Vacuum Dogs - The Dogs that Suck.

While looking at some vacuum clamp heads, I noticed they all had one thing in common. They all have a grid layout that you apply a rubber seal to hold your work. Where have we seen a grid before? The Festool MFT workbench. So why do we need to buy an expensive new vacuum clamping head when we already have something similar?

The Vacuum Dogs allow you to use a single MFT hole or multiple holes to apply a vacuum to hold your workpiece. This could be for sawing, sanding, routing, or virtually anything in woodworking. The rubber strip creates the air gap that will hold the vacuum. The larger the area under the rubber strip that can hold the vacuum, the more force applied to your workpiece. MDF does not hold a vacuum well so it will be necessary to cover the MDF top with shellac or a self leveling urethane.

Vacuum Dogs will work in all the various holes sizes of the MFT. One end accepts 3/8 inch O.D. vacuum hose and the other end has a threaded hole for 1/4- 20 bolts. This is so the dog can act as a plug. When the bolt is installed on the Vac Dog, I call it a Plug Dog since its new duty is to act as a plug to a hole .

The rubber strips can be re-used many times.  It's also possible to carefully remove the rubber strip from the table and still re-use them. The rubber strips  and the plastic tubing are available through local hardware stores so there is no need to re-order through me.


The Vacuum Dogs will be sold as a kit. The kit will consist of 3 Vac/Plug Dogs, 1 Vacuum Manifold that allows up to 3 Vac Dogs to connect to one vacuum source, 4 pieces of 1/4" clear plastic tubing approximately 4 feet long, and 15 feet of foam rubber strips. It is possible to hook up another manifold to the first one and add extra dogs if needed.

I will NOT be supplying the vacuum pump (and filter), vacuum gauge, and foot switch. These are readily available and one source is Harbor Freight.  Vacuum Pump 66466 is $150 or 98076 for $105 will do the job fine. You can also look for a RobinAir or MasterCool pump capable of 3 cfm or more and they will work fine too. Don't forget to try eBay. A household vacuum or a shop vacuum will NOT work. These are designed to have a free flow of air or the motor overheats. A vacuum has no free flow of air so it will overheat these units. Likewise, the vacuum pumps listed do not like the free flow of air, it will cause faster wear and tear; they want a vacuum and will work for hours under those conditions.

A vacuum gauge is optional but it is well worth the money (Harbor Freight 93547 $15). You wouldn't operate your air compressor without the gauges, it should be the same for your vacuum pump.  It is the only way to know how strong your vacuum is. It can be hooked into the pump with a barbed "T' connector or it may be easier to hook it in place of one Vac Dog. Many setups will be using one or maybe 2 dogs, so the vacuum gauge can be left hooked up using the hose from the 3rd dog. The vacuum scale is usually in "Inches Hg" and each inch equals 1/2 psi. We are wanting 20 inches or 10 psi. A higher reading is even better.

There are many foot switches out there and many styles to select from. A cheap effective one is at Harbor Freight (96618 for $15) that is all plastic and has no covering to protect from accidentally hitting the switch. A search on Google will find you all kinds of foot switches with all kinds of prices.

I know most of you would prefer I sell a complete system with all components. The problem is I would have to buy the pumps and switches, un-box them, test them, and re-box. That takes time and I'm entitled to be paid for that time. But if the pump goes bad during shipping, then you have to ship it to me, I have to ship it back to manufacturer, costing me more time and money. Next thing you know I'm too bust taking care of "warranty work" that I can't get any dogs made.

The main problem you will have with Festool's MFT table is the top is made from porous MDF. The MDF will stop you from getting a strong vacuum. You are going to want to cover the MDF with shellac or urethane. We have a found  a "self leveling" urethane such as Benjamin Moore's  CM78 work excellent. You are wanting a thin smooth layer on the top and in the holes. DO NOT let it run or you will be sanding every run out before you will get any vacuum. We just trying to cover small invisible pores so this all you need. If it is absorbed in the top, this is perfect. Let it dry and you're done.

The area where the rubber strip is applied needs to be smooth, flat, and kerf free.  For smaller pieces (under 15 inches) one hole will work fine. Select your hole and install the Vac Dog. Install the rubber strip just shy of the other holes surrounding the selected hole. This should give you a square of about 6 inches per side.  It the workpiece is long and narrow, let's say 18 x 12 inches, it may work better to have the rubber surround 2 holes  giving you a rectangle of about 6 inches by 10 inches.  All the air will leak through the second hole so you need to install another Vac Dog or a Plug Dog (Vac Dog with a bolt in it). You won't get any extra vacuum by using a Vac Dog, it's just a way to stop the air from leaking. A longer workpiece may require surrounding 3 holes with the rubber strip, giving your about 6 inches by 14 inches.

Let's say you are routing a dado in a 4 foot long plywood. You can't let either end wiggle or you will lose the tight fit of the dado. Here you will want to surround one hole near one end of the board and another single hole near the other end of the board. You will want a Vac Dog in each hole so you can apply suction to both ends and stop any wiggle.

If you were sawing a long board, you might consider covering one hole on the extreme left of the table, one hole under the guide rail, and one hole to the right of the guide rail. This gives you positive control of the workpiece and the cut off. If the long board hangs over the table, the vacuum will hold it. If the long board is wide, you might want to use multiple holes under each rubber strip to give extra support. You will still be able to use the Qwas Dogs and Rail Dogs with any of these setups.

With multiple holes in one rubber strip and multiple areas on the table, the clamping options and possibilities are virtually unlimited. The above examples are just a beginning of what you can do. It's possible to use "L" or "T" shapes for 90 degree corners. Or have jigs that use some holes for alignment and Vac Dogs to hold the jig.  A board with a couple of 20 mm holes cloud be attached to the MFT's side extrusions for vertical clamping.

Here is a small video to give you an idea what it's all about:   Vacuum Dog Kit Domeonstration video