[curiousgeorge]

Hey Guys,
I'm building a router table. It has a 2 1/2" port in the back of the router box for my DC and the front is a drop down overlay hinged door. The port comes off a Y fitting that goes on up to the fence. My question is do I need to drill some vent holes in the front for air intake or is it better without them? If needed what size holes, where and how many? Any suggestions would be great and thanks in advance.

 

[Mike]

George, this is an excellent question. Like heating or AC in your home, for it to work you must have circulation. You can not take out unless you also put in. This provides the flow needed to move the dust. With a 2-1/2" hose you will need about five 1" diameter holes to let air into the cabinet. You could have a slot instead of the holes but the idea is to use about the same amount of intake as exhaust. Make sense?

 

[roy clarke]

I am finding out how little I know about using a router, but I would treat dust collection and ventiltion separately. Dust collection needs a surprisingly large airflow to get the fine dust, which is the hazardous stuff. So I would put all the sucking effort I could near the bit.

For ventilation of the router, it would be better to arrange for air not to be sucked past it on it's way to the DC from the fence. This avoids having it living in a dust cloud. It is, however a powerful beast, a couple of kilowatts, and needs a load of air for cooling. I would try and get the air to flow past the router then via the fence to the DC.

 

[Mike]

Roy, in a theoretical world you are correct. In the real world the bit is often partially below the table surface. The routers cooling system sucks air in at the bottom of the motor and expels it at the top. The dust is pulled towards the router like it or not. For this reason we use vacuum above and below the table top. The larger bits of wood and dust are collected by the top hose. The finer dust is collected out of the cabinet. This is the reason it is important to have good air movement in the cabinet. Since we have an air stream being pulled from the front of the cabinet to the back we capture a great deal of the fine dust that otherwise would go through the router motor. It is a good practice to use an air hose on a regular basis to blow dust out of the router motor as well.

 

[curiousgeorge]

Thanks for the info Mike and Roy and yeah, Mike, it does make a lot of sense to me.
Would it be better to put the intake holes along the top above the door for a down draft effect or along the bottom of the door to bring the air straight across the bottom to the port?
The attached pics show the router box and the table. The table is made of pine and I would like to keep a natural look to it so does anyone have a suggestion as to the type of finish to use on it? (Preferably something easy to use)

 

[bobj3]

Hi Roy

Just my 2 cents

This is what I would do, see drawing below, this will allow the air to be pulled around the router and the box and go into the Vac.system.

I would also use a clear poly.spay on the cabinet, two or more coats,not a spay can type job.

Bj

 

[curiousgeorge]

Thanks BJ but doesn't Poly have a tendancy to yellow over time?

 

[Mike]

George, BJ's venting idea would give you a nice clean look. Polyurethane is a good finish to use since it is so durable. Most brands of finish will color your project with a yellowish tint, this is because of the oil base. You can buy water based poly to spray or wipe on and that is a clear finish. Varathane claims their oil based finish is the clearest; it is a soy bean oil base. (I would use either a satin or matte finish, gloss just looks like plastic to me.) Another good choice is Watco danish oil. This is saturated onto the wood in a couple coats and leaves a more natural looking hand rubbed appearance. This project is a good one to experiment on, after all it will be in the workshop and not a museum.

 

[curiousgeorge]

Thanks Mike. I think I will go with the polyurethane since it is so durable and I have used it before..... and I did like BJ's venting idea.
Thanks for all the help and quick answers.

 

[Lee Brubaker]

I like to grab the cuttings as close to the bit as possible so I made up an acrylic chamber that encloses the bit. Have used this about 8 years...works fine.



Lee