Help drilling through weld

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Sorry if this type of issue has been posted before or im in the wrong area.  Heres my problem:'Recently I bought a couple of very expensive turbos from a guy that said holes in the exhaust housing needed to be drilled out and re-tapped.  I talked to about 3 different machine shops about drilling through weld on these turbos and they didnt think it could be done.  I need to drill or have these holes drilled which are filled with the weld and re-tapped with studs. The housing is cast iron, would this pose any issues as well?   Please tell me if this is possible or any other ideas others may have?  I included a few pics so you guys can see what im talking about.  Thanks for any help Attached ImagesLast edited by starkx2; 05-09-2010 at 11:50 PM.
Reply:take the turbos to a muffler shop they can grind down the welds a weld studs on the turbos like they do on a broken header exhaust.Or you can grind down the weld to where it breaks of the turbo housing and then back up the bolts. Why are the bolts welded?
Reply:The bolts were taken out and the holes were welded shut to retap new holes...the stud on the bottom pic is the new one that has to go in
Reply:I'm wondering if the weld goes all the way to the bottom of the hole or it's just a skin over the top. By the looks of the weld I'd bet it's the latter, and done with wire, cast to boot. I think   a case where a Heli-coil might have been a better solution......Mike
Reply:find mate with drill press start with small drill bits and build up this definetly was a jon for heli coil thoCigweld Transmig 265seBoc 140amp StickBoss 200amp AC/DC TIGLincoln Electric Invertec V260-S
Reply:Best bet now is like runningjalapeno advised, the area around the weld will be as hard as HSS tooling.If you want to spend the big bucks, take them to someone who does EDM work. They will have to be taken apart though, and expect a price north of $40 per hole.Matt
Reply:Grind the welds flat.  Find the centers, mark them and punch a dimple with a center punch.  Then fixture the turbo in a drill press and drill out the holes.  The welds likely are not very deep into the casting.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by DesertRider33Grind the welds flat.  Find the centers, mark them and punch a dimple with a center punch.  Then fixture the turbo in a drill press and drill out the holes.  The welds likely are not very deep into the casting.
Reply:Several options on how to make holes, but ...Who the hell takes a "very expensive" cast iron turbocharger housing and then plug welds the mounting holes with a MIG ?!?!?!Turbos are -precision- items.  To even get a MIG weld in there makes me question if the object is -still- a precision object or is now an expensive paperweight.To wit, was the turbo completely dissasembled and then the cast iron housing preheated to the DamnHot stage before welding, then welded, and then returned to the preheat device and allowed to cool back down to room temperature over the course of ohhh about 2 days?  Since it looks like there is rust on/around the welds, I don't think the welds were done with a high-nickel stick electrode.  The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by MoonRiseSeveral options on how to make holes, but ...Who the hell takes a "very expensive" cast iron turbocharger housing and then plug welds the mounting holes with a MIG ?!?!?!
Reply:Originally Posted by Matt_MaguireBest bet now is like runningjalapeno advised, the area around the weld will be as hard as HSS tooling.If you want to spend the big bucks, take them to someone who does EDM work. They will have to be taken apart though, and expect a price north of $40 per hole.Matt
Reply:Originally Posted by starkx2Thanks for the replies....let me get this straight..indeed im not the one who welded this shut...lol...The i bought these from says the most holes are welded as far as the bottom part of the stud you see in the picIm willing to pay the money to have the holes drilled and re-tapped correctly....do you know of any place in the Chicago/Naperville area?  I definately wouldnt be close to comforatable doing this job on my own.Also, looking at some of the replies...it seems like this is a possible job..i was under the assumption that these holes cant be drilled out and re-tapped and to be as strong as the factory holes were.
Reply:Originally Posted by dave powelsonWhat others seemed to have glossed over is:1-Welding cast iron can and does create carbides--very hard spots/areas.'Annealing' the housings won't help at this point.2-The housings would need to be dis-assembled3-Even if the template drilling is successful....the hardest part remains intapping, when hitting hard spots. 4-Suggest using premium, USA, hardened, coated taps--which can only last one holeor not even that. Increasing minor diameter a bit, can help.IOW--this is an R&D project for whoever undertakes it. It may or may not work,but in any case--you should be paying for the effort.If worst comes to worst--threads can be EDM'd-possibly.
