Decreasing the noise of Diamond Pacific 65lb plastic barrel?

[Bob]

I've just acquired a used Diamond Pacific 65lb rotary tumbler from a man who has been running several of them for years.  I got to hear one of them running in his garage.  It's not as loud as I would have predicted it to be with just a plastic barrel with no lining, but it was loud enough to be annoying and I'm not sure my wife is going to like it.  She is in China now and I have a month to get it ready before she gets back and tells me to get rid of it.  The plastic is thin and stiff.  It sounded to me like there were two aspects to the sound.  One was the impact of the rocks against the plastic sides, a steady gravel sound.  The other was kind of a resonating sound I guess from the empty part of the plastic barrel.  It made me realize just how quiet my Lortone C40 barrel is being metal but rubber lined.

I asked him if he knew of anyone who had ever tried to quiet one of these down.  He said no.  This surprised us both.  He said that until I asked he had never thought of even trying it.

It seems to me like there might be several approaches.

1.  Put the entire tumbler in an enclosure of some sort that soaks up sound, even if the top was open.  I'm not interested in anything like this as a running electric motor is asking for trouble in any area in which there isn't good ventilation.  Plus, I inspect my tumblers daily to make sure all okay with regard to shafts, bearings, belts, lid leaks, and excess heat generation.  Being able to see them clearly is one key to safety.

2.  Put some sound dampener material on the outside of the barrel.   A few years back, I put some of this special adhesive sound deadener matt material in my 4Runner to decrease the hwy noise, and it worked great.  It was only maybe 3mm thick and there would be room to put this on the barrel w/o interfering with the contact of the barrel to the drive shafts.  I see no downside to trying this as the weight of it isn't so great as to probably make hardly even difference to strain the motor.

3.  Put some sound deadener inside the barrel.  I can only see this as doable if I was willing to use this barrel only for 1 grit size.  There might be two ways to do this.  One would be the use adhesive to glue in some panels on all the flats inside and maybe the ends too.  There would be gaps and cracks that would catch grit and be messy, but if only for coarse grind this wouldn't matter.  The other would be to pour into the barrel some kind of coating, such as liquid urethane, and run it so that it would get coated all over.  It might decrease the impact sound of the rocks against the plastic barrel.  If it deteriorated over time it would not really matter.  I could redo it if I wanted or not.

Has anyone ever tried 2 or 3 or have better ideas?

[andyiii]

Looking at the Diamond Pacific 65T on their website, which is 30"x18"x18" in size (if yours is older and significantly different then this may not be feasible):

What about a light, lift-off enclosure that encloses the barrel but leaves the motor outside (where it's cool)?  You'd obviously still hear the electric motor but could deaden the sounds from the barrel.  I used to be in the Navy and we had these portable 250gpm fire pumps which were deafening, so we had boxes made of aluminum lined with a fairly thin styrofoam-like material which were surprisingly effective at deadening the noise, even though the motor had to have an air intake hole and exhaust hole.  To do such a thing for the tumbler would require some detailed cutting around where the drive shaft goes to the motor, but a sound barrier need not be "air tight" - maybe try a mock-up out of cardboard then make the real box out of 1/8" plywood.  Then line it with either your aforementioned automotive sound deadener or the acoustic foam panels for audio studios (pretty easy to find now that so many folks are making home studios for youtube recordings...)

Or, if the sizes are compatible, you might be able to modify something like the "Pyle Sound Isolation Recording Shield Box - Microphone Foam Booth Cube" (search it on Amazon.com since I dunno if I can post that link here) depending on how big the tumbler actually is - with the price of plywood and materials these days, cobbling 2 of these boxes together to meet your needs may be a better deal than making it from scratch 

Another thought - USB powered "muffin" fans, primarily used to cool computer and electronics boxes, are now super easy to come by - and cheap.  Build a very simple square box lined with acoustic foam, with 2 fans mounted (one pushing in and one pushing out) and plug it into a USB hub when in use to keep the tumbler cool, voila. 

Ultimate plan:  Go to Goodwill and buy a fully enclosed cabinet, line it with acoustic foam, add 2 fans, and park it in the living room for your wife to sit a flower vase on top of!!!

Now that you've got me looking at this idea, I may try putting something together to quiet my Vibratory tumbler so that I could bear to have it in the basement vice out in the garage...

As to modifying the drum itself, I personally would be afraid of screwing it up and having to then foot the bill for a whole new drum - not cheap.  I don't have any idea about modifying the inside (what would last through constant grinding with rocks and grit?) and I feel like anything on the outside would be only partially effective and probably peel off before too terribly long...

