Vac suction clamp loss of suction

[bonzaican]

Hi ... I have 2 of the vacuum suction clamps each on their own VAC-PMP.  Recently both have lost almost all the suction.  I replaced the Mann filter as these were both full of saw dust.  No improvement though.  Any ideas where I should start in terms of diagnosing the issue?

FYI The pump is still registering in the green in terms of the pressure.  I tried various suction pads (round, skinny rectangular, etc) and same issue regardless.

 

[Mario Turcot]

What material are you using?

 

[grbmds]

If you were trying to clamp MDF, it is too porous and there is air leakage. The more dense material is required. I would imagine that there might be some exotic woods that are porous also. Did you check to see that the heads were truly locked down in place? Sometimes it takes a little extra push to seat them properly and, if they aren't seated so they are locked down, there will be leakage and loss of suction sometimes.

Other than those, I don't know. I suppose it's possible that the tiny hole in the green pop up button on the head is clogged, but I've never had that happen. Push down that green button with the pump on and if you hear air movement it's working. If not, then I would contact Festool to determine the possible causes.

Is there a cut or some imperfection around the edges of the heads?

 

[bonzaican]

Actually it was MDF ... so I tried another offcut that is a veneer on one side and particle board on the reverse.  On the veneer side it gripped nicely & on the reverse no grip.  I hadn't realized MDF or similar would affect it that much so learnt something new & useful today.  Many thanks to above for responses.  So glad it's a material rather than a tool issue  [cool]

 

[grbmds]

The higher density versions of that material work okay and can be used as templates "sucked down" tight via a small hole in the pattern and adhesive backed weatherstripping on the template. Then, piece you are routing to the template's pattern will also suck down tight via the weatherstripping just as if it was mounted directly on the head. However, the  template must be solid wood, plywood, or high density "MDF". Experiment with it if it's something you have a use for. I haven't done it that much, but it allows you to rout completely around the pattern without clamps. (It isn't something I came up with. I learned if from Festool's Brian Sedgeley in a Festool class.