Reply:Originally Posted by starkx2Do you know of any companys that would take this on?  Out of 6 companies i contacted 0 said they could do the job...my thought is....out of all the technology in the world, why cant this be done
Reply:Because there are limits to what people are willing to pay to fix parts.  At some point it's more cost effective to go buy a new part, instead of fix an old beat up part.  I dont doubt that somebody, somewhere could do the job for you, but it may just end up costing way more than it's worth to repair...dang - Dave beat me to it....Millermatic 135Syncrowave 250
Reply:Originally Posted by DesertRider33Grind the welds flat.  Find the centers, mark them and punch a dimple with a center punch.  Then fixture the turbo in a drill press and drill out the holes.  The welds likely are not very deep into the casting.
Reply:Originally Posted by mrmikeyI'm wondering if the weld goes all the way to the bottom of the hole or it's just a skin over the top. By the looks of the weld I'd bet it's the latter, and done with wire, cast to boot. I think   a case where a Heli-coil might have been a better solution......Mike
Reply:Hello Stark I think this torbo can be repaired,I just did a similar repair job on a dodge truck spindle CI ,Customer,s mechanic miged 2 striped threaded holes full of wire weld for caliper pins for re tapping ,however his drill not even colbalt drill bits would not touch weld way too hard!what I did for him was grind his welds flat, center punch to find the center , clamped the spindle on my mill table, milled out welded holes oversized with solid carbide end mill,rewelded hole solid with 99 ni rod ,pre heat and post heat,redrilled holes to size and tapped out new threads, done! charged him $100 bill he was happy as new spindle cost about $500 Good Luck Bob
Reply:Originally Posted by doxieHello Stark I think this torbo can be repaired,I just did a similar repair job on a dodge truck spindle CI ,Customer,s mechanic miged 2 striped threaded holes full of wire weld for caliper pins for re tapping ,however his drill not even colbalt drill bits would not touch weld way too hard!what I did for him was grind his welds flat, center punch to find the center , clamped the spindle on my mill table, milled out welded holes oversized with solid carbide end mill,rewelded hole solid with 99 ni rod ,pre heat and post heat,redrilled holes to size and tapped out new threads, done! charged him $100 bill he was happy as new spindle cost about $500 Good Luck Bob
Reply:Originally Posted by doxieHello Stark I think this torbo can be repaired,I just did a similar repair job on a dodge truck spindle CI ,Customer,s mechanic miged 2 striped threaded holes full of wire weld for caliper pins for re tapping ,however his drill not even colbalt drill bits would not touch weld way too hard!what I did for him was grind his welds flat, center punch to find the center , clamped the spindle on my mill table, milled out welded holes oversized with solid carbide end mill,rewelded hole solid with 99 ni rod ,pre heat and post heat,redrilled holes to size and tapped out new threads, done! charged him $100 bill he was happy as new spindle cost about $500 Good Luck Bob
Reply:Originally Posted by starkx2Thanks for the replies....let me get this straight..indeed im not the one who welded this shut...lol...The i bought these from says the most holes are welded as far as the bottom part of the stud you see in the picIm willing to pay the money to have the holes drilled and re-tapped correctly....do you know of any place in the Chicago/Naperville area?  I definately wouldnt be close to comforatable doing this job on my own.Also, looking at some of the replies...it seems like this is a possible job..i was under the assumption that these holes cant be drilled out and re-tapped and to be as strong as the factory holes were.
Reply:Originally Posted by starkx2Also, looking at some of the replies...it seems like this is a possible job..i was under the assumption that these holes cant be drilled out and re-tapped and to be as strong as the factory holes were.
