Thread: Metal stairs

Originally Posted by whitey56

Have you had a look at " Steel tread riser brackets" on the net, They come ready to weld with holes drilled in black steel, only a few bucks each it won't get any easier than that.

Yes, those ready made stringers are very tempting but I have my head set in making something slightly different, plus I need the stringer to have a dog leg at the landing end and another at the base since it starts up from an existing deck and it has to bolt onto a bracket that comes out between the deck boards.

To answer your original question. If lapping sections such as angle iron to the web of the channel, you must space the sections apart if you want to gain the best protection from galvanising, (a bit of mig wire works well). The explosion concern is not a real issue with most galvanisers, capped hollow sections are the real issue there. If drilling vent holes, consideration must be given to the way that the frame will be rigged while dipping, (most baths are narrow, long and deep). Oh, don't forget to allow a bit over normal hole clearance for bolt holes, you don't want to drill out all your lovely galvanising to fit a bolt in a hole.
If it were me, I would use flat bar and stitch weld it on to the channel. There must however be at least say 50mm of weld on the top surface of the flat bar, either 2 X 25mm or 1 X 50mm. This will serve to prevent the fatigue issue caused by the inevitable flex of timber treads.
Consider using Duragal channel as it will be amply strong and lighter than conventional PFC, (galvanisers charge by weight of the component as well, not just weight of the zinc added).
Make sure that you remove the silicon from the finished Mig weld. The pickling bath will not remove this and it is just as harmful as slag in preventing adhesion of the galvanising. My favourite way is a needle scaler, but a coarse wire brush on an angle grinder will also work.
As far as "T" bar goes, good luck with that. I haven't seen any for years other than the heavy lintel sections. It is however available in Aluminium if that helps.

Initially I had this in mind:
Mono Steel Staircase Stair Stringers Stairs Stringer Steps Decking | eBay
Then I realized two problems. One, I much rather have risers between the threads to comply with council and handrails attached to the stringers and not the threads.
Second if I build the stairs with a mono stringer and the massive brackets that go with this build, a 14 steps stair will weight way more than I can lift on my own to take to the Galvinizing mob.

Originally Posted by Karl Robbers

To answer your original question. If lapping sections such as angle iron to the web of the channel, you must space the sections apart if you want to gain the best protection from galvanising, (a bit of mig wire works well). The explosion concern is not a real issue with most galvanisers, capped hollow sections are the real issue there. If drilling vent holes, consideration must be given to the way that the frame will be rigged while dipping, (most baths are narrow, long and deep). Oh, don't forget to allow a bit over normal hole clearance for bolt holes, you don't want to drill out all your lovely galvanising to fit a bolt in a hole.
If it were me, I would use flat bar and stitch weld it on to the channel. There must however be at least say 50mm of weld on the top surface of the flat bar, either 2 X 25mm or 1 X 50mm. This will serve to prevent the fatigue issue caused by the inevitable flex of timber treads.
Consider using Duragal channel as it will be amply strong and lighter than conventional PFC, (galvanisers charge by weight of the component as well, not just weight of the zinc added).
Make sure that you remove the silicon from the finished Mig weld. The pickling bath will not remove this and it is just as harmful as slag in preventing adhesion of the galvanising. My favourite way is a needle scaler, but a coarse wire brush on an angle grinder will also work.
As far as "T" bar goes, good luck with that. I haven't seen any for years other than the heavy lintel sections. It is however available in Aluminium if that helps.

Yes, I realize that flat bar is the way to go. Will probably make a jig to bend the bar in an L shape so to have a place to bolt the risers to and stop the supports to move at all. Bigger holes, agreed.
Two questions: If I use Duragal, I don't think they can galvanize on top of the duragal (?) and in any case it would be wasted. Why not black U channel. They do come in different thickness.
Silicone on the MIG weld? You got me, what silicone?

Originally Posted by Marc

Yes, I realize that flat bar is the way to go. Will probably make a jig to bend the bar in an L shape so to have a place to bolt the risers to and stop the supports to move at all. Bigger holes, agreed.
Two questions: If I use Duragal, I don't think they can galvanize on top of the duragal (?) and in any case it would be wasted. Why not black U channel. They do come in different thickness.
Silicone on the MIG weld? You got me, what silicone?

Actually, Duragal takes galvanising beauitfully. Been there done that one.
Here at least, Duragal is the most commonly available of the folded channels, discounting of course C section purlin. Duragal is usually pretty well priced also.

Forgot about the silicon.
All mig wire contains silicon as a de oxidiser. The amount is designated in the classification by ES2 ES4 or ES6.
After welding this forms a yellowish brown glassy deposit on the weld.