Have fun!
Andy III

[Bob]

May 29, 2024 18:19:42 GMT -5 andyiii said:

...What about a light, lift-off enclosure that encloses the barrel but leaves the motor outside (where it's cool)?  

That is a very interesting idea!  And potentially doable.  I'm going to ponder this some.  The shafts are belt-driven and it would be very easy to move the motor to various positions if needed to facilitate this.

[catmandewe]

I think the sound dampner on the outside of the barrel is the easiest to do.

Tony

PS- I did make a box out of 2" styrofoam that is held together with long nails so I can take it apart and store it. I use it in the winter so I can run the tumblers out on the deck and the heat from the motor inside the box keeps the barrels from freezing up.

[andyiii]

Great idea, Tony!  Speaking of which, an old cooler with added ventilation would probably make a great sound isolation enclosure!

For a cheap trial, check with local aquarium shops - tropical fish are shipped around in heavy styrofoam-lined boxes that can be quite large.  Often fish retailers have them in stacks and they let them go cheap (or free).  I've been to local fish club events/auctions where these styros go for $1 each...

[liveoak]

Maybe you just need to build a shed away from the house.

shedplans.org/how-to-build-a-shed/

I use our old van as my "tumbling shed"- 

it's insulated & far enough from the house with the doors closed, I can't hear it.

Patty

[iamchris]

Another vote for the Dynamat type material. Cheap(ish), easy, and doesn't interfere with normal operation of the tumbler. Nice find on the 65t!

[Bob]

May 31, 2024 11:41:35 GMT -5 iamchris said:

Another vote for the Dynamat type material. Cheap(ish), easy, and doesn't interfere with normal operation of the tumbler. Nice find on the 65t!

I got a decibel app on my phone.  3' from the side of the tumbler it's 85-95.  I was conservative in filling it only 2/3.  And my experience with other barrels makes me think it might be a little quieter had I filled it 3/4.  I've ordered a material like that made by Amazon and will see what happens.  Enough of the sound penetrates part of my house from the garage that my dog barked off and on for an hour even though I could barely hear it that way.

The inside of the barrel is abraded from over a decade of use and the surface looks to me like it would hold an adhesive or liquid lining quite well when dry.  I have even thought about pouring FlexSeal or something similar in it too create a lining.  If it degraded within a few months, I would not care.

The empty barrel weighs 12lbs, the water was 12lb, the grit was 5lbs, and the whole thing was 115 lb.  Were I not working out in the gym, I would not have been able to lift it onto the base.  Filling that huge open thing was one of the most dramatic moments in my 11 year tumbling career.  

[jamesp]

clay slurry for step 1/2, then fill barrel 80%

[Bob]

Jun 3, 2024 14:21:40 GMT -5 jamesp said:

clay slurry for step 1/2, then fill barrel 80%

I've also thought about anything that would cushion the banging of the rocks on the sides of the plastic barrel but that would not decrease grinding action.  I have lots of sawdust and might try that too.  Hard to believe after hearing this thing that in 15 years his barrels have never worn through.

[jamesp]

Jun 3, 2024 16:31:51 GMT -5 Bob said:

Jun 3, 2024 14:21:40 GMT -5 jamesp said:

clay slurry for step 1/2, then fill barrel 80%

I've also thought about anything that would cushion the banging of the rocks on the sides of the plastic barrel but that would not decrease grinding action.  I have lots of sawdust and might try that too.  Hard to believe after hearing this thing that in 15 years his barrels have never worn through.

Consider cohesive "grinding" force of sticky clay pulling the rocks against each other Bob.
Like mixing cement in a wheelbarrow, it is easier to mix the cement and gravel when they are just wet with water. But once the Portland is added it takes much more force to mix the mixture.

That large barrel should will have more grinding force just due to its shear size. enjoy !

[Bob]

Jun 4, 2024 8:46:12 GMT -5 jamesp said:

...That large barrel should will have more grinding force just due to its shear size. enjoy !

The person I bought it from tumbles almost entirely agates.  He said that 10 days in this 65lb barrel would be equal to 2-3 weeks in my 40lb barrel due to "the distance the rocks travel through each other in the cascade" or something like that.  In one way I hope that is true, in another way not, because that might mean batches getting done so fast I would just be putting in new grit over and over and of course paying for all the grit too.

