Repairing a shaft

Other option. Turn bad part of shaft undersize, press fit a bushing on the shaft. Turn bushing to size. Done no warpage.

find someone who can spray metalize it in alathe

I second the motion. Years back my brother and I had a old 50 HP Mercury Outboard motor that had been used in saltwater for years. We picked up the boat and moter cheap and found that the water pump on the main drive shaft was shot and had worn the shaft. We took it out and to a fellow who did spray metalizing (basically they spin it and spray/weld metal onto the shaft). They sprayed it, then turned it down to the original spec's and we used it for another 5 years.

There was recently a good article on this in either HSM or MW. - GWE

Appreciate the clues.

What types of sh>> find someone who can spray metalize it in alathe

How deep is the groove?

If you are missing a few thou (say, up to three or five) then your best bet is the green locktite bearing retention compound, I think it's one of the 600 series ones. Might be 623 or

That stuff works great. If for some reason the bearing goes on wrong, or you need to change it in the future, use an air/acetlyene torch to heat the shaft up and break loose the joint.

Jim

Total BS... I've welded thousands..... no problem.

Loctited bushing is also a viable solution....

PITA.

I have fixed hundreds of these that didn't hold up..... Even the shops that did these would farm the fixes out to me so they wouldn't have to screw with it again.....

Metallizing is more suited to production than job work...

Good to know--any tips on how to do this? I figger I might not even have to weld around the full 360 degrees, as long as I have, say, 3 good "lines" 120 degrees apart, to hold the bearing on center.

Btw, the groove is just about in the middle of the length of the shaft, and turning down the rest of the shaft for bushings, etc. would be a little problematic.

---------------------------- Mr. P.V.'d formerly Droll Troll

Actually, I wish I had my tombstone! I have a Miller Econotig, which has AC/DC, as well. DC weld the shaft? Tig it? I've tigged alum, but never anything else. Same process? tungsten/argon, plus filler rod?

---------------------------- Mr. P.V.'d formerly Droll Troll

It depends entirely on the OP's talent. The Lincoln Tombstone was my first welder and 35 years later is still my only stick welder in the shop.

Any warping is dependent on even heating and even build of weld material.

Straightening is always a viable alternative.

A straightening press was a very useful tool in my shop for those mechanics that copped an attitude and tossed a shaft off of a roof, thus bending it... It was also an option if I was stupid and warped a shaft....

Actually, not a bad idea, something I had a little familiarity with, and forgot!

Turns out Devcon/Locktite and mebbe a cupla others make two-part epoxies which supposedly are *superior* to the press-fitting of bearings, ito of shear strength. In these apps, you need a min. of .010 on radius for adequate strength. But proly not over .020. But now that ahm thinkin here, I'd say I'm missing about .050 on the radius, which might be a little much for epoxy products. Another problem would be *centering* everything on the shaft. I'd proly have to machine a kind of housing to ensure concentricity, unless there's a quick trick.

When all is said and done, welding/turning would proly be faster, iffin I didn't screw it up.

---------------------------- Mr. P.V.'d formerly Droll Troll

Weld 360 degrees.... smallest electrode practical..... take your time..... weld at 120 degrees... and use 3-4 passes....

check for warpage and adjust accordingly...

soon warpage will not be a factor. Your first attempt may not be your best... :-)

Jim

I dont get the feeling that this shaft has a "groove" shallow enough to allow the Locktite to work. But, I like the idea alot. I have sucessfully used worn shafts with your Locktite method. I thought I'd offer the suggestion that extreemely worn shafts that are fitted with bearing races can be knurled to center the bearing while the Locktite fills the voids as in your method.

Jerry

while it is an intensive process , requiring close attention to detail , prep of the shaft and spray temperature, done right it is the best fix possible for a bearing fit, short of making a new shaft

Having been through this drill many times, I'd suggest that you turn the shaft down to a size where it will fit a new brearing, then put a sleeve around the shaft to adapt it to its original diameter.

If you try to fill in the wear with welding, you'll create a harness problem in both the shaft and the weld that will not last very long.

Harry C.

Personally, Procto, if I were repairing this, I'd turn the shaft down and resleeve it. Rule of thumb for press fit on the bushing is one and a half thou per inch of diameter (assuming steel). Can be made tighter by freezing shaft and heating the bushing.You'd be surprised how much a steel bushing will expand by using a torch on it. I'm not a big fan of spray welding, for if not done correctly, the coating can flake under the bearing. Not that I haven't done it, just not a big fan of it. Also, a quick fix could be done using jb weld or the like, but may also flake/ wear. And be aware of the fit for the bearing. Too much press on the bearing and you'll remove the internal clearance (balls to race) and it may seize when it heats and expands. Measure the shaft before starting and match that diameter when turning down the installed sleeve. In this case, two or three thou oversize isn't "close enough". Ron