Stu's Shed

Had a look at the router table today. It has been quite a while. I was thinking of actually getting out the video camera and doing something else that hasn’t happened in a long, long time- actually produce a podcast. But before doing that, thought the router table deserved to have the intended dust extraction finished.

Outside the router table, there is a 4″ dust tube, connected to a blast gate and from there to the extraction system, ready to go. The other end- well, that is what needed to be connected up.

Inside the router table, directly below the router there is a dust port (tablesaw dust hood) built in that has been emptying dust into the lower storage compartment, because it hadn’t been connected up.

The lower compartment is storage, not dust extraction. The original intention is for a tube to be connected to the extractor, providing negative pressure in the router compartment, drawing air (and dust) in from the routing area, and in through any other gaps, such as around the door that leads to the router compartment. The door is a necessary evil- I still need access to the router itself for speed changes, and router bit changes (I prefer that over using a router bit extender).

So with a large holesaw drill bit, I cut an opening large enough for the dust hose, and hose clamp.

Some 4″ hose was connected to the underside of the port extracting from the router bit compartment, and left sticking out.

Now I planned to use a spare tablesaw dust hood I had on the side of the table to connect the extracton system to (it is a bit overkill, but it is what it is), but how do I connect the hose on the inside?

So I took a second hood (a smaller one that I had originally cut down to make a bit of a vac sweep), trimmed off the remaining 3 sides so it could fit to the inside of the large hood. To join the two together, I chose (not glue, super or otherwise, not screws or bolts, nor tape, double sided carpet tape or duct tape, but) to plastic weld the two together. This is pretty easily done, so long as it is thermo-plastic, and not thermo-set plastic. The difference? One melts with heat, the other doesn’t. Seeing as the most common form of welding is to create a molten boundary between two materials so they fuse together, this can be equally applied to plastic as metal.

The heat source doesn’t have to be achieved by shorting out a high-amp power supply when welding plastic (unlike welding metal), you only need a heat torch – hot air is more than sufficient. This isn’t of course your run of the mill hair dryer – 600 C might create a bit of an undesirable hair style! These are similar to paint strippers, and in this case that is what I used.

I didn’t have any filler rod, but it seemed to work out anyway.

So with a scraper to push the material together as it melted, the blower set to 550 – 600C I welded all round. The result seemed plenty strong enough although I did get a bit of distortion in the dust hood where I got it a bit warm!

Once done, the tube sticking out of the router table was shortened to final length, then another hose clamp put on to attach it to the new attachment point on the inside of the hood.

This was then screwed to the side of the router table, and connected to the dust extraction system. A Y section was added so I could draw some pickup from the router fence, or the free-routing mount.

I used my standard trick of a plumbing connector to connect the 2.5″ hose to the 4″ system. I used duct tape to hold it together. Well actually in this case it was Gorilla Tape. First time I’d used it. And I thought standard duct tape was strong and sticky. Gorilla tape is quite amazing!

So now the router table is connected in, and another long standing job is finally out of the way.

As far as dovetails are concerned you’ll have to wait to my next post or so!

Filed under: Techniques, Tools | Tagged: Dust, Plastic, Welding | Leave a Comment »