Welding Cracked Primary Covers

I have tried a lot of things to try to reduce the amount of oil that comes out of a Norton casting. The best I have been able to do is soak the part for at least a day in de-natured alchohol or laquer thinner and then put it in a ventilated oven at 350 for about 24 hours. Then let it cool and wash it again with alcohol before welding. You sill end up with lots of oil in the weld puddle to deal with.

Pre-heating cast aluminum beyond 150 degrees F. is not generally recommended by automakers anyway. They say that excessive preheat only makes the area of heat damage larger and causes more distortion. They say when welding heads and blocks to start between 100 and 150 F. and keep the welding times short. That has given me the best results.

Iron and it's alloys are a whole different story. Jim

DogT said:

debby said:

Or fit a belt drive, haha.
Debby

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Around here it would probably be cheaper to fit a belt drive from the charges I've gotten from the welders.

What about the aluminum solder, any one use that? I need to get my peg away from that cover, mine is about 1/16" away and I notice it puts a mark on the cover, but then it's probably been dropped on that peg in the past and is bent.

Dave
69S

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Dave, Solder is good on flat thin surfaces, it will be impossible to fill dirty cracks, But it could bridge spider webs, Simpley heat the area, drop on a blob and use the stainless wire brush ,scrubbing into the hot pool. no flux required, The molton pool sheilds the surface from oxidization, Seen it done and looks easy.

john robert bould said:

DogT said:

debby said:

Or fit a belt drive, haha.
Debby

Click to expand...

Around here it would probably be cheaper to fit a belt drive from the charges I've gotten from the welders.

What about the aluminum solder, any one use that? I need to get my peg away from that cover, mine is about 1/16" away and I notice it puts a mark on the cover, but then it's probably been dropped on that peg in the past and is bent.

Dave
69S

Click to expand...

Dave, Solder is good on flat thin surfaces, it will be impossible to fill dirty cracks, But it could bridge spider webs, Simpley heat the area, drop on a blob and use the stainless wire brush ,scrubbing into the hot pool. no flux required, The molton pool sheilds the surface from oxidization, Seen it done and looks easy.

Click to expand...

True it will adhere to the surface. I have done it and it looks great when your done. If your going to paint it it is fine but in a few weeks the solder will oxidize to a dark gray color and not match the rest of the aluminum around it. Of course you can polish it back but it will not hold a shine for long. It might not show in a little crack but if you fill anything larger it will stick out like a sore thumb. Jim [ I learned that the hard way after filling in scratches on the side of a Wilcox aluminum tank.]

I wouldnt want to use solder for any type of case repair, as it wont repair cracks in oil bearing cases as the oil which comes out of the case when its heated to do the soldering will make it very difficult for the solder to take. For anyone unable to get the repair done properly with TIG welding, if its something like a clutch cover then its best to vee out the crack on the inside of the case, heat the area with a blowlamp to burn out oil near the surface, then use something like JB Weld or better still Devcon.