Thread: Source for 150mm pvc fittings

I suggest you look for a local plumbing store, Tradelink or Reece are two possibilities.

Thanks for the tip. I presume that means those sort of places are happy selling to the general public?

Yes, they will. I am doing that exact thing at the moment. The cost is at least three times doing it in 100mm. BTW running a 100mm line to a machine off 150mm is not effective and largely a waste of the 150mm. On a tablesaw you need two lines anyway, one in the cabinet and one overhead, a bandsaw the same. I have 150mm running straight off the jointer and planer as a single line. You will also have issues trying to source blast gates locally, or at least any worth using and I made my own. I also made my own transitions out of perspex and plywood to change from 2 x 100 to 1 x 150. There is a link in one of my other threads here on the Clearvue version I based it off. You can buy Ed's (Clearvue), they are a very good product as anything he makes always is but so expensive against making your own. To do it properly is a long and involved job I have found, best of luck with yours.

The system has to be designed as such and you need to calculate the volume you need to suck up from each machine as well as the losses that bends, gates etc impose on the system. Put the big mess makers like buzzers closest to the dusty. Decide if only one machine will be run at a time, etc etc.

A good source of info on the design can be found here.

Originally Posted by rsser

The system has to be designed as such and you need to calculate the volume you need to suck up from each machine as well as the losses that bends, gates etc impose on the system. Put the big mess makers like buzzers closest to the dusty. Decide if only one machine will be run at a time, etc etc.

A good source of info on the design can be found here.

In the practical world of the home workshop I don't know if the calculations are really necessary due to our inability to flow enough air, the equipment is not that good. Yes, some common sense has to prevail, such as not using 150mm duct on a 1/2hp DE then feeding it all through 50mm runs to machines but that is all. In the US where they have guys using 5hp or more it may even be a consideration but I still doubt it. Just flow as much air as you can and 100mm will not do this as a rule. Siting the machines for max effect is important I guess but in a small average workshop does the difference of one or two metres really make that much difference in practise? I am not saying you are wrong, you are right in theory but in practise for the average small workshop I think the necessity is very small and most probably not necessary. On the other hand if you can do the calcs and implement them it can't hurt and the job won't suffer from doing them, that much is certain.

Bill's website and others provide some rules of thumb so you don't need flow meters.

HVLP stuff is counter-intuitive in some ways to folk raised on vacuum cleaners for dust extraction and it's easy to lose the advantage that 3 HP provides with poor design.

Originally Posted by gonty

Thanks for the tip. I presume that means those sort of places are happy selling to the general public?

Good Morning Johnathon

Provided they do not have a large queue of tradesmen, you will get good service and advice.

PVC comes in two types - UV resistant and stuff to be burried underground - same weight, strength and price - Get the UV resistant one.

You will also need some blue gel (PVC glue). You paint it onto both surfaces, then slide the joint together and align it carefully and quickly. You have about 30 seconds before the gel grips and locks the joint. [Might be worth buying some smaller/cheaper pieces to practice on.]

Cheers

Graeme

I've just sealed my joins with duct tape cos I just know that the setup will change as the workshop does.

Originally Posted by rsser

I've just sealed my joins with duct tape cos I just know that the setup will change as the workshop does.

Likewise, saves buying new fittings when it happens

More good advice..... I just assumed that an unglued joint would not be sufficiently airtight......... But the suction actually sucks the tape into the joint and makes more airtight.

Cheers

Graeme

A light smear of silicone will also seal joints if no duct tape is available. Yes, any trade supplier will sell to the public, same with electrical wholesalers.

Thanks for all the responses, that's given me some more thinking to do. From what I had previously gathered I should run 150mm as far as possible and if I drop that to 100mm at the machines I should always keep to outlets open.

But someone mentioned 150mm fittings cost three times as much as 100mm. So why not save myself some money and just run 2 parallel 100mm pipes? I'm probably missing something obvious there, but am not sure what.

Thanks again.

Jonathan

Good Morning Johnathon

Ern gave you a reference to Bill Pentz's website. It is really worth wading through the theory and data while you are at the design stage. Cheaper in the long run, and more effective.

Basically you need high airflow volume to move the real small particles and fast airflow to move the larger particles. And the smallest particles are the dangerous ones. Smooth tubes of large diameter involve less turbulence and friction. Therefore more efficient. And larger tubes are quieter - an important feature.

Consider the following:
471mm Circumference of a 150mm tube
314mm Circumference of a 100mm tube
628mm Length of two 100mm circumferences.
Compared to one 150mm tube, two 100mm tubes will have about 33% more surface area and hence 33% more surface friction and more turbulence due to the smaller diameter.

One more factor to mull over.

Keep us posted on your thought processes.

Cheers

Graeme

Swallow the cost and use 150mm all the way to the machines. I had to modify my jointer and thicknesser to hook it up, but that wasn't too hard. I will give you an idea of costs...

150mm 45 degree bend $21.87
100mm 45 degree bend $3.85
150mm access cap for end of duct $18.72
150mm connector for above cap $19.47

I have bought 10 45 degree bends, just to give you an idea and there is a lot more besides that I have not got the invoices for. If I get out of it for under $800 I will be happy. Mind you I have made stuff others might buy like two into one transitions, all the blast gates, adaptors for the machines etc so it all works out I guess. The cyclone cost me $700 some years ago as well so I may as well include that in the final reckoning. I have yet to make the overhead guard for the table saw but that should not cost anything as I have all the stuff. Staying healthy isn't cheap but many have to give up this hobby due to not taking care of themselves and developing allergies. They would have been far better off taking precautions in the first place. Those same people most probably frown on smoking but don't mind getting dusted lungs and Emphysema or something similar form wood dust. Do it once and do it properly.