Dust Extractor Noise Reduction

[Kev]

I have an old Axminster 50L drum dust extractor that i use for dust extraction on hand powered tools. Suction is great but the noise is not. So much so that I was thinking of buying a quieter version (think they now do Numatic brand versions which are supposedly much quieter). Looking online, here and on Youtube mainly, there are a number of examples of people building sound reducing boxes to place the extractor/vacuum in to reduce the noise, in some cases reducing the dB quite significantly.

The general consensus seems to be to build a box, insulate it and make and install some type of baffler to dampen the noise that is directed out of the box. This seems sensible. The thing that concerns me more is what do you do with all the heat build up that there surely must be from running it for more than 10 mins. Heat is raised as a concern in a few of the examples but none really seem to have a go at tackling a solution properly. May be it is not an issue at all!

Had anyone had a go at building something like this and if so how effective was it and what did you do, if anything, about heat.

 

[Jasper42]

I have a record power vac which is very loud. I made a box on the outside of my workshop and run the hose and plug through a hole. Works for me although the wife as not overly impressed with the small extension......

 

[Kev]

Did wonder about this approach but to be honest putting the noise outside is not really an option for me.

 

[pollys13]

Did you have the extractor from new? If so has the noise increased since you had it? Don't know anything about the mechanics of an extractor. Perhaps part needs replacing, blockage? Have you contacted Axminster?

 

[selectortone]

Here's a thread on the subject:

camvac-silencer-t99639.html?hilit=%20silencer

 

[Kev]

Did you have the extractor from new? If so has the noise increased since you had it? Don't know anything about the mechanics of an extractor. Perhaps part needs replacing, blockage? Have you contacted Axminster?

Yes have had it from new and no it has not got louder. It is just a very loud extractor which i have only used in short bursts till now so been able to live with it but need to use it a fair bit at moment so become more of an issue. Its not one that Axi make any more as they now have the Numatic ones which are quieter. It has been a very good and useful extractor over the years apart from the noise!

Here's a thread on the subject:

camvac-silencer-t99639.html?hilit=%20silencer

Did see this and like the idea of the baffle box but not sure how useful that would be for me as the noise from the extractor comes from the motor itself and also it does not have an exhaust.

Need to look in the workshop tomorrow and get the model etc of the extractor. Actually just had a quick google search and it is one of these.

 

[Duncan A]

Not sure of the exhaust arrangement on your vac, but the Camvacs could be made significantly quieter simply by putting 2 or 3 metres of hose on the exhaust - no need for a baffle box or to lead it outside.
Duncan

 

[sunnybob]

I have an old Axminster 50L drum dust extractor that i use for dust extraction on hand powered tools. Suction is great but the noise is not. So much so that I was thinking of buying a quieter version (think they now do Numatic brand versions which are supposedly much quieter). Looking online, here and on Youtube mainly, there are a number of examples of people building sound reducing boxes to place the extractor/vacuum in to reduce the noise, in some cases reducing the dB quite significantly.

The general consensus seems to be to build a box, insulate it and make and install some type of baffler to dampen the noise that is directed out of the box. This seems sensible. The thing that concerns me more is what do you do with all the heat build up that there surely must be from running it for more than 10 mins. Heat is raised as a concern in a few of the examples but none really seem to have a go at tackling a solution properly. May be it is not an issue at all!

Had anyone had a go at building something like this and if so how effective was it and what did you do, if anything, about heat.

Its a common misconception about heat build up. There is none.
Youre forgetting that the extractor is pulling shop air into the container and out past the motor. Heat cannot build up inside the cabinet because all the hot air is being pushed out the baffles.
I have a sound deadening cabinet around my 50 litre sip extractor. Its been going fine for over 2 years now and I live in the middle east where summer temps are up to 40c.

The only point to keep in mind is that to reduce noise you have to slow the air down. To slow the air down you need a baffled tunnel that is as big as possible. If you only give a 4" tube as an outlet, it will still be LOUD (and possibly heat up a bit due to friction).

The cabinet is a tight fit to the size of my extractor. The air outlet is a letter box slot 20" x 7", with a foam flap over it to further reduce the noise. The draight from that is barely noticable.
I dont have a decibel meter, but the noise dropped from painfully loud to a background whine like a domestic vacuum cleaner in a separate room with the door closed.

