Welding cases

[Ivor]

Thankyou Terry for sharing your knowledge and experience, I hope it will help anyone embarking on this sort of project . Thank-you for explaining the new welding machines, it makes sense to me now. I must admit that when the engineering shop told me that they could have the cases 'lazier welded' it left me wondering, if it was that easy, why it was not used as a wide spread and well known solution ?
Ivor.

[partshunt]

You had a bad deal by the sound of that. Too bad it is fouling your Indian 4 enthusiasm. Yes, you never know what is next, like mine ran for four years then suddenly, blew a hole in no 4 piston. The others were good so I put it down to porosity and so far with the new piston no problem so far. Blowing the piston was a crazy experience on the freeway because when you had to pull a hill, the fuel charge was detoning in the crankcase and blew the oil and dipstick to kingdom come. The dipstick is still on its way to mars year six now. BTWay, if the tooth was still missing in the bevel drive that caused the case to split apart inially. the broken bevel gear was reinstalled and you had to renew it? Otherwise how would you know the missing tooth broke the cases?. Joe

[Ivor]

Hi Cotten, I'm sorry, but I can't tell you ! When I got the cases back from the second welder about a year ago, they had not welded two parts that had a dodgy looking welding job done years ago, the front right engine mount flange and the bridge that supports the crankshaft between the flywheel and the bevelled gear. The engineer told me that he could Lazer weld those parts and after 3 months he sent me a bill that I paid straight away, it was only months later that he told me that it wasn't necessary to weld those parts, but he has never told me what welding was done if any !! However, from what Terry tells us, Lazer welding is not suitable for this type of job anyway.
Ivor.

[Ivor]

Hi Joe, Yes the motor was rebuilt with a tooth missing, but I got a matched pair from Gerry. What I like about your story is that you ran the shafts out of true and it works ! Where as so many folk nowadays just 'fit new' without testing the boundaries.

[gsottl]

on my 1939 Four I had several spots of the cases laser-welded:

the pictures show 3 examples:

- a partial crack on top of the flywheel casting which had been repaired with metal glue in the past
- torn out threads
- worn surfaces on the engine mount platforms

My upper case was not welded in the past and had some minor issues like the things shown. I have good experience with laser-welding mostly for smaller damages/cracks where a common weld repair would cause a lot of extra machining after the welding as the parts deform from the added heat/energy.

[tator]

The first two pictures are very impressive. Nice neat, clean welds. On the third picture if you notice on the ends of some of the welds there are little pin holes and on the sides of some of the welds. I am assuming this is a flywheel cover and there is no oil behind it. The spots I am referring to , that is the contamination that I was referring to in my post. I am not saying the welding is bad, I am just posting so if you did have a case with a weld with the little spots going over them makes them worse. So what I used to do is take an air blower, put soap and water on the weld and blow it from the back side. If any of them spots leaked where there was oil I would take a sharp punch and peen the weld bead next to it into the hole, pressure check it again. Never had one come back with a leak.

[Ivor]

Thanks Gsotti, your post has made me think that the laser welding was done on my cases to mend the shrinkage cracks left by the tig welding. So the laser welding would never be a solution to the bearing bridge or the engine mount, because it is not 'Man enough'. It's a shame my engineer didn't explain this to me.
I for one, have learned such allot from all of your replies about these cases and the welding of them. And that's the great thing about this forum !
Ivor.

[gsottl]

Thanks for your replies tator and Ivor.

The good thing with the laser is, that after cleaning the weld I can check where there is small spots left that need attention. The welding does not burn the holes bigger and can just be put where the hole was after the spot is cleaned down to the clean basic material. I am lucky to have a friendly and skilled laser welder just a few miles away from me. That helps too of course. And it is definately right that it is not the best solution for all welds, but for some repairs it is very useable and preserves the original substance as good as possible.

[partshunt]

Originally, when I bought 1929 402 resto project. I talked with the previous owner decades ago who is longer with us,he told me he bought the Four in 1942 and those cases were welded then. I could not clean up the welds to look good so that is why I had them realigned and welded with a more modern process. People now are offering the service but I think you need to boil the oil out in a chemical name I don't remember. My point is, they obviously were successful in those day leak wise and strong but not beauty wise like us resto nuts want.. ..Joe

[tator]

Something I would like to touch on is when welding these cases you are welding something that was never intended to be welded. If you are welding normal aluminum like 5052 that is meant to be welded there is welding rod for that purpose. Most welding stores only carry about three or four different kinds of welding rod or heliarc wire. I have had my best luck with a EA5356 rod/wire in 1/8 inch size. It seems to be wet enough to flow nice, it is strong and it machines very well. One time I sent some GM axel castings out to be tested to see what they were made of. They came back with a whole list of stuff that you knew was going to be trouble to weld. Mostly stuff that was outside stuck to the pores that was used as a releasing agent to remove the molds. That was not very much help. So when welding these cases it is not what you do right or wrong, it is how you save it in the end. So you clean and you clean some more, then pre-heat where you are going to weld and when you start welding and start to see little black spots floating in your weld it is time to stop and clean your rod any contamination on the tungsten, then when you finish welding and you have pin holes you can use a small clean drill bit, make sure there is no oil on it, drill them out, then weld them again. When you get done welding, cover the part up with a welding blanket so it cools slow. While it is cooling, listen to see if it makes a "tink" sound, if you hear that sound, you will have a crack in your weld that you will have to repair. When you are cleaning these castings do not use carb cleaner, it has oil in it, or any other oil base product. Do not use brake cleaner, it is Very toxic when you weld. Acetone is very good to clean your welding rods to be free of contaminates. When I am welding these casing I use AC current with high frequency and I use a pure green tungsten with a ball on the end.

[Indiantim]

Hi all,

My cases were weld by a guy who works for Rolls Royce aero engines, it was really a superficial repairs as he said the original weld was probably OK but looked messy. I think some time in the past a gearbox fault damaged the bearing pedestal. Now the motors back together, still waiting on the carburetor a 1 year only Marvel Schebler for 1936, a "specialist" has had it for 3 years!!!! Any one out there is able to help me on parts? I need a float needle valve assy. I've resigned to doing it my self now.

Reading the tales of woe, I'm very lucky with my cases which are matching numbers and perfect in every other respect.