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shop-vac question

Posted by daninthedirt (My Page) on
Sat, Mar 30, 13 at 17:29

I use my shop-vac for everything, including liquids. Did not realize until now that I'm supposed to prep it differently for liquid pickup than for dry pickup. But the instructions are very unclear. Standard cartridge filter by itself gets kind of torn and ugly after sucking on water.

Am I supposed to remove that cartridge filter entirely to suck water? As in, no filter? Am I supposed to leave it there but put a foam sleeve over it? What does the sleeve do? The cartridge filter, if left there under the foam sleeve, is still going to get pretty wet and ugly.

What is the difference between a "reusable dry filter" and the cartridge filter? I reuse that cartridge filter routinely. The manual tells me to put said "reusable dry filter" over the foam sleeve, which I guess is over the cartridge filter. Three filters???

Follow-Up Postings:

RE: shop-vac question

There are two kinds of shop vacs. Wet/Dry(dual tank) and single tank. The dual tank has a separate4 compartment for liquids, which is accessed by switching the hose from the dry side. No special procedure for that type.

If your vac is the single compartment variety, it should have a cage with a ball inside over which the filter is installed.

That ball is there to seal off the compartment when the liquid reaches a predetermined level. To use that type for liquids, simply remove the filter and use. There is really no need for any filter with liquids.

I've had several shop vacs over the years. Some had the filter and the foam covers. Those were actually inefficient and expensive when used in commercial applications(remodeling). Drywall dust will kill a stock shop vac filter very quickly.

Buy an after market or upgrade filter, don't get it wet, clean it periodically and it will last for years.

RE: shop-vac question

I have a Shop-Vac (should have capitalized it) 14gal 5.5HP model. It doesn't have a ball inside the cage, but rather a capped cylinder that can slide up and down freely inside the cage. Maybe it floats? The cartridge filter slides over that cage, and press-seals around it.

So ... if I want to vacuum liquid, can I just remove the cartridge filter (which is permeable paper reinforced with metal screen)? That is, is the purpose of the filter to keep debris out of the motor, and if one isn't sucking debris, one doesn't need it there? And as long as the liquid level doesn't get close to the motor, everything is fine? That's what I'm hearing you say.

RE: shop-vac question

"Am I supposed to remove that cartridge filter entirely to suck water?"


"What does the sleeve do?"

The sleeve "generally" acts as an additional filtering step in an effort to address particulates that pass thru the initial filter.

"What is the difference between a "reusable dry filter" and the cartridge filter?"

A third step in the filtration process and in "general" for fine particulates, IE dust.

"The manual tells me to put said "reusable dry filter" over the foam sleeve, which I guess is over the cartridge filter. Three filters???"


"So ... if I want to vacuum liquid, can I just remove the cartridge filter (which is permeable paper reinforced with metal screen)?"


"That is, is the purpose of the filter to keep debris out of the motor."

No! It's to keep you from recycling particulate debris back into the atmosphere. You should or may have the option to vacume and/or blower, or arrows, or some other method indicating an action.

RE: shop-vac question

Thank you both. Very helpful. Now why couldn't the Shop-Vac manual say this stuff??

I'm still a little puzzled that the Shop-Vac manual seems to recommend using the foam sleeve if vacuuming liquid. As in ...

"Wet pick up requires the foam sleeve (not standard with all models) or cartridge filter (not standard with all models) to be in position over the lid cage."

... though in other places it suggests, as you say, that the cartridge filter can be removed entirely for wet pickup. If the purpose of the sleeve is to add extra filtering, why would that be necessary with wet pickup? Seems that in wet pickup, most particulates would end up drowned in the liquid.

RE: shop-vac question

I have an older Shop Vac brand vacuum and turning it from dry to wet just requires replacing the pleated filter with a foam filter. The foam filter just slides over the plastic "cage".

RE: shop-vac question

Ah, really? That makes more sense -- pulling the foam filter just over the plastic cage. See, the foam filter won't fall apart when it gets wet, as the pleated paper filter will, and I guess in the absence of the cartridge filter, the foam filter catches the debris that the water doesn't drown.

In fact, that's right. The quote I gave from the manual says to put the foam sleeve over the lid cage. NOT over the cartridge filter. But it does say that either the sleeve or the cartridge filter needs to be over the lid cage.

But it still seems to me that the easiest solution is just to have a bare plastic lid cage. No foam, no filter. According to snoonyb, that works.

RE: shop-vac question

There are filters available that will withstand use in wet applications and avoid blowing mist all over the place.

The Clean Stream Teflon coated ones do very well.

in dry use they can be washed out a number of times and reused.

I actually have two for every shop vac so when one clogs I can wash it and use the second till the first is dry.

Just be careful what dry items you vacuum up with or onto a wet filter.

One of my slower guys managed to pick up setting type joint compound after clearing come traps.

One Durabond coated filter resulted.

I have sucked up liquids I would prefer not to atomize and breath. Like clearing out traps.

This post was edited by brickeyee on Sun, Mar 31, 13 at 17:08

RE: shop-vac question

I would surmise that the intend of the foam filter, is in fact, not filtration but as Brickeye suggests reducing the risk of moisture vapor overcoming the seal or being exhausted.

RE: shop-vac question

That Cleanstream filter is pretty slick. Teflon coated, eh? It looks like pleated paper, but I gather it is something more solid. Teflon coated paper? Kinda pricey, but with a 1-year satisfaction guarantee.

And yes, the foam filter must be to prevent exhaust of vapor from the vacuumed liquid. But if I'm just sucking fairly clean water, I don't really care too much about that.

RE: shop-vac question

Thin enough Teflon for a filter is not very strong.

It needs a backing to give it at least some strength to hold its shape.

RE: shop-vac question

I've used the CleanStream filters since they first came out (or close to it). They're worth every penny.

RE: shop-vac question

I have a wet/dry Shop Vac QPL 60 that Shop Vac, free of charge, replaced the whole top assembly for free. The replacement sent me in 2009, a lightly used vac, worked well until a few days ago. When I plugged it in to vacuum my car, the motor made a shrill whine noise and no suction. I checked the filter and it is almost like new. I checked the hose and there were no leaks. I even taped all the connections to and from the hose to the tank, but to no avail. Could you suggest what the problem is and if possible, a cure for the problem or must I spend some 82 dollars for a new unit?.

RE: shop-vac question

didn't know cleanstream made teflon coated filter..
I know they make Gor-Tex based filters...
I've used in several shop vac..even use one as a central house vac going on 20+years..

I've the cleanstream filters while sucking up water..instead of removing the paper filter(which should be done, the foam can stay).

if you have a fine paper type filter..remove it for water. leave the foam filter..helps keep larger chunks from the motor/blower
using a CleanStream/Gor-Tex filter..leave it..


RE: shop-vac question

If I had to vacuum water with debris in it, like wet sawdust let's say, I think the foam sleeve would be just the ticket.

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