Thread: Cyclone

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Yeah, that's pretty common with plastic containers. The best collection drums for these small cyclones are 15 or 20 litre ring lock METAL paint tins.

What vac is on it?

Might need a bit of back story?

Aldi workzone shop vac. I am going to add a relief valve. Using scrap wood and a jack I have straightened it out. Reading more I must have blocked it.

Cheers Paul

That drum will never be the same again. You could look at installing some internal support.

Originally Posted by aldav

That drum will never be the same again. You could look at installing some internal support.

There seem to be about three or four approaches to this problem. For small buckets the easiest is to place the bucket with the cyclone into a second bucket that stops it deforming.

Another approach is to provide the setup with a sacrifical lamb. Make your cyclone out of cheap plastic cups and takeaway containers or put a hole in the barrel and tape down cling wrap across it.

Lots of people will cut a heavy plywood ring and push it into place inside the drum. Like everything in woodworking this is a contentious issue with people saying you should never reinforce, rather you should remove the underlying problem. I could well end up putting one or more rings in the barrel or maybe just buy another: $au30 is probably cheaper than the ply to make the rings. It used to hold almond paste. The mind boggles what you would use 220L of almond paste for and the seller had a big pile of them. I am a little leary of this as the only solution, I have visions of the barrel simply collapsing around the reinforcement,

The other thing people do is create a relief valve. One of the articles on the magnet relief valve had what looked identical to my barrel and they managed to continue with just a relief valve so I have some hope that a big enough valve will solve the problem. The theory is that as long as both sides of the cyclone are open, there should be no pressure in the barrel.

In my brief research I found two types of home made valves. One uses a compression spring on a bolt to hold the valve closure against the barrel - actually saw two types of these depending on which way the spring was. In one version the closure is on the end of a bolt through a bracket outside and on the other side of the bracket is the compression spring. the other one, the bolt is fixed and the plug moves on vacuum into the barrel compressing the spring.

The last type uses a magnet on a bolt through a piece of pipe, to hold a jam jar lid in place. Magnet pull rating was quoted at anything from 1KG to 9.7kg. When the vacuum in the barrel gets high, the jam jar lid is displaced relieving the vacuum. There was also a version that had fishing line on it that you pulled to allow easy reset.

I was thinking about the magnet version. What if instead of a magnet, I ran a piece of string from the jam jar lid to a weight. A pull rating of 1KG is equivalent to a 1L bottle of water. Hang it over the side of the barrel. When the pressure goes down due to blockages in the cyclone, the jam jar lid will be sucked down relieving the vacuum. When the blockage is gone, the lid will automatically return to blocking the hole.

Cheers Paul

When the pressure relief valve operates the contents of the drum may finish up being sucked up and possibly jamming your fan with the large quantity of dust that will hit it.

In my case I just used two 20 L containers sitting one inside the other. That was enough to stop any tendency to collapse.

That sounds like a lot of trouble for not much to me. Not quite sure why you'd want a 220 litre collection drum on a vac system, mine is about 30 litres and when it's half full is a good time to clean the filters in the vac anyway. Besides - the best collection drums for these small cyclones are 15 or 20 litre ring lock METAL paint drums - can't think why you'd bother with anything else and you can get them for free.

Originally Posted by aldav

15 or 20 litre ring lock METAL paint drums ... you can get them for free.

Hi aldav, do you have any suggestions for getting these for free? I know that one could stumble across them, but I haven't yet (I would like to add one more to my existing system to increase capacity). Of course, lockdown doesn't help but I could grab one when things open up. So far I have only found ones that are heavily damaged.

I agree that they work well!

Originally Posted by Bohdan

When the pressure relief valve operates the contents of the drum may finish up being sucked up and possibly jamming your fan with the large quantity of dust that will hit it.

In my case I just used two 20 L containers sitting one inside the other. That was enough to stop any tendency to collapse.

the blower is a shop vac so not too worried about that scenario

Originally Posted by aldav

That sounds like a lot of trouble for not much to me. Not quite sure why you'd want a 220 litre collection drum on a vac system, mine is about 30 litres and when it's half full is a good time to clean the filters in the vac anyway. Besides - the best collection drums for these small cyclones are 15 or 20 litre ring lock METAL paint drums - can't think why you'd bother with anything else and you can get them for free.

Well to create a relief valve using the magnetic method or my proposal will take about half an hour if that. Add that in to the time taken to source the cyclone - a couple of months since the post is slow from china, source the barrel - a couple of days - tie the cyclone down - a couple of hours with the several trips to bunnings to get things I thought I had - and then duct it in - another half hour or so - and you hardly notice it.

Paint drums are only free if you can either find a suitable skip or a friendly painter. 15 to 20l is smaller than the barrel on the shop vac and that is too small. Thicknessing, especially, produces lots of waste. Small boxes don't look right built in 19mm and anything thinner is harder to find. 220L is probably overkill but that was the size available for a lower price than buying something else.

I think I said that all this was contentious I might just pull my head in and stop sharing now.

Originally Posted by Oldmeadow

Hi aldav, do you have any suggestions for getting these for free?

Make some enquiries at any of your local paint specialists, they may be able to supply or direct you to a commercial painting contractor. If you tell them what you want it for it may pique their interest and get you a better response than you might otherwise receive. The other option is to approach a commercial painter directly.

Originally Posted by betchern0t

I think I said that all this was contentious I might just pull my head in and stop sharing now.

Don't get all defensive, up till now you haven't provided any information about your dust collection. Most people don't use vac's for high output activities like thicknessing, I can understand why you'd be looking for a larger container. There's probably other members who are in your position, relying on a vac for all their dust collection needs, who would find your dust collection journey of interest and value.

Many (most?) of us have dust collectors and only use vac's for small equipment. So now that we know what your situation is what if I pull my head in and you continue with your WIP.

Originally Posted by aldav

Make some enquiries at any of your local paint specialists, they may be able to supply or direct you to a commercial painting contractor. If you tell them what you want it for it may pique their interest and get you a better response than you might otherwise receive. The other option is to approach a commercial painter directly.

If there are new houses being built nearby, there might be one or two in the rubbish heaps/skips.

My drum is a 20 litre ex concrete sealer drum so that is another possibility.