I would look at doing 1/4" steel plate similar to what brick masons use to re-inforce them along the length of the step. If you have to go more than few inches, you might as well go the entire way. You will probably have to go thicker than the standard tread thickness eventhough ipe is quite hard. Keep in mind the additional weight of the steel plate as well as the ipe tread as ipe and steel weight a lot when its that thick. Which leads me to the next thing - I'd consider a lot more than just 'blocking' to hold a freeform tread. My guess is that the weight of each treat could be 150lbs but thats not the big issue - its the dynamic load as people are bounding up the stairs. . . You may want to look at 2x12 continuous along the run of stairs or something sturdier than that. Ipe is available in larger pieces as the tree is quite large. You'll just have to find a good specialty lumber supplier that can get it for you. I've seen curved handrails cut out of ipe, so its definitely available. It's just very hard and very heavy.

One thing I didn't see mentioned yet (unless I missed it) is differences in wood type. All woods do not take stain alike. The new darker wood floors you ordered, are they oak as well? And the same kind of oak (white or red)? If you're new floor is not oak, yet your stairs are, the grain/pore differences will show and you might not be so pleased with the resulting "match". Or even if you've got two different types of oak (white oak and red oak) a stain will take differently because of the cellular structure of the wood. The darker the stain applied to oak, it emphasizes the already pronounced wood grain and large pores. Those areas suck up the stain and hold it and are more pronounced than adjacent areas. Conversely, maple for instance, is a dense wood with a closed grain, doesn't take stain as readily as oak, nor does it have the pronounced grain. A piece of oak and a piece of maple side by side with the same exact stain applied will appear different. It's possible, however, and depending on how dark your new floors are, to get two different stain colors for two different woods to come closer in color to each other. But the grain will still come into play. A good paint or better yet woodworking store can help you with tweaking stain tints for differing woods so they come out more similar in color. So if you're talking two different types of wood, the differing end result may or may not end up being a factor that's important to you. Here's an illustration of differing wood grains, click on each for a description of grain, etc., for exotics scroll down a bit. It's personal taste, some appreciate different "flavors" of wood, some feel it's too much. Then there oil-based vs. water based products (water-based will raise some wood grains) and some finishes "amber" while others do not. Not necessarily insurmountable issues, just ones that need some research done. (The woodworking forum here is a good place to get into the nitty gritty details if you tackle the job ;) Otherwise, like everyone has said, it's do-able, but will be messy and time consuming, especially if you've never finished/refinished wood before. (If that's the case, I'd strongly encourage you to practice on a cheapie table you can strip and refinish, or even some oak lumber if your stairs are new, to get a feel for it. The last thing you want is your stair case being a learning tool. ;) An alternative would be to paint. There's a member over in Home Decorating who painted her stairwell and many members find it very appealing. We call her "boo" for short, hers is the 3rd post down and has pics, here. She's really nice, so if painting route fits your scheme and/or appeals to you, I've no doubt she'd be quite happy to share details with you. (She did post details for others I believe, who were interested, but I can't find that particular post, it might have dropped off the search list.)

Hi bus_driver May I ask what brand of urethane you used on your stairs? I have a set of fir stairs in my home that I am currently sanding down to finish...haven't decided what I am going to finish them with however! I will not be using a stain/color on them as I like the natural beauty/color of the fir. Simply need something to 'clear coat' them with for protection and was wondering what product you used...and why you wish you would have done a few extra coats. Cheers

Removing an old finish by sanding, unless you are taking off a lot (like a floor re-sanding), is an extremely poor way to do it. It will not uniformly remove the old finish (from the pores) and can easily result in an uneven finish when staining. I'd recommend a chemical stripper done carefully with masking off areas not being stripped. The "wood conditioners" don't work all that well. They tend to work a bit better if you ignore the label directions and let them dry overnight instead of the less than 30 minutes (or whatever the label suggests). A better approach would be to use a good quality gel stain. There are other "wash coats" that you can use such as 5% solids shellac, hide glue, or other sealers based on your intended top coat. But these are more complicated to find than just grabbing a gel stain off the shelf. Almost all things with Tung Oil on the label are called "Tung Oil Finish" because they somewhat resemble tung oil. In fact, most of them are not tung oil, nor do they contain any tung oil in natural form or as a component of manufacture. Depending upon brand, it's either an linseed oil & oil-based varnish (typically alkyd or urethane) blend or a varnish, both of which are highly thinned (up to 70%) with paint thinner to make it a wiping finish. It's not that oil-varnish blends or thinned varnishes are bad finishes. They have their place. But what you are reading on the label is pure marketing fabrication. Pure oil finishes are very poor in excluding moisture (some are actually hygroscopic). The more percentage of oil in the oil-varnish blend, the less water resistance the resulting finish will have. A 100% oil finish will be an in-the-wood finish and will not have the protection that a varnish will. Hand-oil on a handrail needs periodic cleaning. Oil-only won't be working in your favor. Every true Tung Oil I have ever seen will say something like 100% tung oil and will not have any thinners that can be labeled mineral spirits, stoddard solvent, naphtha, [light]aromatic hydrocarbons, some other alias, or refer to the CAS number for the above on the MSDS, or very rarely, on the label. In my opinion, there is little reason to use pure tung oil. It's more expensive, looks identical to linseed oil, more difficult to apply, and if you don't do it right, sand between all coats, and have enough curing between coats, you get white spots that are irreversible and need to be stripped off. (See, KW, I do know what a "pre-stain" wood conditioner is.)