Reply:As Dave Powelson so nicely said  , there -are- ways to make holes.  Most likely, none will be cheap.  You are talking about areospace or tool-n-die type work there, not a shop with a drill press and a HSS bit.   or  or  depending on how you want to look at it.But before even going there, as I said above CHECK THE REST OF THE TURBO!!!!!  A turbo is a precision device, the idiot who welded the previous mounting holes closed -may- have distorted the close precision dimensions of the turbo housing.  So check all that -first-.  See that impeller blade and how it is kind of close to the turbo housing?  And that is at rest and at room temperature?  Now spin that blade up to oh about 100,000 rpm and red hot and see if things still fit or if the blade touches the housing and then instantly turns into a turbo shrapnel grenade.  The dimension of things in a turbo are kind of important.  To say the least.If the rest of the turbo is OK, then you can investigate getting the mounting holes fixed via $$$ or $$$$.  And that may also involve yet more dimensional checks and possible more machining after your mounting holes are back in place (think engine block and machining it with things torqued up to distort the block and then it is machined to be 'correct' in the torqued up state).Possible to fix things?  Maybe.  But likely not all that easy or cheap to do so.  And all because that idiot with a MIG filled the holes.  Five minutes of welding and now $$$ or $$$$ to try and fix things.  The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by starkx2'Recently I bought a couple of very expensive turbos from a guy that said holes in the exhaust housing needed to be drilled out and re-tapped.  I talked to about 3 different machine shops about drilling through weld on these turbos and they didnt think it could be done. Thanks for any help
Reply:Originally Posted by 4sfedDo you have room for a v-band clamp?  http://www.jegs.com/i/Turbonetics/880/30242/10002/-1There are several styles available.  Turbine housings are high nickel castings and weld well . . . so weld a v-band flange to the housing and and exhaust pipe and forget about the machine work.JimI think I would make or have a a drill guide made like in the drawing making the small end a slip fit into the housing and have the holes laid out and drilled for the tap hole size. Clamp hate guide and the housing in a drill press and drill. Drill and tap and see what you have and go from there, I think you will have to go over size and go to the coil. Attached ImagesLast edited by digr; 05-11-2010 at 10:59 PM.I always tried to work with the oldest hand on the job to gain knowlege but now I can't find any.
Reply:Look at the weld ITS not steel Its brass  Just grind it flat and use your template, center punch and drill
Reply:....ITS not steel Its brass .....
Reply:It might be Everdure and then he is pretty weld screwed. It will be strong as heck. Ha-ha. The only way possible would be with a carbide drill bit. Or EDM, as someone mentioned, you do have to take it apart for EDM. EDM is a moving brass wire that cuts like a bandsaw blade, but instead of teeth it cuts with electricity. It is amazingly accurate. But then the threading would probably be impossible. He may have junk there. Unless you can insert something countersunk from behind. I would just get new ones.        Sincerely,             William McCormick
Reply:Originally Posted by William McCormick JrIt might be Everdure and then he is pretty weld screwed. It will be strong as heck. Ha-ha. The only way possible would be with a carbide drill bit. Or EDM, as someone mentioned, you do have to take it apart for EDM. EDM is a moving brass wire that cuts like a bandsaw blade, but instead of teeth it cuts with electricity. It is amazingly accurate. But then the threading would probably be impossible. He may have junk there. Unless you can insert something countersunk from behind. I would just get new ones.        Sincerely,             William McCormick
Reply:Originally Posted by Crawforddon't see why something like a keensert wouldn't work after the fact?
Reply:Originally Posted by Crawforddon't see why something like a keensert wouldn't work after the fact?
Reply:how deep do those threads go, and what type of pressure are you running? you could grind/mill flat  and use welded studs instead of threaded ones.  Or if you could machine a new cap plate that fits on top of the turbo that could be easily  tapped and then either bolt or weld It to the turbo face.  It's hard to see from the picture what type of clearance, clocking and size tolerances you have.I found that often times when you get to focused on a piece you forget to look at the big picture, instead of asking yourself will it be possible to tap these holes, take a step back look at the whole thing and figure out what other ways you can go about modifying it so it can bolt up.I remember once trying to figure out for hours how to weld this table and route all this wiring upside down through all the nooks and crannies. a guy came by said it would be easier to machine up a simple clamp and just swing the table upside down.  Sure enough he was right.Welding EngineerCertified Scrap Producer
Reply:That sinker EDM is going to cost more then new turbos.        Sincerely,             William McCormick
Reply:You are going to have to find out if this is machinable or not machinable. I suspect that there is a cut off stud in the hole that was welded over. That and a high nickle cast would make this lieky an easy project. Sand down the welds near flush, centerpunch and drill a pilot hole. If it was suseccful then finish the pilot holes and then drill and tap. If you can't get a pilot hole drilled drop it off at teh edm shop and pay.