Hi All,
I have a shop that is approximately 800 sq. ft. I have a Jet 1.5 hp vortex collector with two 4″ ports.
I would like to set this machine at one end of the shop and pipe to it. My intended machines include the table saw, sanding machine, band saw, jointer, planer and perhaps a few other tools, some of which may incorporate a hood-style inlet, others perhaps removable temporary as-needed connections.
I do understand the importance of blast gates.
Questions:
1. do I have the right dust collector?
2. it has two 4″ input ports. I would seem to me I should be running a 5″ or 6″ ‘trunk’ line but reducing t0 4″ at the collector seems incorrect.
3. Am I correct to assume a 4″ rigid trunk line potentially 40′-50′ with some bends is a bad idea? Obviously I wouldn’t use 90′ bends but still …
4. I read in one of these threads that 30 guage is not recommended. why?
5. If I use all drainage (green) or sch. 20 pvc, does running a bare copper wire along it really eliminate the static electricity? I read that somewhere but am not sure.
Sorry for the dumb questions but this has been a stalled project for several years as I really don’t know where to begin. I thought buying the Jet a few years back would be great and get me going but it’s been nothing but a complete pain; rolling the thing around the shop, trying to manage the flexible pipe, and it not really fitting anything has been very frustrating.
thanks!
George
Replies
I'm not an expert, but your collector and 4" pipe is fine for your application. I don't think 40+' runs are a good idea. You want to get the collector as close to your machines as is practical and keep the runs short. You can ground pvc pipe with copper wire, but you need to connect the end to ground, you can screw it to metal on your dust collector which should be grounded.
On grounding, it is not physically possible to generate an explosive air-dust mixture with any plausible workshop setup outside a large factory setting. You simply could not move enough dust fast enough in 4 inch pipe so you can forget grounding. It's a waste of time.
You CAN get fires in shop dust, but it is very, very rare and is caused by hot residue from work or sparks from bits of metal hitting fan impellers NOT by static electricity.
The methods suggested for grounding (usually running a wire along the pipe, possibly pushing some screws into the pipe and wrapping the wire) are laughable from the perspective of physics anyway.
Rod Cole wrote an excellent treatise on this which explains why the grounding of PVC pipes is silly. http://www.woodcentral.com/articles/shop/articles_221.shtml
TL:DR basically you have two issues. 1. PVC pipes do not generate sufficient static charge to cause an explosion because the charge remains evenly distributed due to the insulating properties of PVC. 2. at 500CFM such as might be generated by your machine under real world conditions, you'd have to suck up a pound of dust per minute. It might, arguably be possible to do that if you are vacuuming a pile of dust, but that's a LOT of dust. Note dust not chips. It needs to be fine dust such as from sanding or a table saw. I have a 4HP 12 inch TS and there is no way I could generate anything like that.
Does your DC have a 5 inch port? Most of the cheap 1.5HP models have a 5 inch that splits to 4 inches. If you can run 5 inch pipe from that it will be ideal. it can be hard to secure 5 inch PVC pipe though as 4 inch is more 'home-centery' but if you can get it and run a 5 inch trunk with 4 inch offshoots it will be a little better. - don't be tempted to use flexible pipe unless there is no other choice. 4 inch smooth is better than 5 inch flex over anything other than very short runs.
That having been said, I have a 4 inch pipe system that runs up to 20' off a 1.5HP single stage vac. I use a bin with holes in the lid to catch big stuff and prevent spark formation. It works fine for most things but it's much easier to sweep up the mess from the planer than to hook it up to a system that only collects 80% of the chips anyway.
Blast gates SUCK. They are needed but they really suck. The best ones are home-made and use thicker material. Thin plastic ones do work but expect to spend 20 minutes every now and then picking stuff out of the many that will not close. Don't ask how I know...
Try to keep big chip generators close to the machine. Fine dust from a sander will go a long way (I have no trouble with 20' of plastic pipe and 9' of plastic flex hose to my thickness sander) but bigger chips need higher flow rates and you get those closer to the machine.
Designing a dust collection system is not rocket science. It's pretty basic stuff. You would be better served (and far more accurate) doing the research and calculations yourself vs seeking help from a forum such as this.
You would be wise to stay away from PVC and use metal pipe and fittings (which don't "suck"). Here is a source for info on calculating your needs vs what you have presently to start with. They also have the pipe and fittings.
https://www.spiralmfg.com/designing-efficient-dust-collection-system/
Oneida Air is another good choice for pipe and fittings, they can also offer you accurate advice as well, you might want to start there.
https://www.oneida-air.com/
You'll be making a mistake running 4" ducts. I have (and still have) a Jet 1100 blower with a cyclone. Probably similar to your set up.
The first system I had was 4" pvc pipe and a bag filter. Terrible!! The shop remodel included alot of research on DC which I used 6" trunks and added the cyclone + exhausted outside.
All I can say is the difference between 4 and 6 was astounding.
PVC does generate static I know that b/c when the humidity is low, I get the occasional zap when touching the metal blast gate.
All that said, 1 1/2HP is marginal for a ducted system. I will be changing everything out for a 5HP Clear Vue this year.
I have that same collector.
Regarding question #3 I highly doubt it could reliably pull through a 40’ pipe. Intake ports are at the bottom so if pipe is hung from the ceiling add another 16’ to get up then back down.
Either a cyclone, or two 1100 CFM DCs closer to machines, would be better.
Mike
This is GREAT information; I very much appreciate the responses.
thank you all for your enthusiastic responses. I may have more questions coming but this is great.
for the static electricity, I'm not so concerned about blowing myself up but rather that uncomfortable feeling of getting zapped when using the system. I'm leaning toward a 30 gauge metal pipe. objections or other suggestions welcome.
I also appreciate the inferred observation that sweeping up some larger chips is a better strategy than trying to capture it all. I'm interpreting that as it's better to get the fine dust then the big chips. I can push a broom and would rather not fill my dust collector with big chips unnecessarily.
If you're inclined, keep educating me. Otherwise, thanks for the quick input.
Thanks!
I currently have a Grizzly 2HP collector with a 6" trunk that runs 4" drops to 4" flex hose to a Grizzly cabinet saw, a tabletop planer, and also miter saw station.
I only run one tool at a time. My runs are also pretty short. I only use enough flex hose to not have to use an odd amount of fittings, and also need to be able to move my machines.
I ran my trunk in the ceiling of my shop and down again to my collector. It has a bag filter with a plastic bag container. I know this is not the most efficient, and could probably get better performance if I vented outside, but I have yet to try that out. I am also concerned with removing my shop air since I use a small electric space heater hung from the ceiling.
If I were to do it with an unlimited budget and could buy anything I wanted, I would get one of the Clear Vues, but this is what I have done.
Good luck with your build. I imagine it will be a work in progress, as I believe mine is also.
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