Anyone have an idea as to how I can bore 8″ holes, 6″ deep into 10″ x 10″ douglas fir beams (non structural) for recessed light fixtures? I would imagine there should be some kind of a core bit for concrete but is there any type of a wood bit that size that would do the job? Thanks
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There is a spiral that fits in a drill press that has an arm and a blade that is adjustable that can go out 4" so you would have the required 8" -- I do not know the name of the bit -- adjustable circle trammel bit??? -- I have use it to drill thought 4" thick material that is 5" in diameter -- there is no reason it could not go 8" -- just have to take it easy and let it cool down -- Dudley
Those bits are spec'ed as 'drill press only'. You can do a lotta damage using one in a hand drill. Any deviation from plumb by the drill and it can bind, break or fly off towards you. Flying pieces of tool steel are to be avoided.
I can't see how the cutting bit is going to be anywhere long enough for the depth required.
That said, I don't know how to create this hole either.
Good luck.
I think realistically, you should drill lots of 1" spade bit holes and chisel / pare to the line.
I would be concerned about heat build up if these are incandescent downlights.
Forrest
Maybe you could train a really big carpenter bee - it's that time of year here!
Forrest
I would also do it as McDesign suggested - use a spade bit and chisel out the waste. Or maybe speed it up a little with a hole saw (I say maybe because it makes larger holes then the spade bit but they're shallower).
But first I'd make a template and route the perimeter of the hole with a bearing-guided bit to some reasonable depth (maybe 1/2" or at least 1/4"). Just to get a clean, round edge.
In fact, if you do that first, you might be able to drill a single hole through the beam with your spade bit and cut the waste out with a long blade on a sawzall.
Yep, one needs to make sure that the lights are rated for being completely enclosed and in contact with flammables.Seems like this all would be a lot easier with a hollow box beam.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
Why bother with something that small? Milwaukee Electric Tool sells self-feeding bits that go up to 2 9/16" and in clean wood with no knots, they'll go right in. They also sell extensions up to 15" (IIRC) for these bits. Save a lot of time but unless these cans are vented, they're going to build up a lot of heat. I suppose the same bit could be used to bore the hole for the romex (or BX) and with enough air leakage, they would be cooler.
"I cut this piece four times and it's still too short."
Heat buildup from the lights is the first thing that came to my mind also.
The second is, if someone went to the trouble of having 10" X 10" exposed beams, is putting holes and lights in them a good idea? Perhaps track lighting between the beams or on the bottom of the beams would be easier?
I'd be really afraid of using an 8" bit to bore holes.
I've had some pretty bad catches with a 4", enough to leave bruises.
Couldn't you just use some low-voltage hockey-puck style lights instead?
They could be recessed into the beams much more easily. I think it's a 2" hole. I'd use a Forstner bit for that.
Yeah, all I can find are concrete coring bits, and they run $300+. Regular hole saws seem to top out around 5 inches.
Only other thing that comes close is an 8-inch ice auger.
Another option, if the beams aren't mounted already, is to use a bandsaw (with spot welder) and cut all the way through. Depending on the length of the beam, of course, you'd need a husky guy on the other end to move it.
A clever person with access to machine tools might devise a trammel affair you could mount in the center of the hole and then rotate a "drill rasp" type bit around it. Wouldn't be too complicated.
(Actually, the way to go would be the above fitted with a plunge router bit on an extension, so you could cut 1/4 or 1/2 inch with each revolution. Would probably cut much faster than one of those "drill saw" bits.)
Edited 4/13/2006 5:16 pm by DanH
Well, my first thought was a router on a circle-cutting jig. That is, unti the numbers hit me. Wasn't the thought of finding a 6" long up or down spiral, though. No, here's the equation tha messed me up:
10" nominal; worst case, (9.25 - 8)/2 = 5/8"
That's not much left in the beam to balance any sort of tool on.
So, what about just square cutting-out an 8" x 6" deep x beam width "hunk" of the beam, and whittling the hole out of that on a band saw?
Although, I'd reccomend a surface mounted fixture instead of boring that big a hole in even a decorative beam--but that's me.
