Will it harm a ShopVac to use it as a passive chip collector?

[CarvedTones]

I have a new fairly quiet but fairly small ShopVac and an old large screamer. The old one works as a blower as well, and the output is a standard 2" hose connection just like the input. So it occurs to me that I could daisy chain it to the new one and use it as a big chip collector. I would probably use the foam filter so as not to introduce too much resistance. My guess is that there are fan blades in there that would spin and turn the motor. Would that do any harm?

 

[DonnellyJT]

I would think that you would be better off running them in parallel rather than in series.

 

[CarvedTones]

You are missing the point; I am talking about only running the small one and using the big one like a passive chip collecter because it has more capacity. But the motor on the big one is just too loud to run in the garage at night.

 

[ptt49er]

The only issue I see is that you'll have a lot of losses through the motor of the big one. I don't see how it could hurt the motor in the big one. Try it out and see if it causes your little one to work too hard.

 

[CarvedTones]

I did a quick trial run. Any losses seem pretty minimal and the little vac didn't sound like it was straining. What I did was run the 2" hose from the little vac to the outflow of the big one and then used the reducer and 1.25" hose that came with the little one on the inlet of the big one. I turned on only the little one and used an attachment on the end of the 1.25" hose to vacuum up some chips and dust. It worked pretty well. Not quite as fast as the little one alone and nowhere near as fast as the big screamer alone, but very reasonable for being able to clean up the garage quietly late at night.

 

[Gofor]

Don't know if my comments will help. I had a 2" 10 gal Genie that screamed and bought a 2" 14 gal Ridgid that was quiet. I removed the motor from the Genie and just put blind bolts through the motor mount holes. I use the genie with the foam filter as a chip collector between the Ridgid and my TP, BS, TS, etc. It works well for the big stuff and does filter out some of the fines. I have to dump the chips more frequently, but it extends the time between cleanings of the Ridgid fine filter by about 5 fills of the Genie on the TP. On the BS, TS, and CMS, it probably doubles the fine filter life between cleanings. I have yet to build a good separator which I think will extend it more. I also have a smaller diameter wall-mount shop vac that I just quit using all together because of the high decibel noise.

Go

 

[CarvedTones]

One thing that is different in my case is that the little vac is suitable for single machine DC and some light clean up, but not heavy lifting. Some of its quiet comes from having a less powerful motor. If I need to do a wet pickup or vacuum the car out in the driveway, I will still put up with the noise of the big one.