Tig welding aluminum heat sink (unable to get good penetration)

admin

I'm welding two heat sinks together and I've not been able to get a good pool flowing/weld moving. The heat sink base is just over 3/8" thick. I've got 3/16" of bevel, 70%-30% argon/helium and 4043 rods. Unknown heat sink material. Im using a syncrowave 200 and will be flooring it. I also have it set for max 'dig'. The pool will not develop to a point where I can 'make the weld'.
Reply:Have you tried preheating the area to about 600°F?  I have found that works quite well when welding aluminum thicker than gauge material.  If you do that, you may need to back off on the amps, which shouldn't be a problem since you have remote amperage control.
Reply:Preheat or use a spool gun.David
Reply:Got it! And it's purdy. I heated it with an oxy torch, went to a 1/8" tungsten and cleaned the rods with a scotch brite pad. (I think the rods were introducing contamination)I also tacked it at an angle so it warped into straight. Looks right on!Last edited by Magapp.matt; 01-13-2011 at 02:00 PM.
Reply:WHERES THE PIC?????WE wana seeidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:It's already on the truck to get planed...
Reply:Good thing you had it set to "Max Dig" while Tig weldingEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Whatever, AC balance set on 10 or just below. You know what I mean.
Reply:NO.Actually we didn't know "what you meant".  Just sounded like a guy who didn't have a clue what he was talking about when it comes to tig welding.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Broccoli, that comment cracked me up!Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma