100mm extraction ducting

AJB Temple · 22 Nov 2016

New 2hp cyclone extractor arrives on Friday. Does anyone have any recommendations for a supplier of wall mounted ducting, blast gates etc. Metal versus plastic ducting? Any variation in quality?

System (machines may be re-arranged) will be:
1 Router table with 2.5" outlet I think
2 Disc sander with 2.5" outlet
3 PT with 100mm / 4 inch outlet
4 Bandsaw with 100mm outlet
5 Lathe, which will need some kind of hood
6 Table saw - on other side of workshop and system may need to use a flexible hose connector for that.

I am presuming that metal blast gates are best as they can be taken apart if they jam?

Can I use this system, via a dedicated blast gate, to extract power tools such as the belt sander?
I am presuming that I should not extract metal dust from the sharpening (sorby)/ polishing bench, due to spark ignition risk?

PAC1 · 22 Nov 2016

I would not limit a 2hp system to 100mm duct. Even 125 duct is 60% bigger than 100mm and 150mm is double. My view is install the biggest diameter you can and reduce it as close to the machine as possible.
I got my duct from these http://www.ducting-online.co.uk/Mobile/ ... id=2287389
The brackets and delivery cost more than you expect.

Mike Jordan · 22 Nov 2016

I recommend that you use metal ducting rather than plastic, there is less risk of static build up and it's fire resistant. My own system works well and is assembled as follows. It's a conventional 1.5 HP machine with filter bag on top and plastic chipping bag below, the whole being sited in a separate small room rather than the workshop. The machine is connected to 150mm metal ducting using a minimum length of corrugated plastic flexible pipe, each machine is served by a 100mm pipe decending from the high level 150mm pipe and fitted with a blast gate and short length of 100mm plastic flexible pipe. A 5 metre length of 100 mm flexible pipe is used for cleaning up rather than a brush. Small tools are used with the sweeping up pipe and a reducer to a 1 metre length of 50mm flexible pipe, this is not really recommended practice but it seems to work very well for me. The switch used to turn the extractor on and off is of the type intended for use with a pull cord. It has a suitable rating for the current used and is mounted at the top of the workshop wall and connected to a full length cord running through a number of "vine eyes" screwed into the ceiling. Pull cords are tied to the main cord to allow operation from different handy points in the workshop. The store room containing the machine is vented to open air with a louvred door and clean air enters the workspace through a vent from the roof space. The extractor removes warm air from the workspace which is a shame in the winter but much better than having the fine dust which finds its way through the filter bag polluting your workspace and lungs.
Best of luck with the project
I forgot to mention one of the important features - the pipes decending to each machine enter through the side of the 150mm pipe, if they enter through the bottom the chippings from one machine can fall down any pipes not in use and cause them to get blocked up.
Mike.

deema · 22 Nov 2016

I'd simply drive around any decent industrial estate and look out for metal ducting. I've never bought any and only ever acquired it by politely asking if I can reduce the load in their skip.

If there are any metal fabricators of size, ask to speak with the maintenance chap, again this can be a good source of all sorts that the company is disposing of as rubbish. Go armed whith a bottle of spirits and a few bottles of wine. Once a few people know what your after, again it's amazing how fast it can be found especially if there is a liquid incentive.

I was given a Meddings Pillar drill that needed a little TLC this way, and had opportune for all sorts of stuff. I'm just about to be given a load of racking that is surplus to requirements its a none standard size so they can't repair or replace it going forward so a few bays are now seen a scrap.

SteveF · 22 Nov 2016

I am not ready yet but this may be of interest

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AJB Temple · 22 Nov 2016

Deema - I had to smile. My brother does this, as he lives in the industrial heartland of England and trained as a metal fabrication engineer. I live in the heart of Kent. We are not overburdened with the kind of places who have bits of ducting hanging about sadly and even the industrial estates sell all surplus stuff on eBay.

Mike and Pac I have thanked you. The machine has a 6" inlet that could be used and a branch leading to two 4" inlets. I assumed (I know, stupid) that if the outlets on most of the machines are 4", then I should use 4" trunking as that will require moving less air o move the same volume of air at greater speed. Obviously I am revealing my ignorance here.

I will start with using each machine individually wth flexi hose (that I already have) whilst I get the trunking system built.