The butyl sound matting material arrived yesterday, and man is it heavy.  So putting some panels of it on the outside of the barrel will certainly increase it's weight.  The barrel weighed 115lbs when I lifted it with finger tips put in the end caps from laying sideways on the floor and lifting it wasn't easy.  I bought it w/o a motor, and the 1/6 HP motor that I had as spare and put on it just burned out.  I think specs new are for a 1/3 HP and I have a new one coming.  So I won't know about my sound deadening project for a week or two.

With this, I've got: 1 x 65lb, 1 x 40, 2 x 20, 3 x 12, 1 x 6 and I think that's all I can handle in my life right now.  If the 65 goes well, in a few months I'll probably be looking to get rid of some of the smaller ones.  Those and the 10" lapidary saw hand trimming has maxed out my time on this hobby.  There is something pending nearly every evening.

[jamesp]

Yep, and SiC will grind down very quickly at such fast grinding rates Bob. All good. Fast grinds are worth it. Lucky you.
I don't envy picking that beast up though !
Put that monster in a dog house lined with sound foam. Some modern ones have a flip up roof for access to clean.

[Bob]

Jun 11, 2024 14:17:43 GMT -5 jamesp said:

Yep, and SiC will grind down very quickly at such fast grinding rates Bob. All good. Fast grinds are worth it. Lucky you.
I don't envy picking that beast up though !
Put that monster in a dog house lined with sound foam. Some modern ones have a flip up roof for access to clean.

That was kind of my plan if I can't quiet it down.  In Oklahoma, the winter is only severe 1 to 3 months per year, so having it in the backyard and quite a distance would be doable, though dealing with the weight of it, the loading, the cleanouts, etc. in the grassy yard and especially in the 100+ degree heat of summer would be unpleasant.  When I bought it I could hear the sound and knew it would be a problem.  If I have too, I can also keep it around just for times when I need to be tumbling a very large rock.  If I remember correctly, the max distance flat to flat in my Lorton 40lb barrel is 8.5" and I think the circular opening in this 65lb barrel is 12" so a lot bigger rock can go in there.

[jamesp]

You'll get it figured out. And you'll likely find some enclosure from a yard sale or junkyard.
Been waiting for a biggggg rock to be tumbled. Anxious to see what you produce.

[Bob]

James, I now have about 10-15 polished rocks orange size or larger. Some of them are very striking. Transporting them isn't easy, because it's a lot of weight. A few months ago though, I put 6 of them in a strong briefcase with each in some padding like taking 6 pieces of fruit separated from each other. But the briefcase was so heavy I was worried about it. I took these on a whim to an old timer rock seller in Oklahoma who had heard about me tumbling large rocks and he expressed doubt that it could be true. I got lots of sizeable pieces of obsidian from him, then showed him these rocks.

He just stared at them and didn't speak for a minute. Then he rushed to get his camera, and took photos and said he was going to show them to a lot of his friends who won't believe it. Then he really made me feel good when he spoke of how difficult he knew this was, and took months if not years, and the challenges of bruising that ruins it and all that. He was speaking my language. He asked why in the world was I doing this difficult thing? I didn't have a good answer except it's fun, I'm patient, and I think they look darn impressive. And I added that maybe someday in my retirement I could sell them for a decent amount if I don't fall in love with each of them.

He claimed to know exactly what I need to do to find out what they are worth. He said to rent a booth in a rock show, and have some legit reason excuse for being there, such as having this or that for sale--but not those large rocks. He said just sit a few of them out where people can see them, and when I'm asked what they cost, say they are not for sale. He said this will result in offers over time that will lead over time to my learning of their value. He also said I could place some arbitrary figure on one of them, like $300, or $1,000, just to see what happens. He predicted they would sell for more than I might think. I asked for some guess but he didn't reply. That was all kind of intriguing to me.

What I've thought about doing is keeping some records of each rock and how long it takes, kind of a certificate of authenticity. It would have a before and after photo, ditto for weight, dimensions, and other things that might be interesting to a new owner.

I will admit to once you've been working on one rock for a year or more, the thought of parting with it isn't easy if it's pretty to look at. I've got a piece of tigers eye maybe 7" in diameter going now almost a year, but now and then some more trimming is required, then that area takes months to round over, etc. It's just a lot of work.

[parfive]

Some big rocks in little barrels.

Here’s an oldie, Bob , if you haven’t seen it.
Unfortunately, P-bucket’s marks ruin some nice pics.
forum.rocktumblinghobby.com/thread/13828/tumbled-large-stone-canyon-jasper

Here’s another from Don. I don’t think we ever saw it finished.
forum.rocktumblinghobby.com/thread/79046/tumbling-3-lb-stone-barrel