[OP]
Contributor
Has anyone bought polyester felt filter material and made your own filter bags? The material is much cheaper than ready made bags and dont look that difficult to make. IF so did you sew the seams or fuse them using heat/Glue. Would like to learn from someone who has done this before.
It's how big?
Contributor
I haven't done it, but I'd say that if you need a new bag that nw would be a great time to swap to a canister filter. (I got one from Wynn) I couldn't believe how much difference it made. Air flow through the system seems to have doubled-- collection from my table saw improved dramatically, and there's no cloud of fine dust puffing into the shop air each time I turn the DC on. They really work much better.
If I were doing it I'd sew them, but it will take a reasonably hefty sewing machine.
Contributor
"nw would be a great time to swap to a canister filter"
I would argue otherwise, depending on the situation. Anyone who has overfilled the collector bin and had to clean out a clogged cartridge filter knows what a disagreeable chore that is. Cartridge filters allow more filter area in a given space, but if you have the space available felt bags are far easier to clear.
Sorry I can't advise on making bags. My old system had seamless tubes- I would imagine any seams are potential leak points. The material is fairly thick so you would probably need a heavy duty sewing machine. I believe Oneida still sells the tube filters as does American Fabric Filter in addition to custom sizes.
More area is better. I think conventional practice is to provide at least 1 sq. ft. of filter for 10 cfm airflow
I'm also in the camp that if you move to a cartridge filter you also want a cyclone. That being said, bag material for collection is one thing, bag material for filtering is another. I'm not sure how much cheaper you could make a bag that filters to a somewhat safe level than having it made by someone like American Fabric Filter. I have a 60% rule; if it costs me 60% of a "real one" and I have to do the work, I just buy the thing. This is tempered one way or the other if I want to make or do what I am considering. I can save money painting my own house but, I don't want to paint a house and the right someone who does it for a living can do it faster and better. Of course, sometimes we just have more time than money for the item being considered. Just food for thought.
P.s. Kevin makes a good point about the sewing machine. Your average household machine is not going to stitch the material my AFF bags are made of.
"A hen is only an egg's way of making another egg".
– Samuel Butler
Contributor
I've been looking into this, but haven't been able to find a source for "raw" filter fabric. Dave, did you find a source?
[OP]
Contributor
I found some 1 micron singed polyester felt sheets 5.5 yards by 65 inches rom Duda Diesel (Duda Energy). Cost of about $60 shipped, and would make 4-5 33 inch bags, but I was planning to make extra long bag (about 7 ft long). Bunches cheaper than standard bags and the extra length would reduce the back pressure of the bag. I have a thread injector that has no problem with Denim so it should handle the poly felt.
It's how big?
1 micron is not very good filtering. It takes out most of the visible dust & just allows the dangerous stuff to float around freely.
[OP]
Contributor
That's interesting, as its the best material available for dust collector bags and equivalent to MERV12 filtration canisters. I guess unless you can afford the best possible product you just have to put up with 'not very good'. Maybe I'm just not rich enough for this woodworking stuff.Originally Posted by Frank Pratt
It's how big?
If you're sewing denim, you'll be fine with the felt. You may want to check your sizing. The bags that come with machines are laughably undersized. Manufacturers need to hit a price point and make a visually attractive unit to sell. The following will give you a better idea of how big a bag should be for a given machine:
AFF Matrix.JPG
So. for example, for a 1000 CFM machine with a 14" opening for the bag you are looking at a bag 60" long.
How big is the stuff I'm breathing?
microns.JPG
Last edited by glenn bradley; 05-22-2020 at 7:07 PM.
"A hen is only an egg's way of making another egg".
– Samuel Butler
Contributor
It's not that a 1 micron filter is useless, you just have to go in with your eyes open & know that you need to wear a respirator while doing dusty stuff & for a good while after you turn off the collector. While the collector is running it continues to keep that super fine stuff circulating & suspended in the air.
A good HEPA air cleaner will help reduce that wait.
Contributor
I notice looks of talk about critical piping for 4-5 feet before the cyclone for lamiar flow etc. Very little mention of the baghouse plumbing other then sweeping bends are recommended but seldom seen.
Bill D
Contributor
FYI: The filter fabric for paint spray booths is around 10 micron so no use for saw dust except as a prefilter.
Bill D
Contributor
Sorry, I was assuming a cyclone in the system already. Canisters will undoubtedly clog without one, thought I do have one such small system for collecting sanding dust at the lathe. It has an internal beater in the canister to knock the dust down. Been using it for months now and it hasn't clogged significantly, but I don't run chips and sawdust into it.
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