My suggestion, do not capitalize each word. Thats reserved for titles.
Now on topic, Josh (Trucklover) built an N scale one, I'm sure he can be of assistance.
Yup, If I member corrcet, Mine took me about 33 hours or so to complete. I did mine in N scale and boy this was the biggest and most complex structure that I have ever and it was the N scale one, the HO one should be just about the same if not a lil easyer as the parts and pieces are about twice as big as N scale. The N scale Blast Furnace is bigger then any of the buildings that I have in HO scale just to give you an idea of just how MASSIVE this structure will be in HO scale.
Also, PAINT AS YOU GO, you will thank me and yourself for doing this. It is much EASYER to paint the parts as you go rather then paint the whole thing when your done. I am so glad that I painted as I built, makes the building process a bit slower but makes it 100 times easyer in the long run and well worth the extra time. Painting as you go also gives the parts that were previously assembled a lil more drying time to set better.
And make sure you are following and reading the instructions VERY WELL. Dont just read the instructions once as your building in that step, go back and read it a few times before you glue anything together. Also test fit the pieces and trim away any flash, just make sure the pieces fit together well before any glue is applied. I messed up a few times because I didnt test fit and make sure that piece really went in the spot that I had just glued it into. Its not easy nor is it fun when you mess up and you realize it 20 mins later after it has already pretty much dried. Lucky this building is so big that my small mess-ups cant really be noticed or seen without close inspection.
You can see my thread by clicking the link in my signature thats tittled
Blast Furnace under the
Building the Walthers N scale section/line in my signature.
If you have any other questions please feel free to ask away and I or someone else will do the best we can to answer. This is just a few of the main things I could think of right now as far as advise goes for building this truely AMAZING structure
Cant wait to see some pics of your Blast Furnace and Steel Mill