# Dust collection issues.. leaks?



## Rhaugle (May 12, 2017)

Hi all,
Having problems with my SDD... Pictures attached... I have the 2hp HF unit mounted to the wall right above my SDD. I am using a rubber plumbing coupling to go from the DC to the SDD (I have a 6" to 4" adapter on the SDD). The HF outlet is 5" and the top of the SDD is 4. So the coupling I found is bigger than both of the lines, but I am able to clamp it down tight (I think it's tight at least). I can bring a handful of sawdust up to it and none of it moves. So I don't think my leak is there. The SDD is sitting on a fiber barrel with a locking lid. I have silicone all around the base of the SDD and on the inside around d the bolts. I have a bit of sawdust buildup in my line to the filter bag, and there is a fair amount of dust in the collection bag. How do I go about finding my leak? Or is this working as it should? I have a smaller DD on my shop vac and in 6 months of use, I have less dust than what has accumulated in my larger setup in less than a week's use. The picture of the dust bag is after one night's work... About 30 cuts. That seems like a lot to me. 

I do have some 5" hose that the DC came with that I could replace the rubber coupling with if that's the problem.


----------



## Catpower (Jan 11, 2016)

Is the pipe to the inlet of the SDD reduced? and also if you could run metal pipe instead of the ribbed pipe that would help

It would be best to run the lines as big as you can to a certain point, if too big the dust will lose velocity and plug the pipe, if too small you increase the static pressure which lowers the CFM and velocity so you lose the centrifugal force to keep the dust against the outside wall of the SDD


----------



## Rhaugle (May 12, 2017)

The line into the SDD (from the tools) is a 4" hose, reduced from 5" with a metal duct piece.


----------



## Rhaugle (May 12, 2017)

The pipe on top of the SDD (to the DC) is reduced from 6 to 4"


----------



## Rhaugle (May 12, 2017)

The line with dust in it is after the DD into the dust bag/filter. So that has all accumulated after going through the DD..


----------



## Carl10 (Feb 3, 2017)

You can check for leaks with an incense stick, match,etc.. but your issue maybe as simple as airflow. Your HF unit has limited airflow to begin with due to the smaller impeller it uses. So when you narrowed the source of airflow down to 4" you are limiting flow right from the source to about 400CFM, then when you add the SDD, you further reduce airflow. Follow that with your ducting (4" ??) to your tool and you again reduce airflow with more added SP. From the Oneida website the SDD "We recommend an operating airflow of at least 350 CFM for the 5" cyclone to effectively separate 99% of debris from the airstream." You are probably well below that level.

My first suggestion would be to eliminate the 4" reduction between your HF input (5") to the (6") SDD. The 5" Opening will provide just over 600CFM. These numbers all assume a typical velocity of 4500FPM.

Hope that helps. Let us know what you do.

Carl


----------



## Rhaugle (May 12, 2017)

Thanks for the ideas Carl... I did take some incense and found out my lid leaks about 3/4 of the way all around.. will pick up some weather stripping for the inside tomorrow.. hopefully that'll take care of my issue! If not, will move on to taking out as many of the reductions as possible.


----------

