Intercooler Re-weld

admin

Had a customer come to the shop today asking about repairing a very shotty weld job on some intercooler piping. He had a guy who claimed he knew how to weld aluminum attempt fabrication with a Mig. My customer is requesting I grind down the "globs" and rewrld the joints. I've never done a rework of someone else's aluminum welding. If it was steel, it would be just another day at the office. Anything I should watch out for? The customer did leave me some new tubing that was not used in the installation in case I needed a new flange or elbow (some of the existing welds are pretty rough). My plan is to grind down the nasty welds, re-weld with the TIG, and replace the flanges that are gouged and undercut. When all is said and done, I will be polishing to a nice bright shine.
Reply:Nice thing about metal is that you can add more or grind it off till it looks right.
Reply:I recently had a similar job, I had the guy buy all new pipeing and just used the original as a sample and built new. He was very happy he waited! I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:Be sure to use a grinding disc that has NEVER been used to grind steel.  Any ferrous material that gets deposited into the base material will make for a bad day welding.
Reply:Pictures would help alot.Tight joints might require the use of a carbide burr. You can hardly do any worse than he did. Good luck.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:If the boost tubes (or intercooler?  confused which you are being asked to repair) have actually been in service, and have any oil residue on the back side of the areas where you'll be "re-welding", be sure to get that really thoroughly cleaned before re-welding.  Any oil on the back side of an aluminum weld joint will make hydrogen porosity and an absolute mess of a porous, low-strength weld deposit.  You want the aluminum clean and dry.Also you'll ideally want the surfaces oxide-free, at least where the liquified metal needs to flow and where the the TIG cleaning action can't get to (works well on the front side only, and for a relative thin thickness of oxide film thickness only).  If your pieces are already joined together, you might need to use like shovelon mentioned, a carbide burr to get this done.Trapped oxides from poor prior welding attempts can sometimes be "floated" out to the surface if you use enough heat and penetrate deeply enough.  I'm not sure if you can realistically expect full penetration for this kind of repair (assuming you don't cut the welds apart first to properly clean the back sides, and eliminate all oxide inclusions), so for strength it may be a good idea to (in addition to getting as good penetration as you can underneath the surface) building up some reinforcement on the front side (aka leaving a bit of a "proud" weld bead) than is usually performed.Really thick oxides from poor previous welding could be really though to clean and deal with.  Carbide burr is a good tool for reaching down underneath the surface where needed, and cleaning any really bad areas of oxide inclusions.Pics would help us understand exactly what you're dealing with here better.  Best of luck -Last edited by jakeru; 04-24-2013 at 01:17 PM.
Reply:Aluminum is a little different than carbon steel, aluminum is much more sensitive to type of filler metals used.You need to know what the series the base material is and that will lead you to the best filler to use.In my experience in shipyard piping and hull construction, the more that aluminum is welded, ground, rewelded the more it has a tendency to crack and deform, making more problems.If you have the material it may be easier to just start over.Pics would sure help
Reply:Here's a taste of what I'm dealing with. After disassembling this thing, I'm seeing its way worse than I thought.  Attached Images
Reply:holy mess it would be easier to start with new pipe  cheaper too if you add in man hours
Reply:Wow!  That is a terrible mess.On the first joint he should have quit welding (or stopped smokin it).  Start new...Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I personally wouldn't try to fix that because It would look terrible in the end. Cut and replace.Welding/Fab Pics: www.UtahWeld.com
Reply:yup cut and replace that tubing is toast unless you want to  spend hours with a die grinderMiller Xmt 350Lincoln Ln-25Ahp 200xSmith Gas Mixer AR/HTig is my Kung FuThrowing down dimes and weaving aboutInstagram http://instagram.com/[email protected]
Reply:New tube! Plenty of length left on the BOV flange to cut and reuse. Looks like all cheap ebay tubing anyhow so not much of a loss there. Could also be part of the welding problem. I have had some people bring me cheap *** ebay tubing that would not take a weld for ****.
Reply:Luckily, the customer had the remaining pieces of the kit that he didn't use and left them with me. Only problem is there are no more 90 degree elbows so I'm going to have to cut these things back then weld new flanges on. I'll post finished product pictures when I'm finished. Should make its way onto the welding table next week.
Reply:Yikes!I guess start grinding. Leave the inside to him to port out. I would use soluble oil for cutting lube. Wash with water based cleaner, then acetone, then alumiclean aluminm prepGood luck..Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Wish I could weld like that *SARCASM*Miller Maxstar 200 SDPiperliner #10 Gold
Reply:That is one strange BOV flange. Never seen that one before.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Originally Posted by GambleThat is one strange BOV flange. Never seen that one before.
Reply:It looks threaded which is strange. But I haven't been in the car sceen for a few years so who knows what crap china came up with.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:That looks like something I would do. Ha, I wouldn't even present that if I was doin anything for someone else... I would grind it and run an entire spool of wire if I had to keep grinding and redoing for it to be presentable. Couldn't you just cut the welded sections out and replace with some straight tubing? Wouldn't need a 90, just remove and replace the joints.Good luck,JW
Reply:Here's an update on this job. I managed to piece together enough new tubing from the surplus materials the customer supplied. I only have this one picture showing one of the newly fabricated tubes and the air cleaner mock up.