top hat height

[sneezy]

First I want to say hi, and also say how glad I am to have stumbled on this great sight while surfing. It looks like a Thien Baffle will solve my dust collector problems. I have a pretty powerful 2 H.P. blower I picked up used,from a cabinet making business. It's mounted on a 50 gal barrel and blows into a 2' dia. by 6' high bag. Dust is collected very well but 2/3 goes into the barrel and 1/3 into the bag. Needless to say it's a major effort to empty. There is hardly any fine dust settling in the shop.

Finally the questions - I notice that top hat sizes seem to be determined by duct size and container diameter. I plan on mounting a top hat on top of an airtight square box that will hold a 26 gal trash can with a plastic garbage bag in it. I thought a 20" dia. baffle would be good but wonder if a 10" top hat height with a 6" inlet at the top of the wall might work. My thinking is that my blower is quite strong ( I don't know it's ratings but we try to keep cats and small puppies clear of intakes), and this might slow down the air stream and help settle some of the finer dust.  Do you think I'm close, or out to lunch? Also, would the plastic bag be sucked out of the container or do you think it would be O.K.

I don't mind experimenting but I'm so impressed by the knowledge and ideas of this group that I thought I could tap into that. and get off to a flying start instead of beginning with a crash.

Thanks all.
J.C.

[galerdude]

Hi Sneezy, welcome to Phil's great forum. Sounds like the Thien separator is exactly what you're needing to complete your great DC system. I'm not well enough informed to offer a comment on your proposed height of the top hat. I do remember reading in the forum about others using a bag in the lower container. It seems they had to use a wire cage of sorts to keep the bag from sucking out and there were then issues with the bag puncturing and also the issue with pulling the cage out of the filled bag once it was full enough to be emptied. Things to consider, I suppose. It also seems, if the 26 gal. container, just sits in the sealed box, with out being sealed to the bottom of the Thien top hat separator, that it might give you less than desirable results when it comes time to empty your 26 gal. can, i.e. the box would have collected sawdust in it.
Just my thoughts.

Thanks,
Gale

[phil (admin)]

Square box with a trash can with a bag?  I can sort of see that not working.

How about building it on top of a 30-gallon drum with a bag and something to keep the bag from getting sucked up (like a rolled-up piece of laminate)?

[sneezy]

Thanks for the fast replies. I'll forget the bag.
Phil, what about the top hat height and the location of the inlet ?


JC

[phil (admin)]

Those dimensions (10" height with 6" inlet at top) would be fine.

[sneezy]

Thanks again - I'll give it a shot

[Pop Pop]

Do you think there is an issue with a square box for the dust bin or is the issue the bag in the square box?  It seems to me once the dust falls thru the baffle, the shape of the container wouldn't matter.  Am I incorrect in that assumption?

[sneezy]

The reason I was considering a square box was to hold a trash can with a bag in it . I was thinking of putting pipe insulation around the top and keeping the trash can tight to the top of the box. I wasn't sure if the vacuum would be enough to suck the bag up but it looks like that would happen.
so I'll just put the top hat right on the can. After that windy reply, I've read previous posts that claim there is no problem with a box.
JC

[Peter]

I seem to recall reading that someone used what amounts to one of those wire cages used to support tomato plants inside his trash can below his separator to keep the garbage bag liner from being sucked up into system. I think a section of wire fencing rolled into a cylinder to match the shape of the can might work as well. Anything to avoid emptying 30 gallons of loose sawdust is a good thing.

[phil (admin)]

Do you think there is an issue with a square box for the dust bin or is the issue the bag in the square box?  It seems to me once the dust falls thru the baffle, the shape of the container wouldn't matter.  Am I incorrect in that assumption?

A squarish bottom container is fine.  I was just concerned that with the square box with the round can inside it, with the bag inside the can, that there would be a lot that could go wrong.  For example, the bag could get sucked up.  Or the debris could fall between the square box and the round can, and hit the bottom of the box.  Or there could be a leak in the square box somewhere.

[SteveSawyer]

Sneezy - don't give up on the bag idea!!

I have a 60-gallon plastic drum (they can be had very cheap or free - find one that was used to hold foodstuffs rather than something toxic), lined with a 2.7 mil plastic bag that comes on a roll from McMaster-Carr. (www.mcmaster.com). Cut a piece of laminate (WilsonArt or Formica) the height of the drum, roll it into a cylinder that fits easily into the drum, and fasten it with pop rivets. Put a couple of 1" holes at the top with a Forstner bit to make it easier to grab, then slip this inside the bag. This will keep the bag from getting sucked up into the separator, and when the bag is full, it literally just slips out, you close the top of the bag with a piece of duct tape, lay the drum on its side and slide the bag out. I can empty my drum and have it back in operation in about 5 minutes.

[galerdude]

 8) Cool idea! I like the sound of that.

Gale

[sneezy]

Yes it is cool Steve. When I've finished my top hat, (Closing in on 80 so I don't move like greased lightning) I'll get some laminate and give that a shot. Sounds like it will make emptying and carting to the recycle site much easier.
Thanks