[TheForge] Hammer foundations

[Ralph Sproul]

        Hi Steve,   I think your friends's treadle hammer might crack a
driveway that would be 1 - 1 1/2" thick of hot top.........but I don't think
it would touch a 7 1/2" concrete slab.  A rubber pad under it would help
considerably with shock applied directly to the crete.  If you question it,
the plate you mention to spread the load would be cheap insurance to cut the
lbs per sq inch the hammer would transfer to the floor.
        Talking of rubber pads - that's how I'd deal with the air hammer
also.  I've had my air hammer (50 lb Kinyon clone) on the 5 1/2" thick
concrete floor in my shop with no problems(for five years now).  One thing
out here in Maine you want to do is make sure any new gravel under the floor
is WELL compacted.  Having the gravel settle under your floors is the
fastest way to split them if using a hammer on the floor.  Don't skimp on
renting a compactor before pouring your floor would be my advice in the
construction of your barn.
        If you intend to put a mechanical hammer in and need a footing like
you mention with the threaded rod and pipe into the footer, let me know.  I
can send you pictures of what Eric Ziner did at his shop up on Deer Isle,
Maine.  It keeps the shock isolated from the floor and makes for a removable
foundation system for other hammers in the future.  Pretty clever, but you'd
need to plan ahead before pouring your floor........or you'll be cutting out
a section, and 7 1/2" is pretty thick to cut out if it sets for a while.

Ralph

----- Original Message -----
From: "Steve Smith" <sos@alum.mit.edu>
To: <theforge@mailman.qth.net>
Sent: Sunday, August 10, 2003 7:40 AM
Subject: [TheForge] Hammer foundations


> I get a small part of the barn we're having put up, about 300 sq. feet.
> It is being built with a floating slab, 7 1/2" thick. I need to consider
> an air hammer and a treadle hammer.
>
> Treadle hammer:
> A friend of mine put his TH in the driveway with no pad. The drive is
> cracking and chipping under the anvil end. Clearly a pad is a good idea;
> how large of a footprint does a TH need? Mine is on the small side, and
> I'm wondering if I should put a metal plate under, then a pad or if just
> a pad will do. The base on mine is about 12" wide 5/8" thick, with two
> 6" ears at the anvil end.
>
> Air Hammer:
> The yet unfinished air hammer will be about 40 pound head weight, self
> contained variety. I used to have a 25 pound Little Giant, which I
> mounted per recommended foundation plans. For those who aren't familiar,
>   the recommended approach has the mounting bolts made from threaded rod
> which ties into the rebar, and runs up through pipe sleeves so the ends
> of the rod have some give. While I think this approach makes good sense,
> I've just moved and many of my shop tools aren't easily set up (not
> having a shop...). Does anyone have experience with simpler methods of
> mounting?
>
> Thanks,
> Steve Smith
>
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