Machining pockets for wrought iron stair spindles

[OldHector]

Hi,
I am re-modelling our staircase and want to use square wrought iron spindles.
I don't want to use the type that comes with a socket or bracket as this looks clumsy to me :wink:
This leaves me with the option of machining square holes in the oak handrail and base rail and of course many of them are angled at around 40 degrees to vertical.
I don't own a chisel mortiser but can justify getting one on the back of this project.
Then of course it is a matter of finding a size of spindle and chisel that match.

Has anyone experience in cutting pockets in this fashion, particularly at an angle?
Any ideas and tips are very welcome.
(I have already ruled out the idea of cutting these by hand!!)

Thanks

Hector

 

[Eric The Viking]

Have you looked at any old staircases that have wrought iron balusters? I'd find the oldest and copy what they've done.

In the ones I've seen, there's an iron (steel?) band running under the handrail, let into it underneath by a groove. That takes care of the upper end, but the lower end, I don't know about.

Setting it out would be 'interesting', and I'm not sure you could cut the square holes you want on a morticer, because of the angle - simply getting the stock under the chisel would be your first problem, and keeping the hole edges clean would be the next one.

The traditional way of fitting wrought iron railings outside houses was to set the top of the wall with well-dressed capping stones, and fit strong stanchions at around 4- or 6-foot intervals. These determine the overall neatness and have to be dead plumb,and properly aligned, and they go up to, and support, the top rail. That rail has round holes punched in it at intervals to take the 'spears'. You drop the spears through the holes, so that they dangle into holes in the capping stones. It's all locked into place in the capping stones by pouring molten lead into the holes. The effect is that the spears are supporting the top rail, but actually it's the other way round.

Since you can't use molten lead, I think you'll struggle to find a nice fixing for the bottom of the3 balusters that doesn't involve another rail or brackets.

There are a number of stair makers on here who can comment, but it might also be worth talking to a blacksmith who does ornamental work.

I think you have a bit of a challenge. Could you do something similar in wood?

 

[Jacob]

....
Has anyone experience in cutting pockets in this fashion, particularly at an angle?
...

No prob with the right morticer. You will need a good depth to work with and even with tilting table might need to tilt the machine to accommodate stair strings at an angle.

 

[RobinBHM]

Rather than cut pockets, could you machine a groove in the base rail the width of the iron spindles and then cut oak spacers to fill the gap between each spindle.

 

[OldHector]

Hi,
Wow, I've just joined this forum and am amazed at the speed and depth of the replies! Thanks to all.
Some serious thinking to do here, but like Eric the Viking I have serious misgivings about cutting good quality 40 degree mortises with the kind of machine that is within my budget, particularly in oak. I can imagine the chisel hitting the wood before the point gets anywhere near it although I guess that might be adjustable in some cases.
Robin, the oak spacer idea has a lot of merit, after all it is what they routinely do with wooden spindles, and you can get rails with the groove already machined but they would be quite a bit wider than required.
I'm starting to see why these shoe brackets are so popular...

Hector

 

[Random Orbital Bob]

The bracket solution is the least effort which is why its so popular. Depends how much time/money you're prepared to invest.

 

[AndyT]

This thread https://www.ukworkshop.co.uk/forums/victorian-stairs-t77994.html has some pictures of cast iron spindles on an original staircase, and may be useful to compare with yours. In this case, the iron work fits into the steps, not a string, so all the mortices are square. I suspect that will have been the usual way.

FWIW, the open string stairs in our house (1897) have the (wooden) spindles simply cut off at the same angle as the string and are nailed onto it. There are no awkward angled mortices - the strength all comes from the newels and the hand rail. This makes sense; the spindles are fitted after the staircase is installed, and it would be no fun trying to chisel mortices into the middle of a twelve foot long string, which would bounce about all over the place.

You could try treating your iron spindles as if they were wood, ie cut the bottom at the required angle, drill a slanting hole through and nail (or screw) into place.