So, i've got a project i'm about to start working on with a friend, involving some 16ga 304 stainless. The key is, i'm going to be doing some welds on the inside, that i DONT want visible on the backside. No 100% penetration wanted. My welder is a Northern Tool 115v inverter, 80a max, goes down to 20a....obviously scratch start, i've got a 9v torch, 3/32 (or 1/16) 2% Thoriated, stubby gas lens kit..for now, i'm practicing on some 16ga mild steel, i know it wont QUITE be the same, but it's close enough to practice on....er70s2 for now, and 308L for when i do the stainless....
Anyway, if i do 50a, i'm getting 100% penetration on fillet welds, no problem at all....if i do 30a, i'm still getting a ton of burn through to the backside...i dont WANT to back purge, as i only have a 20cf tank, so i'd rather not eat up more gas than i need....i dont NEED 100% penetration on this job, as it will hold together fine without, and wont kill anyone if it breaks lol...any thoughts? do i just need to keep going down lower on the dial? bottom it out at 20a and see what happens?
- TRACKRANGER
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Weldmonger
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Joined:Wed Aug 06, 2014 12:48 am
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Location:Melbourne, Australia
Can you firmly attach a heatsink to the back side of the area to be welded? A copper or aluminum block clamped to the panel?
Expect some HAZ coloration, but this could be scrubbed afterwards
Just an idea anyway.
Oh, and welcome to the forum!
Trev
Expect some HAZ coloration, but this could be scrubbed afterwards
Just an idea anyway.
Oh, and welcome to the forum!
Trev
EWM Phonenix 355 Pulse MIG set mainly for Aluminum, CIGWeld 300Amp AC/DC TIG, TRANSMIG S3C 300 Amp MIG, etc, etc
NathanHamler
- NathanHamler
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New Member
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Joined:Tue Jul 21, 2015 7:28 pm
mmmmmm that's true, i like that....i'll have to do some experiments, thanks!TRACKRANGER wrote:Can you firmly attach a heatsink to the back side of the area to be welded? A copper or aluminum block clamped to the panel?
Expect some HAZ coloration, but this could be scrubbed afterwards
Just an idea anyway.
Oh, and welcome to the forum!
Trev
- big gear head
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Ace
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Joined:Thu May 07, 2015 11:46 am
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Location:KY.
I use aluminum for backing a lot when welding 304 SS. It works pretty well. You are going to have to pay close attention to dipping. If you miss a dip you may have a spot that burns through. Dipping cools the puddle, so a missed dip means that spot got hotter. It will show up more on SS than it does on mild steel.
Freddie