Welding Tips and Tricks

I need to weld somebody's botched repair job from a broken head bolt on an aluminum engine block. It is a Isuzu 6vd1. I read through the Automotive Aluminum booklet, but didn't find the specific alloy information I was looking for. So I was wondering what methods are available to help me determine how to do this repair. I could weld it with a Spool gun, or TIG it, but I don't know if there is a fix-all rod (like Hastelloy W, or 312 in the steel family). I'm pretty sure I'm going to need some preheat, but I don't want to anneal this and have a tension failure, from too much. machine work afterwards, is expected, but I don't want to end up buying a new block Anyway, advice on this is greatly appreciated.

In an "unknown alloy" situation, I think (were it my job to do) I'd use 3003 rod. It's soft enough to allow stretch and/or compression hopefully without cracking at the fusion line. I'd also "dummy" the bolt with a stainless rod fit to the ID of the threads, and re-tap when finished. (The 3003 will cut nicely, but may not take the same torque as originally specified for that bolt.

Your mileage may vary, and you may get better advice if you're patient.

Steve S

I could not tell you exact alloy. I will offer what I would prolly do in your position. For cast aluminum I typically use 4043 for repairing engine cases, differentials, transmission cases and such. I find the added silicon in 4043 helps with the crude in the cases. I might preheat the whole thing in an oven to 350. Depends though if I think I could get away with local preheat or not. I have used some of new 4943 filler on a couple of cast aluminum things have not decided to due the majority of cast stuff with it yet. Waiting to see how a few work out over time. I could not give opinion on using stainless bolt as a form. I would be afraid of getting air pocket in threads. Therefore would rather grind out some of original cast build it up then drill and tap it. Doesn't take to long to drill and tap aluminum. If the support around bolt was thin which led to the breakage, now would be a good time to add more support then what was there originally. If you have room to do that.

I put one cast project up here at this link. Plus on next page a description on cleaning method I use and welding description of doing cast.

http://forum.weldingtipsandtricks.com/v ... start=1310

Since I didn't seem to be getting any new information, I went with my gut. I carved out the old bolt and heli-coil with a grinder, and welded it up with 4043. I tried to clean it up as best as I could with brake cleaner, then a button brush on a die grinder. I stayed away from the head surface to reduce the number of machining operations (and cost) of the repair. I will pick it up from the machine shop on Tuesday, and maybe post a picture or two, in case anybody else gets in this same jam, so they don't end up scrapping a repairable block. I will also post an update on the overall repair, just in case I pull all the threads out torque-ing down the head.

I got this back from the machine shop today, and here is what it looks like. I was thinking I would smooth down those welds, but they aren't in the way of anything, I need as much material as I can get, and most nobody will ever see them.
I'll keep everyone (both of you) informed of the overall project success.

hosermeyer wrote:...I'll keep everyone (both of you) informed of the overall project success.

Trust me, many more are reading than are commenting.

Steve S

I'm following this one close. Because I have nothing much to offer but a lot to learn on this topic.

Good looking welds for cast.

Sent from my SM-N910R4 using Tapatalk

I haven't forgot about this, I just haven't been making much progress.