.homemadeturbo.com/forum/...formation.html
mile high assassin is offline  
Old 03-23-2009, 12:51 AM
  #3  
3.0 BAR
 
Join Date: May 2005
Posts: 1,811
Default

solarflux sucks. its too expencive compaired to the minute amount of argon needed to purge this size piping.

if you dont want to build some caps shove a line running around 5cfh into one end of the pipe, surround it with some bread, close off SOME of the other end. if you close the whole end off, letting the argon pressurize the pipe it will blow holes in your welds.
Toysrme is offline  
Old 03-25-2009, 01:31 PM
  #4  
0.5 BAR
 
Join Date: Mar 2009
Location: Richmond, VA
Posts: 119
Talking

I was told to back purge Ti. Stainless only on medical stuff. .02
shoyass is offline  
Old 03-25-2009, 08:05 PM
  #5  
3.0 BAR
 
Join Date: May 2005
Posts: 1,811
Cool

stainless
magnesium
ti
duplex, alloy & nickel steels
some nickel alloys
some copper alloys
should all be back purged
the only time you wouldn't want to back purge stainless is on your own personal piping if you are cheap

aluminum does not require a backing gas. however, it can be very helpful at more manly feeds and travel rates to use a copper backing plate to prevent burn through.


both aluminum and mild steel benefit from backpurging, however at lower dimensions, feeds & travel rates it is not critical to getting good weld quality.
Toysrme is offline  
Old 03-26-2009, 06:13 PM
  #6  
0.0 BAR
Thread Starter
 
Join Date: Mar 2009
Posts: 14
Default

Thanks for the info.

I have read mixed reviews about SolarFlux. This is a cat-back so I really don't care if there are leftovers inside.
mile high assassin is offline  
Old 03-26-2009, 07:09 PM
  #7  
0.5 BAR
 
Join Date: Mar 2009
Location: Richmond, VA
Posts: 119
Default

Originally Posted by Toysrme View Post
stainless
magnesium
ti
duplex, alloy & nickel steels
some nickel alloys
some copper alloys
should all be back purged
the only time you wouldn't want to back purge stainless is on your own personal piping if you are cheap

aluminum does not require a backing gas. however, it can be very helpful at more manly feeds and travel rates to use a copper backing plate to prevent burn through.


both aluminum and mild steel benefit from backpurging, however at lower dimensions, feeds & travel rates it is not critical to getting good weld quality.

From all this I take it that you weld everyday for a living?
shoyass is offline  
Old 03-28-2009, 03:43 AM
  #8  
3.0 BAR
 
Join Date: May 2005
Posts: 1,811
Cool

Toysrme is offline  
Old 03-29-2009, 04:04 PM
  #9  
1.0 BAR
 
Join Date: Feb 2007
Posts: 293
Default

^ props... hardcore...
Turbo News is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
GTI SYNCRO
Fabrication
6
11-25-2007 08:11 PM
Turdbo
Fabrication
10
06-18-2006 11:24 AM
91efate
Fabrication
19
02-27-2006 05:18 PM
BLACKSI
Fabrication
11
10-30-2005 01:49 PM
B16Drag
General Discussion
30
10-14-2004 01:28 PM


Thread Tools
Search this Thread
Quick Reply: back purging


Contact Us - Sitemap - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.