Mike Spencer -- Artist Blacksmith

Alldays & Onions Air Hammer Overhaul

Air hammer and rigging

So it's Spring and time to get the wraps off the Alldays & Onions 300cwt air hammer, set up some stageing and rigging. Time to have a look at the bores, the tup, the compressor piston, bearings and whatnot.

The tup was seized when the hammer arrived. Last fall my son and I got the lower die out, making room for a hydraulic jack. That freed the tup up readily and it's been soaking in kerosene and oil all winter. This spring it lifted out easily.
Tup, die removed Tup, seen from crown

Note the threaded hole in the crown for a lifting clevis. How nice! The top die was held in with about 4" of wedge and so tightly that it had to be cut out with a torch. Happily it was possible to do that without damaging either the tup or the die. Surprise! The tup is hollow! And the mating faces are in good condition so refitting the die will only be as hard as making a new wedge.

Only a little scuffing on the surface and in the bore. I'm guessing that the helical groove in the tup is to let oil work its way down from above but it might have some other purpose.

The compressor

The compresor piston was a bit harder. Just the head was a biggish chunk of iron. Fortunately, it, too, had a threaded lift point. Gee, these Brits think ahead. Go, Brits! The hammer stood out of doors for several years and the well in the head stayed full of water so it was pretty rusty. But the lift point threads cleaned up okay. Here it is, brushed up and painted.

The connecting rod had to come out with the piston. That meant getting the big end bearing off. What do you know? Somebody added a zirk fitting that was hidden under all that grease. An no little dinky bearing shells here. Heavy pieces of bronze with babbitt lining.

Big end conrod bearing in place Big end bearing parts on the bench

Okaayyyy! How about wheedling that piston out of there?

Mike on the staging, the piston starts to ease out

Not such a very heavy load but a bit of a strain on my guy rope with the scissors tilted over so far. The guy rope runs through a block to another come-along but I think when I put the piston back, I'll replace the single rope with a set of double sheave blocks. That guy rope has a splice in it and it was pretty taut.

Mike with the piston and come-along

All the rigging is working right and the come-along is doing just fine. Everything is creaking a bit and my son is down below, giving the connecting rod a nudge with a 2x4 whenever the piston sticks a bit in the bore.

Piston emerging from the bore Piston out of the bore and suspended

It's coming out....................................................................................... And there it is.

Piston being lowered Piston on the bench

Coming down............................................................................................And safely landed.

Valve Bore

The control valve sleeve runs the width of the hammer and there's some kind of filter of deflector missing on top of the hammer that exposes the sleeve to weather and passing trash so I wrassled that out, too. Here's the valve bore showing the port toward the tup. Note a little groove on the far side of the bore at about 6 o'clock: a set screw is tapped into the joint between the sleeve and the bore to keep the sleeve from turning. Took an hour to get that out.
Valve bore showing compressor port

And here's the view toward the compressor.

Progress

So the wrist pin is out of the piston (with a 12# hammer) and refitted so that it goes in with gentle bumping from a 5# hammer. The rings were glued in place with grimy oil but once removed, have cleaned up nicely and are undamaged. The small end bushing has some nasty gouges in the bronze — some foreign object got in there and churned around for awhile — but it doesn't have much wiggle so I think it will be fine with generous lubrication. Working on that now — something easier to use and harder to ignore than the old-fashioned grease cup that was mounted on the conrod and way up inside the hammer body.

Footnotes

Come-Along

Yep, that's the same Wright Hoist Model 2-B come-along that got my name into The Last Whole Earth Catalog. I got two of them in the early 60s. Thirty-five years later, I broke my last spare 35¢ pawl release spring. Isn't the internet wonderful? On the net I traced the the company through buy-outs and mergers to England and back to the USA and a phone number. They haven't made the 2-B for decades but the woman on the phone had the same parts diagram on her computer that I had squirreled away for just this occasion. And no, they didn't have any springs but yes, a remainder house in Chicago had all their obsolete parts stock. Primed with the proper part number, the Chicago guys would be happy to sell 4 of their 10 springs. For five bucks each (or about 8 bucks in my money.) But not to me. I had to go through their rep in Moncton, New Brunswick. The guy who answers the phone in Moncton never heard of the Chicago company but he'll check into it. Gee, they're going to charge me 40% and tax, right? So these springs are going to cost maybe C$50, right?

A few day later, my little box of 4 springs arrives in Halifax — priority courier from Chicago to Moncton, priority courier from Moncton to Halifax and who knows what else tacked on for good measure — COD C$129.00. After some, umm.... heated negotiation, I still paid $100. So I have four of the nicest little $25 springs you ever saw, happily, in all likelihood, a lifetime supply.

Photos

Thanks to my son David for taking the photos and getting them digitized and back to my computer on CDs!

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Mike Spencer — Updated Sun May 25 2003