Difficult Cast Iron Exhaust Manifold Welding Repair

what's going on guys welcome back my name is Brandon and today we've got a challenging cast iron repair to make stick around [Music] the customer brought me this cast iron manifold and we're going to take a quick look at it and I'll tell you what's going on with it so as you can see it's broken in half and you can see the material all around here here is where it connects into here has been broken for a while and you can see the Virgin cast material right down at the very bottom well the story behind this is that the customer brought this to me it's a local shop and it fits a Dodge pickup I believe it is apparently this is such a common issue that Dodge is only getting one of these manifolds per week so it's going to be two months before this manifold can be purchased for this vehicle in an effort to get their customer back on the road until the new one arrives they ask that I try to repair this manifold which is what we're going to try to do today after two months they'll put the new one on so we're hoping that this repair will last two months so we are going to do a follow-up to see how this works this is a tough break there's a lot of things going on here but this will be a great video to show a lot of the steps there's more to this than just welding it back together it would be great to clamp this down and then weld it but the issue with clamping it down and Welding it is that it's going to create stresses additional stresses in it while you're welding it so we're not going to really be able to clamp it down per se so there's a lot of steps that we need to do to make this repair because it's completely broken in half and I'm going to show you how to do those today should be a really interesting educational video as always I'm going to get all kinds of suggestions about everything that I'm doing wrong in this video and people are going to say that the process should have been some other process and how much experience they've had with what worked well for them this is the process that I'm choosing there's no right or wrong this is what has worked good for me it is a thousand different ways to repair cast iron and everybody's got a different way that works well and everyone says that is a way that doesn't this has to last two months that's it it's just to get this customer back on the road so their vehicle isn't sitting until the new manifold arrives from Dodge to make this repair we going to be using silicon bronze and we're going to be MIG welding it but there's a lot of steps that we have to take to do this as opposed to just repairing a crack I'm going to be doing a preheat with this as well so what I've got to do is I've got to tack this together as it Keys together you can see how it fits a certain way and it only goes one way because it fits in tight if I bevel this all out right now and V it all out to make room for the weld it's not going to key in as good and the alignment is important on this because this has to bolt back up to the vehicle the flanges do but what I can do is video in certain areas and we have to get beyond all of this so this is going to be a full penetrating weld we'll probably have to do it in multiple passes because I got to get rid of all this burnt cast you can see how all burnt out that is the only area that isn't burnt out is this area down here it'll probably be brittle because it's an exhaust manifold but this area here is all virgin metal same thing over here but you can see how long this has been cracked it's been cracked all the way around the only part holding this manifold on was this little area right down here so to get this to key in properly what we're going to do is I'm going to do probably a corner grind bevel right here bevel it on the other side get attack in there and then flip it over and do the same thing on the underside so that way we can get this thing held together then I can V out everywhere else throw this in a preheat get this thing heated up in the oven it would be next to impossible to have these parts at you know 500 Degrees each and in two halves and then try to get everything lined up perfectly tack everything together and then flip it all around and still maintain the heat in this because we need to maintain about a 500 degree temperature in this part and we want to keep it there for a while which will eliminate the chances of cracking that's the issue with cast iron is that it has a tendency to crack while it's cooling so our goal is to keep this insulated in a blanket and in sand and allow this to cool down slowly over a duration of time probably 24 hours it doesn't hurt to say a little prayer and be hopeful that it's not going to crack but yeah I've got probably a 60 or 70 percent success rate on our parent cast iron we'll see this is completely broken I can tell you that silicon bronze is one of the strongest filamentals that I've tested to date and it's it's almost as strong as unbroken cast iron but this will never be as strong as it was from the factory it obviously broke the original casting broke for a reason and I have no reason to believe that any type of repair is actually going to be better or stronger than the original casting we could plate this there's all kinds of things we could do to reinforce it to make it a little bit better but we're not going to be doing that today that's a whole other video so one thing that I'm noticing guys as I do this I've got this laid out on my flat plate and look at this Gap right here I'm wondering if this might have been casted with some tension in this originally which is causing these to break potentially my plate is flat but watch I can lift this edge up and close that Gap up but I'm off the ground when I do that watch this crack but watch right here when I pick that up well I close that Gap up just like that look that leaves a little Gap underneath there I'm thinking that this might have got casted with a little bit of stress or tension in this part which is maybe causing this to break so this Plate's flat we're going to weld it just like this flat rather than try to close that Gap up we're going to weld it just like this better yet I've got a 5 8 piece of stainless right here that will sit right on top look at that guys well let me show you what I was doing guys so I've got these two halves now push together but there is a little bit of movement in this part and I want to make sure that we have it perfectly in line so that when they go to bolt this back up to the motor so what I've done is as you can see these are the bolt holes that bolt this back on to the engine so what I've done is this plate has a straight edge on it right here so I just took the light and shined it at the