I have a 4" thick, 10.5" wide by 120" long poplar board (read heavy) that I was originally going to saw into workbench bench legs but now want to saw into a handrailing. Any ideas on how to saw so that it is 4" wide?
I have Laguna 14BX 14" bandsaw, do you think if it is properly supported (I have a king resaw blade on it) that will work? Otherwise I have a 3hp sawstop, but wound't cut all the way through nor a circular saw. Thanks for the help, it'd be expensive or worse to mess it up.
You could rip it both on the table saw and on the band saw.
With the table saw, you'll need to do at least two cuts, as the depth of cut probably is around 3". If the board is straight and has a clean edge and the table saw is well setup you should have a nearly seamless cut. I've done the same on 4x4's with great success.
Band saws typically have good height capacity, and I'm sure your 14" saw can handle 4" to thickness (my 10" Delta will easily resaw 6" with a good blade).
In both cases, support both the infeed and the outfeed. You could experiment with a piece of 2x6 that you rip to 4" width and then rip again facing up (i.e. the 1.5" side sitting on the table of the saw). Do this with a 2' piece to get the feel of sawing your 4" thick board.
What I'd suggest is using a circular saw and clamping a guide to the board. And if you don't need the full 10' for your railing then cutting it to the rough length will help.
Instead of needing to move the heavy piece through stationary equipment this makes the piece stationary. You probably would need to get a little creative to find a straight-edge that's long enough, and if you take your time setting it up you can use a couple pieces. You can finish the cut by flipping it and repeating it on the other side--or using a handsaw following the kerf of the circular saw.
You could always use your stationary tools--a bandsaw will work well, as long as you have 10' both in front and behind the saw and appropriate infeed/outfeed support (and/or a second person).
A tablesaw would also work, but as you noted a 10" tablesaw won't be able to cut all the way through. Typically they have a max cutting depth of about 3 inches--and that's a lot to do in a single pass, especially with a full-kerf blade. You'd likely want to cut about 1" deep, raise the blade another inch, and do another pass, flip it, and repeat (or use a handsaw to cut the last inch or so). If the board is isn't straight and true you won't get a perfect cut this way, but if you leave extra you can clean it up.
I think I'd do it with a circular saw myself. 4" x 11" x 120" is just a little too much wood to jockey through a bandsaw...and maybe a table saw.
With a circular saw and the right setup it could be done quite easily. I'd build a "shoe" to guide the saw and keep it the proper distance from the edge of the wood then just walk it along the board.
You'd need to flip the board over to complete the cut, but you wouldn't have to guide the heavy board.
