Busted my powerhammer

[imagedude]

I managed to break my hammer today, a Blacker model C. The lower parallel arm broke, you can see from the oil that had penetrated the initial crack that it has been starting to break over a long period of time, hardly surprising given that the hammer is 70 years old:

I'll fabricate a temporary replacement from strips of flat bar, I'll then forge a new bar. You can't simply use round bar as it tapers considerably. If both arms had busted at the same time it would have been interesting.

[HWooldridge]

Can you vee it out and reweld it? Might save you some work until you can make a new one.

[skunkriv]

Bummer. Just got her going too. Looks like that crack has been there awhile as you say.

"would have been interesting"...that is quite an understatement LOL

[irnsrgn]

yup looks like a welding project. position it so it fits back together, tack in 3 places. then put a bead of 1/8 7018 all the way around. set up in an angle iron jig, (piece of 1/4 angle with a piece of 3/8 by 2 flat skip welded on edge to the V so you have 2 45 angles off the flat, then cut out a section of section of the angle at the center). clamp the piece with the weld over the center opening and using an acet torch, cut a narrow V where the weld goes around (about 5/8 to 3/4 wide at the outside) and a little over half way thru. weld up using 7018 1/8 all exept the cap pass using stringer beads. roll it half over, and cut out the other side over half way, just so you barely cut into the first weld. and weld it up too. chip and clean well, then put a cap pass all the way around. check for warpage, and straighten while hot. then grind or machine the weld down making sure to leave no scratches or lathe tool grooves as it will break at the scratch.

this is a tried and true method I have used many times for repairs similar in nature.

[imagedude]

It'd be a brave man that tried to fix this with a weld, the metal is too far gone!

[ApprenticeMan]

WOW, that looks like cracks are running all up and down that bar.

[HWooldridge]

That almost looks like cast iron. I find it hard to believe the maker would have used that material in this application but maybe it was done to get a net shape part within a shorter cycle time. They overbuilt on the assumption it wouldn't break within reasonable limits. Somehow, your hammer developed a stress riser that propagated with time.

If it is steel, it can be successfully welded as Jr described. I have welded large driveshafts that twisted in half using similar techniques and they held up.

[irnsrgn]

Where did it go? Its just a normal fatigue fracture. I used to see them all the time. Never had a problem repairing things like that. But then what do I know, I only fixed simple things like that for 50+ years.

[cpd23]

Another way you can go is to pull the two ends to the lathe. Find the centers drill and tap both ends. Use a good grade of all thread and thread them together. Then you can v-notch and weld as suggested above. I can not see both ends of the project and so I do not know if you are able to do this, but it is an alternative fix.

Best of luck

[John B]

Just phone Neville Barnes up and he will send you a new one at reasonable cost, probably has them in stock


Blacker Hammers and spares, (UK) 01427 838245
Neville Barnes Ltd, The Forge Padmore Lane, Upton, Gainsborough, Lincs. DN21 5NH