hole now if you look you see how the edge of that hole you can see just a little bit of light off the edge of that plate down in there you can see a little bit of light off that edge a little bit of light off that edge of the plate that's all I'm doing same thing over here so you can get a little bit of light off the edge of that hole a little bit of light off the edge of that hole so I know that this flange is in alignment straight down through that way so then I can get at least attack and attack maybe even one at the bottom over there so that way we know it's straight along that flange we've done the best we can do to make sure that that's lined up now I'm going to grind a little flat spot in this so I have a place to make my repair weld foreign that to almost paper thin that's veed right out almost to the other side so we're going to end up filling all of that cavity up with silicone bronze but we're going to start out just by getting attack like over here and over here and then we can pick the part up flip it over and get the rest of this cut out and fixed but yeah she definitely needs some work so we're going to do one last inspection to make sure nothing's moved and see a little bit of light down through that hole a little bit of light through that one a little bit of light through that one a little bit of light through that one we're doing this with a spool gun and I'm using again Thirty thousandths silicone bronze now when we're done with this this repair will have like a gold color to it can you see the wire right there it's 30 000. I'm using blue demon wire now you could use this setup through like on a spool through your Mig gun and push it through your liner I would recommend a Teflon liner but you can do it with a steel liner there's a couple advantages of the Teflon liner because the Silicon bronze wire is actually soft it'll push through a lot easier with a Teflon liner than with a steel liner plus you don't have to worry about the contaminants of getting the steel embedded into the Silicon bronze as you're trying to weld and then as far as Drive rolls you'd want to use the u-groove drive rolls the same ones you'd use for aluminum wire but you can use the v-groove as well and that's for the reason that the wire is soft I have it set up with DC electrode positive and the gun travel angle and the travel is going to be the same with short circuit Mig you can drag it you can push it it doesn't matter either way and you're going to be using Straight 100 argon with silicone bronze I'm they'll probably start out a little lower here and maybe increase it as we make our second pass for this repair you're going to want a respirator if you don't have good ventilation gloves obviously a welding hood so here we go [Applause] foreign the welds with a chipping hammer right there a needle scaler works good too I just get a little nervous with a needle scaler around a lot of cast iron especially sometimes if it's brittle I kind of just like doing it by hand but what that does is basically you're just taking that metal that molten metal that's and you're just mashing it down inside that Weld and it's kind of taking some of that tension out of the joint is what it's doing so and you can see right here I actually blew a Hole uh through it right here so we're definitely getting full penetration you guys probably heard me like just triggering it in I was clicking clicking clicking to get this to fill in here so we're probably pretty good here again I'm not trying to put a whole lot of heat in this part because I don't want it to crack these are just little tacks to hold this together just so we can get this joint beveled out and we can get it into the heat source so that we can get a preheat on it but I will spin this over and we'll prep the back side and get a little bit of weld on that too boy that's a tough repair guys being where it is all the material that's got to come out you can see it's right there all the way up around that flange see it right there kind of around that back side we'll work that back side a little bit right here probably try to get attack right in here then that'll hold it together real nice and then we can work in here and get this all grooved out real good [Music] you can see right there I started poking through just a little bit on that crack kind of came up into our attack a little bit ground the length of that right on top of that crack and I'll probably throw a tack right here generally you don't want to tack on corners but I'm going to be going over this with two passes and it'll kind of be out of the way so I'm going to throw one right in the corner right here we'll flip it around to the other side then we get the rest of this all prepped out we know it won't break apart but again the reason I'm doing it this way is because we have this keyed together you see how tight this is this joint is fitting right now it's because we've keyed it together it's locked in to its natural place where it wants to be from where it broke so we want to keep it in that position so I'll throw a tack right over here and do the same thing on the other side then we can finish grinding out all of this and then once it's all ground out and it's ready to be welded we'll throw this in a 500 degree preheat which will be the oven and then we'll let it sit for about an hour so it's fully heat soaked and we'll bring it back into the workshop and get it welded out the reason for a preheat guys is it helps to eliminate some cracking not always but it does help so let's just use a thousand degrees fahrenheit as an example for welding temperature let's say that we're welding it at a thousand this part is at 70 degrees so at 70 degrees this would have a 930 degree temperature swing well if we can get this up to 500 Degrees the difference between 500 and 1000 is only a 500 degree temperature swing so it'll have a tendency less to crack because it's not going through a wide range of hot and cold make sense another key tip when you're doing this guys is get that ball off the end of that wire you see the little ball on the end of that trim that off because it takes more voltage to get that started all right if you want to prevent BBS from sticking to your Fab table just spray it down with some vegetable oil it won't adversely affect your weld at all I think that's why it broke in the beginning guys I think these had actually tension built into these this thing's all wobbling at all now now it's completely flat and smooth maybe it had tension built into this uh into this flange and that's why it broke but I don't know I'll report back once we're done and we'll see if we get more than two months out of this repair be curious to know all right I'm gonna finish v'ing this