View Full Version : Rolls Royce Exhaust Manifold...
01-14-2010, 04:23 PM
I had a call on Tues. from a reference to weld a cast manifold. The car dealer who sells/services only in very expensive foreign cars, brought it in & asked if I could do it by the weekend.... I said, no problemo. Related the owner was leaving for Fla on Mon & needed it ASAP.
He indicated that it was previously repaired & broke again as is quite visible. It looks like a very light surface weld was done just to get it back together & finally just simply rusted thru. A new one from Rolls was quoted at $800+.
I wire-wheeled to clean, brushed with acetone to remove any contamination & beveled with a 45*/.125W on each side so as to do a root pass & finish with a cover pass. The break did mate up very nice to insure perfect alignment. I did the cold-weld MIG process as I do with all cast repairs that has been very successful with 309L SS wire(.030) & 98/2 gas(15cfh) & ran at 80A. I did the first (2) tacks at 180* apart, waited 15min. & did the the other (2) tacks at 180*. I ran 1/2"L beads on the root & peaned immediately after welding. The manifold was barely warm too the touch. Did all the followups the same way & then ran the cover pass identically. Came out quite nicely. Here are some pics.
01-14-2010, 05:31 PM
Beautiful job! I wish I could watch you do one like that...my cast attempts always seem to have that dreaded "Ping" about 4 or 5 minutes later. Does the peening eliminate that? Just keep tapping with a pointy hammer all the way around rapidly??:confused:
01-14-2010, 05:57 PM
Thanks.... it really isn't hard, although I was fortunate to get a half-dozen broken manifolds from my bro to practice on to really get the settings to an optimum. I always try to stress to the youngsters & newbies to do as much practice as possible....that's how solutions come to fruition.
After tacking & insuring the cast is back to room temperature, I start to run a root pass, about a 1/2"L, & then immediately pean the weld with a slightly rounded point on my slag hammer. I also use .030 dia wire. I wait till the cast is back to room temp. before starting the next bead. The peaning is not a hard pounding, just a light "tapping" on the entire length that does make a slight indent on the weld bead. This technique is really emphasized on the research I investigated to use this process. It is the main factor that eliminates those dreaded "tinkles"(yup, a crack). Each subsequent bead is done the same & all following beads are on opposite sides till finished. I also wanted to add that I have the manifold clamped very flat on my welding table & when I have to rotate to do the flat side(underside) of the manifold, I clamp a piece of 1/4" plate to the manifold to maintain flatness. I do the cover pass the same way to insure consistency & so far, not one problem with all the cast jobs I have done. I will stay with this technique for all the cast projects I get, unless size would dictate another process or parameter. Hope this helps you a bit.
01-14-2010, 06:42 PM
Very nice job. Do you have pics of the weld before finishing?
01-14-2010, 07:30 PM
Any chance straight argon would work? I already have C25 and Argon , hate to buy another just to "play". I'll have to get a small roll of 309L (What's the "L" for?) and try.
I continue to be really surprised by my 125EZ's ability to "stick" cast iron together with Flux Core...I may try the peening with it, as well. Little broken cast iron parts keep coming in, and I turn most away.
Thanks for the tips, Yorkieman!:)
01-15-2010, 12:33 PM
I never tried straight Ar as all my research, including Ed Craig's Weld Reality, dictated that best results were acquired with the 98/2 mix, although any mix with no more than 5% CO2 will work well. Since I use the 98/2 strictly for cast repairs, I have a 40cf bottle that lasts fairly well. The fellow at my LWS who fills the bottles did me a favor & keeps a 40cf bottle on the side for me as they usually only refill the large(250+ cf) bottles with that mix. So, as you can see, sometimes your LWS can be quite beneficial to those of us who need oddities at times. The 309 wire is used for austenitic to ferritic applications & the "L" designation is for the "L"ower carbon content. You can also use the reg. 309 as I have used both. Listen, if you can get some broken cast pieces as I did from my bro, it wouldn't take you too much time to get the "feel" using this process. I will say that there is quite a niche for these repairs, & believe me, quite lucrative($$$).
Hey Monte: I didn't have a chance to photo all the steps with the repair as I was buried with other demanding repairs. The next one I get in, I'll photo each step in progression to further illustrate each bead. This economy had led to quite an influx of repairs with everyone in the service/repair arena staying very busy. Seems most are just trying to stay afloat by getting stuff repaired rather than replace due to everyone cutting back. I love it.....
01-15-2010, 01:05 PM
I'm a little confused. Did you use mig for the entire process? If so, how do you know the amps? None of my migs display amps. What machine did you use? I would like to be able to do cast
01-15-2010, 04:07 PM
Yes... I use MIG for the entire process. I use my Miller Sidekick. I marked my heat selector switch with the voltage outputs listed in the owners' manual & my neighbor set up his test equipment quite a while back to measure amperage per w/f settings. I made a little chart to list amperage readouts & I also did the same for my Challenger 172. He said it wasn't hard to install an ammeter if I wanted, but I didn't want to cut any holes in the unit. The chart is accurate enough for all the applications I do & I always run test beads prior to starting any job or project. It is just a reference that provides base parameters with heat. If you want to do cast, simply find some broken castings from a garage or maybe a junkyard & practice to find your optimum settings. As I related to Hotfoot, it is not hard.... just takes some practice seat-time. I really clean the cast well prior to starting & bevel according to thickness.
01-15-2010, 05:02 PM
thanks for the info
01-15-2010, 10:15 PM
You guys on this forum are going to ruin another night's sleep for me for wondering why my welds don't look like yours!
Nice Repair Yorkiepap. I'll have to try your setup some time.