Setting up new small garage shop, want table saw advice, dust collector, etc. - Page 3 - Woodworking Talk

area123 · 01-16-2008, 12:15 AM

Quote:

Originally Posted by Paul K

I think you got a lot of good replies here, but I would agree those that suggest you look on Craigslist or other such lists. You may have to wait a few months to find one, but there are deals on great cabinet saws. Consider looking on sites like OWWM or others for sales of tools. I see unisaws and the like that are often $600 and sometimes much less. I have a unisaw and a powermatic 66 with a sliding table. Both are very good saws and I do believe that having a good saw is one of the most important things in the shop. As to your question about dust collection, I would look at the CFM that is required. I agree that larger systems are very nice, and if you are going to run permanent ducting to all the machines, and use blast gates, you probably need more than the 1 or even 1 1/2" collector. The problem is that by having a longer run, it just can't carry the particles in suspension for long distances with a smaller motor. I suggest that 1 hp or 1 1/2 hp probably shouldn't have a run longer than 10 feet to 20 foot max for the 1 1/2. (By the way, most table saws are NOT very good with dust collectors. There is usually too much leakage around the motor, the elevation adjustments, etc. It is probably true here that newer machines are better, but I wouldn't make that a reason not to buy an older saw) If you can't get a bigger dust collection system, move it around your shop.
good luck

I ended up buying the JDS 1.5hp dust collector, will be delivered in about 2 weeks from amazon, cost about 300. I bought some good quality flexible duct from peachtree along w/ blast gates and various connectors for my router, etc. I'll only need about 15' along 1 wall for about 4 tools so I should be ok. So now all I need is that table saw, might have to wait till after the tax refund. I'm pretty set on the JET proshop saw.

btw-I still love that Rigid planer. Would have never thought of buying Rigid tools until I read about them here on the forums.

Thanks for all the help.

bigredc · 01-16-2008, 07:57 AM

I threw this together last night. I found it in that book. That book has lot's of good idea's, but according to it, I should be installing 6" metal tubing. PVC creates static. It calls for 4" to sanders. That seem's like overkill. That's one thing my shop vac handles fine. The main thing is to put the things the make the most dust closer to the vac.

Paul K · 01-16-2008, 08:41 PM

PVC does create static charge. As the dust particles go thru the piping, they are rubbing against the pvc and build up a pretty good charge. It is probably not a great idea to use PVC. Tales of explosions (remember sawdust does explode or burn well if in the right amount of air and density). However i don't know first hand of explosions. I have metal ducting in my shop, 6" with a 3 hp Oneida cyclone. But with the smaller 1 1/2 Delta i use in the other building, i just use 5 inch hose. (think it is 5? but might be 4") If you use the PVC, just make sure that there are nice "sweeps" for angles not sharp bends. And i suspect that it woudl be a good idea to run a copper wire around the tubing and ground it somewhere. (not inside the tubing) i know that i build up a lot of static on my drum sander and have about shocked the bejesus out of myself leaning over and accidentally touching the hose. I have since learned to ground out the hose. By the way, when they mention sanders, i am sure they don't mean 4" for small sanders. They mean 4" for drum sanders or small wide belt sanders. Actually these type of machines really need MAXIMUM dust collection, so they need at least 4". For your hand sander, or even your stationary belt/disc sanders, 2 1/2" is more than enough.
best
paul

bigredc · 01-16-2008, 10:41 PM

The book I have say's run bare copper wire inside and outside of PVC pipe. My saw is a 70 year old Delta. I completely rebuilt it. works beautiful, but it was shocking the heckk out of me. I had it mounted on a wood base with only the belt connecting it to the motor. I figured it was static. I ran a ground down to the motor housing. I spent about an hour on e bay looking at used dust collectors tonight. There are like 5 or more pages of them.

daryl in nanoose · 01-17-2008, 12:28 AM

Your copper wire starts at your machine and wrapes around the pipe and connects to the collector. Every so often you use a low profile head bolt that the head is in the pipe and the wire wrapes around the bolt and then place a nut and washer.
5 inch is a good choice but since you have lots of 4 inch you could put a 5 inch main with 4" drops. It improves the system a litlle and apparently worth it. If you can keep a straight run into the collector at least 3 feet this helps a lot.
Min 4 " for larger sanders and 2- 1/2" for small portable stuff is a good choice.

bigredc · 01-18-2008, 06:46 AM

I found this on another thread.

From WOODWEB
WOODWEB DISCLAIMS any and all RESPONSIBILITY and LIABILITY for the accuracy and application of the information below. Readers agree to evaluate the significance and limitations of the information provided, and accept full responsibility for the application of this information. Read More ...
?
PVC piping -- OK for dust collection?

Why PVC piping is not safe for your dust collection system. March 19, 2001

Question
I hear you're not supposed to use plastic pipe for dust collection. Why?
Forum Responses
The main reason why PVC pipe is not recommended is the buildup of static electricity and the high risk of explosion.

Plastic pipe systems are not designed for dust collection use. A necessary diversity of fittings to meet design requirement does not exist. Also, plastic pipe elbows have a very short radius and plastic tee fittings are improper for dust removal. It is these types of problems that lead to an inefficient dust collection system.
With a metal dust collection piping system, static electrically won't develop. Elbows and other various fittings are properly designed for conveying dust. The diversity of fittings and accessories will enable you to meet design requirements.

I have found no problems using schedule 40 PVC. You do need to run a ground wire to each machine. As far as elbows are concerned, you can use electrical sweeps, which ease the bends. Also, don't use tees, use Y fittings.

I used plastic in my first shop. The static electric buildup was amazing. I tried to control it with ground wires, but still had problems. Don't take a chance on a dust explosion--use metal. Commercial heating contractors often stock the spiral duct and fittings since they are used in big buildings for air handling.

The National Fire Protection Agency recommends non-combustible ducting when conveying combustible material. As we know, wood dust is combustible, as well as PVC pipe, never mind the static buildup, which is a source of ignition.
When we create a duct system, the interior should be as obstruction-free as possible. A copper wire will snag chips and curls. In addition, many extraction systems are abrasive, such as the conveying of hardwood chips. This material will wear the copper wire.

When we had a PVC system in our shop, I had a chance to discuss the plastic pipe/static situation with an electrical engineer well-versed in industrial issues. According to him, there is virtually no way to protect a plastic based system. The static builds on the surfaces (inside or out) of the pipe and nothing but a continuous metallic ground (more like a coating than a wire) inside the pipe would mitigate the static buildup. He convinced me to get rid of the plastic and redo our system with metal pipe and fittings.
While removing the plastic (prior to a metal install) on a Monday after a non-working weekend, I noticed that the pipe still held a charge from the previous Friday's work. As a precaution I put on light duty rubber gloves. I got zapped right through the gloves by the static discharge from a length of pipe connected to the planer, which had been working hard the previous week. A few minutes later I picked up a piece of pipe that had also been connected to the planer and watched as a large spark arced from the pipe to my chest. These shocks were not life-threatening, as the discharge was mostly voltage with little amperage. That said, they made me painfully aware of the potential for static build-up. You may get away with a plastic system for years, but some day when you are collecting large quantities of fine dust through your new wide-belt sander, disaster may strike. I'd never consider using anything but metal pipe for dust collection.

daryl in nanoose · 01-18-2008, 10:04 AM

this is a very good read on Static Electricity and PVC
http://mywebpages.comcast.net/rodec/.../DC_myths.html