 

[pollys13]

Depending on any machines you run,you should be wearing hearing protection? If not perhaps look into Db reduction of various types.

 

[sunnybob]

Yes, I wear hearing protection if any machine is running for more than a minute (with the thicknesser i put the headphones on before switching on)
The dust extractor has gone from being the second loudest machine, to the stage where I cant tell if its running or not when the bandsaw is on.

Dust mask and goggles also used.

 

[pollys13]

OK I was actually wondering if Kev the OP did the same? When I used a dust mask and goggles even though mask, had an exhaust valve I found goggles misted up quite badly, I did use a drop of dishwasher liquid wiped off inside that was pretty effective at stopping misting.Also got a pair of Dewalt " anti misting goggles " at a decent price but didn't find them so great. I now have a powered respirator as well as a big drum extractor and a Record Power ceiling mounted filter, the Record air flow is on par with the Jet one but quite a bit, significantly cheaper and a 5 year warranty replacement filters are quite reasonable too.
Do you have, had a problem with misting goggles?

 

[Kev]

Do you have, had a problem with misting goggles?

I feel your pain. I do have some problems with misting but in all honesty it depends upon what i a doing. Tend to use goggles (actually wrap round glasses which I feel allows more air flow) on large machines (tablesaw/planer thicknesser) with ear defenders and found this can be very 'foggy'. When using hand power tools tend to wear a full face mask for no other reason than find it more comfortable. Always have a workshop air filter going which I would not do without now and would highly recommend to anyone who doesn't have one.

The cabinet is a tight fit to the size of my extractor. The air outlet is a letter box slot 20" x 7", with a foam flap over it to further reduce the noise. The draight from that is barely noticable.
I dont have a decibel meter, but the noise dropped from painfully loud to a background whine like a domestic vacuum cleaner in a separate room with the door closed.

Have you put sound insulation on the inside of the box as well. I have seen a few plans where the baffle box consists of almost a small maze of insulation to prevent sound being directed straight out. seems to make sense.

 

[sunnybob]

Kev, i made mine very cheaply from 22 mm mdf. That has much more sound deadening qualities than plywood.
The internal walls are coated with bits of old blanket loosely taped to the sides. The air exits below the container main chamber into a set of up and over baffles, finally exiting at the bottom front of the cabinet. All surfaces are coated with blanket.

There are some pictures here somewhere from a year or two ago, I'll see if I can find the old thread. Total cost... not very much but I cant remember exactly now.

Polly, if your goggles are misting up, then the mask does not fit you properly. There should be NO air escape either breathing in or out. If the air is coming out to mist your goggles, then fine dust is going back in the same way. I use disposable masks to FFP3 standard, and make sure to pinch the metal band over the nose very tight BEFORE putting it on. That way your nose pushes the sides out and gets a good fit.

I use wide angle side protected glasses rather than goggles. Googles all by them selves cause misting problems if you are sweating, and in my climate, thats 8 months of the year (today is an overcast 32c. with 65% humidity)

I dont wear safety glasses all the time, depends on what machine I'm using. Bandsaw or drill press or sander, no. Router table is MANDATORY. Chop saw or anything else that might throw chips out then yes.

 

[sunnybob]

I found the thread, but my pics arent showing up any more so I'll post them again.
WARNING!!!! These are NOT pretty pictures, I made this as cheap as poss (and it shows), because I wasnt convinced it would work. It turned out to work so well that I left it alone rather than make another "nice" one that nobody would see anyway.

 

[pollys13]

" Polly, if your goggles are misting up, then the mask does not fit you properly. "
Mind you, at the time I had a full beard and mustache, have since removed both. I think the beard, even though had mask on as tight as I could get, allowed air out. I see you are using a Solent airtight box, if anyone reading this, are cheaper on Ebay than buying from Solent direct.

 

[sunnybob]

Nope, thats an IKEA box. Again, tried it for a quick set up, found it works so well its still there. When I first fitted it all together i had 4 clips, but then I made a silicone gasket for it because i thought it was not holding vacuum, but then realised I just needed more clips around the edge. I have 8 clips now and its fine. And the cyclone has been upgraded to a medium sized road traffic cone with 62 mm in and out.