out off camera once I'm all done I'll bring you back in but this is going to take me a little while to do this okay so I'll get it all beat out all prepped ready for weld I'll show you what that's going to look like and we'll go throw it in the oven for an hour all right guys we'll let the fun begin so we're going to set this on the grill right now you can see we got it all prepped out see notched all the way around all grooved out I ended up cutting right through the whole back strap right there just so I could get down real deep inside that Groove to get that crack you know this is just like painting a lot of ways guys the prep is what takes all the time the welding doesn't really take a whole lot of time at all it's it's the prep work that leads up to that so yep we got it all grooved out good throw it on here let it sit for about 45 minutes to an hour we'll get it up to 500 degrees or so and take it right out we'll immediately wrap it up in a fiberglass blanket welding blanket bring it into the workshop weld it up then we're going to immediately bury it in sand time is on we'll let this sit for a while now all right here we go wow she's hot changed completely a different color all right now wrap it up our goal is to keep this as warm as possible let's go weld it up we're going to work fast we want this part to cool off too much are we starting on the back work my way to the front wow yeah she's hot [Music] [Applause] [Music] all right I'm gonna flip it over to the top trying to kind of alternate the forces that are being applied here [Applause] oh she got hot [Music] now a little bit of a blowout we have to fill it in guys [Music] laughs I'm just going to keep alternating until it's filled in [Applause] [Music] [Applause] this product can feel the heat radiating off it here we go yeah that'll work fine guys [Applause] [Music] [Applause] [Music] [Applause] [Applause] [Music] [Applause] [Music] thank you [Applause] all right a little tiny pinhole right here crater Gonna Fill it here we go all right let's get this in some sand and Berry so it can cool down I haven't seen any issues yet so so far this telling me this is gonna be a good repair and that's it now you say a little prayer and hope because uh cast iron can be really fussy obviously if the original casting broke from the factory I have no reason to believe that a repair is actually going to make the casting stronger to begin with it's not it's not going to be stronger if it does fail or crack generally it'll crack at the toe of the weld right at the very outside edge but I think this is going to be a good repair and we'll take a look at it tomorrow so we'll have to come back 24 hours later see how it looks and then we'll give it back to the customer if it's fine then we'll check back in with them in two months because they do have one of these on order from Dodge we'll get it back from them I'll see if they'll give it back to me and we'll take a look and if it's not cracked maybe we'll do some destructive testing on it see if we can break it and how much tension it took to break it to date and I'll have a link to a video up above silicon bronze is by far the strongest filamental that we've ever tested I want to say I think it's within seven percent of natural virgin unbroken cast iron that's pretty impressive in itself we'll come back in 24 hours later check this out and see how it looks all right well the next day let's open this up and see it looks like we'll wire brush this up and see what we can see I heard something when I was like revealing it like Drop it was part of this like retainer clip I guess for this manifold yeah no issues here you can see we got a couple passes on this side got just a little tiny tiny low spot right here that if I was going to keep this and it had to be in service for a long time I'd probably go back and fill that but I'm actually not going to overly worry about it this two passes up under that anyways that's especially where the tack was so I'm not going to get too fancy there like I said it's only going to last a couple months I believe this is the bottom side of the manifold and then we've got the back side of the manifold so yeah now this process guys is actually called Mig brazing and the reason it's called braising is because that's done at under like 1600 degrees welding temperature is much higher than that with Mig brazing you're actually laying in the filler metal but you're not melting the base metal I really like silicone bronze because I think of it in the aspect of like a caulking it's very forgiving you're just kind of like mealing this into the repair joint or the repaired area and it's just very forgiving and I think this has like a 50 000 PSI tensile strength as well well it's a really nice filamental so yeah this was a successful repair and we will get this back to our customer hopefully everything goes well they get this all bolted up everything should line up really nice because of the way we did it and uh yeah we'll ask for him to for have it back and maybe we can like clamp this down to the bench see what kind of weight it takes to snap this off and break it in half once they're done using it always leaves a lot of questions of after you repair something of you know when is it going to crack or how will it crack how long is it going to last well we'll see if we can get it back in a couple months and maybe we can answer some of those questions this is a successful repair and I'm glad to be able to bring it to you and show it to you because this could save you a little bit of time and a little bit of money potentially you could actually do this on your vehicle if you had a broken exhaust manifold which is going to save you from having taken off a lot of stuff just make sure you disconnect the battery if you're going to do that so you're not affecting your computer so as always guys as new videos every Friday I want to thank you guys for watching thank you guys for tuning in and if this is something that you like please don't forget to rate comment subscribe it and share until next Friday guys I will see you then take care stay safe and God bless come come on [Music]

Channel: Brandon Lund

Views: 120,782

Keywords: Welding Metal Fabrication Steel Steel Fabrication Metal Welding Mig Welding, welding, cast iron, cast iron welding, exhaust manifold repair, mig welding, welding repairs, welding repair, manifold restoration, fix, repair, how to, diy, do it yourself, brandon lund, Welding Cast Iron Exhaust Manifold MIG Repair, silicon bronze, weld, how to weld, welding cast iron, how to weld cast iron, exhaust manifold, manifold, mig welding techniques, Brandon lund

Id: -OzGdxzik54

Length: 23min 57sec (1437 seconds)

Published: Fri Jul 28 2023