I built a timber frame house and had a similar dilemma. I didn't like the idea of trapping in all that heat, and my wife didn't like the look of track heads, so I dropped the ceiling down by framing nailers along the sides of the beams and using 1x6 t&g for the new ceiling. I then installed 4 " can lights which only needed 5" of depth. It looks great, and I still have 4" of beam below the new drop ceiling level. Even where the dropped ceiling meets the full height ceiling, it looks good.
By the way, why do you need an 8" hole for the cans? What size cans are you using?
free hand chainsaw should do it - if it doesnt do you first.
I think I'd use an 8" outside circle template and flush trim router bits. Hog-out the majority, and start flush-trimmin! Sure would give you clean accurate holes.Problem is making the template .. maybe use that trammel-type bit to make your template?
Chainsaw is kind of what I thought. I wasn't sure I wanted to be the one to recommend it, though.
Unless there are a bunch of them and it's worth making a special tool for, I would second Forrest- waste out with a ship auger of whatever size, pare it with a sharp chisel, and then use a little drum sander on a drill if you want it really nice in there.
zak
If the beams have not been installed yet, then take them to a machine shop with large CNC machines and see if they will take pity on your situation and mill them out for you. They can cut holes like that with long end mills in a few minutes each.(Some of the ones we use are a foot long.)
That said, I put in another vote for a built-up box beam, and save the fir beams for something structural.
;-) Or you can put some 36 grit in an 8" disc sander. Park it over the beam with the switch taped on. And go for lunch! ;-)
say, where is the electric feed for the lights going to go? if you are going to do all that work to recess the cans.... can you mount cans/ tracks to the outside of the beams?
Take the beams to a sawmill. Have them cut about 1/2" off the bottoms and both sides. Take the 9" x 9 1/2" middles home with you and don't say anything to anybody about them. Cut your holes in the part that came off the bottom with a jigsaw. Carefully glue the bottoms to the sides. Install them when nobody's looking.
The lights will run much cooler because of the air space. The hollow beams will be much easier to install. And if you don't get caught, you get to keep some nice big pieces of wood. ;-)
Seriously, though, making holes that big in wood that big is just a disgusting idea. Even though it's not structural, it's such a waste.
-- J.S.
Edited 4/14/2006 6:13 pm ET by JohnSprung
if they aren't installed...
find a concrete core bit guy... give him a few bucks for a wornout used up concrete core bit... get out your 4" grinder cut some rude looking teeth around the edge of the bit... with a hammer add a little rake.... and core drill em just like you would concrete... i did this with a 6" bit where we had concete poured over a 4" thick wood floor... cut the concrete then swithed to my homemade wood core bit... took 45 seconds a hole
p
I was thinking like junkhound , Here is a place for chainsaw carveing.
Maybe some precision torch work?
Your ingenuity cracks me up!FThere he goes—one of God's own prototypes—a high powered mutant of some kind never even considered for mass production. Too weird to live and too rare to die.—Hunter S. Thompson
from Fear And Loathing In Las Vegas
8" dia. post hole digger, auger type. Getit real sharp.
~Peter
Easter comes on Sunday this year.
I have to also say that the heat factor from the lights is the first thing that I thought of. Make sure you have the required proper ventilation, otherwise it's a real fire hazard.
Also, have you made some sort of mock-up of the thing to be sure that you will like the way it looks? I had the exact same thing going on in the addition I built on my own house a few years ago, it has a cathedral cieling and two large truss cross beams that I wanted some sort of lighting attached to. I was origionally going to do a small recessed LV but didn't because of venting, also, I made a model of it and ended up really not liking the way it looked even though it seemed like a cool idea. I ended up pickling the beams (they were rough cedar), and mounting very small inconspicuous white LV tracks on the bottom with small heads. It really looks great and always gets "ooo's and ahhhs", from whoever is visiting.
To answer your question, I would go with what JoeWood said. Make a router template for the 8" hole and get a template collet for the router base and plunge it to cut down as far as the bit will take you, then hog out the rest with spade bits and gouges and chisels like they used to do with the brace & bit when cutting hidden mortises. It's the face of the thing that you want looking clean and your router cut will give you that.
But with the given dimensions one needs to be careful to not break through the sides when hogging out the middle.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
>But with the given dimensions one needs to be careful to not break through the sides when hogging out the middle.<
You speak the truth Kimosabi....
I would reconsider the whole thing. Once that hole is made, you either go with it or don't.